CN201141601Y - Gas-air evenly mixing device for premixed combustion - Google Patents

Abstract

The utility model relates to a gas-air premixing device used for the premixed combustion. The gas-air premixing device comprises an upper wall surface in the shape of the lateral surface of the truncated cone, a flow guide wall surface in the shape of the lateral surface of the truncated cone and with a smooth inner wall, a lower wall surface and a cylindrical thin wall gas ejector, the flow guide wall surface is tightly connected with the large bottom surfaces of the lower wall surface and the upper wall surface respectively, the central axis of the ejector is coincided with the central axis of the premixing chamber, and the height of the ejector is equal to the height of the flow guide wall surface. The premixed gas outlet opening diameter is 1.5 to 2.0 times the height of the ejector, the height of the upper wall surface is 9 to 11 times the height of the ejector, the included angle of the central axes of the flow guide wall surface and the premixing chamber is 42 degrees to 46 degree, the distance between the large bottom surface of the guide wall surface and the intersecting point of the central axes of the premixing chamber and the extending line of the flow guide wall surface is 1.5 to 2.0 times the height of the ejector. The fuel gas-air premixing device can be used when the gas pressure is instable, the gas is homogeneously mixed, the flame is homogeneous, stable and secure, and the temperature difference of catalyst is lower than five degrees. The fuel gas-air premixing device is suitable for the use of the catalytic combustion boiler, the combustion turbine and the kiln stove.

Description

A kind of premixed combustion is evenly mixed device with combustion gas-air

Technical field

The utility model relates to a kind ofly to be strengthened combustion gas-air molecule contact and mixes in the premixer, having the combustion air evenly mixes, flameholding safety, the premixed combustion of advantages such as compact conformation and operating cost are low is evenly mixed device with combustion gas-air, be applicable to all kinds of catalytic combustion boilers, gas turbine and High-temp. kiln, premixed type dispersed combustion device uses.

Background technology

Combustion reaction thermodynamics and kinetics condition is the principal element that influences combustion process speed.When burning tissue at first requires the combustion gas molecule fully to contact with oxygen molecule and evenly mixes, and is the premixed gas generation combustion reaction of having mixed and by full consumption then.The former is a combustion heat mechanical condition, is determined by combustion gas in the stove and air flow mode.When combustion heat mechanical condition can not satisfy, unburned carbon loss can increase, and black smoke occurred and pollutant emission exceeds standard, and workshop air pollutes problems such as aggravation.

It is the catalytic combustion important prerequisite that combustion gas and air are pre-mixed.Form premixed gas in the premixer, evenly by the combustion reaction of catalytic body generation surface catalysis, combustion gas is partly or entirely consumed premix gas molecule.Catalytic body inside evenly is provided with gas channel, and the premixed gas in the different passages requires flowing velocity, and temperature and combustion gas molecular concentration are roughly the same, and premix gas flows through catalytic body with piston stream mode, has only along the one-dimension temperature of gas channel direction to change.Premixer's combustion air mixes inhomogeneous, forms tangible fuel-rich region territory and lean-burn zone, and catalyst combustion reaction is inhomogeneous, catalytic body heat absorption and temperature distributing disproportionation are even, localized hyperthermia district and catalyst localized burn inactivation occur, bed temperature can't be regulated and control, and finally threatens the burner safe and stable operation; Combustion air in premixer mixes inhomogeneous, can cause that the igniting of ignition stage is unstable, occurs missing of ignition, stop working and take off fiery problem; Fire air in addition and mix quality and also influence the gas-phase combustion behavior of catalytic body downstream, it evenly is the important prerequisite that gas-phase space is organized dispersed combustion that the combustion air is mixed.The space, premixer is little, and combustion gas is obviously different with kinetic energy with air pressure potential energy, and premixer's structure, shape and combustion gas and air draught not being flowed is optimized, and inaccessible combustion air is evenly mixed purpose.The advanced air of combustion is reliably mixed the development that technology can promote catalytic combustion technology, simultaneously premixed combustion, dispersed combustion and the operation of chemical field fluid Mixed Design is also had important reference function.

The space is little in order to solve, air pressure and speed difference are significantly fired in existence for the utility model content, the combustion air molecule is difficult to evenly mix problem, utility model is according to Hydrodynamics Theory, optimize premixer's air current composition and premixer's shape and size, design a kind of combustion air pre-mixing chamber, improving the catalyticing combustion process thermodynamic condition, satisfy burning fully, requirements such as safety and stability and low pollutant emission.

Premixed combustion is evenly mixed device with combustion gas-air, comprise sky combustion gas premixer, it is characterized in that: the upstream wall that also comprises frustum of a cone side shape, the water conservancy diversion wall of frustum of a cone side shape and inner wall smooth, lower wall surface and be cylindric and side wall surface and evenly be drilled with gas injector less than the 1.5mm pore, the little bottom surface of water conservancy diversion wall closely is connected with lower wall surface, the big bottom surface of water conservancy diversion wall and the big bottom surface of upper wall surface closely are connected, the central axis of gas injector overlaps with the premixer, the height of gas injector and water conservancy diversion wall equate and bottom surface on the same cross section vertical with premixer's central axis, at the lower wall surface center air intlet is set, the central axis of air intlet and the central axes of premixer, the little bottom surface of upper wall surface is the outlet of premix gas, it is 1.5～2.0 times of injector height that premix gas goes out port radius, the upstream wall face height is 9～11 times of injector height, water conservancy diversion wall and premixer's central axis angle are 42～46 °, and the distance of the big bottom surface of water conservancy diversion wall and premixer's central axis and water conservancy diversion wall extended line joining is 1.5～2.0 times of injector height.

The utility model is simply compact, easy to install, and the combustion air is mixed evenly, catch fire reliable, do not have flame-out and take off fiery problem, premixer's outlet combustion completion is stable, potential safety hazard such as no combustion gas delay in the premixer, unburned carbon loss reduces, no black smoke, and efficiency of combustion improves.Use catalytic combustion boiler, gas turbine and the High-temp. kiln of oil liquefied gas, natural gas or artificial fuel gas, premixed type dispersed combustion device, the chemical field fluid mixer all can use the utility model.

Description of drawings

Fig. 1 evenly mixes structure drawing of device for the premixed combustion that utility model relates to combustion gas-air.

Below in conjunction with accompanying drawing the utility model is further described.

The specific embodiment

As shown in Figure 1, premixed combustion is evenly mixed device with combustion gas-air and is mainly comprised air intlet pipe 1, fuel gas inlet pipe 2, and along air current flow direction lower wall surface 3, gas injector 4, water conservancy diversion wall 5, upper wall surface 6 and premix gas outlet 7.Upper wall surface 6 and water conservancy diversion wall 5 are frustum of a cone side, and the big bottom surface of water conservancy diversion wall 5 closely is connected with the big bottom surface of upper wall surface 6, and the little bottom surface of water conservancy diversion wall 5 closely is connected with lower wall surface 3, and upper wall surface 6, water conservancy diversion wall 5 and lower wall surface 3 connect into premixer's housing.The fuel gas inlet pipe closely is connected with lower wall surface 3 and gas injector 4 sealings respectively.Air intlet pipe 1 vertically closely is connected air intlet pipe 1, gas injector 4 and premixer's central axes with lower wall surface 3.The little bottom surface of upper wall surface 6 is premix gas outlet 7.

Water conservancy diversion wall 5 is cylindrical, and inner wall smooth, jet-flow are run into water conservancy diversion wall 5 back generation minute surfaces and reflexed to premix gas outlet 7.Gas injector 4 is positioned in the middle of the premixer, highly equates with water conservancy diversion wall 5 and goes up bottom surface all on the same cross-sectional vertical with premixer's central axis.Gas injector 4 walls are very thin, do not have guide functions, and tiny jet-flow is along penetrating with high speed perpendicular to premixer's central axial direction.Be drilled with 4～6 layer of 4～6 row's combustion gas ejiction opening on gas injector 4 sidewalls, evenly distribute perpendicular to combustion gas ejiction opening on the same cross section of premixer's central axis, the combustion gas ejiction opening is positioned on same premixer's central axis parallel lines on the different cross section.

Can arbitrarily angledly install and use.Air passes the downstream wall along premixer's central axis and enters the premixer through air intlet pipe 1, combustion gas with certain pressure enters gas injector 4 through fuel gas inlet pipe 2, and the gas port from gas injector 4 also sprays to water conservancy diversion wall 5 at a high speed along evenly flowing out perpendicular to premixer's central axial direction again.Combustion gas flows to premix gas outlet 7 again under the choked flow reflex of water conservancy diversion wall 5.Air enters the premixer and flows to gas injector 4 along premixer's central axial direction.Under the choked flow effect of gas injector 4, air is disperseed to flow out from the void space between the jet-flow, when flowing to premix gas and exporting 7 near zones and combustion gas intersect again, evenly mix the contact back and flow out premixers from premix gas outlet 7 along being parallel to premixer's central axial direction.The combustion gas that sprays at a high speed from the combustion gas ejiction opening that is positioned on the water conservancy diversion wall 5 handle facial planes flow to the little bottom center of upper wall surface (being that premix gas exports 7 centers) just after the reflection of water conservancy diversion wall, the combustion gas that sprays at a high speed from the combustion gas ejiction opening that is positioned on the water conservancy diversion wall 5 big planes, bottom surface flow to the little bottom edge of upper wall surface (being that premix gas exports 7 edges) just after the reflection of water conservancy diversion wall.When gaseous-pressure was higher, the high fast direction training wall face 5 of combustion gas energy, diversed again wall 5 reflexed to central axis zone, premixer and air evenly mixes.When gaseous-pressure is low, combustion gas is penetrated less than water conservancy diversion wall 5, gaseous-pressure just is reduced to the level that is more or less the same with air pressure in not far zone, combustion gas ejection back, the fuel gas flow direction is folded to and is parallel to the little bottom surface that premixer's central axial direction flows to upper wall surface 6, thereby mixes equably with air.

Premixer's temperature is lower than 250 ℃, and handling safety is reliable.The gradient of premixer's upper wall surface 6 is parallel with the jet-flow flow direction after 5 reflections of water conservancy diversion wall, eliminates combustion gas trapping phenomena in the premixer to greatest extent.The premixed gas flow export is too small, and more combustion gas is reflected by premixer's top board, has both increased the loss of premixed flow dynamic resistance, causes that again the premixer is detained the potential safety hazard of combustion gas.Studies show that: at premix gas outlet radius R is 1.5～2.0 times of gas injection device height h, upstream wall height H is 9～11 times of gas injection device height h, water conservancy diversion wall and premixer's central axis angle theta are 42～46 °, the distance H of the big bottom surface of water conservancy diversion wall and premixer's central axis and water conservancy diversion wall extended line joining ₁Be that air and fuel gas flow resistance minimum in the premixer do not have the combustion gas retention areas, combustion gas and air mixed effect the best under 1.5～2.0 times of conditions such as gas injection device height h; Premixer's height and volume minimum, manufacturing cost and operating cost are minimum.

Use the catalytic combustion experiment test and the application of honeycomb heat accumulation body and catalytic body to show: it is low no matter the gaseous-pressure height still is a gaseous-pressure, combustion gas can both distribute more equably, the uniform and stable mitigation of combustion flame on the catalytic body, catalytic body end face diverse location temperature difference is no more than 5 ℃; Premixer's outlet is caught fire reliable, and the catalytic body downstream does not have the fire of taking off, and the premixer does not have the tempering fire and explosive risks; There is not black flame; Catalyst life is long.

Claims (2)

1. premixed combustion is evenly mixed device with combustion gas-air, comprise sky combustion gas premixer, it is characterized in that: the upper wall surface that also comprises frustum of a cone side shape, the water conservancy diversion wall of frustum of a cone side shape and inner wall smooth, lower wall surface and be cylindric and side wall surface and evenly be drilled with gas injector less than the 1.5mm pore, the little bottom surface of water conservancy diversion wall closely is connected with lower wall surface, the big bottom surface of water conservancy diversion wall and the big bottom surface of upper wall surface closely are connected, the central axis of gas injector overlaps with the premixer, the height of gas injector and water conservancy diversion wall equate and bottom surface on the same cross section vertical with premixer's central axis, at the lower wall surface center air intlet is set, the central axis of air intlet and the central axes of premixer, the little bottom surface of upper wall surface is the outlet of premix gas.

2. premixed combustion according to claim 1 is evenly mixed device with combustion gas-air, it is characterized in that: it is 1.5～2.0 times of gas injector height that described premix gas goes out port radius, the upper wall surface height is 9～11 times of gas injector height, the central axis angle of water conservancy diversion wall and premixer is 42～46 °, and the distance of the big bottom surface of water conservancy diversion wall and the central axis of premixer and water conservancy diversion wall extended line joining is 1.5～2.0 times of gas injector height.