A kind of Waste water concentrating system and method for utilization fume afterheat based on fluid column evaporation
Technical field
The present invention relates to energy and environment field, more particularly to a kind of waste water of utilization fume afterheat based on fluid column evaporation is dense
Compression system and method.
Background technology
Coal fired thermal power plant is the rich and influential family of China's water for industrial use, and its water consumption and displacement are very huge, in water for industrial use
About 40% is used for coal fired thermal power plant, and the annual draining of coal fired thermal power plant accounts for the 10% of national industrial undertaking's discharge capacity.As water is provided
The growing tension in source and environmental requirement it is increasingly strict, the water saving of coal-fired power plant subtracts dirty imperative.Coal-fired power plant's waste water
Zero-emission can be minimum utilization water resource, to greatest extent reduce or do not carry out wastewater disposition, with good environment
Benefit and economic benefit.Wastewater zero discharge is realized, finally needs waste water to solidify, curing process includes function of mechanical steam recompression
(MVR) and high-temperature flue gas spray evaporation, its investment and operating cost are directly related with wastewater treatment capacity.
Waste water MVR evaporative crystallization techniques at home and abroad have been obtained for widely studied and practical application, using in vaporizer
The indirect steam of generation, the compression of Jing compressors, pressure, temperature are raised, and heat content increases, be then delivered to the heating chamber of vaporizer as
Plus vapourss are used, the heating of feed liquid to be evaporated is carried out, and add vapourss itself to be then condensed into water.Steam latent heat obtains abundant profit
With while reclaiming condensed water, salinity realizes that solidification is reclaimed in water.The technology maturation reliability, but investment cost and processing cost
Height, typically with Waste water concentrating technique connected applications, while MVR vapo(u)rization systems are higher to water quality requirement.
At present, in the handling process of coal-burning power plant's waste water, gradually received using high-temperature flue gas spray evaporation coal-burning power plant waste water
To concern, will spray evaporation technology be used for the advanced treating of wet flue gas coal-burning power plant waste water, in boiler back end ductwork air
Region between preheater and cleaner unit arranges atomizer, and coal-burning power plant's waste water is pumped in atomizer, sprays into and divides
In being scattered to high-temperature flue gas environment, after absorbing flue gas heat, waste water atomized drop is evaporated to water vapour and discharges with flue gas, former
Dry ash and solidss in waste water is then suspended in flue gas and enters into electric cleaner and caught by electrode, finally outer with flying dust
Row.But during high-temperature flue gas spray evaporation, the extraction of high-temperature flue gas have lost part boiler efficiency, increased power plant
Coal consumption, extract high-temperature flue gas amount depend on spray into wastewater flow rate.
Either MVR technologies or high-temperature flue gas spray evaporation technology, its investment and operating cost are and wastewater treatment capacity
Directly related, the concentration for realizing waste water is very necessary.Current main flow concentration technique is reverse osmosis membrane technology, reverse osmosis membrane
Operation it is higher to the water quality requirement of waste water.Calcium ions and magnesium ions are high in coal-burning power plant's waste water, need to be adjusted by flocculation sediment, pH value,
The techniques such as ion exchange resin realize waste water except hard, its pretreatment expense is very high.On the other hand, coal-fired plant flue gas waste heat
Not yet it is fully used, if Waste water concentrating can be realized using fume afterheat, the cost of wastewater zero discharge will be substantially reduced.
The content of the invention
An object of the present disclosure is to provide a kind of Waste water concentrating system of utilization fume afterheat based on fluid column evaporation, the system
By arranging evaporating column, there is no heat-transfer surface in the mode for taking fluid column to evaporate in evaporating column, without the need for pretreatment,
Overcome nozzle in spray evaporation easily block, wall dust stratification the problems such as.
Second purpose of the invention is to provide a kind of Waste water concentrating method of utilization fume afterheat based on fluid column evaporation, the method
Middle coal-burning power plant's waste water evaporation and concentration under fume afterheat, can substantially reduce the treating capacity of waste water, cost-effective;Smoke absorption
Desulphurization system is entered after the moisture of part, unit can reduce desulfurization water rate of water make-up;Flue-gas temperature into desulphurization system is reduced,
Desulfuration efficiency can be improved.
In order to reach above-mentioned purpose, first technical scheme that the present invention is provided:
A kind of Waste water concentrating system of utilization fume afterheat based on fluid column evaporation, including:
Evaporating column, evaporating column is connected located at the side of desulfurizing tower inlet end and with desulfurizing tower;Spraying zone is set in evaporating column,
The fluid column spray orifice for spraying waste water that spraying zone is vertically arranged including several, flue gas enters same from the smoke inlet of evaporating column
The waste water heat and mass sprayed by fluid column spray orifice that is vertical with flue gas or intersecting, waste water absorbs heat of vaporization and produces vapor entrance
In flue gas, exited in desulfurizing tower by evaporating column exhanst gas outlet, fluid column spray orifice is connected with wastewater holding chamber, evaporating column with it is useless
Waste water after the connection evaporation of water storage pool realizes that waste water circulation is concentrated into wastewater holding chamber, or the waste water after evaporation is directly from steaming
Send out tower to discharge.
In the Waste water concentrating system, flue gas and waste water heat and mass decreasing temperature and increasing humidity, using fume afterheat, waste water is by heat exchange
Heat is extracted, water vapour is flashed to, thus waste water be concentrated, while flue-gas temperature is reduced, greatly make use of fume afterheat, kept away
Thermal waste, part SO are exempted from2Can be absorbed;By flue gas and the waste water water column perpendicular contact of fluid column spray orifice injection, it is possible to decrease
The pressure loss, flue gas enters desulphurization system after evaporating column interior suction receiving portions moisture, and unit can reduce desulfurization water rate of water make-up;
Flue-gas temperature into desulphurization system is reduced, and can further improve desulfuration efficiency;Additionally, in evaporating column, flue gas release heat
Temperature reduces absorbing moisture simultaneously, and fluid column absorbs heat of vaporization, i.e. fluid column surface intensification evaporation and flue gas cool-down humidification process.Return
Receipts utilize fume afterheat for the fluid column evaporation and concentration of coal-burning power plant's waste water, achieve significant energy-saving effect and economic benefit,
Avoid the problem of pretreatment in conventional water treatment, overcome nozzle easily block, wall dust stratification the problems such as.
Wherein, for the contact area for increasing flue gas and waste water in evaporating column, the two ends of the evaporating column are smaller in size than
Size in the middle part of evaporating column, evaporating column can be formed by flue duct retrofit before desulfurizing tower, also can be realized by bypassing.
The fluid column spray orifice is located at the bottom of the spraying zone, after the waste water of such fluid column spray orifice injection sprays upward and certainly
By falling bodies, increase time of contact of the waste water with flue gas and contact area.If flue gas intersects setting, intersecting angle with fluid column spray orifice
Between 60 °~120 °.
Further, multiple fluid column spray orifices are arranged in parallel in a row, and fluid column spray orifice arrangement is according to crossed array
Either matrix arrangement or fan-shaped array are arranged.
Waste water circulation pump is set on the fluid column spray orifice and the connecting line of wastewater holding chamber, waste water circulation pump enters to waste water
Row supercharging, so as to fluid column spray orifice sprays in evaporating column water column is formed, and accelerates evaporation of the waste water in evaporating column, additionally, at this
Effusion meter, thermocouple and pressure gauge are set on connecting line.
The exhanst gas outlet of the evaporating column is connected with described desulfurizing tower, and in the exhanst gas outlet of evaporating column demister is arranged,
Demister is used to stop that drop is carried that flue gas to enter desulfurizing tower body after demister.
In this scenario, the bottom of evaporating column arranges the second pipeline and connects with wastewater holding chamber, and concentrated solution is back to water storage
Pond, and constantly circulate.
The present invention provide alternative plan be:
A kind of Waste water concentrating method of utilization fume afterheat based on fluid column evaporation, in the inlet end of desulfurizing tower evaporation is arranged
Tower, flue gas is entered from the smoke inlet of evaporating column, the waste water injection direction being pressurized sprayed by fluid column spray orifice in evaporating column
Vertical with flue gas direction, waste water and flue gas heat and mass, waste water absorbs the vapor that heat of vaporization produces and enters in flue gas, from steaming
Send out tower flue gas outlet to exit in desulfurizing tower.
In the above-mentioned methods, the waste water is pressurized to after 0.1-0.5MPa and is injected in evaporating column.
The waste water of the fluid column spray orifice injection is highly less than evaporating column top wall 0.5-1m, to prevent waste water to be sprayed onto evaporation
Tower wall face causes fouling, corrosion etc., jetting height to realize by adjusting spray flow, pressure etc..
Demister is set in the exhanst gas outlet of the evaporating column, and demister can be horizontal type, chevron shaped, V-shape, X
Type or perforating etc..
Additionally, the evaporating column is connected by the first pipeline with wastewater holding chamber, waste water circulation is set on the first pipeline
Pump, effusion meter, thermocouple and pressure gauge;
Further, the smoke inlet in evaporating column is respectively provided with temperature point and pressure-measuring-point with exhanst gas outlet;
The evaporation tower bottom is additionally provided with the second pipeline to discharge waste water, equally, in order to the waste water after evaporation and concentration
It is monitored, it is same on the second pipeline that effusion meter, thermocouple and pressure gauge are set.
So, waste water can be concentrated into evaporating column repeatedly by waste water circulation pump, be concentrated to after finite concentration and discharged;When one
When secondary evaporation capacity reaches concentration ratio requirement (concentration ratio sets, and can be obtained by online TDS monitorings), evaporating column
Outlet waste water is expelled directly out, and does not enter back into wastewater holding chamber circulating and evaporating, for this purpose, the bottom of evaporating column arranges at least two band valves
The wastewater outlet of door a, wastewater outlet is connected with wastewater holding chamber, and another is connected with subsequent treatment process.
The present invention has advantages below:
1), there is no heat-transfer surface in coal-burning power plant's waste water and flue gas direct contact heat transfer, without the need for pretreatment, gram
Taken nozzle in spray evaporation easily block, wall dust stratification the problems such as;
2) coal-burning power plant's waste water evaporation and concentration under fume afterheat, can substantially reduce the treating capacity of waste water, cost-effective;
3) desulphurization system is entered after the moisture of smoke absorption part, unit can reduce desulfurization water rate of water make-up;
4) by flue gas and waste water water column perpendicular contact, to SO2There is certain clearance;
5) investment and operating cost are relatively low, it is only necessary to increase an evaporating column, or realize that water column is sprayed by the former flue of transformation,
Operating cost is only the power consumption of pump.
6) present invention make use of fume afterheat on the basis of do not lose boiler efficiency, it is to avoid blockage problem, drop significantly
The treating capacity of low waste water and desulfurization water moisturizing, takes into account raising desulfuration efficiency and part removes SO2, reduce desulfurization pressure tower, energy
Energy-saving and water-saving effect is enough reached, huge economic benefit and environmental benefit is produced.
Description of the drawings
Waste water concentrating system diagrams (highly enriched ratio) of the Fig. 1 using fume afterheat based on fluid column evaporation, wherein, 1- evaporating columns,
2- spraying zones, 3- fluid column spray orifices, 4- demisters, 5- desulfurizing tower bodies, 6- waste water circulation pumps, 7- wastewater holding chambers, 8- waste water row
Go out pump
Waste water concentrating system diagrams (low cocnentration factor) of the Fig. 2 using fume afterheat based on fluid column evaporation, wherein, 1- evaporating columns,
2- spraying zones, 3- spraying zone spray orifices, 4- demisters, 5- desulfurizing tower bodies, 6- waste water circulation pumps, 7- wastewater holding chambers, 8- waste water
Excavationg pump.
Specific embodiment
Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear, complete
Whole description.
Evaporating column smoke inlet and outlet are respectively arranged with temperature and pressure measuring point, for monitoring flue gas, the flue gas of evaporating column 1
Outlet is provided with demister 4;Exhanst gas outlet is connected with desulfurizing tower body 5, has spraying zone 2 in the evaporating column 1, is provided with difference
The fluid column spray orifice 3 of arrangement mode;Flue gas intersects that setting is vertical or intersecting setting with fluid column spray orifice, if flue gas intersects with fluid column spray orifice
Arrange, intersecting angle sets between 60 °~120 ° between the waste water inlet of 1 spraying zone of the evaporating column 2 and wastewater holding chamber 7
Be equipped with waste water circulation pump 6, effusion meter, thermocouple, pressure gauge, for monitoring evaporation and concentration before wastewater flow, temperature, pressure, with
Temperature into the waste water in evaporating column 1, pressure and flow are controlled, it is to avoid temperature is too high, the too small situation of pressure;Institute
State the wastewater outlet of evaporating column 1 and be arranged on evaporation tower bottom, can be connected with wastewater holding chamber 7 by the first pipeline, also can be by the
Two pipelines are discharged and are for further processing, and are set on the first pipeline and the second pipeline and are provided with effusion meter, thermocouple, pressure gauge,
The flow of waste water, temperature, pressure after for monitoring evaporation and concentration, as depicted in figs. 1 and 2.
The exhanst gas outlet of the evaporating column 1 is provided with demister 4, for stopping that drop is carried, with Desulphurization for Coal-fired Power Plant tower sheet
Body phase connects;
The evaporating column 1 can be formed by flue duct retrofit before desulfurizing tower, be carried out according to field condition and wastewater treatment capacity size
It is determined that, flue is typically arranged horizontally before desulfurization, is realized by increasing the height at flue center;May also be arranged on bypass;
The arrangement of fluid column spray orifice 3 classification has crossed array, matrix arrangement, fan-shaped array etc.;
In Waste water concentrating system of the above-mentioned utilization fume afterheat based on fluid column evaporation, waste water can be anti-by waste water circulation pump 6
Concentrate into evaporating column again, be concentrated to after finite concentration and discharge;When flush distillation amount reaches concentration ratio requirement, evaporating column goes out
Mouth waste water is expelled directly out by the second pipeline, does not enter back into the circulating and evaporating of wastewater holding chamber 7.
Additionally, the Waste water concentrating method using a kind of utilization fume afterheat of said apparatus based on fluid column evaporation, including such as
Lower step:
1) coal-burning power plant's waste water is concentrated by pipeline and is stored in wastewater holding chamber 7, is pressurized to by waste water circulation pump 6
After 0.1-0.5MPa, Jing spraying zones 2 spray into evaporating column 1;
2) flue gas direct contact heat transfer mass transfer of the waste water in fluid column form in evaporating column 1 with 100-150 DEG C, using flue gas
Waste heat is evaporated concentration;
3) waste water evaporation in evaporating column 1, water vapour enters desulfurizing tower with flue gas after demister 4.
4) waste water after concentrating reenters wastewater holding chamber 7 by the outlet at bottom of evaporating column 1, can pass through waste water circulation pump
6 reenter evaporating column 1 concentrates, and after concentration to a certain extent, is discharged by waste water excavationg pump 8, is for further processing;When one
When secondary evaporation capacity reaches concentration ratio requirement, the outlet waste water of evaporating column 1 is expelled directly out, and does not enter back into wastewater holding chamber circulation and steams
Send out.
The step 1) in enter fluid column wastewater flow rate need to according to actual operation parameters determine (actual parameter include waste water temperature
Degree, flue gas flow, flue-gas temperature, concentration ratio, spray orifice arrangement etc.).
The step 2) in the evaporation capacity of waste water be by wastewater temperature, flue-gas temperature, flue gas flow rate, spray orifice arrangement etc.
What factor determined jointly.
Embodiment 1:
By taking 300MW unit concentration cycles water as an example.Mark condition flue gas flow is about 1000000Nm3/ h flows are 100t/h, complete
Salt amount squeezes into evaporating column spraying zone for coal-burning power plant's recirculated water draining Jing waste water circulation pumps of 3000mg/L, is sprayed into by spray orifice and is steamed
Fa Tanei and flue gas direct contact heat transfer mass transfer, waste water enters wastewater holding chamber by the outlet of evaporating column bottom after concentration, leads to
Cross the concentration of waste water circulation pump further circulating and evaporating, it is to be concentrated to total salt quantity be 60000mg/L, wastewater flow be 5t/h, pass through
Waste water excavationg pump is discharged, and is for further processing.
Embodiment 2:
By taking 300MW units concentration desulfurization wastewater as an example.Mark condition flue gas flow is about 1000000Nm3/ h, flow be 10t/h,
Total salt quantity squeezes into evaporating column spraying zone for the Desulphurization for Coal-fired Power Plant waste water Jing waste water circulation pumps of 30000mg/L, is sprayed into by spray orifice
With flue gas direct contact heat transfer mass transfer in evaporating column, after concentration waste water total salt quantity be 150000mg/L, flow be 2t/h, by steaming
The outlet for sending out tower bottom is expelled directly out, and is for further processing.From unlike the technological process of embodiment 1, it is dense that waste water needs
When contracting ratio is relatively low, the concentration waste water of evaporating column outlet need not be circulated concentration into wastewater holding chamber, directly by waste water
Excavationg pump is discharged, into next step process.
The foregoing description of the disclosed embodiments, enables professional and technical personnel in the field to realize or using the present invention.
Various modifications to embodiment will be apparent for those skilled in the art, as defined herein general
Principle can in other embodiments be realized without departing from the spirit or scope of the present invention, is not described in detail
The part presented with partial enlargement, is prior art, and here is not repeated.Therefore, the present invention is not intended to be limited to herein
These shown embodiments, and it is to fit to the most wide scope consistent with principles disclosed herein and feature.