The method of preparation of the mixture of air and fuel and its combustion in the combustion chamber of teploenergostroi and device for its implementation
(57) Abstract:Usage: in the heat to reduce the intensity of formation of nitrogen oxides, combustion of the fuel mixture. The essence of the invention: method of preparing a mixture of air and fuel and its combustion in the combustion chamber of teploenergostroi, including a preliminary mixing and combustion of the mixture when the coefficients of excess air more or less stekhiometricheskogo values in a mixing units create a homogenized mixture of air and gaseous fuel ratios of excess air, serve them on separate channels to the mouth of the burner, providing at the output of the channel averaged over the cross section of the flow ripple values of the coefficient of excess air pre-mixed parts of the mixture stirred between them and the components of the combusted mixture components, and then burn the mixture. In the device for implementing the method in some of the channels for supplying the components of the mixture in the combustion chamber at the entrance set the mixing nodes, which hosted sites for the degeneration of pulsations concentration in the mixture, the mixing units installed turbulizers elements 7 the second mixture, used in teploenergostantsij TPP, TPP, production-heating boilers, and other heating units, and aims to reduce emissions of oxides of nitrogen.There is a method of preparing a mixture of air and fuel for combustion in the combustion chamber of teploenergostroi and device for its implementation.The known method includes a preliminary mixing and combustion of the mixture when the coefficients of excess air greater than or less than the stoichiometric value.A device for implementing this method contains the channels for supplying the components of the mixture in the combustion chamber.However, the known method is impossible or very difficult to uniformly mix the fuel and air supplied to the burner.The technical result that is achievable with the use of the invention is to reduce the pulsations of the concentration of the fuel combusted mixture by step training.The technical result is achieved by creating in the mixing units homogenized mixture of air and gaseous fuel ratios of excess air that have values outside the limits of Flammability, served their Otaci values of the coefficient of excess air pre-mixed parts of the mixture stirred between them and the components of the combusted mixture components, and then burn the mixture, and the ripple factor values pre-mixed part of the mixture at the outlet of the channels is determined according to the following ratios:
< / BR>where < - the instantaneous value of the coefficient of excess air at the point of the cross section of flow in the channel with the probability density distribution P();
- averaged over time, the value of the coefficient at the point of the cross flow;
- average expense ratio value.In the device for implementing the method in some of the channels on the mixing units, which hosted sites for the degeneration of pulsations concentration in the mixture, the mixing units installed turbulizers elements.In Fig.1 shows the proposed device; Fig. 2 - section A-A in Fig.1; Fig.3 - node I in Fig. 1.The device comprises a reservoir 1, the mixing unit that includes the block to the gas feed holes 2, the site for mixing the gas jets with the air supplied through the channel 3, channel 4 on plot M-N, the hole 5 channel 6 and the turbulent element 7.Of the collector 1, the gas is fed into the mixing unit, located between the planes M and P, air is supplied through the channel Alu 4 on the section M-N degenerate ripple concentration. Channel 6 through the opening 5 in the same area is served extra fuel, which is mixed with a previously prepared air-fuel mixture.The method is based on the reduction of pulsations concentration of fuel combusted mixture by step training.Perenesennosti gases in the mixture is estimated by the magnitude of the heterogeneity of the average concentrations and the level of fluctuations of the concentrations at the point of flow section. The concentration is determined by the ratio of the mass of the impurity (impurity - gas with less consumption) in the selected volume to the bulk of this volume.Typically the mixture in a section of the flow is characterized by the magnitude of heterogeneity, defined by the formula
< / BR>where is averaged over time, the concentration of impurities in the point section of the stream;
- average expenditure concentration of impurities, determined by the cost of mixed gases.To assess the heterogeneity of the average concentrations is also another more obvious and easily measured in experiments, the value of
< / BR>where the maximum and minimum values of the average concentration in the section.It is possible and appropriate to characterize the mixture the size of a cat who's of the devices to withstand < 0,05.More adequately characterize perenesennosti mixture value associated with the instantaneous concentrations.If C is the instantaneous concentration of impurities in the cross-sectional point of the thread with the probability density distribution P(C) then
< / BR>The variance of the instantaneous concentration at a point is defined as
< / BR>Similarly, we can determine the average concentration for flow and pulsation concentration in cross section. It is easy to see that point, and in section
The relative ripple concentration at the point of the cross section of flow is determined by the value of
Moving from concentrations to the air excess factor , it can be shown that
< / BR>and then the above formula can be represented in the form
< / BR>where to put the indices corresponding to the indices in C.Value as <C'>/C is a measure of the homogeneity of the mixture: = 0 corresponds to the mixture homogenized to the molecular level.By thorough mixing of air and gaseous fuel, as you can see, you can significantly reduce the emissions of NOx. However, there is a serious problem: risk of ignition in the burner mixture in the breakthrough plateni, when mixture is not ignited. For natural gas at the temperature of 25oC lower flammable limit = 1.8 and and top = 0,65.When > 1.8 and < 0,65 mixture explosion proof. This mixture can be mixed in a mixing node and to submit to the mouth of the burner and combustion additionally serve fuel, in particular mixed with air from the calculation that the zone of combustion was maintained for a total value of > 1, 2 or < a 0.9. Should probably go from mixtures with > 1.8 and add to the desired fuel (in pure form or in mixtures in air, as well as possible additional supply of liquid fuel, such as fuel oil), because the amount of this additional fuel mass is small. If pre-prepared mixture of 0.65, then the zone of combustion will need to submit the air or mixture of air and fuel with > 1 in large quantities, which will cause difficulties in ensuring good mixing of the primary and secondary flows before burning. 1. The method of preparation of the mixture of air and fuel and its combustion in the combustion chamber of teploenergostroi, including a preliminary mixing and combustion of the mixture when the coefficients of excess air greater than or men is by a mixture of air and gaseous fuel ratios of excess air, having values outside the limits of Flammability, serve them on separate channels to the mouth of the burner, providing at the output of the channel averaged over the cross section of the flow ripple values of the coefficient of excess air pre-mixed parts of the mixture stirred between them and the components of the combusted mixture components, and then burn the mixture, and the ripple factor values pre-mixed part of the mixture at the outlet of the channels is determined according to the following ratios:
< / BR>< / BR>where <>2- dispersion that characterizes the dispersion of values of the coefficient of excess air;
- the instantaneous value of the coefficient of excess air at the point of the cross section of flow in the channel with the probability density distribution P () ;
- averaged over time, the value of the coefficient at the point of the cross flow;
- average expense ratio value.2. Device for preparing a mixture of air and fuel and its combustion in the combustion chamber of teploenergostroi containing channels for feeding the components of the mixture in the combustion chamber, characterized in that at least some of the channels on the mixing units, which hosted sites for degeneration is the Plac CE turbulizers elements.
FIELD: gas-turbine plants.
SUBSTANCE: proposed method includes changing of fuel rate depending on power by metering out delivery of fuel into manifolds of coaxially installed pilot and main burners of burner assemblies with preliminary mixing of fuel and air. Burner assemblies are installed in two tiers, and fuel is delivered into burners of both tiers. At starting fuel is fed into manifold of pilot burners of outer tier and before idling, into manifold of pilot, burners of inner tier. At idling amount of fuel fed into pilot burners of outer and inner tiers is maintained equal. Then fuel delivery into pilot burners of outer and inner tiers is increased. Prior to operation under no-load conditions fuel is fed to main burners of outer and inner tiers. In the range from no-load to rated load, fuel delivery into main burners is increased with simultaneously decreasing relative portion of fuel fed through pilot burners. Invention provides reduction of content of nitrogen oxides NOxin exhaust gases of gas-turbine plant.
EFFECT: provision of stable burning of lean mixtures under any operating conditions.
4 cl, 2 dwg
FIELD: gas-turbine engines.
SUBSTANCE: proposed fuel-air burner has fuel injector in the form of body with fuel feed and spray holes as well as axial- and tangential-flow air swirlers, air flow regulator disposed between rear side of injector body and inlet end of axial-flow swirler that forms slit duct together with its inlet end. Axial- and tangential-flow air swirlers are made in the form of open-end channels accommodating blades and each is provided with converging-diverging nozzle having internal and external channel walls. External channel wall of converging part of axial-flow swirler nozzle has curvature inverse relative to internal channel wall of tangential-flow swirler nozzle. Diverging part of axial-flow swirler is made in the form of cone whose vertex is disposed upstream of nozzle critical section. Angle between burner axis and generating line of cone is 30 to 90 deg. Critical section of axial-flow swirler converging-diverging nozzle is disposed upstream of point of intersection between external channel wall and fuel spray cone generating line.
EFFECT: reduced emission of pollutants in exhaust gases, improved starting characteristics and fuel economic efficiency, enhanced reliability of combustion chamber.
1 cl, 2 dwg
FIELD: mechanical engineering; gas-turbine engines.
SUBSTANCE: proposed gas-turbine engine has central stage arranged in gas duct of engine from its part arranged higher relative to direction of main gas flow to part lower in direction of main gas flow and provided with exhaust gas cone forming device in direction of main gas flow, and guide arrangement. Gas-turbine engine has group of blades, group of fuel nozzles and group of igniters. Guide arrangement is located in zone of edge of exhaust gas cone-forming device arranged higher relative to direction of main gas flow. Group of blades is located in gas duct out of the limits of central stage. Blades are provided with atomizing guides extending through blades. Fuel nozzles are installed on inner ends of corresponding atomizing guides. Each nozzle is provided with input, output and passage between input and output. Passage has part arranged to direct fuel flow to first part of passage surface located across and widening downwards in direction of flow with subsequent deflection fuel flow by first part of surface and its outlet from nozzle. Igniters are arranged in corresponding atomizing guides for igniting fuel from corresponding fuel nozzle.
EFFECT: provision of reliable lighting up in afterburner, improved recirculation of fuel in flow.
13 cl, 8 dwg
FIELD: fuel systems.
SUBSTANCE: the fuel-injection nozzle for a turbo-machine combustion chamber outfitted with two fuel-injection nozzle units has the first fuel-supply tube, connected to which is an annular nozzle end for injection of primary fuel into the combustion chamber, the second fuel-supply tube that envelops the mentioned first tube, and connected to which is a cylindrical extension piece for injection of secondary fuel into this combustion chamber. The extension piece has an annular groove, whose diameter exceeds the diameter of the mentioned second fuel supply tube and runs over its entire length. The third tube is provided that envelop the second tube, an connected to which is a tubular separating component introduced in the mentioned annular groove of the cylindrical extension piece in such a way that two annular cavities are formed, in which the cooling agent can circulate up to the end of the fuel-injection nozzle within 360 degrees in the whole cross-section of the mentioned cavities.
EFFECT: provided protection of the fuel systems, prevented clogging of the fuel-injection nozzles with coke due to effective cooling without considerable variations of the nozzle overall dimensions.
8 cl, 3 dwg
FIELD: fuel systems.
SUBSTANCE: the device for supply of fuel to the combustion chamber has at least one main nozzle and one preliminary-injection nozzle, pump, the first actuator valve installed in the first pipe-line connected to the preliminary-injection nozzle, the second actuator valve used for control of fuel consumption in the secondary pipe-line connected to the preliminary-injection nozzle through the first actuator valve rated at a lower consumption rate. The first pipe-line is also connected to the main nozzle for control of consumption of fuel supplied to the nozzle by the first actuator valve, provision is made for a direction- selecting valve installed past the first valve, and an intermediate line connecting the first and second lines that are used for fuel supply to the main nozzle and/or to the preliminary-injection nozzle.
EFFECT: provided stable fuel supply to the combustion chamber.
8 cl, 2 dwg
FIELD: continuous combustion chambers using liquid or gas fuel.
SUBSTANCE: fuel nozzle comprises first valve that closes when the pressure of inflowing fuel reaches a given value and second batching valve mounted at the outlet of the first valve, which is opened under the action of the second given value of fuel pressure. The second valve is open when the pressure increases so that to provide the inflow of fuel to the consumers. The batched fuel flow rate is a function of the flowing sections of the openings made at the level of the second valve. The nozzle is additionally provided with means for individual adjusting of the second threshold value of pressure made so that to provided the uniform injection of fuel to the combustion chamber.
EFFECT: expanded functional capabilities.
4 cl, 6 dwg
FIELD: continuous combustion chambers.
SUBSTANCE: combustion chamber comprises hollow cylindrical housing whose wall receive scroll and air radial swirlers with blades that provide swirling in opposite directions, shells, bushings mounted for permitting movement in radial direction, branch pipe, swirling chambers, and nozzle. Each combined nozzle has centrifugal nozzle whose outer side is in a contact with inner side of the bushing and jet nozzle with cylindrical housing mounted coaxially in the inner space of the branch pipe between the outer wall of the housing of the jet nozzle and inner wall of the branch pipe. The outlet section of the housing of the jet nozzle is bent to the passage of the scroll spiral of the radial swirler. The outlet section of the jet nozzle is parallel to the wall of the inlet section of the branch pipe and is at a distance of 0.8-1.2 of the diameter of the jet nozzle housing from it.
EFFECT: reduced hydraulic drag and oxides emission.
FIELD: engine engineering.
SUBSTANCE: method comprises filling with solder the radial spaces made in the ring nozzle tip provided with the first nozzle openings for injecting primary fuel and in the cylindrical nozzle that embraces the ring nozzle tip and has second nozzle openings for injecting secondary fuel, setting the ring nozzle tip inside the cylindrical nozzle, mounting both of the members on the first fuel supply pipe for primary fuel and second fuel supply pipe for secondary fuel that embraces the first pipe and on the outer wall of the fuel nozzle, and setting the nozzle spryer assembled into the chamber where it is heated to provide adhesion of the members with solder.
EFFECT: expanded functional capabilities and eased assembling.
6 cl, 7 dwg
FIELD: gas-turbine engine engineering.
SUBSTANCE: ring combustion chamber comprises fire tube and vortex burners arranged over periphery of its face and made of fuel-air scroll and air swirlers with outlet conical branch pipe having cylindrical section. The shell is secured to the face coaxially to each branch pipe defining a ring space. The outer side of the end cylindrical section or inner side of the shell located above it is provided with longitudinal ribs distributed uniformly over periphery and defining insulated passages. The through openings connected with the ring space are made in the face of the fire tube under the shell.
EFFECT: enhanced reliability and expanded functional capabilities.
2 cl, 2 dwg
FIELD: gas-turbine engine engineering.
SUBSTANCE: method comprises separating the fuel supply through small fuel nozzle from that through high-flow rate nozzle, with controllable fuel supply realized directly in the device. The device comprises outer housing, high-flow rate nozzle made of outer housing of the small fuel nozzle and secured to it, piston-slide valve, and spring, interposed between the outer housings of the device and high-flow rate nozzles provided with the passages for fuel supply. The fuel supply is controller by opening passages for supplying fuel to the small nozzle and closing the passages for supplying fuel to the high-flow rate nozzle. When the pressure of fuel increases, the passages for supplying fuel to the high-flow rate nozzle are opened, and the passages for supplying fuel to the small nozzle are simultaneously closed.
EFFECT: enhanced efficiency.
2 cl, 5 dwg