32results about How to "Improve the efficiency of denitrification reaction" patented technology

The present invention discloses a SCR system automatic control method based on ammonia spraying sensitive valve locking. The method comprises three steps: firstly, performing comprehensive analysis of varying load condition operation characteristics of the SCR system based on a field test and a CFD numerical simulation technology to obtain flue gas 'NOx flow' regional continuous distribution characteristics matching an AIG type; then determining the weight of each ammonia spraying branch pipe valve, locking a certain number of sensitive valves according to a preset sensitive valve locking principle, and installing an automatic regulating valve at a corresponding ammonia spraying region; finally, developing an ammonia spraying logic controller and corresponding main control and sub-control logics, realizing multistage optimization setting of parameters of the control system, and realizing the accurate automatic control of the main ammonia spraying regulating valve of the SCR system and the locking sensitive valves. The SCR system automatic control method based on ammonia spraying sensitive valve locking is able to overcome the problems of characteristics of the SCR system such as nonlinearity, large delay and the like so as to realize the accurate automatic control of the ammonia spraying of the SCR system, substantially enhance the SCR denitration reaction efficiency, save the dosage of ammonia, reduce the ammonia escape and effectively inhibit the generation of ABS.

The invention provides a flue gas denitration reaction system, belonging to the technical field of flue gas denitration. The flue gas denitration reaction system comprises a first ammonia spraying grid, a catalyst pre-reaction area, a second ammonia spraying grid and a catalyst main reaction area, wherein the first ammonia spraying grid, the catalyst pre-reaction area, the second ammonia spraying grid and the catalyst main reaction area are arranged in a flue in sequence along a flue gas flowing direction, the first ammonia spraying grid is connected with an inlet flue, and the catalyst main reaction area is connected with an outlet flue. Under the condition of keeping certain catalyst content and ammonia content, by separately arranging the catalyst pre-reaction area and the catalyst main reaction area and correspondingly matching the first ammonia spraying grid and the second ammonia spraying grid, the denitration efficiency is improved; the amount of ammonia escape caused by insufficient denitration reaction and uneven flow field distribution is reduced, and meanwhile the economical efficiency of the system is improved.

The invention provides a flue gas denitration flow field simulation checking method and system. The method comprises the following steps of: establishing a flow field model based on field working conditions, meteorological data of a site where equipment is located and the structure size of target denitration SCR equipment; according to preset pre-simulation basic data, the flow field model and a simulation equipment operation result, obtaining current simulation data; comparing the similarity between the current simulation data and an actual operation result with a similarity threshold value; if the similarity accords with the similarity threshold value, outputting the pre-simulation basic data corresponding to the simulation result, the actual operation result and the current simulation data to obtain a check result; if the similarity does not accord with the similarity threshold value, calculating optimal pre-simulation basic data according to a threshold value deviation result, simulating an equipment operation result again after performing updating, so as to generate a new current simulation database, and repeating the comparison of the similarity with the similarity threshold value until obtaining a new check result. The method is reasonable in scheme, rapid in simulation, and accurate in checking and can facilitate subsequent data optimization and structural design.

The invention relates to the technical field of cement production, and discloses ultra-low emission denitration equipment for cement production, and solves the problems of incomplete denitration of flue gas discharged during cement processing at present, easy blockage of an SCR denitration catalyst and reduction of denitration efficiency. The equipment comprises a reaction cylinder, the upper end of the reaction cylinder is connected with a cylinder cover; one side of the upper part of the reaction cylinder is connected with a gas inlet pipeline, and the lower part of one end of the reaction cylinder is connected with a gas outlet pipeline. According to the invention, through the arrangement of the dust blowing mechanism, the blockage of the catalyst layer is effectively avoided so that the denitration reaction effect is good; through the arrangement of the spoiler, the rotating shaft rotates to drive the blowing pipeline to rotate, and the spoiler rotates along with the blowing pipeline to flap airflow in the reaction cylinder so that the turbulence of the airflow is increased, the airflow in the reaction cylinder is disordered, the contact time of flue gas between catalyst layers is prolonged, the flue gas can be in full contact with the catalyst layer, and thus the denitration reaction efficiency is improved, the denitration effect is better, and ultralow emission is realized.

The invention discloses an SCR denitration reducing agent preparation device with a flue gas heating system and a method. The preparation of an SCR denitration reducing agent is completed by utilizing the flue gas heating system. A reducing agent solution is directly sprayed into a high-temperature flue of a flue gas heating system, ammonia gas evaporated from high-temperature flue gas is mixed with the high-temperature flue gas and then fed into an original flue gas flue through the high-temperature flue to be mixed with original flue gas, a reducing agent required by denitration is provided, and the reducing agent solution can be ammonia water or a urea solution. Compared with a traditional SCR denitration reducing agent preparation system, an evaporator, an ammonia-air mixer, a dilution fan, a dilution air heating device, an ammonia spraying grid and the like do not need to be arranged, and the system has the advantages of being simple, easy to control, small in investment and the like.

The invention relates to an ultra-clean emission system for cooperatively treating VOCs-containing waste gas and coke oven flue gas. The ultra-clean emission system comprises a combustion device, a cooling device, a desulfurization device, a dust removal device, a heating device, a denitration device and an emission device which are connected in sequence, wherein the combustion device is used for carrying out combustion treatment on the VOCs-containing waste gas; the cooling device is used for cooling the combusted waste gas; the desulfurization device is used for carrying out desulfurization treatment on mixed gas of the coke oven flue gas and the cooled waste gas; the dust removal device is used for carrying out dust removal treatment on the desulfurized gas; the heating device is used for heating the dedusted gas; the denitration device is used for carrying out denitration treatment on the heated gas; and the emission device is used for discharging the denitrated gas into the atmosphere. The system can be used for cooperatively treating VOCs-containing waste gas and coke oven flue gas, has the characteristic of simultaneously treating VOCs, sulfur dioxide and nitric oxide, can enable the treated flue gas to reach the ultra-clean emission standard, and is simple in process flow, stable in operation and relatively low in cost.

The invention discloses a circulating fluidized bed boiler and an in-boiler SNCR denitration device and process. The SNCR denitration device comprises an injection system, a medium inlet of the injection system is communicated with a cooling air system, a urea conveying pipeline and a compressed air conveying pipeline; the injection system comprises a plurality of multi-point continuous injectiondevices; the multi-point continuous injection device is coaxially provided with a injection device casing pipe, a compressed air pipeline and a urea solution pipeline from outside to inside; a plurality of injection device atomizing nozzles are arranged in the axis direction of the multi-point continuous injection devices; the injection device atomizing nozzles are communicated with the injectiondevice casing pipe, the compressed air pipeline and the urea solution pipeline; a reducing agent solution and compressed air are distributed and then enter the multi-point continuous injection devices, then atomized and then jetted into the flue gas in a downstream manner to realize section coverage; and meanwhile, the device is cooled, so that the denitration efficiency can be improved, the consumption of a reducing agent and the operation cost are reduced, and the problem that the ultralow emission of nitric oxide of a circulating fluidized bed boiler meets the standard under the medium-lowload condition is solved.

The invention discloses a high-temperature and high-dust SCR denitrification apparatus for a cement kiln. The apparatus comprises a reaction assembly and an ammonia spraying assembly, wherein the ammonia spraying assembly is fixedly installed on the reaction assembly, an ammonia gas delivery pipe is connected with an ammonia inlet, ammonia gas overflows into connecting pipes through through-holes,the connecting pipes, connecting plates and ammonia storage tanks form an ammonia circulation pipeline, and ammonia gas enters nozzles through the circulation pipeline and overflows into a reaction container body to react with flue gas. A power output end of a motor drives a rotation cover to rotate, a rotating process of the connecting pipes is realized, and the connecting pipes drive the connecting plates, the ammonia storage tanks and ammonia conveying pipes to move together, so that overflow points of ammonia gas are constantly changed inside the reaction container body, and the arrangement of rubber rings has no effects on the moving process of the ammonia conveying pipes, and can ensure the airtightness of the reaction container body to the greatest extent, so that the flue gas inside the reaction container body can fully react with ammonia gas, the uneven reaction between the flue gas and ammonia gas is avoided, and the denitrification reaction efficiency is improved.

The invention discloses a low-temperature denitration device for hazardous waste incineration flue gas, and the device comprises an alkali spraying and deacidification system which is used for carrying out an acid-base reaction on to-be-treated flue gas and alkali liquor to remove acidic gas in the flue gas to obtain first flue gas; the bag-type dust collector is used for capturing fly ash in the first flue gas to obtain second flue gas; the ammonia spraying system is used for mixing ammonia gas with the heated air to obtain mixed gas, and inputting the mixed gas into the low-temperature denitration reactor, so that the second flue gas reacts with the ammonia gas to convert oxynitride into nitrogen to obtain third flue gas; the low-temperature denitration control system is used for controlling the content of oxynitride and ammonium sulfate in the third flue gas, so that the amount of alkali liquor input by the alkali spraying and deacidification system and the concentration of atomized ammonia sprayed by the ammonia spraying system are controlled and adjusted according to the content of oxynitride and ammonium sulfate. The technical problems of various blockage and low-temperature corrosion in the process line process in the prior art are solved.

The invention discloses a telescopic in-furnace denitration device arranged at the top of a boiler. The telescopic in-furnace denitration device comprises a telescopic spray gun, a spray gun height control system, a spray gun cooling system, a positive pressure sealing device and a reducing agent and compressed air conveying and distributing device. The height of the gun barrel can be automatically adjusted according to the flue gas temperature, the spraying point is always kept in the optimal reaction temperature interval of the reducing agent, the denitration efficiency in the furnace is improved to 55%-65%, and the denitration reaction efficiency is improved; reducing agents such as ammonia water and urea are saved, and the operation cost is reduced. And in combination with a flue gas recycling process, the waste incineration power plant with the average value of nitrogen oxide emission index per hour being 90 milligrams per standard cubic meter can achieve up-to-standard emission without using an SCR denitration system, so that the equipment investment and the operation cost are greatly saved.

The invention discloses an intermediate temperature efficient modified SNCR denitration device of a layer-burning boiler and a method, and belongs to the technical field of coal-fired boiler pollutant control. Amino and imido free radicals are generated by urea under the synergistic effect of H2O2 and organic acid (formic acid or acetic acid or propionic acid), and due to the fact that amino free radicals .NH2 or imido free radicals .NH has higher reaction activity and selectivity on nitric oxide, a temperature window of an SNCR reaction can be greatly reduced; meanwhile, a modified reducing agent atomizing nozzle is located in a furnace outlet turning room of the layer-burning boiler, sufficient mixing of a modified reducing agent and nitric oxide can be assisted by the area, and thus the utilization rate of urea is increased. The device and the method are economical and environmentally friendly, implementation is easy, and the denitration efficiency is high; besides the layer-burning boiler, the device and the method are also applicable to coal-fired power plants and other coal-fried industrial processes, and have wide application prospects and high market popularization value.

The ammonia spraying grid of the SCR denitration system comprises an ammonia spraying main pipe, ammonia spraying branch pipes, spraying heads and a rotational flow mixer, wherein the ammonia sprayingmain pipe is provided with the multiple ammonia spraying branch pipes, the ends, away from the ammonia spraying main pipe, of the ammonia spraying branch pipes are arranged upwards and connected withthe spraying heads, and the rotational flow mixer is fixed to the spraying heads; the rotational flow mixer comprises a barrel, a support and rotational flow blades, the barrel is of an up-down hollow structure, the inner wall of the barrel is connected with the spraying head through the support, and the rotational flow blades are fixed to the portion, above the support, of the inner wall of thebarrel in a circumferential array mode. The system has the advantages that through the arrangement of the rotational flow blades, flue gas in the SCR denitration system can generate strong rotationalmotion after flowing through the the rotational flow blades and can entrainment ammonia gas sprayed out of the spraying heads at the upper parts of the ammonia spraying branch pipes, so that the ammonia gas is strongly mixed with the flue gas, the mixing effect of the flue gas and the ammonia gas is enhanced, and the denitration reaction efficiency is improved.

The invention discloses a strengthened biological water treatment denitrification reaction device. The lower end of the reaction device is provided with an inlet water distributor, the upper end of the reaction device is provided with a sludge settling area, and the lower end of the sludge settling area is provided with a sludge backflow seam; a downflow weir is arranged between the reaction device and the sludge settling area. According to the strengthened biological water treatment denitrification reaction device, the denitrification reaction efficiency is high, and the mud-water separation effect is good; the settling area is constructed at the upper part of a reaction region, the structure is compact, a secondary sedimentation tank and a sludge backflow facility are saved, the size of a constructed structure is reduced, and damage of a reflux pump to granule sludge is avoided; reaction sewage continuously flows up at a certain speed in a device, and in the up-flowing process, the sewage makes full contact with the granule sludge to strengthen a mass transfer process; a dead zone does not exist in the reaction device, the fluidifying property of the sludge is good, and the runnability is stable; the reaction device has very good biological denitrification performance.

The invention relates to a flue gas treatment system. The flue gas treatment system comprises an ammonia injection device, a first dividing wall type heat exchanger, a flue gas heater and a denitration reactor, wherein a heat absorption side flue gas inlet of the first dividing wall type heat exchanger is used for receiving flue gas, a heat absorption side flue gas outlet of the first dividing wall type heat exchanger is connected with a flue gas inlet of the ammonia injection device, and a flue gas outlet of the ammonia injection device is connected with a flue gas inlet of the denitration reactor; a flue gas outlet of the denitration reactor is connected with a heat release side flue gas inlet of the first dividing wall type heat exchanger, a heat release side flue gas outlet of the first dividing wall type heat exchanger is connected with a chimney, and treated flue gas is discharged through the chimney; and the flue gas heater is arranged between the first dividing wall type heat exchanger and the ammonia injection device and can heat flue gas which passes through the first dividing wall type heat exchanger and is less than 280 DEG C to 280-300 DEG C. The flue gas treatment system disclosed by the invention is used for improving the reaction efficiency of the denitration reaction of the flue gas treatment system when the flue gas temperature is relatively low, and the risk that the discharged flue gas harms the environment can be reduced.

The invention relates to a flue gas cyclone mixing device of an SCR denitration system. The flue gas cyclone mixing device comprises a cyclone mixer homogenizing device arranged behind ammonia spraying branch pipes in a flue gas flowing direction, wherein the cyclone mixer homogenizing device is composed of a plurality of cyclone mixers which are arranged in a tiled mode, and the rotational flow mixers are arranged to face the ammonia spraying branch pipes and used for covering diluted ammonia sprayed out of the ammonia spraying branch pipes; and each cyclone mixer is composed of an inner cyclone blade set and an outer cyclone blade set, the rotating directions of the two cyclone blade sets are opposite, and a circular partition plate used for dividing an airflow channel is arranged between the two cyclone blade sets. With the flue gas cyclone mixing device in the invention, the mixing effect of flue gas and diluted ammonia gas can be enhanced, and denitration reaction efficiency is improved.

The invention relates to the technical field of treatment of nitric oxide in flue gas from industrial kilns, in particular to a denitration device for flue gas from a cement kiln and a use method of the denitration device. The denitration device comprises a kiln tail flue, an SNCR denitration reaction unit, a preheater, a low-temperature dust removal unit, an SCR denitration reaction unit and a chimney which are sequentially connected along a flue gas flowing direction, wherein the SNCR denitration reaction unit comprises a first mixer; the SCR denitration reaction unit comprises a second mixer and an SCR reactor which are sequentially connected along the flue gas flowing direction; an ammonia gas source sprays ammonia gas into the first mixer and the second mixer respectively; and the low-temperature dust removal unit comprises a low-temperature dust remover. According to the denitration device for the flue gas from the cement kiln provided by the invention, denitration operation cost is reduced on the basis of ensuring denitration efficiency.