CN102330968A - Two-stage flue gas heat exchanger system applied to thermal power plant - Google Patents

Two-stage flue gas heat exchanger system applied to thermal power plant Download PDF

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Publication number
CN102330968A
CN102330968A CN2010102248592A CN201010224859A CN102330968A CN 102330968 A CN102330968 A CN 102330968A CN 2010102248592 A CN2010102248592 A CN 2010102248592A CN 201010224859 A CN201010224859 A CN 201010224859A CN 102330968 A CN102330968 A CN 102330968A
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China
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flue gas
heat exchange
condensate
gas heat
level
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Inventor
叶勇健
施刚夜
林磊
冯琰磊
申松林
李佩建
邓文祥
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China Power Engineering Consulting Group East China Electric Power Design Institute Co Ltd
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China Power Engineering Consulting Group East China Electric Power Design Institute Co Ltd
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Priority to CN2010102248592A priority Critical patent/CN102330968A/en
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Abstract

The invention provides a two-stage flue gas heat exchanger system applied to a thermal power plant, which comprises a boiler unit for exhausting flue gas, a flue gas waste heat utilizing unit, a flue gas dust removing unit and a flue gas desulfurization unit, wherein the flue gas waste heat utilizing unit comprises a preheater, a flue gas dust removing unit, a first-stage flue gas heat exchanger arranged at an inlet of the flue gas dust removing unit and a second-stage flue gas heat exchanger arranged at an inlet of the flue gas desulfurization unit; the first-stage flue gas heat exchanger and the second-stage flue gas heat exchanger are respectively flue gas-condensed water heat exchangers provided with flue gas sides for radiating heat and condensed water sides for absorbing heat; a water source at each condensed water side is condensed water in a condensed water system of a steam turbine; and the first-stage flue gas heat exchanger is connected with the second-stage flue gas heat exchanger according to one of modes: the flue gas side of the first-stage flue gas heat exchanger is connected with the flue gas side of the second-stage flue gas heat exchanger in series; the condensed water side of the first-stage flue gas heat exchanger is connected with the condensed water side of the second-stage flue gas heat exchanger in parallel; and the flue gas side and the condensed water side of the first-stage flue gas heat exchanger are respectively connected with the flue gas side and the condensed water side of the second-stage flue gas heat exchanger in series.

Description

Be applied to the two-stage flue gas heat exchange device system in thermal power plant
Technical field
The present invention relates to a kind of environment protection energy-saving equipment, relate more specifically to a kind of reduction soot emissions that are applied to the thermal power plant, improve desulfuration efficiency, the fume afterheat of the smoke comprehensive optimization of conserve water consumption utilizes system.
Background technology
Along with development and national economy, society constantly improves the demand of electric power.For the new developing country that carries out industrialization and rapid economic development, like China, the consumption of electric power and the installed capacity in power plant increase sharply.As far as China, owing to receive the maintenance variety and storage quantitative limitation of its primary energy, the fuel in power plant is main with coal in recent decades, reached more than 70%, and this trend does not in a foreseeable future have basic change.Though coal fired thermal power plant has advantages such as cost is lower, fuel source is extensive for China, there are shortcomings such as efficient is lower, pollutant emission is more in coal fired thermal power plant.Because be discharged into the burning that pollutant in the atmosphere derives from coal basically, so the coal consumption amount positive correlation of the discharge capacity of pollutant and thermal power plant, the while is also relevant with the gas cleaning efficient of flue gas purifying equipment.Therefore, system is optimized to coal steam-electric plant smoke, when reducing thermal power plant's coal consumption amount, improves the purification efficiency of flue gas purifying equipment, and reducing thermal power plant's discharging of pollutant in atmosphere in the time of with the realization energy savings is a promising technology.
Generally speaking, can adopt following three kinds of methods to reduce the coal consumption amount of thermal power plant.(1) pressure and temperature of raising steam.After having improved the pressure and temperature of steam, Efficiency of Steam Turbine will improve, and hear rate descends, and can improve the efficient of whole thermal power generation system, reduce coal consumption.At present, the steam pressure of the fired power generating unit of main flow and temperature are brought up to supercritical parameter from subcritical parameter, further bring up to ultra parameter.Do unremitting technical research both at home and abroad at present for further improving vapor (steam) temperature.But step of the every raising of vapor (steam) temperature and pressure, boiler and steam turbine all need adopt the higher material of calorific intensity and resistance to corrosion, have improved the construction maintenance cost of unit greatly.(2) the steam discharge parameter of reduction steam turbine.After having reduced the steam discharge parameter of steam turbine, also can improve Efficiency of Steam Turbine, reduce the hear rate of steam turbine.The steam discharge parameter that reduces steam turbine promptly need reduce the recirculated cooling water temperature of steam turbine; Owing to receive the restriction of power plant geographical position of living in and weather conditions; The recirculated cooling water temperature is in certain scope, to change, so the steam discharge parameter decline scope of steam turbine is limited.For areal, the steam discharge parameter of steam turbine is certain.(3) the discharging heat loss of minimizing boiler smoke.The flue gas that produces after the boiler combustion, different according to boiler form and coal-fired kind, its temperature is generally between 110 ℃~170 ℃.Generally boiler smoke directly is discharged into atmosphere after through purified treatment, and the discharged flue gas temperature does not almost change, and promptly the heat in the flue gas directly is discharged into atmosphere and is not used.In adopting the technology of smoke-gas wet desulfurization, flue gas in desulfuration absorbing tower under the spray effect of desulfurizer slurry temperature drop to 40 ℃~50 ℃, the heat of flue gas is taken away by slurries in this process, has evaporated the moisture in the slurries.Flue-gas temperature is high more, and is big more to the evaporation capacity of moisture content in the slurries, and the water consumption of power plant is big more.Some power plant are owing to receive environmental protection requirement; Requirement discharged flue gas temperature in atmosphere is not less than 72 ℃~80 ℃; The flue gas of desulfuration absorbing tower outlet need be heated to this more than temperature; Therefore adopted flue gas-flue gas heat exchange device or the gas-water-flue gas heat exchange device flue gas with the lower temperature of the flue gas heating desulfuration absorbing tower discharge of the higher temperature of boiler discharge, because the flue gas after the heating still is discharged in the atmosphere, the heat of the flue gas of boiler emission still is not recovered utilization.
This shows, be the effective way that reduces the coal consumption amount of thermal power plant for the utilization of residual heat from boiler fume.To the utilization of residual heat from boiler fume, have many design and practices both at home and abroad, all adopt the pattern of flue gas heat exchange device, through heat exchanger the heat in the flue gas is replaced to other medium to be used.This flue gas heat exchange device is called as various titles such as " low-level (stack-gas) economizer ", " low-pressure coal saver ", " gas cooler ", " cigarette water-to-water heat exchanger ", its essence is same or analogous
Particularly, the flue gas heat exchange device of prior art is arranged as follows:
(1) the flue gas heat exchange device is arranged in boiler tail, adopts condensate to absorb fume afterheat.For example, domestic certain boiler of power plant exhaust gas temperature is higher, in order to reduce exhaust gas temperature, improves the performance driving economy of unit, has installed low-level (stack-gas) economizer additional in the outlet of boiler tail air preheater, adopts condensate to absorb fume afterheat, sees accompanying drawing 1.When the former Soviet Union reequips the boiler unit in order to reduce flue gas loss,, adopt hot net water to absorb fume afterheat at the bottom installing low-level (stack-gas) economizer of boiler to flow through shaft.
(2) the flue gas heat exchange device is arranged in before the desulfuration absorbing tower, adopts condensate to absorb fume afterheat.The Germany Schwarze Pumpe 2 * 800MW of power plant brown coal generating set has installed gas cooler additional between electrostatic precipitator and fume desulfurizing tower, adopt condensate to absorb fume afterheat, sees accompanying drawing 2.
In sum, existing these flue gas heat exchange device schemes have all adopted one-level cigarette water-to-water heat exchanger or flue gas-air heat exchanger, and it mainly act as the recovery fume afterheat, reduce the generating set coal consumption amount, so function ratio are more single.
Those skilled in the art is devoted to obtain a kind of modifying device of above-mentioned flue gas heat exchange device layout, and it has the soot emissions of reduction, reduces sulfur dioxide (SO2) emissions, practices thrift the desulphurization plant water, prevents the air preheater cold end corrosion, reduces multinomial functions such as blower fan power consumption and the coal consumption of saving unit.
In sum; The fume afterheat that this area is needed a kind of improved thermal power plant badly utilizes system, it its have the soot emissions of reduction, reduce sulfur dioxide (SO2) emissions, practice thrift the desulphurization plant water, prevent the air preheater cold end corrosion, reduce the blower fan power consumption and practice thrift multinomial functions such as unit coal consumption.
Summary of the invention
First purpose of the present invention is to provide a kind of modifying device of above-mentioned flue gas heat exchange device layout, and it has the soot emissions of reduction, reduces sulfur dioxide (SO2) emissions, practices thrift the desulphurization plant water, prevents the air preheater cold end corrosion, reduces multinomial functions such as blower fan power consumption and the coal consumption of saving unit.
The modifying device that second purpose of the present invention is to provide a kind of above-mentioned flue gas heat exchange device to arrange carries out the method that fume afterheat utilizes, and it has the soot emissions of reduction, reduce sulfur dioxide (SO2) emissions, practice thrift the desulphurization plant water, prevent the air preheater cold end corrosion, reduce the blower fan power consumption and practice thrift multinomial functions such as unit coal consumption.
The 3rd purpose of the present invention is to provide a kind of thermal power plant system that contains the modifying device of above-mentioned flue gas heat exchange device layout, and it has the soot emissions of reduction, reduces sulfur dioxide (SO2) emissions, practices thrift the desulphurization plant water, prevents the air preheater cold end corrosion, reduces multinomial functions such as blower fan power consumption and the coal consumption of saving unit.
First aspect present invention provides a kind of two-stage flue gas heat exchange device system that is applied to the thermal power plant, comprises that the boiler unit, the fume afterheat that discharge flue gas utilize unit, flue gas ash removal unit and flue gas desulfurization unit, and said fume afterheat utilizes the unit to comprise:
-preheater;
-be arranged on the first order flue gas heat exchange device of said flue gas ash removal unit inlet, and the second level flue gas heat exchange device that is arranged on said flue gas desulfurization unit inlet;
Wherein,
Said first order flue gas heat exchange device and second level flue gas heat exchange device are the flue gas-condensate heat exchanger of the condensate side of the fume side that is provided with heat release and heat absorption; The water source of described condensate side is the condensate in the steam turbine condensate system; And
Said first order flue gas heat exchange device and second level flue gas heat exchange device are according to a kind of connection the in the following mode:
The fume side of the two is that serial arrangement connects, and the condensate side of the two connects with parallel way; Or
The fume side of the two all is connected with serial arrangement with the condensate side.
In a preference, the downstream of said flue gas ash removal unit are provided with air-introduced machine and optional desulfurization booster fan, get into follow-up second level flue gas heat exchange device after making flue gas through said air-introduced machine and desulfurization booster fan adherence pressure.
In a specific embodiment of the present invention, the water side water source of said first order flue gas heat exchange device and second level flue gas heat exchange device also comprises turbine system condensate, hot net water, heating ventilation air-conditioning system water, power plant and other domestic water of adjacent machine.
In a specific embodiment of the present invention, said condensate derives from certain one-level low-pressure heater outlet of steam turbine condensate system or gathering of some grades of low-pressure heater outlets.
Particularly, condensate is got back to certain one-level low-pressure heater import or export after absorbing heat through the flue gas heat exchange device.
In a preference, said steam turbine condensate system also is provided with condensate booster pump.
In a preference, flue gas heat exchange device and certain one-level or some grades of low-pressure heaters are polyphone or parallelly connected or promptly have polyphone that parallelly connected relation is arranged again on the condensate flow process.
In a preference; Said condensate is got back to certain one-level low-pressure heater import or export through after the first order flue gas heat exchange device heat absorption, and promptly first order flue gas heat exchange device and certain one-level or some grades of low-pressure heaters are polyphone or parallelly connected or promptly have polyphone that parallelly connected relation is arranged again on the condensate flow process.
In a specific embodiment of the present invention, said first order flue gas heat exchange device or second level flue gas heat exchange device adopt surface-type heat exchanger.
In a specific embodiment of the present invention, said first order flue gas heat exchange device or second level flue gas heat exchange device adopt heat-pipe heat exchanger.
In a specific embodiment of the present invention, said first order flue gas heat exchange device or second level flue gas heat exchange device adopt the indirect-heating heat exchanger that intermediate carrier is arranged.
In a preference, the heating agent of said intermediate carrier is liquid.Said liquid heating agent is selected from water or other lower boiling liquid, preferred ethylene glycol.
In a specific embodiment of the present invention, each grade heat exchanger is a heat exchanger, perhaps is several heat exchangers of parallel connection
Second aspect of the present invention provides a kind of method that adopts two-stage flue gas heat exchange device of the present invention system to carry out flue gas waste heat recovery, and this method can reduce the method for smoke dust discharge concentration, water consumption and air-introduced machine, booster fan power consumption, and it comprises the steps:
The flue gas that the boiler unit is produced passes through the preheater in the flue gas heat exchange device system, obtains 110 ℃~170 ℃ preheating flue gas;
Said preheating flue gas carries out waste heat recovery at first order flue gas heat exchange device, makes its temperature drop to above 5~10 ℃ of flue gas acid dew point temperature, obtains the flue gas of one-level through waste heat recovery; Reduced flue gas simultaneously and improved efficiency of dust collection realization reduction smoke dust discharge concentration, reduced flue gas simultaneously and submit to flow to realize reducing air-introduced machine, booster fan power consumption than resistance;
Said one-level temperature after the flue gas of waste heat recovery is through second level flue gas heat exchange device is reduced to 20 ℃~25 ℃ or required optimum flue-gas temperature more than the water dew point temperature, obtains the flue gas of the second level through waste heat recovery; Reduce desulphurization system water consumption simultaneously;
The said second level gets into the flue gas desulfurization unit through the flue gas of waste heat recovery.
Particularly, described optimum flue-gas temperature is decided according to the mixed economy technology of the income of the power plant coal consumption of the arrangement space that takies of the manufacturing cost of flue gas heat exchange device, flue gas heat exchange device and saving.
In a preferred implementation, said one-level gets into the flue gas ash removal unit through the flue gas of waste heat recovery, and gets into second level flue gas heat exchange device after promoting flue gas pressures through air-introduced machine and optional desulfurization booster fan.
The present invention also provides a kind of thermal power plant system that fume afterheat of the present invention utilizes system that contains.
Description of drawings
Fig. 1 is the layout of the flue gas heat exchange device of prior art, and it is arranged in boiler tail, adopts condensate to absorb fume afterheat;
Fig. 2 is the layout of the flue gas heat exchange device of prior art, and it is arranged in before the desulfuration absorbing tower, adopts condensate to absorb fume afterheat;
Fig. 3 is an optional embodiment of two-stage flue gas heat exchange device of the present invention system;
Fig. 4 is an optional embodiment of two-stage flue gas heat exchange device of the present invention system;
Fig. 5 is an optional embodiment of two-stage flue gas heat exchange device of the present invention system;
Fig. 6 is an optional embodiment of two-stage flue gas heat exchange device of the present invention system;
Fig. 7 is an optional embodiment of two-stage flue gas heat exchange device of the present invention system;
Fig. 8 is an optional embodiment of two-stage flue gas heat exchange device of the present invention system;
Fig. 9 is an optional embodiment of two-stage flue gas heat exchange device of the present invention system;
Figure 10 is an optional embodiment of two-stage flue gas heat exchange device of the present invention system.
The specific embodiment
Designer of the present invention is through extensive and deep research, and the fume afterheat that through improving preparation technology, obtained a kind of reduction soot emissions that are applied to the thermal power plant, improves the smoke comprehensive optimization of desulfuration efficiency, conserve water consumption utilizes system.Accomplished the present invention on this basis.
Technical conceive of the present invention is following:
The present invention has adopted two-stage boiler smoke heat exchanger and system thereof, adopts condensate cooling pan kiln gas in the steam turbine condensate system.After adopting this system; Can reduce coal consumption amount, raising flue gas purifying equipment--the efficient of electrostatic precipitator of fired power generating unit; Reduce the discharge capacity of flue dust, the air-introduced machine of reduction flue gas system and power consumption, the minimizing flue gas purifying equipment of booster fan--the water consumption of fume desulfurizing tower and the efficient of raising fume desulfurizing tower, reduce the discharge capacity of sulfur dioxide.
If specifically do not indicate, term of the present invention is known to those skilled in the art.Concrete example is as can be referring to described in " Thermal Power Station " of China Electric Power Publishing House.
Among this paper, said " boiler unit " mainly comprises boiler plant.The not concrete restriction of said boiler plant only otherwise goal of the invention of the present invention is produced restriction to get final product, is well known by persons skilled in the art.Can adopt π type boiler, tower boiler etc., all in protection scope of the present invention.
Among this paper, said " preheater " not concrete restriction only otherwise goal of the invention of the present invention is produced restriction to get final product, is well known by persons skilled in the art.Can adopt tubular preheater, rotary preheater etc., all in protection scope of the present invention.
Among this paper, said " flue gas ash removal unit " is meant the equipment of catching dust in the flue gas.The preferred design of adopting the control flow velocity and optimizing the flue gas flow field distribution.Only otherwise goal of the invention of the present invention is produced restriction to get final product, be well known by persons skilled in the art.Can adopt electrostatic precipitator, cloth bag flue gas ash removal unit, electricity bag flue gas ash removal unit, moisture film flue gas ash removal unit etc., all in protection scope of the present invention.
Among this paper, said flue gas desulfurization unit comprises the various traditional desulphurization plants in this area.
Among this paper, described each grade flue gas heat exchange device is a heat exchanger, perhaps is several heat exchangers of parallel connection.
Among this paper, the not concrete restriction of said air-introduced machine only otherwise goal of the invention of the present invention is produced restriction to get final product, is well known by persons skilled in the art.
Among this paper, the not concrete restriction of said desulfurization booster fan only otherwise goal of the invention of the present invention is produced restriction to get final product, is well known by persons skilled in the art.
Among this paper, the flue gas heat exchange device comprises flue gas, air direct heat exchanger or the indirect-heating heat exchanger of middle heating agent is arranged.Be preferably pipe heat exchanger or rotary type heat exchanger.Preferably adopt liquid heating agent.Said liquid heating agent comprises water or other lower boiling liquid, preferred ethylene glycol.Said heating agent is kept it through heat medium circulation pump and between fume side/air side and heating agent side heat exchanger, is flowed.Liquid heating agent preferably is provided with the gas-liquid separation equipment that condenses when adopting lower boiling liquid on closed circuit, circulating pump is arranged on the downstream of this equipment.
Among this paper, steamer turbine condensate system can be the part of Steam Turbine Regenerative System, but is not limited to this, for example can also be turbine system condensate, hot net water, heating ventilation air-conditioning system water, power plant and other domestic water of adjacent machine.Steamer turbine condensate system of the present invention overcomes the flue gas heat exchange device through the condensate pump in the steam turbine condensate system and imports and exports the condensate resistance of condensing water conduit; Perhaps, overcome the condensate resistance of flue gas heat exchange device and import and export condensing water conduit thereof through condensate booster pump.The scope of boosting of needed booster is well known by persons skilled in the art.Wherein can comprise low-pressure heater at different levels.The implication of said low-pressure heater is known to those skilled in the art.
Among this paper, the not concrete restriction of the turbine system condensate of said adjacent machine, hot net water, heating ventilation air-conditioning system water, power plant and other domestic water only otherwise goal of the invention of the present invention is produced restriction to get final product, is well known by persons skilled in the art.
Below detail to various aspects of the present invention, if specifically do not indicate, term of the present invention is known to those skilled in the art.Concrete example is as can be referring to described in " Thermal Power Station " of China Electric Power Publishing House.
Be applied to the two-stage flue gas heat exchange device system in thermal power plant
First aspect present invention provides a kind of two-stage flue gas heat exchange device system that is applied to the thermal power plant; Comprise that the boiler unit (100), the fume afterheat that discharge flue gas utilize unit (200), flue gas ash removal unit (300) and flue gas desulfurization unit (400), said fume afterheat utilizes unit (200) to comprise:
-preheater (2);
-be arranged on the first order flue gas heat exchange device (31) of said flue gas ash removal unit (300) import, and the second level flue gas heat exchange device (32) that is arranged on said flue gas desulfurization unit (400) import;
Wherein,
Said first order flue gas heat exchange device (31) and second level flue gas heat exchange device (32) are the flue gas-condensate heat exchanger of the condensate side of the fume side that is provided with heat release and heat absorption; The water source of described condensate side is the condensate in the steam turbine condensate system; And
Said first order flue gas heat exchange device (31) and second level flue gas heat exchange device (32) are according to a kind of connection the in the following mode:
The fume side of the two is that serial arrangement connects, and the condensate side of the two connects with parallel way; Or
The fume side of the two all is connected with serial arrangement with the condensate side.
Among the present invention, two-stage flue gas heat exchange device is contacted on flue gas flow, on the condensate flow process, is parallelly connected.
Perhaps, two-stage flue gas heat exchange device is contacted on flue gas flow, on the condensate flow process, also connects.For two-stage flue gas heat exchange device, the flow direction of flue gas and condensate is following current.
Perhaps, two-stage flue gas heat exchange device is contacted on flue gas flow, on the condensate flow process, also connects.For two-stage flue gas heat exchange device, the flow direction of flue gas and condensate is an adverse current.
In a specific embodiment of the present invention, said first order flue gas heat exchange device (31) or second level flue gas heat exchange device (32) adopt surface-type heat exchanger.
In a specific embodiment of the present invention, said first order flue gas heat exchange device (31) or second level flue gas heat exchange device (32) adopt heat-pipe heat exchanger.
In a specific embodiment of the present invention, said first order flue gas heat exchange device (31) or second level flue gas heat exchange device (32) adopt the indirect-heating heat exchanger that intermediate carrier is arranged.
In a preference, the heating agent of said intermediate carrier is liquid.Said liquid heating agent is selected from water or other lower boiling liquid, preferred ethylene glycol.
In a specific embodiment of the present invention, adopt two-stage flue gas heat exchange device, be separately positioned on the import of deduster and the import of desulfuration absorbing tower.Each grade flue gas heat exchange device is a heat exchanger, perhaps is several heat exchangers of parallel connection.Each grade heat exchanger is a heat exchanger, perhaps is several heat exchangers of parallel connection
In a preference; The downstream of said flue gas ash removal unit (300) are provided with air-introduced machine (5) and optional desulfurization booster fan (6), get into follow-up second level flue gas heat exchange device (32) after making flue gas through said air-introduced machine (5) and desulfurization booster fan (6) adherence pressure.
In a specific embodiment of the present invention, the water side water source of said first order flue gas heat exchange device (31) and second level flue gas heat exchange device (32) also comprises turbine system condensate, hot net water, heating ventilation air-conditioning system water, power plant and other domestic water of adjacent machine.
In a specific embodiment of the present invention, said condensate derives from certain one-level low-pressure heater outlet of steam turbine condensate system or gathering of some grades of low-pressure heater outlets.
Particularly, condensate is got back to certain one-level low-pressure heater import or export after absorbing heat through the flue gas heat exchange device.
In a preference, said steam turbine condensate system also is provided with condensate booster pump.
In a preference; Certain the one-level low-pressure heater outlet of the condensate of flue gas heat exchange device source or some grades of low-pressure heaters outlets also gather, and promptly flue gas heat exchange device and certain one-level or some grades of low-pressure heaters are polyphone or parallelly connected or promptly have polyphone that parallelly connected relation is arranged again on the condensate flow process.
In a preference; Said condensate is got back to certain one-level low-pressure heater import or export through after the first order flue gas heat exchange device heat absorption, and promptly first order flue gas heat exchange device and certain one-level or some grades of low-pressure heaters are polyphone or parallelly connected or promptly have polyphone that parallelly connected relation is arranged again on the condensate flow process.
More preferably, overcome the condensate resistance of flue gas heat exchange device and import and export condensing water conduit thereof through the condensate pump in the steam turbine condensate system.
Perhaps, overcome the condensate resistance of flue gas heat exchange device and import and export condensing water conduit thereof through condensate booster pump.
The method that two-stage flue gas heat exchange device system carries out flue gas waste heat recovery
Second aspect of the present invention provides a kind of method that adopts two-stage flue gas heat exchange device of the present invention system to carry out flue gas waste heat recovery, and this method can reduce the method for smoke dust discharge concentration, water consumption and air-introduced machine, booster fan power consumption, and it comprises the steps:
The flue gas that boiler unit (100) are produced utilizes the preheater (2) in the unit (200) through fume afterheat, obtains 110 ℃~170 ℃ preheating flue gas;
Said preheating flue gas carries out waste heat recovery at first order flue gas heat exchange device (31), makes its temperature drop to above 5~10 ℃ of flue gas acid dew point temperature, obtains the flue gas of one-level through waste heat recovery; Reduced flue gas simultaneously and improved efficiency of dust collection realization reduction smoke dust discharge concentration, reduced flue gas simultaneously and submit to flow to realize reducing air-introduced machine, booster fan power consumption than resistance;
Said one-level temperature after the flue gas of waste heat recovery is through second level flue gas heat exchange device (32) is reduced to 20 ℃~25 ℃ or required optimum flue-gas temperature more than the water dew point temperature, obtains the flue gas of the second level through waste heat recovery; Reduce desulphurization system water consumption simultaneously;
The said second level gets into the flue gas desulfurization unit through the flue gas of waste heat recovery.
Particularly, described optimum flue-gas temperature is decided according to the mixed economy technology of the income of the power plant coal consumption of the arrangement space that takies of the manufacturing cost of flue gas heat exchange device, flue gas heat exchange device and saving.
In a preferred implementation, said one-level gets into flue gas ash removal unit (300) through the flue gas of waste heat recovery, and promotes entering second level flue gas heat exchange device (32) after the flue gas pressures through air-introduced machine (5) and optional desulfurization booster fan (6).
Fume afterheat utilizes the thermal power plant system of system
The present invention also provides a kind of thermal power plant system that fume afterheat of the present invention utilizes system that contains.
The invention has the advantages that:
Adopt two-stage flue gas heat exchange device; Be separately positioned on the import of deduster and the import of desulfuration absorbing tower; Adopt the condensate in the Steam Turbine Regenerative System to absorb the heat in the flue gas; Compare with the system that the flue gas heat exchange device is not set of routine or system that first-class heat exchanger is set, have and reduce soot emissions, reduce sulfur dioxide (SO2) emissions, practice thrift the desulphurization plant water and practice thrift the advantage of unit coal consumption.
Specify like nothing, various device of the present invention all can obtain through commercially available.
Other aspects of the present invention are because the disclosure of this paper is conspicuous to those skilled in the art.
Below in conjunction with specific embodiment, further set forth the present invention.Should be understood that these embodiment only to be used to the present invention is described and be not used in the restriction scope of the present invention.The experimental technique of unreceipted actual conditions in the following example usually according to normal condition, or carries out according to the condition that manufacturer advises.Unless otherwise indicated, otherwise all umbers are weight portion, and all percentages are weight percentage, and described polymer molecular weight is a number-average molecular weight.
Only if definition or explanation are arranged in addition, all specialties used herein are identical with the meaning that scientific words and those skilled in the art are familiar with.Any in addition with the institute similar content of putting down in writing or the equalization method and material all can be applicable in the inventive method.
Below in conjunction with accompanying drawing flue gas heat exchange device of the present invention system is further described, wherein, described flue gas energy-saving and emission-reduction water-saving system is made up of following major part:
(1) boiler 100
(2) air preheater 2
(3) first order flue gas heat exchange device 31
(4) deduster (flue gas ash removal unit 300)
(5) air-introduced machine 5
(6) booster fan 6
(7) second level flue gas heat exchange device 32
(8) desulfuration absorbing tower 400 (flue gas desulfurization unit)
(9) chimney
(10) low-pressure heater 7 (being called for short " low adding ")
(11) condensate booster pump 8
(12) circulating pump 9
(13) condenser 10
(14) condenser 11
(15) turbine low pressure cylinder 12
(16) generator 13
(17) condensate pump 14
(18) flash vessel 15
Embodiment 1 (corresponding diagram 3, Fig. 4)
The flue gas that boiler 100 burning produces is through behind the air preheater 2, different according to boiler form and coal-fired kind, and its temperature is generally between 110 ℃~170 ℃.Flue gas drops to more than the flue gas acid dew point temperature about 10 ℃ through first order flue gas heat exchange device 31 back temperature.First order flue gas heat exchange device 31 is a heat transferring medium with flue gas-condensate, fume side heat release, condensate side draught heat.Flue gas derives from the boiler smoke of air preheater outlet.Condensate derives from the steam turbine condensate system; Promptly derive from 7 outlets of certain one-level low-pressure heater or some grades of low-pressure heater 7 outlets and gather; Condensate is got back to certain one-level low-pressure heater 7 import or export after through first order flue gas heat exchange device 31 heat absorption, and promptly first order flue gas heat exchange device 31 and certain one-level or some grades of low-pressure heaters 7 are polyphone or parallelly connected or promptly have polyphone that parallelly connected relation is arranged again on the condensate flow process.Flue gas gets into deduster 300 through behind the first order flue gas heat exchange device 31, and through getting into second level flue gas heat exchange device 32 after air-introduced machine 5 and the desulfurization booster fan 6 lifting flue gas pressures.In this programme, booster fan 6 can omit, and adopts the higher air-introduced machine of lift 5 to accomplish the function that promotes flue gas pressures.Second level flue gas heat exchange device 32 is a heat transferring medium with flue gas-condensate, fume side heat release, condensate side draught heat.Flue gas derives from the flue gas of booster fan 6 or air-introduced machine 5 outlets.Condensate derives from the steam turbine condensate system; Promptly derive from 7 outlets of certain one-level low-pressure heater or some grades of low-pressure heater 7 outlets and gather; Condensate is got back to certain one-level low-pressure heater 7 import or export after through second level flue gas heat exchange device 32 heat absorption, and promptly second level flue gas heat exchange device 32 and certain one-level or some grades of low-pressure heaters 7 are polyphone or parallelly connected or promptly have polyphone that parallelly connected relation is arranged again on the condensate flow process.
Two-stage flue gas heat exchange device is contacted on flue gas flow in this scheme, on the condensate flow process, is parallelly connected.
The resistance of the condensate system of this scheme can be overcome by the condensate pump in the steam turbine condensate system 14, also condensate booster pump 8 can be set in addition, is overcome by condensate booster pump 8, and these schemes also belong to protection scope of the present invention.
Condensate in this scheme plays the reduction flue-gas temperature, improves the effect of condensing water temperature simultaneously.The water source of other types, the domestic water that needs like the turbine system condensate of adjacent machine, hot net water, power plant and other unit etc. also can be used as the water side water source of flue gas heat exchange device, and these schemes also belong to protection scope of the present invention.
Condensate is from the selection of which rank of low-pressure heater outlet or the outlet of which grade low-pressure heater, and the needed heat exchange area of flue gas heat exchange device depends on following factor: the condensing water temperature of (1) these leading points; (2) flue-gas temperature of flue gas heat exchange device import and export; (3) purchase cost of flue gas heat exchange device; (4) Turbo-generator Set energy consumption that causes extracted steam from turbine to reduce practicing thrift owing to the rising of condensing water temperature or electrical power that can the fecund life; (5) blower fan that causes of the resistance of the fume side that increases of flue gas heat exchange device system and condensate side and the increase of condensate pump 14 power consumptions; (6) the water consumption profit brought of desulphurization system saving; (7) deduster reduces the discharging profit brought of fume amount; (8) desulfurizing tower improves the desulfuration efficiency profit brought; (9) variation of configuration of the equipment of other power plant thermal systems that cause because being provided with this scheme and air and gas system and system configuration.
Embodiment 2 (corresponding diagram 5, Fig. 6)
The flue gas that boiler 100 burning produces is through behind the air preheater 2, different according to boiler form and coal-fired kind, and its temperature is generally between 110 ℃~170 ℃.Flue gas drops to more than the flue gas acid dew point temperature about 10 ℃ through first order flue gas heat exchange device 31 back temperature.First order flue gas heat exchange device 31 is for there being the indirect-heating flue gas-condensate heat exchanger of intermediate carrier, and intermediate carrier absorbs the fume side heat, and heat-setting water.Flue gas derives from the boiler smoke of air preheater outlet.Condensate derives from the steam turbine condensate system; Promptly derive from 7 outlets of certain one-level low-pressure heater or some grades of low-pressure heater 7 outlets and gather; Condensate is got back to certain one-level low-pressure heater 7 import or export after through first order flue gas heat exchange device 31 heat absorption, and promptly first order flue gas heat exchange device 31 and certain one-level or some grades of low-pressure heaters 7 are polyphone or parallelly connected or promptly have polyphone that parallelly connected relation is arranged again on the condensate flow process.Flue gas gets into deduster 300 through behind the first order flue gas heat exchange device 31, and through getting into second level flue gas heat exchange device 32 after air-introduced machine 5 and the desulfurization booster fan 6 lifting flue gas pressures.In this programme, booster fan 6 can omit, and adopts the higher air-introduced machine of lift 5 to accomplish the function that promotes flue gas pressures.Second level flue gas heat exchange device is indirect-heating flue gas-condensate heat exchanger that intermediate carrier is arranged, and intermediate carrier absorbs the fume side heat, and heat-setting water.Flue gas derives from the flue gas of booster fan or air-introduced machine outlet.Condensate derives from the steam turbine condensate system; Promptly derive from 7 outlets of certain one-level low-pressure heater or some grades of low-pressure heater 7 outlets and gather; Condensate is got back to certain one-level low-pressure heater 7 import or export after through second level flue gas heat exchange device 32 heat absorption, and promptly second level flue gas heat exchange device 32 and certain one-level or some grades of low-pressure heaters 7 are polyphone or parallelly connected or promptly have polyphone that parallelly connected relation is arranged again on the condensate flow process.
Two-stage flue gas heat exchange device is contacted on flue gas flow in this scheme, on the condensate flow process, is parallelly connected.
The resistance of the condensate system of this scheme can be overcome by the condensate pump in the steam turbine condensate system 14, also condensate booster pump 8 can be set in addition, is overcome by condensate booster pump 8, and these schemes also belong to protection scope of the present invention.
Intermediate carrier in this scheme is liquid, can be water, also can be other lower boiling liquid, and like ethylene glycol etc., intermediate carrier is kept it through circulating pump and between fume side and water-side heat, flowed.As adopting lower boiling liquid that the gas-liquid separation equipment that condenses can be set on closed circuit, circulating pump is arranged on the downstream of this equipment.These schemes also belong to protection scope of the present invention.
Condensate in this scheme plays the reduction flue-gas temperature, improves the effect of condensing water temperature simultaneously.The water source of other types, the domestic water that needs like the turbine system condensate of adjacent machine, hot net water, power plant and other unit etc. also can be used as the water side water source of flue gas heat exchange device, and these schemes also belong to protection scope of the present invention.
Condensate is from the selection of which rank of low-pressure heater outlet or the outlet of which grade low-pressure heater, and the needed heat exchange area of flue gas heat exchange device depends on following factor: the condensing water temperature of (1) these leading points; (2) flue-gas temperature of flue gas heat exchange device import and export; (3) purchase cost of flue gas heat exchange device; (4) Turbo-generator Set energy consumption that causes extracted steam from turbine to reduce practicing thrift owing to the rising of condensing water temperature or electrical power that can the fecund life; (5) blower fan that causes of the resistance of the fume side that increases of flue gas heat exchange device system and condensate side and the increase of condensate pump power consumption; (6) the water consumption profit brought of desulphurization system saving; (7) deduster reduces the discharging profit brought of fume amount; (8) desulfurizing tower improves the desulfuration efficiency profit brought; (9) variation of configuration of the equipment of other power plant thermal systems that cause because being provided with this scheme and air and gas system and system configuration.
Embodiment 3 (corresponding diagram 7)
The flue gas that boiler 100 burning produces is through behind the air preheater 2, different according to boiler form and coal-fired kind, and its temperature is generally between 110 ℃~170 ℃.Flue gas through first order flue gas heat exchange device after temperature drop to more than the flue gas acid dew point temperature about 10 ℃.First order flue gas heat exchange device 31 is a heat transferring medium for flue gas-condensate, fume side heat release, condensate side draught heat.Flue gas derives from the boiler smoke of air preheater outlet.Condensate derives from the steam turbine condensate system, promptly derive from 7 outlets of certain one-level low-pressure heater or some grades of low-pressure heater 7 outlets and gather, condensate through first order flue gas heat exchange device 31 heat absorption backs to second level flue gas heat exchange device 32 imports.Flue gas gets into deduster 300 through behind the first order flue gas heat exchange device 31, and through getting into second level flue gas heat exchange device 32 after air-introduced machine and the desulfurization booster fan lifting flue gas pressures.In this programme, booster fan can omit, and adopts the higher air-introduced machine of lift to accomplish the function that promotes flue gas pressures.Second level flue gas heat exchange device 32 is a heat transferring medium for flue gas-condensate, fume side heat release, condensate side draught heat.Flue gas derives from the flue gas of booster fan or air-introduced machine outlet.Condensate derives from the outlet of first order flue gas heat exchange device 31 condensate; Perhaps the condensate with certain one-level low-pressure heater 7 outlet or some grades of low-pressure heater 7 outlets gathers, and condensate is got back to certain one-level low-pressure heater 7 import or export after absorbing heat through second level flue gas heat exchange device 32.First order flue gas heat exchange device 31 and second level flue gas heat exchange device 32 and certain one-level or some grades of low-pressure heaters 7 are polyphone or parallelly connected or promptly have polyphone that parallelly connected relation is arranged again on the condensate flow process.
Two-stage flue gas heat exchange device is contacted on flue gas flow in this scheme, on the condensate flow process, also connects.For two-stage flue gas heat exchange device, the flow direction of flue gas and condensate is following current.
The resistance of the condensate system of this scheme can be overcome by the condensate pump in the steam turbine condensate system 14, also condensate booster pump 8 can be set in addition, is overcome by condensate booster pump 8, and these schemes also belong to protection scope of the present invention.
Condensate in this scheme plays the reduction flue-gas temperature, improves the effect of condensing water temperature simultaneously.The water source of other types, the domestic water that needs like the turbine system condensate of adjacent machine, hot net water, power plant and other unit etc. also can be used as the water side water source of flue gas heat exchange device, and these schemes also belong to protection scope of the present invention.
Condensate is from the selection of which rank of low-pressure heater outlet or the outlet of which grade low-pressure heater, and the needed heat exchange area of flue gas heat exchange device depends on following factor: the condensing water temperature of (1) these leading points; (2) flue-gas temperature of flue gas heat exchange device import and export; (3) purchase cost of flue gas heat exchange device; (4) Turbo-generator Set energy consumption that causes extracted steam from turbine to reduce practicing thrift owing to the rising of condensing water temperature or electrical power that can the fecund life; (5) blower fan that causes of the resistance of the fume side that increases of flue gas heat exchange device system and condensate side and the increase of condensate pump power consumption; (6) the water consumption profit brought of desulphurization system saving; (7) deduster reduces the discharging profit brought of fume amount; (8) desulfurizing tower improves the desulfuration efficiency profit brought; (9) variation of configuration of the equipment of other power plant thermal systems that cause because being provided with this scheme and air and gas system and system configuration.
Embodiment 4 (corresponding diagram 8)
The flue gas that boiler 100 burning produces is through behind the air preheater 2, different according to boiler form and coal-fired kind, and its temperature is generally between 110 ℃~170 ℃.Flue gas drops to more than the flue gas acid dew point temperature about 10 ℃ through first order flue gas heat exchange device 31 back temperature.First order flue gas heat exchange device 31 is for there being the indirect-heating flue gas-condensate heat exchanger of intermediate carrier, and intermediate carrier absorbs the fume side heat, and heat-setting water.Flue gas derives from the boiler smoke of air preheater outlet.Condensate derives from the steam turbine condensate system, promptly derives from outlet of certain one-level low-pressure heater or some grades of low-pressure heater 7 outlets and gathers, and condensate is got back to second level flue gas heat exchange device 32 imports after through 31 heat absorptions of first order flue gas heat exchange device.Flue gas gets into deduster 300 through behind the first order flue gas heat exchange device 31, and through getting into second level flue gas heat exchange device 32 after air-introduced machine and the desulfurization booster fan lifting flue gas pressures.In this programme, booster fan can omit, and adopts the higher air-introduced machine of lift to accomplish the function that promotes flue gas pressures.Second level flue gas heat exchange device 32 is for there being the indirect-heating flue gas-condensate heat exchanger of intermediate carrier, and intermediate carrier absorbs the fume side heat, and heat-setting water.Flue gas derives from the flue gas of booster fan or air-introduced machine outlet.Condensate derives from 31 outlets of first order flue gas heat exchange device; Perhaps the condensate with certain one-level low-pressure heater 7 outlet or some grades of low-pressure heater 7 outlets gathers, and condensate is got back to certain one-level low-pressure heater 7 import or export after absorbing heat through second level flue gas heat exchange device 32.First order flue gas heat exchange device 31 and second level flue gas heat exchange device 32 and certain one-level or some grades of low-pressure heaters 7 are polyphone or parallelly connected or promptly have polyphone that parallelly connected relation is arranged again on the condensate flow process.
Two-stage flue gas heat exchange device is contacted on flue gas flow in this scheme, on the condensate flow process, also connects.For two-stage flue gas heat exchange device, the flow direction of flue gas and condensate is following current.
The resistance of the condensate system of this scheme can be overcome by the condensate pump in the steam turbine condensate system 14, also condensate booster pump 8 can be set in addition, is overcome by condensate booster pump 8, and these schemes also belong to protection scope of the present invention.
Intermediate carrier in this scheme is liquid, can be water, also can be other lower boiling liquid, and like ethylene glycol etc., intermediate carrier is kept it through circulating pump and between fume side and water-side heat, flowed.As adopting lower boiling liquid that the gas-liquid separation equipment that condenses can be set on closed circuit, circulating pump is arranged on the downstream of this equipment.These schemes also belong to protection scope of the present invention.
Condensate in this scheme plays the reduction flue-gas temperature, improves the effect of condensing water temperature simultaneously.The water source of other types, the domestic water that needs like the turbine system condensate of adjacent machine, hot net water, power plant and other unit etc. also can be used as the water side water source of flue gas heat exchange device, and these schemes also belong to protection scope of the present invention.
Condensate is from the selection of which rank of low-pressure heater outlet or the outlet of which grade low-pressure heater, and the needed heat exchange area of flue gas heat exchange device depends on following factor: the condensing water temperature of (1) these leading points; (2) flue-gas temperature of flue gas heat exchange device import and export; (3) purchase cost of flue gas heat exchange device; (4) Turbo-generator Set energy consumption that causes extracted steam from turbine to reduce practicing thrift owing to the rising of condensing water temperature or electrical power that can the fecund life; (5) blower fan that causes of the resistance of the fume side that increases of flue gas heat exchange device system and condensate side and the increase of condensate pump power consumption; (6) the water consumption profit brought of desulphurization system saving; (7) deduster reduces the discharging profit brought of fume amount; (8) desulfurizing tower improves the desulfuration efficiency profit brought; (9) variation of configuration of the equipment of other power plant thermal systems that cause because being provided with this scheme and air and gas system and system configuration.
Embodiment 5 (corresponding diagram 9)
The flue gas that boiler 100 burning produces is through behind the air preheater 2, different according to boiler form and coal-fired kind, and its temperature is generally between 110 ℃~170 ℃.Flue gas drops to more than the flue gas acid dew point temperature about 10 ℃ through first order flue gas heat exchange device 31 back temperature.First order flue gas heat exchange device 31 is a heat transferring medium for flue gas-condensate, fume side heat release, condensate side draught heat.Flue gas derives from the boiler smoke of air preheater outlet.Condensate derives from 32 outlets of second level flue gas heat exchange device; Perhaps the condensate with certain one-level low-pressure heater 7 outlet or some grades of low-pressure heater 7 outlets gathers, and condensate is got back to certain one-level low-pressure heater 7 import or export after absorbing heat through first order flue gas heat exchange device 31.Flue gas gets into deduster 300 through behind the first order flue gas heat exchange device 31, and through getting into second level flue gas heat exchange device 32 after air-introduced machine and the desulfurization booster fan lifting flue gas pressures.In this programme, booster fan can omit, and adopts the higher air-introduced machine of lift to accomplish the function that promotes flue gas pressures.Second level flue gas heat exchange device 32 is a heat transferring medium for flue gas-condensate, fume side heat release, condensate side draught heat.Flue gas derives from the flue gas of booster fan or air-introduced machine outlet.Condensate derives from the steam turbine condensate system, promptly derive from 7 outlets of certain one-level low-pressure heater or some grades of low-pressure heater 7 outlets and gather, condensate through second level flue gas heat exchange device 32 heat absorption backs to 31 imports of first order flue gas heat exchange device.First order flue gas heat exchange device 31 and second level flue gas heat exchange device 32 and certain one-level or some grades of low-pressure heaters 7 are polyphone or parallelly connected or promptly have polyphone that parallelly connected relation is arranged again on the condensate flow process.
Two-stage flue gas heat exchange device is contacted on flue gas flow in this scheme, on the condensate flow process, also connects.For two-stage flue gas heat exchange device, the flow direction of flue gas and condensate is an adverse current.
The resistance of the condensate system of this scheme can be overcome by the condensate pump in the steam turbine condensate system 14, also condensate booster pump 8 can be set in addition, is overcome by condensate booster pump 8, and these schemes also belong to protection scope of the present invention.
Condensate in this scheme plays the reduction flue-gas temperature, improves the effect of condensing water temperature simultaneously.The water source of other types, the domestic water that needs like the turbine system condensate of adjacent machine, hot net water, power plant and other unit etc. also can be used as the water side water source of flue gas heat exchange device, and these schemes also belong to protection scope of the present invention.
Condensate is from the selection of which rank of low-pressure heater outlet or the outlet of which grade low-pressure heater, and the needed heat exchange area of flue gas heat exchange device depends on following factor: the condensing water temperature of (1) these leading points; (2) flue-gas temperature of flue gas heat exchange device import and export; (3) purchase cost of flue gas heat exchange device; (4) Turbo-generator Set energy consumption that causes extracted steam from turbine to reduce practicing thrift owing to the rising of condensing water temperature or electrical power that can the fecund life; (5) blower fan that causes of the resistance of the fume side that increases of flue gas heat exchange device system and condensate side and the increase of condensate pump power consumption; (6) the water consumption profit brought of desulphurization system saving; (7) deduster reduces the discharging profit brought of fume amount; (8) desulfurizing tower improves the desulfuration efficiency profit brought; (9) variation of configuration of the equipment of other power plant thermal systems that cause because being provided with this scheme and air and gas system and system configuration.
Embodiment 6 (corresponding Figure 10)
The flue gas that boiler 100 burning produces is through behind the air preheater 2, different according to boiler form and coal-fired kind, and its temperature is generally between 110 ℃~170 ℃.Flue gas drops to more than the flue gas acid dew point temperature about 10 ℃ through first order flue gas heat exchange device 31 back temperature.First order flue gas heat exchange device 31 is for there being the indirect-heating flue gas-condensate heat exchanger of intermediate carrier, and intermediate carrier absorbs the fume side heat, and heat-setting water.Flue gas derives from the boiler smoke of air preheater outlet.Condensate derives from 32 outlets of second level flue gas heat exchange device; Perhaps the condensate with certain one-level low-pressure heater outlet or some grades of low-pressure heater 7 outlets gathers, and condensate is got back to certain one-level low-pressure heater 7 import or export after absorbing heat through first order flue gas heat exchange device 31.Flue gas gets into deduster 300 through behind the first order flue gas heat exchange device 31, and through getting into second level flue gas heat exchange device 32 after air-introduced machine and the desulfurization booster fan lifting flue gas pressures.In this programme, booster fan can omit, and adopts the higher air-introduced machine of lift to accomplish the function that promotes flue gas pressures.Second level flue gas heat exchange device 32 is for there being the indirect-heating flue gas-condensate heat exchanger of intermediate carrier, and intermediate carrier absorbs the fume side heat, and heat-setting water.Flue gas derives from the flue gas of booster fan or air-introduced machine outlet.Condensate derives from the steam turbine condensate system, promptly derive from 7 outlets of certain one-level low-pressure heater or some grades of low-pressure heater 7 outlets and gather, condensate through second level flue gas heat exchange device 32 heat absorption backs to 31 imports of first order flue gas heat exchange device.First order flue gas heat exchange device 31 and second level flue gas heat exchange device 32 and certain one-level or some grades of low-pressure heaters 7 are polyphone or parallelly connected or promptly have polyphone that parallelly connected relation is arranged again on the condensate flow process.
Two-stage flue gas heat exchange device is contacted on flue gas flow in this scheme, on the condensate flow process, also connects.For two-stage flue gas heat exchange device, the flow direction of flue gas and condensate is an adverse current.
The resistance of the condensate system of this scheme can be overcome by the condensate pump in the steam turbine condensate system 14, also condensate booster pump 8 can be set in addition, is overcome by condensate booster pump 8, and these schemes also belong to protection scope of the present invention.
Intermediate carrier in this scheme is liquid, can be water, also can be other lower boiling liquid, and like ethylene glycol etc., intermediate carrier is kept it through circulating pump and between fume side and water-side heat, flowed.As adopting lower boiling liquid that the gas-liquid separation equipment that condenses can be set on closed circuit, circulating pump 9 is arranged on the downstream of this equipment.These schemes also belong to protection scope of the present invention.
Condensate in this scheme plays the reduction flue-gas temperature, improves the effect of condensing water temperature simultaneously.The water source of other types, the domestic water that needs like the turbine system condensate of adjacent machine, hot net water, power plant and other unit etc. also can be used as the water side water source of flue gas heat exchange device, and these schemes also belong to protection scope of the present invention.
Condensate is from the selection of which rank of low-pressure heater outlet or the outlet of which grade low-pressure heater, and the needed heat exchange area of flue gas heat exchange device depends on following factor: the condensing water temperature of (1) these leading points; (2) flue-gas temperature of flue gas heat exchange device import and export; (3) purchase cost of flue gas heat exchange device; (4) Turbo-generator Set energy consumption that causes extracted steam from turbine to reduce practicing thrift owing to the rising of condensing water temperature or electrical power that can the fecund life; (5) blower fan that causes of the resistance of the fume side that increases of flue gas heat exchange device system and condensate side and the increase of condensate pump power consumption; (6) the water consumption profit brought of desulphurization system saving; (7) deduster reduces the discharging profit brought of fume amount; (8) desulfurizing tower improves the desulfuration efficiency profit brought; (9) variation of configuration of the equipment of other power plant thermal systems that cause because being provided with this scheme and air and gas system and system configuration.
Performance embodiment
With certain 1000MW unit is example, adopts the scheme of embodiment 5 to put two-stage flue gas heat exchange device system.The input gas temperature of first order flue gas heat exchange device 31 is 128 ℃, and exit gas temperature is 105 ℃, and the input gas temperature of second level flue gas heat exchange device 32 is 110 ℃, and exit gas temperature is 86 ℃.The incoming condensing water temperature of second level flue gas heat exchange device 32 is 59.9 ℃, and behind second level flue gas heat exchange device 32 and first order flue gas heat exchange device 31, the condensing water temperature of outlet is 82.30 ℃.This two-stage flue gas heat exchange device system can come out the heat of 7070KW from the flue gas displace, being used for steam turbine increases acting.Can reduce generating standard coal consumption 1.6g/Kw.h, by generating set annual utilization hours 5500 hours, annual every generating set can be practiced thrift about 9000 tons of standard coals.Simultaneously, be reduced to 86 ℃ by 128 ℃, can practice thrift the about 80t/h of desulfurizing tower water consumption, amount to annual 440000 tons of water owing to get into the temperature of desulfuration absorbing tower.The efficient of electrostatic precipitator can rise to 99.86% from 99.7%, the dust contained flue gas concentration of the deduster outlet 16.7mg/Nm that descended 3, year reduction of discharging dust 136t.
Discuss
The present invention is based on steam turbine thermodynamic cycle basic principle.Condensate cooling pan kiln gas in the steam turbine condensate system is also returned the steam turbine condensate system after the flue gas heating, because drawing gas in the part low-pressure heater squeezed in the rising of condensing water temperature, under the constant situation of steam turbine throttle flow; The acting of being squeezed of in steam turbine, expanding of drawing gas; Therefore, under the constant situation of unit coal consumption amount, increased the generated energy of steam turbine generator, in like manner; Under the constant situation of steam turbine generator generated energy, the coal consumption that can practice thrift unit.
The present invention is based on following technological means and utilize the heat in the boiler smoke through the flue gas heat exchange device:
Flue gas descends through temperature behind the first order flue gas heat exchange device, the also corresponding decline of ratio resistance of flue gas.For electrostatic precipitator, its efficiency of dust collection rises along with flue gas has comparatively significantly than the decline of resistance.Therefore, in the deduster import first order flue gas heat exchange device is set and reduces flue-gas temperature, can improve the efficiency of dust collection of deduster, reduce the discharging of flue dust.
Flue gas descends through temperature behind the first order flue gas heat exchange device, and the volume flow of general formula flue gas also descends, with the power consumption that reduces air-introduced machine, booster fan.Therefore, in the deduster import first order flue gas heat exchange device is set and reduces flue-gas temperature, can reduce the air-introduced machine that is arranged on the deduster downstream and the power consumption of booster fan, can practice thrift the station service of unit.
Temperature descended after flue gas passed through first order flue gas heat exchange device and second level flue gas heat exchange device, and the flue-gas temperature that causes getting into desulfuration absorbing tower reduces.For the technology of smoke-gas wet desulfurization, need with flue gas in desulfuration absorbing tower under the spray effect of desulfurizer slurry temperature drop to 40 ℃~50 ℃, the moisture in the slurries has been evaporated in the heat release of flue gas in this process.Flue-gas temperature is high more, and is big more to the evaporation capacity of moisture content in the slurries, and the water consumption of desulphurization system is big more.Therefore, be provided with the first order and second level flue gas heat exchange device after, the flue-gas temperature that reduce to get into desulfuration absorbing tower can reduce the evaporation of water amount of desulfuration absorbing tower, reduces the water consumption of desulphurization system greatly.
Temperature descended after flue gas passed through first order flue gas heat exchange device and second level flue gas heat exchange device, also caused the volume flow of flue gas to descend.After flue gas gets into desulfuration absorbing tower; The flow velocity of flue gas descends, and the time of staying of flue gas in desulfurizing tower spray zone increases, and promptly increased the time of contact of sulfur in smoke and desulfurization slurry; Can improve the desulfuration efficiency of desulfuration absorbing tower, reduce the discharging of sulfur dioxide.
The above is merely preferred embodiment of the present invention; Be not in order to limit essence technology contents scope of the present invention; Essence technology contents of the present invention is broadly to be defined in the claim scope of application, and if any technological entity or method that other people accomplish are defined identical with the claim scope of application; Also or a kind of change of equivalence, all will be regarded as and be covered by among this claim scope.
All documents in that the present invention mentions are all quoted as a reference in this application, are just quoted such as a reference separately as each piece document.Should be understood that in addition that after having read foregoing of the present invention those skilled in the art can do various changes or modification to the present invention, these equivalent form of values fall within the application's appended claims institute restricted portion equally.

Claims (10)

1. two-stage flue gas heat exchange device system that is applied to the thermal power plant; Comprise that the boiler unit (100), the fume afterheat that discharge flue gas utilize unit (200), flue gas ash removal unit (300) and flue gas desulfurization unit (400); It is characterized in that said fume afterheat utilizes unit (200) to comprise:
-preheater (2);
-be arranged on the first order flue gas heat exchange device (31) of said flue gas ash removal unit (300) import, and the second level flue gas heat exchange device (32) that is arranged on said flue gas desulfurization unit (400) import;
Wherein,
Said first order flue gas heat exchange device (31) and second level flue gas heat exchange device (32) are the flue gas-condensate heat exchanger of the condensate side of the fume side that is provided with heat release and heat absorption; The water source of described condensate side is the condensate in the steam turbine condensate system; And
Said first order flue gas heat exchange device (31) and second level flue gas heat exchange device (32) are according to a kind of connection the in the following mode:
The fume side of the two is that serial arrangement connects, and the condensate side of the two connects with parallel way; Or
The fume side of the two all is connected with serial arrangement with the condensate side.
2. flue gas heat exchange device as claimed in claim 1 system; It is characterized in that the water side water source of said first order flue gas heat exchange device (31) and second level flue gas heat exchange device (32) also comprises turbine system condensate, hot net water, heating ventilation air-conditioning system water, power plant and other domestic water of adjacent machine.
3. flue gas heat exchange device as claimed in claim 1 system is characterized in that, said condensate derives from certain one-level low-pressure heater outlet of steam turbine condensate system or gathering of some grades of low-pressure heater outlets.
4. flue gas heat exchange device as claimed in claim 1 system is characterized in that, said first order flue gas heat exchange device (31) or second level flue gas heat exchange device (32) adopt surface-type heat exchanger.
5. flue gas heat exchange device as claimed in claim 1 system is characterized in that, said first order flue gas heat exchange device (31) or second level flue gas heat exchange device (32) adopt heat-pipe heat exchanger.
6. flue gas heat exchange device as claimed in claim 1 system is characterized in that, said first order flue gas heat exchange device (31) or second level flue gas heat exchange device (32) adopt the indirect-heating heat exchanger that intermediate carrier is arranged.
7. flue gas-air heat exchanger as claimed in claim 1 system is characterized in that each grade heat exchanger is a heat exchanger, perhaps is several heat exchangers of parallel connection
8. a method that adopts the described two-stage flue gas heat exchange of claim 1 device system to carry out flue gas waste heat recovery is characterized in that, comprises the steps:
The flue gas that boiler unit (100) are produced utilizes the preheater (2) in the unit (200) through fume afterheat, obtains 110 ℃~170 ℃ preheating flue gas;
Said preheating flue gas carries out waste heat recovery at first order flue gas heat exchange device (31), makes its temperature drop to above 5~10 ℃ of flue gas acid dew point temperature, obtains the flue gas of one-level through waste heat recovery;
Said one-level temperature after the flue gas of waste heat recovery is through second level flue gas heat exchange device (32) is reduced to 20 ℃~25 ℃ or required optimum flue-gas temperature more than the water dew point temperature, obtains the flue gas of the second level through waste heat recovery;
The said second level gets into flue gas desulfurization unit (400) through the flue gas of waste heat recovery.
9. method as claimed in claim 8; It is characterized in that; The downstream of said flue gas ash removal unit (300) are provided with air-introduced machine (5) and optional desulfurization booster fan (6), get into follow-up second level flue gas heat exchange device (32) after making flue gas through said air-introduced machine (5) and desulfurization booster fan (6) adherence pressure.
10. one kind contains the thermal power plant system that the described fume afterheat of claim 1 utilizes system.
CN2010102248592A 2010-07-12 2010-07-12 Two-stage flue gas heat exchanger system applied to thermal power plant Pending CN102330968A (en)

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CN102759096A (en) * 2012-07-24 2012-10-31 西安交通大学 Smoke waste heat utilization system
CN103939932A (en) * 2014-04-28 2014-07-23 中冶华天工程技术有限公司 Blast furnace gas boiler flue gas waste heat deep recycling system
CN104235827A (en) * 2013-06-13 2014-12-24 烟台龙源电力技术股份有限公司 Boiler smoke waste heat utilization system
CN104235826A (en) * 2013-06-13 2014-12-24 烟台龙源电力技术股份有限公司 Boiler flue gas waste heat recycling system
CN104654340A (en) * 2015-02-12 2015-05-27 中国电力工程顾问集团华东电力设计院有限公司 Tubular GGH (gas-gas heater) system for thermal power plant
CN104930539A (en) * 2015-06-29 2015-09-23 山东大学 Coal-fired power plant flue gas heat regenerative system and energy-saving water-saving ultra-clean discharging method
CN105457440A (en) * 2016-01-16 2016-04-06 杨德俊 Device for achieving flue gas power generation and removing harmful substance in flue gas simultaneously
CN105627341A (en) * 2016-03-22 2016-06-01 中国能源建设集团广东省电力设计研究院有限公司 Dust remover rear flue gas system provided with flue gas heat exchanger
CN106322417A (en) * 2016-08-25 2017-01-11 关文吉 Comprehensive heat exchange system for flue gas and blowdown water of power plant boiler as well as heat exchange method
CN106382645A (en) * 2016-08-25 2017-02-08 关文吉 Dry flue gas heat exchange system and heat exchange method of boiler of power station
CN106439882A (en) * 2016-08-26 2017-02-22 舒少辛 Desulfuration wastewater treatment device utilizing flue gas waste heat
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CN111219720A (en) * 2020-01-20 2020-06-02 山东电力工程咨询院有限公司 Flue gas waste heat utilization system and method for waste incineration power plant

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CN102645112B (en) * 2012-04-19 2014-08-27 浙江清科电力科技有限公司 Waste heat recovery system for improving efficiency of electric dust collector
CN102645112A (en) * 2012-04-19 2012-08-22 浙江清科电力科技有限公司 Waste heat recovery system for improving efficiency of electric dust collector
CN102759096B (en) * 2012-07-24 2015-01-07 西安交通大学 Smoke waste heat utilization system
CN102759096A (en) * 2012-07-24 2012-10-31 西安交通大学 Smoke waste heat utilization system
CN104235827A (en) * 2013-06-13 2014-12-24 烟台龙源电力技术股份有限公司 Boiler smoke waste heat utilization system
CN104235826A (en) * 2013-06-13 2014-12-24 烟台龙源电力技术股份有限公司 Boiler flue gas waste heat recycling system
CN103939932A (en) * 2014-04-28 2014-07-23 中冶华天工程技术有限公司 Blast furnace gas boiler flue gas waste heat deep recycling system
CN104654340A (en) * 2015-02-12 2015-05-27 中国电力工程顾问集团华东电力设计院有限公司 Tubular GGH (gas-gas heater) system for thermal power plant
CN104930539A (en) * 2015-06-29 2015-09-23 山东大学 Coal-fired power plant flue gas heat regenerative system and energy-saving water-saving ultra-clean discharging method
CN105457440B (en) * 2016-01-16 2018-06-29 湘南学院 The device of flue gas harmful substance is removed in a kind of flue gas power generation simultaneously
CN105457440A (en) * 2016-01-16 2016-04-06 杨德俊 Device for achieving flue gas power generation and removing harmful substance in flue gas simultaneously
CN105627341B (en) * 2016-03-22 2017-10-13 中国能源建设集团广东省电力设计研究院有限公司 Flue gas system after deduster with flue gas heat-exchange unit
CN105627341A (en) * 2016-03-22 2016-06-01 中国能源建设集团广东省电力设计研究院有限公司 Dust remover rear flue gas system provided with flue gas heat exchanger
CN106322417A (en) * 2016-08-25 2017-01-11 关文吉 Comprehensive heat exchange system for flue gas and blowdown water of power plant boiler as well as heat exchange method
CN106382645A (en) * 2016-08-25 2017-02-08 关文吉 Dry flue gas heat exchange system and heat exchange method of boiler of power station
CN106439882A (en) * 2016-08-26 2017-02-22 舒少辛 Desulfuration wastewater treatment device utilizing flue gas waste heat
CN106931424A (en) * 2017-03-29 2017-07-07 中国能源建设集团广东省电力设计研究院有限公司 Thermal power generation system and its heat energy apparatus, flue gas waste heat utilization device
CN111219720A (en) * 2020-01-20 2020-06-02 山东电力工程咨询院有限公司 Flue gas waste heat utilization system and method for waste incineration power plant

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