Device for the cleaning of flue gases of a boiler plant of nitrogen oxides from
(57) Abstract:The invention relates to heat engineering, can be used in thermal power stations and other industrial sites associated with the combustion of fuel, and can improve the cleaning efficiency of the combustion products from nitric oxide. According to the invention a device for cleaning the flue gases of a boiler plant NOx containing placed in its pass across the flue gas stream bundle of parallel tubes having feed holes in the flow of the mixture of ammonia with transporting agent (gas or steam), the relative step S/d openings in the pipe meets the condition of
< / BR>where S is the step holes; d - diameter holes; wc- speed mixture of ammonia transfer agent at the exit of the hole; wr- the speed of the flue gases;cthe density of the mixture at the exit of the hole,gthe density of the flue gas, 1 C. p. F.-ly, 1 Il. The invention relates to heat engineering and can be used for cleaning flue gases from nitrogen oxides in boiler plants that burn fossil fuels.Widespread cleaning of flue gases by selective negotitions ammonia with a high consumption of processed flue gas temperature zone 900 - 1100oC, at which most effectively proceed the reaction (1), the ammonia must be submitted in a mixture with transporting agent (gas or steam).Closest to the invention is a device for cleaning the flue gases of a boiler plant NOx containing placed in its pass across the flue gas stream bundle of parallel tubes having feed holes in the flow of the mixture of ammonia transfer agent (1).In this device the holes in the pipe is placed with a relative step
where S is the step holes;
d - diameter holes.It was envisaged that this embodiment of the device will ensure uniform mixing of the ammonia with the flue gases and thus high efficiency purification from nitrogen oxides. Indeed, the choice of the step S in the above condition ensures uniform mixing, however, it requires considerable consumption of carrier agent that causes a significant loss of energy. When applying ammonia gas (air) necessary energy to drive the compressor, and when the supply of steam taken from the turbine, a reduction in its power and necessary costs to fill parushim agent by reducing the consumption of the latter.For this purpose, the device for cleaning of flue gases of a boiler plant NOx containing placed in its pass across the flue gas stream bundle of parallel tubes having feed holes in the flow of the mixture of ammonia with transporting agent, the relative step S/d openings in the pipe meets the condition of
< / BR>where Wc- speed mixture of ammonia transfer agent at the exit of the holes;
Wr- the speed of the flue gases;
cthe density of the mixture at the exit orifice;
gthe density of the flue gas.Parameters Wrandgthe cross section of the flue, where the device is determined from thermal calculation of the boiler in normal mode or test.Parameters Wcandcdetermined by a preselected pressure and temperature of the transporting medium.The selection step according to the formula (C) allows, as shown by experiments, to obtain a sufficiently uniform mixing of the ammonia with the flue gases, but reducing several times the flow rate of carrier gas (steam), and thus the corresponding energy loss. If step S to choose less than the left limit in formula (3), unreasonably tion: if the step S is greater than the right limit (3), then, as the experiments showed, rapidly deteriorating the uniformity of mixing of the ammonia gas in the zone of optimum temperature, which reduces the efficiency of nitrogen oxides (the axis of the holes in the pipes should preferably be angled 9045oin relation to the flow velocity of gases).As shown by measurements on boilers with horizontal flue, temperature profile has a significant irregularity: the average temperature close to the optimum for the chemical reactions (1), in the upper part of the flue gas temperature in the direction of travel of the gases may exceed the lower limit. In this case, in accordance with the invention, the ends of the bundle of parallel tubes in the upper part of the flue can be derived beyond, skipped out of the duct in the direction of the combustion zone to the place of their subsequent entry into the flue gas duct in cross-section, the temperature regime in which the optimal conditions for the reaction of nitrogen oxides with ammonia.The drawing schematically shows performed in accordance with the invention, the device is placed in the flue of the boiler installation.The bundle of parallel tubes 1 and collector 2. has 3 holes for filing in the flow of the mixture AMI meets the condition (3).The beam 1 is placed in the zone temperatures of 900 - 1100oC, at which the effective reaction (1).If at the top of the flue in the setup of the beam and parallel tubes 3 flue gas temperature is below the lower limit required for the reactions (1), which may be established on the basis of calculations or experiments, the ends 6 of the pipe (shown in the drawing by the dashed line) are displayed through the ceiling duct outside and skipped towards the combustion zone to the place of their subsequent entry into the flue gas duct in cross-section, the temperature regime in which the optimal course of chemical reactions (1).During operation of the boiler system, the mixture of gas or vapor with ammonia enters the collector 2 and the tube bundle 1, where through holes 3 in the form of streams flows into the flue gas duct 4, where for a small along the flow area of the L are evenly mixed with the flue gas stream, providing the entire area of the flue reactions (1) to reduce the emissions of nitrogen oxides from gases leaving.Using equation (3) allows the use of relative steps, much greater recommended (1). For example, if the transport agent is water vapor from the flue, where Wr= 10 m/s andg-0,27 kg/m3then (Wc/Wr95, and the valid interval of the selection relative steps, respectively 42,5 - 190. While it is preferable to select a specific value of S/d near the center of the interval, i.e. 80 - 110, however, there is far more variance within it depending on the length of the flue temperature zone corresponding to the optimal conditions of chemical reactions linking nitrogen oxides. At small length of this zone requires organization of the most intensive mixing of the ammonia mixes with the combustion gases, which requires the approximation of S/d to the lower boundary of the interval and correspondingly high energy costs when the length of the specified temperature range, sufficient to complete the chemical reactions (1) for large values of S/d, the relative step can be increased within the limits calculated according to (C) interval until its upper boundary. When you choose a step S/d at the specified interval, you can also increase or decrease its height, thereby changing the distribution of the flow rate of ammonia at the height of the flue, to take into consideration the unevenness of the concentration of nitrogen oxides in flue gases for the conditions of the concrete is carried by the absence of impact erosion and clogging of the holes on the bandwidth.The device, made in accordance with the invention, was tested on boiler # 7 Toliatinskoe CHP. The resulting reduction in emissions of nitrogen oxides by more than 50% when the boiler to coal dust For the transportation of ammonia with a flow rate of 0.2 t/h was required steam flow rate of 9 t/h, which amounted to 1.5% of the steam capacity of the boiler. If instead of the condition (3) to select the step S hole was made, the condition (2) of the prototype, the steam consumption would exceed 50 t/hFrom the above example implementation shows that the proposed device with the simplicity of the design ensures energy savings, as evidenced by the test results.Literature
Skorik L. D. and other Industrial inspection method of flue gas of thermal power plants from oxides of nitrogen entering the ammonia in the high temperature circuit. Power, 7. 1986, S. 58 - 59. 1. Device for the cleaning of flue gases of a boiler plant NOx containing placed in its pass across the flue gas stream bundle of parallel tubes having feed holes in the flow of the mixture of ammonia with transporting agent, characterized in that the relative pitch holes in the pipe meets the condition of
< / BR>where S step open is tertia;
Wgthe speed of the flue gases;
cthe density of the mixture at the exit orifice;
gthe density of the flue gas.2. The device under item 1, characterized in that the ends of a bundle of parallel tubes in the upper part of the flue withdrawn beyond, skipped out of the duct in the direction of the combustion zone to place the entry in the flue section, a temperature which corresponds to the optimal temperature reactions of ammonia and oxides of nitrogen.
FIELD: heat power engineering.
SUBSTANCE: boiler plant comprises chimney with air passage between the reinforced concrete shaft and lining, which define gas discharging passage, air heater mounted under the gas discharging passage, and fan for supplying heated air to the air passage in the chimney. The air passage is separated by two vertical baffles into two sections. The pipe is provided with a box for discharging the heated air from one section of the air passage to the other.
EFFECT: enhanced efficiency.
FIELD: technologies for combustion of flush gases, including those under high pressure, during extraction and processing of natural gas and oil.
SUBSTANCE: body of burner, mounted on gas inlet pipe, is made conical with widened portion at upper portion, in the body additionally mounted are two catalyst elements, at lower portion on inlet section first catalyst element is positioned, and above on outlet section - second catalyst element, rotary shutters are mounted on base of conical body in additional way, so that in closed position they are in contact with first catalyst element, and open position between first catalyst element and body gap is formed, also, device is additionally provided with one or more main torches, mounted in gas inlet pipeline below rotary shutters and first catalyst element. Relation of diameters of first and second catalyst elements matches relation of debits of hydrocarbon gas, fed in normal mode and during salvo exhaust. Catalyst elements are manufactured either in form of cell-like structured blocks with direction of channels in parallel to direction of feeding of flush gases, or in form of block sections with granulated catalyst, for example, Rachig rings, or in forms of block sections with active-catalyst metallic shavings, or in form of blocks with active-catalyst metallic meshes.
EFFECT: higher ecological safety and fullness of combustion of flush gases in broad flow range, simplified construction and comfort of maintenance.
6 cl, 3 dwg
FIELD: water heating.
SUBSTANCE: boiler can be used for heating and hot water supplying. Boiler has rectangular closet provided with heat insulation and casing. There is furnace with burner, heat exchanger and branch pipe for letting combusting gas through outer wall of room's wall are disposed inside the closet. The branch pipe is provided with cassette filled with adsorption matter. Cassette is hermetically placed in branch pipe for letting combustion products out between casing of rectangular heat-protected closet and internal surface of outer wall of the room. Branch pipe for letting products of combustion out behind outer wall of the room is mounted in vertical and has cone-shaped muzzle with curvilinear planes and guides and twisting ribs.
EFFECT: improved ecological parameters of exploitation.
FIELD: methods of purification of flue gases.
SUBSTANCE: the invention is pertaining to the method of purification of flue gases and may be used to decrease the outbursts of nitrogen oxide with the help of the method of the high-temperature selective non-catalytic reduction. The method provides for feeding of the previously prepared steam-gaseous reduction mixture into the gas flue of the flue gas burning aggregate with the temperature of the flow of the purification gases of 700-1200°C. At that the steam-gaseous reduction admixture is prepared in the connected to the gas flue high-speed reactor during 0.5-5 seconds by introduction of a water solution of carbamide with a superheated steam at the pressure of 3-10 atm. Concentration of the water solution of carbamide makes 20-40 mass %. The time of the contact of the water solution of carbamide with the superheated steam predominantly makes 0,5-2 seconds. The pressure in the reactor predominantly makes 3-6 atm. The temperature of the superheated steam makes 200-400°C. The invention ensures simplification of the production process of purification of the effluent gases from nitrogen oxides, to increase the level of purification of such a gas in the broad range of the temperatures of the purified combustion products, and also to decrease significantly the share of the secondary contaminant - ammonia, in the purified gases.
EFFECT: the invention ensures simplification of the production process of the effluent gases purification from nitrogen oxides, to increase the level of purification of the gases in the broad range of the temperatures of the purified combustion products, to decrease significantly the share of the secondary contaminant - ammonia in the purified gases.
5 cl, 2 ex, 1 dwg, 2 tbl
FIELD: consuming industrial waste.
SUBSTANCE: method comprises securing the housing filled with the charge of the solid rocket fuel to the front part of the gas duct of the plant for using the charges of the solid rocket fuel, burning the solid rocket fuel, and processing the combustion products by cooling the combustion products with a material with high heat capacity, dry cleaning of gas with a neutralizer-sorbent, and afterburning the combustion products.
EFFECT: enhanced efficiency.
7 cl, 2 dwg
FIELD: arrangements or devices for treating smoke or fumes.
SUBSTANCE: head comprises gas supply pipe with gas gate and protecting shield mounted outside and coaxially at the top end of the gas supply pipe. The protecting shield is composed of two baffles made of two hollow trancated cones mounted one on the other. The grater base of the top baffle faces downward, and that of the bottom baffle faces upward. The smaller base is connected with the gas supply pipe.
EFFECT: enhanced reliability and prolonged service life.
2 cl, 2 dwg
FIELD: ferrous metallurgy; heat and power industry; other branches of industry; systems of production of the smoke-gas discharges utilization.
SUBSTANCE: the invention may be used in an iron and steel industry, at the enterprises of the heat and power industry and in the other branches of industry. The system the gas-smoke pipe with the gas duct on the metallic supports, the water-sprinkle installation, the water-collecting reservoir with the water outlet, the air duct, the water duct, the pumping station. The gas duct is made in two levels, at that the lower level of the gas duct ends with the muzzle, inside which there is the figured metallic plate forming near the muzzle throat the supercharge of the "C"-shaped form with the maximum clearance in the top point of the muzzle. The butt of the figured metallic plate of the "C"-shaped supercharge is dipped inside the muzzle and the butt of the muzzle is partially located under the water-sprinkler. The top level of the gas duct is located above the body of the water-sprinkler and starts with the gas collector with the open lower part. On the body of the water-sprinkler with the trilateral acid-resistant sheathing there is the grating with a net for the catalysts.
EFFECT: the invention ensures improved design and efficiency of the system operation.
FIELD: recuperation of energy from hot gas.
SUBSTANCE: proposed method is used for recuperation of energy from hot gas having temperature above 650°C and absolute pressure above 1.7 bar; gas contains non-solidified compounds of alkali metals and particles. Proposed method includes the following stages: cooling gas to temperature below 550°C with the aid of shell-and-tube heat exchanger where hot gas is passed via inter-tube space and cooling water is passed via space inside tubes where steam is formed from which steam energy is recuperated; particles of gas are separated by means of one or more centrifugal separating units arranged in succession to obtain content of dust below 400 mg/Nm3; gas is expanded in expansion machine for recuperation of energy.
EFFECT: enhanced efficiency of recuperation.
16 cl, 1 dwg
FIELD: heat power engineering.
SUBSTANCE: device comprises housing covered with a conical shield and provided with bottom conical chamber for collecting condensate, air heat exchanger coaxially mounted inside the housing, and base mounted on the head of the chimney shaft and provided with the air heat exchanger. The housing is provided with the cylindrical funnels for sucking cold air and discharging cleaned gases, the shell of the air heat exchanger provided with straight flow pipe bank with transverse supporting cross-pieces made for permitting change of the direction of air sucking into the interpipe space and mounted with a minimum space 1-3 mm in the oval opening in the sloping plate welded to the housing. The edge of the plate is flanged upward to define a sloping chute for descending the contaminated condensate. The base is shaped into the ring and provided with oval ports inclined to the side and receiving tips made of magnetic steel sheet and used for control of the magnetic field. From one side of the base, there is a cooled magnetic catcher connected with the space and branch pipe for collecting and removing condensate. In front of the catcher, there is a funnel for sucking a part of the hot chimney gases with dust from under the bottom tube bank of the air heat exchanger to the system for recirculation of the chimney gases. The method for catching emissions is also described.
EFFECT: expanded functional capabilities.
4 cl, 3 dwg
FIELD: treatment of combustion products.
SUBSTANCE: method comprises step supply of oxidizer and supplying vapor ammonium mixture. The secondary air is supplied upstream of the afterburning plant, and vapor ammonium mixture is introduced to the zone of the afterburning plant downstream of the set of fireproof surfaces.
EFFECT: reduced emission of nitrogen acids.