Flue gas waste heat recovery apparatus based on station boiler hydrophily GGH fibre selection
Technical field
The present invention relates to a kind of Power Plant Equipment, the boiler smoke temperature that is specifically related to a kind of thermal power plant is controlled and flue gas waste heat recovery apparatus.
Background technology
The energy of China be take coal as main, and according to statistics, China's capacity of installed generator moderate heat electricity installed capacity at present reaches more than 74%.In following a very long time, the coal-fired pollution causing is still an important environmental problem, and < < thermal power plant air pollution emission standard (GB13223-2011) the > > implementing in January, 2011 is reduced to 100mg/Nm the highest permission concentration of emission of station boiler nitrogen oxide limit value
3, smoke dust discharge concentration is reduced to 30mg/Nm
3, sulfur dioxide is reduced to 100mg/Nm
3.And walk in the thermal power plant that reduces discharge prostatitis, fired power generating unit pollutant emission target having been fixed on to higher standard (dressing with gas turbine discharge standard), i.e. coal-fired plant flue gas discharge sulfur dioxide is no more than 35mg/Nm
3, oxynitrides is no more than 50mg/Nm
3, flue dust is no more than 5mg/Nm
3, before chimney, flue-gas temperature is not less than 80 ℃, to eliminate chimney " white cigarette " and " gypsum rain " phenomenon.Realize above target, must carry out a large amount of scientific and technical innovations, technological transformation.Wherein hydrophily flue gas heat-exchange unit (hereinafter to be referred as hydrophily GGH) is used as the new equipment of realizing the application of minimum discharge means.This equipment is tubular type pattern, take water in medium is placed in desulfuration absorbing tower front and back flue, before absorption tower, in hydrophily GGH high temperature section, recirculated water absorbs high-temperature flue gas heat, water circulation after heat absorption is carried out heat release to the hydrophily GGH low-temperature zone of arranging behind the front absorption tower of chimney, with heating, enter the flue-gas temperature of chimney, prevent chimney " white cigarette " and " gypsum rain " phenomenon.And because hydrophily GGH is tubular type pattern, be different from traditional swinging flue gas heat-exchange unit (GGH), there is not leakage problem in high-temperature flue gas.Hydrophily GGH can effectively prevent from leaking in flue gas and cause discharge higher and chimney " white cigarette " and " gypsum rain " phenomenon.
But hydrophily GGH system relative complex, because of diversity and unit load fluctuation that boiler uses coal, actual hydrophily GGH high temperature section import cigarette temperature and design load can produce more greatly and depart from, and cause hydrophily GGH job stability poor.When hydrophily GGH high temperature section import cigarette temperature (boiler air preheater outlet) is higher, need to open hydrophily GGH bypass to control low temp. electric dedusting import cigarette temperature, so cause boiler heat loss to increase.When hydrophily GGH high temperature section import cigarette temperature (boiler air preheater outlet) is on the low side, just need to drop into very early hydrophily GGH system filling heater, to improve hydrophily GGH low-temperature zone water temperature, meet exhaust gas temperature requirement, the input in advance of filling heater, wastes a large amount of steam, less economical.
Summary of the invention
For solving the deficiencies in the prior art, the invention provides a kind of flue gas waste heat recovery apparatus based on station boiler hydrophily GGH fibre selection, when making generating set air preheater outlet cigarette temperature be higher under heavy-duty service, increasing fibre selection and waste-heat recovery device water effluent amount absorbs flue gas heat and is recycled to steam turbine therrmodynamic system, reduce flue gas heat loss, and because flue gas heat is recycled to thermodynamic system of steam tur, can reduce the thermodynamic system of steam tur heating steam of drawing gas; When load reduction air preheater outlet cigarette temperature declines, reduce the inflow of fibre selection and waste-heat recovery device, improve hydrophily GGH import cigarette temperature, can postpone the time of putting into operation and the heating steam amount of hydrophily GGH concurrent heating heater, reach energy-conservation object.Meanwhile, it is object that the feedwater flow regulation of fibre selection and waste-heat recovery device be take hydrophily GGH high temperature section import cigarette temperature, regulates with clearly defined objectively, avoids causing hydrophily GGH system works uncertain because cigarette temperature departs from, and improves hydrophily GGH system works stability.
The present invention realizes in the following manner: the flue gas waste heat recovery apparatus based on station boiler hydrophily GGH fibre selection, comprise fibre selection and waste-heat recoverer, one flue being communicated with described fibre selection and waste-heat recoverer gas approach end, the hydrophily GGH high temperature section being communicated with described fibre selection and waste-heat recoverer smoke outlet, and the feedwater piping being connected with described fibre selection and waste-heat recoverer, the front end of described feedwater piping is by being communicated with steam turbine low-pressure tube, heater inlet road, rear end is communicated with steam turbine low-pressure heater outlet conduit, described steam turbine low-pressure heater is connected with extracted steam from turbine pipe.
Between original air preheater and hydrophily GGH high temperature section, set up fibre selection and waste-heat recoverer, fibre selection and waste-heat recoverer fume side are connected with boiler smoke side, make boiler smoke pass through successively air preheater, fibre selection and waste-heat recoverer, hydrophily GGH high temperature section, electric precipitation, desulfurizer, hydrophily GGH low-temperature zone, chimney.Water side is with steam turbine condensate system low-pressure heater phase and connect, and makes can partly or entirely flow through as required fibre selection and waste-heat recoverer of steam turbine feedwater carry out hydrophily GGH high temperature section import fibre selection, and realizes flue gas heat and reclaim.
As preferably, described fibre selection and waste-heat recoverer feed water circuit inducer, steam turbine low-pressure heater feed-water inlet section are equipped with a feed water flow regulating valve, for regulating the distribution that enters feedwater flow in fibre selection and waste-heat recoverer and low-pressure heater.Described fibre selection and waste-heat recoverer feed water circuit outlet section are provided with a transfer isolating valve, for controlling the logical state that closes of fibre selection and waste-heat recoverer water side piped water.
As preferably, described fibre selection and the waste-heat recoverer fume side port of export, hydrophily GGH high temperature section gas approach end are established one group of smoke temperature measurement device, for the control of fibre selection and waste-heat recoverer feedwater flow regulation.
As preferably, on described steam turbine low-pressure heater extraction line hypomere, connect a pressure regulator valve is set.For regulate heating steam amount when low-pressure heater confluent changes.
Outstanding beneficial effect of the present invention: set up fibre selection and waste-heat recoverer between original air preheater and hydrophily GGH, fibre selection and waste-heat recoverer fume side are arranged in boiler flue, and water side is in parallel with thermodynamic system of steam tur.Make boiler smoke pass through successively air preheater preheater, fibre selection and waste-heat recoverer, hydrophily GGH high temperature section, thermodynamic system of steam tur feedwater can be by fibre selection and waste-heat recoverer feedwater piping flow through fibre selection and waste-heat recoverer, at fibre selection and waste-heat recoverer and low-pressure heater feedwater piping inducer, flow control valve is set and distributes to discharge.It is target that fibre selection and waste-heat recoverer be take hydrophily GGH high temperature section import fibre selection.When unit heavy-duty service, regulate more feedwater flows to fibre selection and waste-heat recoverer, and can turn down the low-pressure heater amount of drawing gas; When performing low-load running of machine set, regulate more feedwater flows to low-pressure heater, improve hydrophily GGH high temperature section import cigarette temperature, can reduce hydrophily GGH system filling amount.Thereby guarantee that generating set economical operation improves hydrophily GGH system works stability simultaneously.In addition, the present invention has advantages of that system breaks down does not affect the features such as main system is normally moved, confluent can be adjusted as required, and system is simple, and improvement cost is low, easy to operate.
Accompanying drawing explanation
Fig. 1 is pipeline structure schematic diagram of the present invention;
Fig. 2 is generating set pipeline structure schematic diagram;
In figure: 1, fibre selection and waste-heat recoverer, 2, flue, 3, air preheater, 4, feedwater piping, 5, low-pressure heater, 6, hydrophily GGH high temperature section, 7, feed water flow regulating valve, 8, flow-through orifice, 9, electronic isolating valve, 10, temperature measuring equipment, 11, flow control valve, 12, steam turbine, 13, extraction line, 14, extraction check valve, 15, extraction control valve, 16, flue gas temperature measurement device, 17, electric precipitation, 18, air-introduced machine, 19, desulfurizer, 20, hydrophily GGH low-temperature zone, 21, circulating pump, 22, filling heater, 23, condensing water conduit, 24, solidifying feed pump, 25, condenser, 26, chimney, 27, boiler.
The specific embodiment
Below in conjunction with specification drawings and specific embodiments, substantive distinguishing features of the present invention is further described.
The flue gas waste heat recovery apparatus based on station boiler hydrophily GGH fibre selection as shown in Figure 1, by fibre selection and waste-heat recoverer 1, one flue 2 being communicated with described fibre selection and waste-heat recoverer 1 gas approach end, the hydrophily GGH high temperature section 6 being communicated with described fibre selection and waste-heat recoverer 1 smoke outlet, the feedwater piping 4 being connected with described fibre selection and waste-heat recoverer 1 and extracted steam from turbine pipeline 13 form, described fibre selection and waste-heat recoverer 1 fume side are communicated with air preheater 3 and hydrophily GGH high temperature section 6, the front end of described fibre selection and waste-heat recoverer 1 water side feedwater piping 4 is by being communicated with steam turbine low-pressure heater 5 inlet channels, rear end is communicated with steam turbine low-pressure heater 5 outlet conduits.
Described feedwater piping 4 inducers are established a feed water flow regulating valve 7, flow-through orifice 8, outlet section is established electronic isolating valve 9 and a temperature measuring equipment 10, described steam turbine low-pressure heater 5 feed-water inlet ends are provided with a flow control valve 11, described fibre selection device 1 fume side outlet section arranges one group of smoke temperature measurement device 16 and flue-gas controlling system, and the water back 13 that draws gas of described steam turbine low-pressure heater 5 is provided with the electric control valve 15 that draws gas.Described feedwater piping 4 inducer feed water flow regulating valves 7 and described steam turbine low-pressure heater 5 feed-water inlet end flow control valves 11, regulate for fibre selection and waste-heat recoverer 1 water side assignment of traffic; Described steam turbine low-pressure heater 5 electric control valve 15 that draws gas, regulates for 5 heating steams of steam turbine low-pressure heater.
When generating set turns round, by following flow process, complete hydrophily GGH import fibre selection and flue gas waste heat recovery operation (as shown in Figure 2):
1, the flue gas that boiler 27 produces under the effect of air-introduced machine 18 successively through air preheater 3, flue 2 enter fibre selection and waste-heat recoverer 1, after 6 heat releases of hydrophily GGH high temperature section through electric precipitation 17 dedustings, after desulfurizer 19 desulfurization, enter afterwards 20 heat absorptions of hydrophily GGH low-temperature zone, the flue gas temperature that reaches uniform temperature after heat absorption enters atmosphere finally by chimney 26.
2, the steam after steam turbine 12 works done is condensed into water through condenser 25, by condensate pump 24 adherence pressures, minute two-way after condensing water conduit 23, one tunnel enters fibre selection and waste-heat recoverer 1 through feedwater piping 4, feed water flow regulating valve 7, flow-through orifice 8, then enters steam turbine condensate line through electronic isolating valve 9; One tunnel is converged on Yu Shang mono-tunnel after flow control valve 11 enters steam turbine low-pressure heater 5 heat absorption, and condensate water finally enters boiler and is heated into steam and generates electricity to steam turbine work done.
3, when hydrophily GGH high temperature section 6 import cigarette temperature are during higher than design load, drop into fibre selection and residual neat recovering system.Open electronic isolating valve 9, open feed water flow regulating valve 7.Open as required large feed water flow regulating valve 7 and close control valve for small flows 11, until hydrophily GGH high temperature section 6 import cigarette temperature meet the demands.When turning down, until while closing flow control valve 11, turn down low-pressure heater 5 motor-driven valve 15 that draws gas.Above adjustment process realizes fibre selection and guarantees hydrophily GGH working stability object, and realizes flue gas waste heat recovery simultaneously and reduce the low-pressure heater 5 heating steam amounts of drawing gas, and reaches energy-conservation object.
4, when hydrophily GGH high temperature section 6 import cigarette temperature are during lower than design load, turn down until close feed water flow regulating valve 7, open large flux control valve 11 simultaneously, to improve hydrophily GGH high temperature section import cigarette temperature, and can reduce filling heater 22 heating steam amounts.
In concrete operations, generating set can switch according to its payload between two kinds of patterns:
Pattern one: when generating set high loaded process, the flue-gas temperature of discharging from boiler 27 is higher, take hydrophily GGH high temperature section 6 import cigarette temperature as controlling target, and fibre selection and residual neat recovering system automatically put into operation.Open electronic isolating valve 9, open and regulate feed water flow regulating valve 7, turn down and adjust flux control valve 11, turn down and regulate the motor-driven valve 15 that draws gas.
Pattern two: when generating set low load operation, the flue-gas temperature of discharging from boiler 27 is lower, take hydrophily GGH high temperature section 6 import cigarette temperature as controlling target, automatically exits fibre selection and residual neat recovering system.Open large flux control valve 11, open large and regulate the motor-driven valve that draws gas, turn down feed water flow regulating valve 7, when hydrophily GGH high temperature section import cigarette temperature continues to reduce, exit fibre selection and waste-heat recovery device.