CN107110492A - Side feed forced ventilation formula biomass combustion cooking furnace - Google Patents

Side feed forced ventilation formula biomass combustion cooking furnace Download PDF

Info

Publication number
CN107110492A
CN107110492A CN201580056465.1A CN201580056465A CN107110492A CN 107110492 A CN107110492 A CN 107110492A CN 201580056465 A CN201580056465 A CN 201580056465A CN 107110492 A CN107110492 A CN 107110492A
Authority
CN
China
Prior art keywords
gas
nozzle
stove
egr
combustion chamber
Prior art date
Application number
CN201580056465.1A
Other languages
Chinese (zh)
Inventor
M·W·迪福特
N·洛伦茨
J·米齐亚
J·巴帕斯
K·德斯基诺
Original Assignee
科罗拉多州立大学研究基金会
恩威罗菲特国际股份有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority to US201462048884P priority Critical
Priority to US62/048,884 priority
Application filed by 科罗拉多州立大学研究基金会, 恩威罗菲特国际股份有限公司 filed Critical 科罗拉多州立大学研究基金会
Priority to PCT/US2015/049760 priority patent/WO2016040851A1/en
Publication of CN107110492A publication Critical patent/CN107110492A/en

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24BDOMESTIC STOVES OR RANGES FOR SOLID FUELS
    • F24B5/00Combustion-air or flue-gas circulation in or around stoves or ranges
    • F24B5/02Combustion-air or flue-gas circulation in or around stoves or ranges in or around stoves
    • F24B5/028Arrangements combining combustion-air and flue-gas circulation
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23BMETHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
    • F23B50/00Combustion apparatus in which the fuel is fed into or through the combustion zone by gravity, e.g. from a fuel storage situated above the combustion zone
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23BMETHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
    • F23B50/00Combustion apparatus in which the fuel is fed into or through the combustion zone by gravity, e.g. from a fuel storage situated above the combustion zone
    • F23B50/02Combustion apparatus in which the fuel is fed into or through the combustion zone by gravity, e.g. from a fuel storage situated above the combustion zone the fuel forming a column, stack or thick layer with the combustion zone at its bottom
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23BMETHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
    • F23B50/00Combustion apparatus in which the fuel is fed into or through the combustion zone by gravity, e.g. from a fuel storage situated above the combustion zone
    • F23B50/02Combustion apparatus in which the fuel is fed into or through the combustion zone by gravity, e.g. from a fuel storage situated above the combustion zone the fuel forming a column, stack or thick layer with the combustion zone at its bottom
    • F23B50/04Combustion apparatus in which the fuel is fed into or through the combustion zone by gravity, e.g. from a fuel storage situated above the combustion zone the fuel forming a column, stack or thick layer with the combustion zone at its bottom the movement of combustion air and flue gases being substantially transverse to the movement of the fuel
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23BMETHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
    • F23B50/00Combustion apparatus in which the fuel is fed into or through the combustion zone by gravity, e.g. from a fuel storage situated above the combustion zone
    • F23B50/02Combustion apparatus in which the fuel is fed into or through the combustion zone by gravity, e.g. from a fuel storage situated above the combustion zone the fuel forming a column, stack or thick layer with the combustion zone at its bottom
    • F23B50/10Combustion apparatus in which the fuel is fed into or through the combustion zone by gravity, e.g. from a fuel storage situated above the combustion zone the fuel forming a column, stack or thick layer with the combustion zone at its bottom with the combustion zone at the bottom of fuel-filled conduits ending at the surface of a fuel bed
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23BMETHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
    • F23B50/00Combustion apparatus in which the fuel is fed into or through the combustion zone by gravity, e.g. from a fuel storage situated above the combustion zone
    • F23B50/12Combustion apparatus in which the fuel is fed into or through the combustion zone by gravity, e.g. from a fuel storage situated above the combustion zone the fuel being fed to the combustion zone by free fall or by sliding along inclined surfaces, e.g. from a conveyor terminating above the fuel bed
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23BMETHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
    • F23B80/00Combustion apparatus characterised by means creating a distinct flow path for flue gases or for non-combusted gases given off by the fuel
    • F23B80/02Combustion apparatus characterised by means creating a distinct flow path for flue gases or for non-combusted gases given off by the fuel by means for returning flue gases to the combustion chamber or to the combustion zone
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24BDOMESTIC STOVES OR RANGES FOR SOLID FUELS
    • F24B1/00Stoves or ranges
    • F24B1/02Closed stoves
    • F24B1/028Closed stoves with means for regulating combustion
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23BMETHODS OR APPARATUS FOR COMBUSTION USING ONLY SOLID FUEL
    • F23B2700/00Combustion apparatus for solid fuel
    • F23B2700/013Combustion apparatus for solid fuel for use in baking ovens or cooking vessels
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23MCASINGS, LININGS, WALLS OR DOORS SPECIALLY ADAPTED FOR COMBUSTION CHAMBERS, e.g. FIREBRIDGES; DEVICES FOR DEFLECTING AIR, FLAMES OR COMBUSTION PRODUCTS IN COMBUSTION CHAMBERS; SAFETY ARRANGEMENTS SPECIALLY ADAPTED FOR COMBUSTION APPARATUS; DETAILS OF COMBUSTION CHAMBERS, NOT OTHERWISE PROVIDED FOR
    • F23M2900/00Special features of, or arrangements for combustion chambers
    • F23M2900/13003Energy recovery by thermoelectric elements, e.g. by Peltier/Seebeck effect, arranged in the combustion plant

Abstract

Disclosed herein is helping to reduce the granular material discharged system and device of biomass stove, such as by using being ejected at gas in the zoneofoxidation of combustion chamber or neighbouring.In addition disclose to help gas injection and/or collect system and device that the pump or air blower of waste gas provide electric energy.It is the thermoelectric generator that can also be used for energizing for other devices there is provided the device of electric energy in certain embodiments.In many examples, gas injection at or near the zoneofoxidation of system and device in the combustion chamber of biomass stove.The gas being injected into the area can be fresh air, burning waste gas or its combination.It is pumped into gas propulsive may also aid in the help of the pump of waste gas or air blower into combustion chamber.

Description

Side feed forced ventilation formula biomass combustion cooking furnace

The cross reference of related application

The application requires the interests for the priority that September in 2014 is submitted on the 11st according to 35U.S.C. § 119 (e), and the U.S. faces When patent application no.62/048,884, therefore the entire disclosure of which is merged by quoting.

Technical field

The invention discloses the gas for example by using being injected into combustion chamber, at or near zoneofoxidation helps to subtract The system and device of the emission of few biomass stove.The system and device for producing electric energy from biomass stove are also disclosed, with Operation helps gas injection and/or collects the pump or air blower of waste gas.

Background technology

The global commerce market of modified form cooking furnace is a newborn market.Although carrying out stove with tens of years Improvement planning, but be short in understanding due to poor durability and performance, or to market (such as price point), the benefit that mistake is delivered Patch, lacking stimulates and educates, and these influence of city layout are limited.Many expected public interests of the cooking furnace of improvement are discussed herein below.

To the health effect of the rural area common people

Have been observed that such as CO and less than about 10 or 2.5 microns in the house of the rural areas of developing country Grain thing (PM10、PM2.5) the ambient concentrations of airborne contaminants exceeded the exposure limit of the World Health Organization (WHO) up to 30X and the limit 100X for exceeding Environmental Protection Agency.This room air pollution (IAP) with global disease burden Nearly 3% is associated and be to cause up to annual 2000000 early death principal element.Advanced gasification cooking furnace has been proven that it Reduce the potential of the PM and CO emission related to three stone stoves.

Exhaust gas recirculation (EGR) can further reduce emission, and generally hundreds thousand of users are benefited.

Brief description of the drawings

Fig. 1 shows the various embodiments of presently disclosed EGR cooking furnaces and device.

Fig. 2 shows that discharge of the one embodiment compared with three stone stoves for disclosed EGR model machines is improved.

Fig. 3 shows the careful PM emissions datas of one embodiment for EGR stoves.

Fig. 4 shows (a) N in the co-flow of 30% oxygen purity2+O2, (b) CO2+O2, (c) Ar+CO2+O2In The number concentration of coal smoke volume fraction, primary particle size and primary distribution of particles.These are the non-premixed fire of co-flow The section view " picture " (being shot using time-resolved laser induced vehement light (TIRE-LII) and TEM) of flame.Fuel and three kinds of differences Admixture of gas coaxially flow, the composition of admixture of gas is marked in the subscript of figure.

Fig. 5 shows the various embodiments of the power supply of the egr system of fans drive disclosed herein.

Fig. 6 shows the photo of the embodiment of the EGR license biomass stoves for test.

Fig. 7 shows that EGR permits the schematic diagram and the cutting drawing of EGR device of the embodiment of biomass stove (top).

Fig. 8 is the embodiment for permitting stove for testing the EGR of emission reduction parameter.

Fig. 9 is the embodiment from Fig. 8 shown in front portion, wherein, two injection nozzles are located in the oral area of stove.

Figure 10 describes the EGR device for being added on biomass stove.

Figure 11 describes one embodiment of disclosed device, wherein, permit the injection nozzle in stove has excellent positioned at EGR The position of choosing.

Figure 12 describes one embodiment of disclosed device, wherein, permit the injection nozzle in stove has excellent positioned at EGR The geometry of choosing.

Figure 13 is for testing gas temperature to the system and one embodiment of device disclosed in the effect of discharge Photo.

Figure 14 shows the result of the start-up period flow velocity analysis of one embodiment progress to disclosed stove.

Figure 15 shows the result of the stable state firepower stage flow velocity analysis of one embodiment progress to disclosed stove.

Figure 16 shows the various positions with nozzle associated with disclosed device and system.

Figure 17 shows test researching and analysing as the discharge capacity of the function of temperature.

Figure 18 shows the starting as the function of flow velocity and stable state discharge capacity for various nozzle locations.

Figure 19 shows the result for the speed optimization of side injection nozzle air jet stream.

Figure 20 shows the optimization PM as the function of nozzle diameter for side injection nozzle2.5The test result of discharge capacity.

Figure 21 shows the injection orifices stable state flow velocity for various diameters and the result of optimization discharge capacity.

Figure 22 shows local peaking's discharge capacity for 3.2mm nozzles.

Figure 23 shows local peaking's discharge capacity for 5.7mm nozzles.

Figure 24 shows the flow distribution in the fast lower combustion chamber of different air jet streams and the effect to discharge.

Figure 25 shows the various eject positions tested in G3300.

Figure 26 shows some pictures of the embodiment of chimney ring spray mouth.

Figure 27 shows the air velocity effect at top jet position.

Figure 28 shows the spray angle tested at chimney bottom.

Figure 29 shows the embodiment of angled chimney ring spray mouth.

Figure 30 shows the G3300 for the side injection nozzle with 1.5mm diameter injection orifices, starts and stable state PM and flow velocity.

Figure 31 shows the G3300 for the side injection nozzle with 2.3mm diameter injection orifices, starts and stable state PM and flow velocity.

Figure 32 is shown for the chimney ring at the bottom of combustion chamber of top with 1.5mm diameter injection orifices G3300, is started and stable state PM and flow velocity.

Figure 33 is shown for the chimney ring in top combustion chamber middle with 1.5mm diameter injection orifices G3300, is started and stable state PM and flow velocity.

Figure 34 shows the G3300 for the chimney ring in top combustion chamber eminence with 1.5mm diameter injection orifices, Start and stable state PM and flow velocity.

Figure 35 is shown for the chimney ring at the bottom of combustion chamber of top with 1.5mm diameter injection orifices G3300, is started and stable state PM and flow velocity.

Figure 36 is shown for the chimney ring at the bottom of combustion chamber of top with 3.0mm diameter injection orifices G3300, is started and stable state PM and flow velocity

The content of the invention

Disclosed herein is the system of the discharge capacity for reducing biomass combustion device (such as stove) and device.Disclosed System and device may include scheme for exhaust gas circulation system (EGR) and/or reduce the fresh air spraying system of particulate emission.Disclosed System and device can also be used to increase the thermal efficiency of biomass combustion device (such as stove).It is used for many realities of injection in waste gas Apply in example, a part of emission (burning waste gas) of biomass combustion system is captured and is ejected into again in combustion zone. In some embodiments, waste gas can be combined with fresh air before spraying again.It can be helped using disclosed system and device Reduce the discharge (such as CO and particulate matter) of biomass combustion device, and electric energy can be provided in certain embodiments, so as to for Spray fan/blower and the energy supply of other electronic installations (such as phone or battery).

Disclosed herein is the device of the discharge capacity for reducing biomass stove, described device includes:Fluid intake aperture;Tool Have an entry conductor of outer surface and inner surface, the inner surface limits inlet, the inlet via the entrance aperture with The appearance fluid communication, for directing fluid, (such as gas, such as air, it may include greater than about 15% for interior chamber Oxygen, O2);In the inlet and positioned at the fan of the entrance aperture distal end, the fan is used to take out fluid Inhale by the entrance aperture and be drawn into the room, and enter;Delivery channel, the delivery channel, which has to limit, to be exported The inner surface of room, the downstream chamber is in fluid communication with the inlet;One with the inside being in fluid communication with the downstream chamber Individual or multiple nozzles, the nozzle is used to direct fluid in the combustion chamber of biomass stove;And it is limited at the nozzle Surface on multiple exit apertures, the exit aperture is designed to allow the inside that fluid leaves the nozzle. In some embodiments, the nozzle is located at or near the top of lower combustion chamber.In certain embodiments, the exit aperture With the average diameter between 0.5 and 3.5mm, and circular, square, triangle or ellipse are limited, by circle, just The center of square, triangle or ellipse measures the average diameter.In certain embodiments, from one or more of nozzles The volume of escaping gas is greater than about 10 Standard Liters per Minutes and less than about 100 Standard Liters per Minutes, and gas can be from hole Mouth is escaped with the speed of about 5-25 meter per seconds.In certain embodiments, the nozzle is linear nozzle or round nozzle, is such as justified Ring, it is located above the lower combustion chamber and in the lower half of top combustion chamber, and is designed to allow burning Gas is directly through jeting area.

The emission by biomass stove is also disclosed (for example, particle emission, in some cases, particle are less than about 2.5 Micron) method that reduces by about 20% to about 90%, methods described includes:Gas is placed into the interior chamber of nozzle, the spray Mouth is located at or near flame;Increase the pressure of the gas in the nozzle (such as by using fan or pump with by gas Body is advanced to nozzle interior);The multiple outer apertures limited by the outer surface by the nozzle are certain from nozzle discharge Measure the gas;And the gas sprayed is guided into the flame in the combustion chamber of the biomass stove, wherein, the gas Body reduces the amount at least one pollutant for leaving the biomass stove.In certain embodiments, the gas body discharged from nozzle Product is between about 10 Standard Liters per Minutes and 100 Standard Liters per Minutes.In certain embodiments, the nozzle limit linear tube or Annulus, and exit aperture is in the inner surface of the ring, to help gas injection to the center of the ring, the outlet Aperture has the diameter between 0.5 and 6.0mm.In certain embodiments, the exit aperture and the bottom surface of the combustion chamber An equal distance away, and by one or more apertures with the speed between 5 and 25 metre per second (m/s)s the gas is discharged.Permitted In many embodiments, with about -10 degree to about+30 degree between angle by the gas injection into flame.

There is disclosed herein the method for the granular material discharged thing for reducing biomass stove, methods described includes:Gas is aspirated Into room, the gas includes greater than about 15% O2;The gas is directed to inner surface and outer surface from the room Nozzle in, the nozzle limits round tube, and the round tube has multiple exit apertures on round inner surface, wherein, The exit aperture allows that gas is advanced from the inside of the pipe towards the center of circle;Increase described in the inside of the nozzle The pressure of gas;A certain amount of gas-pressurized is discharged from the nozzle with the speed between about 5 metre per second (m/s)s and 20 metre per second (m/s)s;And The gas sprayed is guided into the flame in the combustion chamber of the biomass stove, wherein, the gas reduction is left described The amount of at least one pollutant of biomass stove, its decrement lacks the stove of gas-pressurized than lacking in nozzle or the nozzle About 25% more than situation.It is pumped into gas propulsive may also aid in the help of the pump of waste gas or air blower into combustion chamber.

Embodiment

The stove and furnace accessory for combustion product is circulated back to combustion chamber is described herein.In certain embodiments, stove and stove are matched somebody with somebody Part can be such that it is mixed with fresh air before combustion product is led back into combustion chamber.In certain embodiments, waste gas is followed Ring can provide the strong interaction with the burning based on diffusion without premixing into combustion chamber, and latter burning occurs in biology Between matter and the naturally air inlet of suction.

Although multiple embodiments of the EGR and system disclosed in disclosing, to those skilled in the art It will be apparent according to other embodiment described in detail below., can be to disclosed system and device as will be apparent Each substantially aspect modify, these modification without departure from the spirit and scope of the present invention.Therefore, detailed description will be recognized To be regarded as illustrative in nature and not as restrictive.

The adverse effect of incomplete biomass combustion is destruction locality and global environment.In addition, although biomass is because latent In carbon can be provided and energy and praised, but they be not weather neutralize because the significant portion included in fuel Carbon is used as the gaseous species (CH with global warming potential4And NMHC) discharged again.Cooking furnace design tool described herein There is the potential for substantially reducing this pollution.

In addition, recent research shows that black carbon (BC) particle emission is CO2Second important Global climate change afterwards Driving factors.For the whole world, it is estimated that family cooking produces always consider BC 50% be discharged into every year in environment, and utilizes Technology (all cooking furnaces as described herein) largely reduces whole world BC emissions and has been promoted as resisting most having for short-term global warming One of desired strategy.

Global saving of fuel

Biomass stove is to about 1/8th of net forest harvesting amount and the therefore net people to being discharged into air according to estimates Class CO2The 1.5% of increment is responsible.More partly say, women and children will take for weekly up to 20 hours to gather firewood, This activity prevents their growth and makes them in many cases exposed to violence (whole world cleaning cooking furnace alliance).

Ultra-clean biomass cooking furnace substantially has three kinds of main analogs.These analogs are that (1) forces the gas of air-flow half Change stove, (2) natural airflow half-gasification oven, and (3) side feed wind furnace.Disclosed herein is various commercially available stoves and novelty simultaneously And the surprising side of efficiency is fed a large amount of performance datas of wind furnace.Mass market experience based on Envirofit, it has been found that:

The pressure gas-flow gasification furnace of fuel treatment is needed to be unsatisfactory for market expectations on price and convenience.

When (1) fuel quality changes, (2) are during starting and closing down, and ground of (3) user outside optimization window During side's operation stove, the Operational Figure Of Merit of natural gas flow and pressure air-flow half-gasification oven causes maximum discharge may.

On the contrary, side feed stove is met on fuel flexibility and using the consumer anticipation of easness.Even if in addition, not Fan is operated, also allows that stove suitably works.Although conventional rocket stove is unsatisfactory for 90% emission reduction targets, they meet Rational emission reduction is also ensured that up to 70% emission reduction, therefore even in fault mode.

Because side feed wind furnace meets all aspects of consumer demand, expection and performance with maximum potential, because This correspondingly needs the more efficient side feed wind furnace for meeting 90% or higher emission reduction targets.This target helps to realize it The interests that improvement rural area common people health, the influence of reduction global environment and the global biomass of reduction of preceding description are used.

Although the commercially available stove of such as Envirofit G3300 stoves is used as underlying biological by many embodiments described herein Matter burner, but side feed stove and side feed wind furnace of the present invention available for various designs.Fig. 1 shows some commercially available Side feed wind furnace design:Stove Tec (top);BioLite (centre);(bottom has and not had Envirofit Adapter).

Various forms of waste gas circulations (EGR) have been used for other situations, to control flame characteristics.It is main in internal combustion engine To utilize EGR.EGR primary and foremost purpose is to reduce NO in internal combustion enginexFormed.It so does in the following manner, i.e. by inciting somebody to action Slightly inert waste gas introduces cylinder, therefore reduces the ratio of fuel gas and by heat energy distribution in bigger quality.This Reduce peak flame temperature, therefore reduce N2Thermal decomposition and consequential NOxFormation.But it is due to these engines Operated close to stoichiometric levels, therefore addition waste gas can form the regional area of the stoichiometric levels less than oxygen.This Promote imperfect combustion and therefore generally increase the total output of particulate matter (partially combusted hydrocarbon).But, It was found that increase CO2Concentration can help to alleviate the PM yield increase caused by EGR.

Influence in view of EGR to internal combustion engine, due to three main causes, it is to violate that EGR is applied into biological cooking furnace Intuition.First, the NOx in biomass cooking furnace forms inessential.Because the peak combustion temperatures in stove are sufficiently low, because And the N of negligible part2Molecule will be thermally decomposed.Second, because biomass stove generally has relatively low peak compared with engine It is worth ignition temperature, therefore skilled worker can assume that imperfect combustion can be promoted simultaneously by the temperature being introduced into waste gas reduction cooking furnace And the formation of increase particulate matter.3rd, because biomass cooking furnace (particularly rocket bend pipe stove) is using so high excessive O2Value (for M5000, excessive air and the ratio of stoichiometric air are about 2.3) to be operated, therefore with wanting help Alleviate the CO in the engine EGR of PM production problems2Cmin is compared, the CO in cooking furnace EGR2Concentration is likely to very little.

With expected results described above on the contrary, applicant have unexpectedly discovered that EGR is applied into biomass cooking furnace Meeting (1) reduces particulate matter yield and (2) increase CO oxidations, as is seen in figures 2 and 3.The EGR phases combined with combustor Than, it is presently disclosed be the discovery that it is counterintuitive.Current document can provide to it is this observe emission reduction some be based on after The bright theory seen.

As previously mentioned, by CO2Particulate matter yield is caused to reduce in the combustion chamber for being recycled to biomass cooking furnace One feasible mechanism, although it is probably smaller to be reduced in view of this particulate matter yield of air ratio excessive in rocket bend pipe stove Reduction.The CO in non-premixed flame is have recorded in file2Addition is to granular material discharged influence.These research concerns are same Coal smoke in matter fuel (such as propane and ethene) is formed.Early literatures report that addition carbon dioxide can pass through chemical phase interaction Reduced with the coal smoke formation of convection type diffusion flame is caused.More recent study is indicated, adds the particle caused by carbon dioxide Thing reduction is due to reduction and the CO of flame temperature2Both chemical interactions.Fig. 4 shows the experiment number that Oh et al. is collected According to it clearly demonstrate that obtains coal smoke using carbon dioxide is added into oxidant in co-flow diffusion flame section Reduce.In figure, fv represents the volume fraction of coal smoke in flame, and dp is primary particle size, and Np is primary in flame The number concentration of grain.According to Oh et al., " with CO2Instead of N2As in the situation of diluent, primary particle size and coal smoke Volume fraction is drastically reduced ".Again, according to Oh et al., the reduction of coal smoke formation is contributed to following:

Due to CO2Increase thermal capacity, flame temperature reduction

By introducing carbon dioxide diluting reaction gaseous species

The direct chemical effect of carbon dioxide

These researchs confirm CO2The granular material discharged effect to the nonpremixed flames of co-flow is added, still This effect that the document that there is currently all does not burn for solid biomass certainly again.More shockingly, applicant has sent out Existing other other compositions and injection characteristics (speed, direction, position, angle, volume) influence PM is reduced.

There are other potential mechanism that granular material discharged reduction can be explained further, such as increase mixing, increase O2Level, Change the total flow by stove and then change the residence time of combustible component, change the peak combustion temperatures in stove and break The particulate matter of bad circulation.These mechanism both not by comprehensive understanding or were not easy estimated.It there is currently no and assess these mechanism to life The text of the effect (the particularly effect related to applying EGR in biomass cooking furnace) of particle emission in material cooking furnace Offer.

In addition to the profit potential that EGR is formed to particulate matter, experimental data and data in literature are indicated and passed through using EGR The water of catalysis CO oxidations, is likely to reduced carbon monoxide in mechanism, such as increase mixing and waste gas stream.

In certain embodiments, stove and furnace accessory may include the device for actively moving air, and the device can be by Power supply is energized.In certain embodiments, air moving device can be fan or air blower.Power supply can be battery, and it can be wrapped Include adapter and/or charging circuit.Fig. 5 shows several feasible embodiments.In one embodiment, power supply includes having The AC/DC adapters of battery and charging circuit.This embodiment is probably that some markets are desired, such as India, in India's mesh Electric energy can be touched when at least some in one day more than 70% in mark market.Another embodiment may include that hand is operated Formula generator (or ergometer).Hand operated type generator can be combined with charging circuit described above and battery.For about 1-3 watts Special expection fan power consumption, it is manual powered will not be excessively heavy.Fig. 5 also illustrates thermoelectric generator (TEG) energy supplying system, its The heat from stove can be used to produce electric energy.In many cases, TEG can be produced more than 1-3 watts, and this can also allow for battery And/or the charging of other electronic installations (lamp, light source, mobile phone, computer etc.).It is attractive to produce the potential of excessive amount of electrical energy 's.Other options are obvious to those skilled in the art, and are consistent completely with invention described herein.

Fig. 6-9 depicts some embodiments of disclosed stove and furnace accessory.Embodiment shown in Fig. 6 includes commercially available Stove, Envirofit G3300.This embodiment is used for the stove of test request right and many aspects of furnace accessory.For example, Fig. 2 and 3 Shown emission data are produced using this embodiment.

Fig. 7 shows the second embodiment of disclosed stove and furnace accessory.If this embodiment of EGR license stoves is used to analyze Dry variable, for example, can influence discharge performance (such as gas injection position, nozzle geometry structure, gas path temperature, the flow velocity of stove With TEG positions) variable.Fig. 7 embodiment also includes commercially available stove, Envirofit M5000.Fig. 7 it is not shown by gas from EGR outlet guides the side into stove to be fed the conduit being open.Show Fig. 7 not in the embodiment described in both Fig. 8 and 9 The conduit shown.Gas is guided the side into stove to be fed and is open by these conduits from EGR outlet.Pulse width modulator and power supply are set It is standby to be included in the disclosed apparatus, to help the speed for controlling fan/blower motor.In addition, being integrated into Fig. 7's TEG in the EGR path of embodiment helps to describe the feature for the energy production/recovery for carrying out cycle gas.

Figure 10 depicts another embodiment that EGR permits stove.How this embodiment diagram can add EGR furnace accessories To stove as accessory, for example, EGR device can be added to rocket bend pipe stove.In this embodiment, waste gas is drawn through into hole Grid, entering grid of holes can be located at or near furnace roof portion, as described herein.Waste gas, which flows through, to be placed around the circumference of pot surrounding edge Conduit.Waste gas in this conduit then via one or more extra conduits flowings at or near pot surrounding edge front portion and It is injected back into the oral area of combustion chamber.The air blower of fan or injection air can be located between ingate and spray-hole.At some In embodiment, as depicted by figure 10, fan is located at the rear side of pot surrounding edge.Power supply can be located near fan.

As discussed above, the air blower of injection air can be supplied with electric energy, the electric energy by such as thermoelectric generator, too Positive energy battery, the manually power supply of energy supply generator (crank charger) or house power are provided.The selection of power supply can be based on cost Assess and the contrast with the market demand.Thermal environment, chemical environment and the mechanical environment that can be exposed to according to material are changed into Stove and the material of furnace accessory selection.In many examples, the part in device can change and need not with it is discussed above Envirofit G3300 or M5000 stoves in utilized those are same or similar.In many examples, EGR device can be held Perhaps stove is suitable in egr system closing and/or failure and efficiently works.

For most of embodiments of disclosed egr system, stove may include by wooden fuel or similar biomass to Expect the air/fuel entrance (or oral area) in fire door portion, and air is sucked into oral area by convection current.In these implementations In example, burning generally occurs in combustion chamber.The geometry and material of combustion chamber can be optimized, so as to suitably biomass burning And minimize the heat transmission to furnace main body.In many examples, the waste gas produced by biomass combustion can be drawn upwardly Inhale by top combustion chamber and enter one or more exhaust gas entrance apertures.In certain embodiments, exhaust gas entrance aperture is limited It is scheduled in the ring structure at or near the top of combustion chamber of top.This ring structure can be referred to as " EGR entrance surrounding edge ", and its Inside can limit accumulation chamber of waste gas.Fig. 7 depicts the one embodiment of " EGR entrance surrounding edge ".Pump/blowing plant can be integrated Into stove, to help Abgasabsaugung into EGR entrance surrounding edge.Waste gas is advanced through conduit and passes through pump/blowing plant Into one or more injection catheters, until it is injected into the combustion chamber of stove.

In many examples, waste gas can enter the induction port that can be located at or near top of combustion chamber.The aperture can With the internal fluid communication of accumulation chamber of waste gas, collecting chamber can be in fluid communication with one or more waste gas ducts, the waste gas duct Waste gas comprising waste gas and is directed to the pump or air blower being in fluid communication with waste gas duct.Pump or air blower help by waste gas from Waste gas duct is moved in one or more injection catheters on one's own initiative, and waste gas is directed one or more injections and sprayed by injection catheter In mouth.Injection nozzle has the multiple apertures allowed inside waste gas effusion injection nozzle.

Test instruction to disclosed device and system, the row of eject position, nozzle geometry structure and flow rate effect stove Put performance.Therefore, for the various combinations of eject position and nozzle geometry, it is determined that optimization flow velocity.Then, various knots are contrasted The minimum PM emissions of conjunction, to determine the optimization design of test furnace.Disclosed test identification is for eject position and nozzle Some of geometry are preferably in conjunction with the embodiments, although incomplete optimization.Some exemplary combinations are described below.

Exemplary stove nozzle design

There are some positions to place injection nozzle in a combustion chamber.Equally, the injection orifices in nozzle plane are limited at Can have some geometries and configuration.Various designs are tested, and obtain an implementation for disclosed stove Example configures for the preferred eject position and nozzle of PM emission reductions.Figure 11 and 12 depicts this of eject position and nozzle geometry structure Plant preferred embodiment.In this embodiment, injection nozzle position is at or near top of combustion chamber.

In this embodiment, two injection nozzles are located at or near the side of combustion chamber.Other embodiment may include many In two nozzles or a nozzle.In the present embodiment, nozzle is fired parallel to and perpendicular to combustion product by the top of stove The airflow direction for burning room is placed.In certain embodiments, nozzle can be not parallel to or perpendicular to air-flow.In the present embodiment, 6 Individual injection orifices are limited in nozzle surface.In the present embodiment, injection orifices are with 9/16 inch of centre-to-centre spacing centre distance Separate, and each aperture has about 3/16 inch of diameter.In many examples, for example wherein nozzle limits fundamental line The embodiment of the tubular construction of property, all embodiments as depicted in figs 12 and 16, (position is near the hole of combustion chamber oral area in the first aperture Mouthful) be located at about 1/2 inch away from combustion chamber oral area.In other embodiments, nozzle can limit ring structure, and ring structure can be located at upper At or near the wall of portion room (or chimney).

Injection nozzle can limit the injection orifices being restricted in the horizontal section of combustion chamber.In many examples, water Flat section be less than about 20cm, 19cm, 18cm, 17cm, 16cm, 15cm, 14cm, 13cm, 12cm, 11cm, 10cm, 9cm, 8cm, 7cm, 6cm, 5cm, 4cm, 3cm, 2cm or 1cm, and more than 0.5cm, 1cm, 2cm, 3cm, 4cm, 5cm, 6cm, 7cm, 8cm, 9cm, 10cm, 11cm, 12cm, 13cm, 14cm, 15cm, 16cm, 17cm, 18cm or 19cm.In certain embodiments, such as scheme 16th, the embodiment shown in 26 and 29, aperture is substantially planar located in combustion chamber and parallel to the bottom surface of combustion chamber.When going out When oral pore mouthful is in same plane with bottom surface, the center of each exit aperture and the bottom surface of combustion chamber at a distance of same distance (or away from From change be less than about 0.5cm) place.In certain embodiments, the change of the distance from bottom surface to each aperture is less than 0.5cm、1cm、2cm、3cm、4cm、5cm、6cm、7cm、8cm、9cm、10cm、11cm、12cm、13cm、14cm、15cm、16cm、 17cm, 18cm or 19cm (when change is less than about 0.5cm, it may be said that aperture is plane).When nozzle limits ring structure, hole Mouth can be located at ring everywhere and be designed to guide gas into ring center.

In many examples, preferable flow rate may be present in the waste gas stream for flowing in combustion chamber, and it can help to reduce assembling The PM discharges of the stove of disclosed system.In many examples, preferable flow rate can be about 20 to 70 Standard Liters per Minutes (SLPM).For the nozzle configuration shown in described above and Figure 11 and 12, the preferable flow rate for PM emission reductions is marked 50 to 70 Change between quasi- Liter Per Minute.In most embodiments, flow velocity can increase with the increase of firepower, to minimize PM rows Put.For example, under 2.4kW firepower, preferable flow rate can be about 50SLPM, and under the firepower more than 2.6kW, preferable flow rate 70SLPM can be increased to, to minimize PM discharges.In some cases, firepower is less than about 2.4kW, and flow velocity may need to be conditioned To below 50SLPM, to avoid flame blow-off, for example, less than about 40SLPM, 30SLPM, 20SLPM, 10SLPM or 5SLPM.Permitted In many embodiments, gas flow rate is related to the firepower of stove.For example, desired PM is obtained in 2.5kW stoves and is reduced may need about 40SLPM flow velocity, and reduced for the PM of phase same level, 20kW stoves (such as chimney draft stove) need about 60SLPM flow velocity. In certain embodiments, flow velocity be smaller than about 110SLPM, 100SLPM, 90SLPM, 85SLPM, 80SLPM, 75SLPM, 70SLPM, 65SLPM, 60SLPM, 55SLPM, 50SLPM, 45SLPM, 40SLPM, 35SLPM, 30SLPM, 25SLPM or 20SLPM, and greater than about 10SLPM, 20SLPM, 25SLPM, 30SLPM, 35SLPM, 40SLPM, 45SLPM, 50SLPM, 55SLPM, 60SLPM, 65SLPM, 70SLPM, 75SLPM, 80SLPM, 85SLPM, 90SLPM, 100SLPM or 110SLPM.

For the test of cold start boiling water, the embodiment for the EGR license stoves that Figure 11 and 12 is described can be by PM10Discharge from (the corresponding PM of every million Jiao energy is transmitted for the 275mg/MJd of the basic M5000 stoves with pot surrounding edge to water10Milligram number) reduce To the 125mg/MJd of the identical stove for the EGR rate with optimization.

In order to more fully understand the embodiment that Figure 11 and 12 is described influence PM emission reductions variable, can experimentally analyze Some latent variables.These experiment displays, a mechanism for reducing PM mass discharges is the size of oxide regions due to fire The O improved in flame2Concentration and increase, this then increases the fuel close to oxidant.Oxide regions be in flame oxygen to be enough The region that the concentration of support burning is spread.In addition, these tests are shown, when closer to the beginning of oxide regions (closer to At the minimum point of flame front) injection O2When, it is more effective to reducing particulate matter quality discharge.On the contrary, pointing to the injection of charcoal substrate Or be directly injected in fuel or be found that higher PM mass discharges can be caused on fuel.

The embodiment that Figure 11 and 12 is described uses the nozzle location (near top of combustion chamber), and the position is allowed gas Body is injected near the bottom of oxide regions, but sufficiently above fuel, to prevent from smouldering or flame blow-off and thus caused Higher discharge.

Its dependent variable that PM can be influenceed to discharge also is assert in these researchs.For example, particle increased Sojourn times in zoneofoxidation Between (such as via circulation) help to reduce PM discharges, Forced Mixing burning gases also can be such.But, in many cases, The effect for manipulating the two variables seems to be not so good as to improve the O in the oxide regions of flame2The effect of concentration.In addition, according to determination, CO2 The influence that the buffer action of circulation is discharged to PM is less than raising O2Concentration.In some cases, in disclosed EGR license stoves Fuel consumption rate increase is observed in some embodiments, this can be discharged independently result in PM increases.But, when these effect quilts When combining, because they are present in many disclosed EGR licensing systems, it was observed that PM mass discharge only reduces.

Because test shows the O improved in flame oxidation region2Concentration is a mechanism of PM Mass losts, therefore is utilized Higher O should be equally provided2The fresh air (non-EGR) of concentration sprays to test same nozzle configuration and eject position.Profit Sprayed with completely new fresh air, cold start boiling water test PM10Discharge is reduced to 91mg/MJd.This display has this nozzle several What structure and the EGR embodiments of eject position can provide the PM CERs more than or equal to those embodiments using waste gas.

As described below, disclosed egr system and device can be changed in various manners, to reduce biomass combustion The discharge of stove.For example, fresh air injection, nozzle location and nozzle geometry can be changed.It may include to disclosed system Other modifications with method, change and replace, further to reduce PM mass and these are included within the scope of the disclosure.

All bibliography disclosed herein, either patent is also non-patent, is all incorporated herein by reference, seemingly often The full content of individual quotation is embraced within this., will be (including any fixed with this specification in bibliography and during specification contradiction Justice) it is defined.

Although describing the present invention with certain exact level, it should be appreciated that, the present invention is to do by way of example Go out, and details or structure can be changed in the case where not departing from the spirit of the invention that appended claims are limited Become.

Example II-EGR-PM emission reductions analysis

Fig. 7 embodiment is used for the initial test for performing waste gas circulation.Specifically, particulate matter is measured during these tests (PM2.5), to test effective emission reduction.Some variables of test analysis, for example:The temperature of cycle gas, exhaust gas constituents, exhaust blast Position and nozzle configuration and waste gas flow velocity.

Cycle gas composition

In order to ensure minimizing the surrounding air amount being sucked into EGR pots of surrounding edges, in EGR rate, eject position and spray In the case of mouth configuration consistency but entrance configuration difference, two groups of boiling waters tests (WBT) of operating:One group utilizes ring described above Structure is performed, and second group of data is collected using the conduit of waste gas is directly extracted from the center of combustor exit.This second Configuration ensure that all or almost all gases in the system of being sucked into all include waste gas.Utilize and be located in whole test Gas analyser (TESTO) in the path of egr system is sampled to the concentration of molecular oxygen.By comparing oxygen concentration, it may be determined that Whether surrounding air (fresh air or non-waste gas) enters system with high flow rate.

The temperature of recyclegas

By the way that the heating tape with PID (PID) temperature controller is merged into test platform, test is followed The temperature of ring waste gas.The photo of this visible test system of Figure 13.

10 cold start boiling water tests are completed, wherein, in addition to the temperature of recyclegas, test variable is kept not Become.Averaging loop gas temperature changes between about 20 DEG C to 100 DEG C.The lower limit of test temperature replicates and has been completely cooled down to ring The effect of the waste gas of border temperature.The upper bound of test temperature represents a kind of circumstances, and the wherein EGT of pot lower edge is being entirely Entered in system from waste gas in being ejected into combustion chamber and keep nearly constant.By using ice bath cooling gas temperature, to reduce gas Temperature, and resistance-type heating tape is for raising gas temperature.It is used to measure with the interval of one second along the thermocouple of EGR path Measure gas temperature.

Nozzle and flowing rate process

These researchs are additionally operable to the minimum PM of the various nozzle configurations of comparison2.5Discharge.Develop for estimating specific spray roughly The minimum PM of mouth configuration2.5The unique nozzle and flowing rate process of discharge.Make in these tests being discussed further below Two hypothesis are gone out.Usually, the progress of test process includes step 1-design and manufacture nozzle, step 2-determined to get angry The flow velocity in power stage, the optimization flow velocity in step 3-determine stable state firepower stage, and step 4 are cold to optimize flow velocity operating Start boiling water test.

In the EGR optimum experimentals part studied at this, complete repeatedly for three times of this process.The sampling in process is discussed below The details of each step in repeatedly.Step 1:Design and manufacture nozzle.Using hydrodynamics and burning concept combination and it Preceding experimental result design nozzle.Step 2:In step 2, determine start-up period is used for PM2.5The optimization flow velocity of emission reduction.It is right In each data point, standard cold start boiling water test process, which followed by, to be carried out and terminates at 30 DEG C of water temperature.30 DEG C Water temperature is chosen to be the stop value of these tests.When water temperature reaches 30 DEG C, firepower is no longer on transient state and entered Enter stable state.Flow velocity is changed with 10 to 20SLPM interval, and each flow velocity is collected into 1 to 2 data point.Figure 14's The sampling structure of visible start-up period flowing rate in chart.This chart shows the starting rank optimized for this example data group Section flow velocity is about 40SLPM.

In step 3, determine that the stable state firepower stage is used for PM2.5The optimization flow velocity of emission reduction.Tested using boiling is planned (quasi-simmer test) method determines that stable state optimizes flow velocity.First, furnace main body, pot and water are brought to the temperature that will seethe with excitement Degree.Once reach that stable state, by boiling temperature, just removes charcoal and the fuel burnt, while pot and water are stayed in into original Position.Then the fuel of known weight is lighted using propane torch in a combustion chamber.Propane torch be used to light fuel, because from The beginning each sampled uses stable state firepower stage (pine branches of 3-3/4 " × 3/4 " × 12 ") fuel feedstock method. Start to sample PM2.5Fire burning one minute is allowed before.Delay in this minute prevents from carrying out PM during branch is lighted2.5Sampling. Then PM is sampled2.5Emission ten minutes, or until branch almost exhausts, while firepower keeps constant level.Complete PM2.5Take During the sample cycle, remove and weigh remaining fuel and charcoal.Then ignition procedures again are repeated at different flow rates and subsequent Ten minute sampling period.The whole process tested herein, water and pot are left in place and keep being in boiling temperature.In addition, taking Time between the sample cycle is less than 3 minutes, and this prevents stove and/or pot from substantially cooling down.This test process allows that rough estimation is stable The PM that specific nozzle is set during the state firepower stage discharges the relation between flow velocity.PM discharges consume quality by unit of fuel The PM of discharge2.5Quality (be referred to as emission factor (EF)) describe.When calculating EF, for moisture and sample time, The consumed weight of fuel of amendment.Example results of visible stable state firepower stage flowing rate in fig .15.It is visible It is that the steady state phase flow velocity of exemplary optimization is about 80SLPM.

In step 4, the minimum PM discharges of specific nozzle are determined.It is complete using the optimization flow velocity determined in step 2 and 3 Into the experiment of cold start boiling water.The optimization flow velocity determined in step 2 is used in, until about 30 DEG C of water temperature, in cold start Remaining time is used in the optimization flow velocity determined in step 3.PM discharges the supplement with being drawn from step 2 and 3 caused by step 4 Conclusion is used for the design of next nozzle together.

Some hypothesis are made during these experiments.Specifically, in these test process, cold start boiling water test quilt It is divided into two stages, start-up period and steady state phase.Test result be start-up period during (now in the presence of more transient state simultaneously And usual relatively low firepower) discharge and the row in stable state firepower stage (now there is stable and generally higher firepower) Put difference.Therefore it is presumed that different firepower will need different pressure air-flow velocities to realize the PM emission reductions of maximum.Therefore, such as If fruit flow velocity tracks real-time firepower, the discharge of cold start boiling water test can be minimized.In order that flow velocity is persistently followed in real time Firepower, can develop the function on firepower and flow velocity.This function allows to determine the optimization flow velocity of many firepower, and lasting monitoring The control system of firepower.Alternatively, controller can be acted as to time-based function (ladder, block or continuous) With.

In order to save the time, during only determining the optimization flow velocity in two distinguishing firepower stages, and cold start test Flow rate with step function pattern.The hypothesis of this method inherently is tested using the cold start of two stage models of firepower Measure PM2.5Discharge will be similar to that the discharge that flow velocity persistently follows the cold start of real-time firepower to test.

Gas injection flow velocity can change according to firepower yield.In certain embodiments, the fan in exhaust path can Help to adjust flow velocity based on firepower.In other embodiments, during fan operation, flow velocity can keep constant.In other reality Apply in example, fan can be operated by multi-ladder speed, wherein, there is two or more service speeds.In many examples, It can be programmed based on firepower (it can be measured) controller or use time with various fan speed function pair controllers.

In some cases, the use of the flow velocity to being determined by stable state flow velocity optimization process, which is depended on, assumes air-flow stream Speed does not significantly affect the thermal efficiency of stove during the stable state firepower stage.The reason for making this hypothesis is to obtain in these tests The accurate measurements for the energy for being sent to water during testing herein are unpractiaca.

Tested nozzle

Finally, for EGR stoves, complete repeatedly for three times of this optimization process.Visible three tested differences in figure 16 The configuration of nozzle.These settings occupy two main eject positions.The eject position of estimation is listed in the section view at Figure 16 lower right sides Lower section in figure.Divergent nozzle is designed to below fuel bed gas injection and below fuel.Air curtain nozzle quilt It is designed at or near oral area or entrance and the gas injection at top of combustion chamber.Side injection nozzle is also designed to Gas injection at or near top of combustion chamber.Air curtain embodiment shown in Figure 16 has about 4 " × 1/4 " wide gap, and Relative to horizontal direction with about 45 degree of the downward gas injection of angle.Side injection nozzle shown in Figure 16 embodiment, which has, to hang down The straight natural gas flow in stove sprays the hole of 4.9 mm dias of air.Figure 16 divergent nozzle embodiment has two 3/4 ' directly The pipe in footpath, shown pipe is crushed and guides gas below the metal grate of perforation.

Cycle gas composition-result/discussion

The composition of recyclegas can significantly affect the concentration of nitrogen in combustion chamber, oxygen, carbon dioxide and carbon monoxide. As discussed above, surrounding air (fresh air or non-waste gas) can be sucked into EGR pots of surrounding edge entrances with high EGR rate In, influence test result.Hereinafter, table 1 shows the average oxygen concentration configured using two entrances described above.

The cycle gas composition of table 1.

The result of table 1 is proved, when the modified EGR entrance of installation (it directly obtains waste gas from the center of combustor exit) When, the average oxygen concentration in cycle gas seems to be slightly increased.But, if surrounding air is sucked into EGR pots of surrounding edges of standard In entrance, then the oxygen concentration in cycle gas is expected higher than the situation for installing modified EGR entrance.Not it was observed that this effect, This indicates be seldom with or without surrounding air to be sucked into standard EGR entrance with high EGR rate.It was observed that opposite relation The fact that may indicate that on the contrary, when install modification EGR entrance when, gas is in available O2Burning is pumped into before completing Enter.

The temperature of recyclegas

Pass through the effect of the temperature of one group of eight cold start WBT test loop gas.Test four different gas paths Set point temperatures, and each temperature is repeated twice.Figure 17 depicts the result of these tests.It is plotted in the temperature value in x-axis Represent the average measured temperature of the gas measured at once before combustion chamber is injected into whole WBT.It should be noted that for All tests, using air curtain formula nozzle, and EGR rate is kept uniformly in about 70SLPM.

The result of these experiments shown in Figure 17 does not assert strong correlation between gas temperature and PM discharges.Although some are implemented Example may include the isolation structure being located in gas path, but many embodiments may not include the gas path of isolation.In order to hereafter The subsequent test of description, the isolation structure along EGR path is not associated with.

Nozzle and flowing rate

The initial flow rate optimization to air curtain nozzle, divergent nozzle and side injection nozzle is listed in Figure 18,19 and 20 respectively Result.Table 2 summarizes the main result of flowing rate.By selecting approximate minimum position in Figure 18 drawing, determine excellent Change the value of flow velocity.PM in table 22.5Value representing optimized EGR rate at stage specific discharge.

Table 2.EGR nozzle flowing rates

Using visible optimization flow velocity in table 2, the cold start WBT of each nozzle configuration is completed.In table 3-1 it is visible these The result of test.The PM of these tests2.5Discharge represents the PM of each nozzle configuration2.5Discharge minimum.It is visible in table 3, The side injection nozzle sprayed near top of combustion chamber causes the PM of maximum2.5Emission reduction, from basic M5000PM2.5Discharge (is shown in Table 3- 2 M5000 basic values;PM;The 248mg of 461mg bases vs sides injection nozzle;Unit energy PM 280mg/MJd bases vs sides The 150mg/MJd of face injection nozzle) reduce 44%.Compared with common basic firepower and the firepower of other two nozzle configurations, Also appear to increase firepower using side injection nozzle.

Table 3-1. utilizes the minimum PM of EGR various nozzles2.5Discharge

Table 3-2. bases M5000 performances

Using the emission factor found in table 2, and in the case of the total amount of fuel consumed in knowing WBT, it is contemplated that The PM gross weights of discharge.It is expected that PM and measurement PM between contrast allow determine flow velocity test in measurement result whether may be used To provide the relatively accurate representative of the discharge to complete cold start WBT.The PM of visible estimated and measurement discharges it in table 4 Between contrast.

The PM of the estimated vs measurements of table 4.2.5Discharge

Error amount seen in table 4 indicates that the shorter test for flowing rate can be used for exactly it is expected that always optimizing cold Start discharge capacity.In addition, this constant efficiency indicated in the step 3 of nozzle optimization process is assumed to introduce significant inaccurate Really.

Finally, the result of this part is indicated, can be by the way that egr system is applied into existing stove (such as Envirofit M5000 Stove) realize emission reduction.Test is also provided to being produced and being tested the support that new nozzle is configured using above-described four steps process.

The variable being related in example III- analysis EGR emission reductions

Forward part described in test in, showing can be by realize emission reduction using EGR.This part utilizes similar Test is assert, isolated and measures the various mechanism for the influence emission reduction observed when EGR is by side injection nozzle.

Test platform

M5000 is again used to these tests;But, EGR stoves test platform have passed through compared to platform described above to be repaiied Change.First, the route of conduit is provided, so that during gas can be injected into M5000 from compressed gas cylinder.Pass through high property Energy Alicat mass flow controllers adjust the flow velocity of gas injection.

Method of testing

It is assumed that the PM emission reductions of EGR cooking furnaces can be the net result that following mechanism is combined:

Increased particle residence time;

O2/CO2Chemical action;

Mixing;

Dilution;

Temperature;And

Firepower.

This test is performed, to isolate and determine to configure in these mechanism relative to EGR sides injection nozzle as far as possible Each relative importance.

Increased particle residence time

By the increased Sojourn times that the EGR gas injections of agranular duplication are determined to granular materials in flame into stove Between effect.EGR replicates gas by 15%O2, 5%CO2And 80%N2Constitute, the composition of measurement similar to more than.With with for The mass velocity injection that the optimization mass velocity of side injection nozzle is equal replicates gas.In above-described experiment, it is determined that For starting and the optimization flow velocity of stable state firepower stage side injection nozzle is respectively 50 to 70SLPM.But, in side In the whole cold WBT to optimize EGR rate progress of face injection nozzle, the temperature survey at air blast wheel indicates flat at fan Equal temperature is about 333K.In order that the mass velocity of EGR gases is matched with the EGR gases replicated, using temperature adjustmemt and make With 44.7 to 62.6SLPM flow velocity (wherein, SLPM is according to Alicat mass flow controller specifications, 298K and 14.7psi).Always It, replicates gas using EGR and completes three cold start WBT duplications.

CO2/O2The chemical action of circulation

In order to replicate/isolate O2Chemical action, by pure molecule O2It is ejected into the stove configured using side injection nozzle. Two important considerations must be made, to estimate the O seen in the EGR stoves test described before2Chemical action.The One, the pure O of injection2Mass velocity should be similar to the O that sprays in the test of the EGR stoves of optimization2Mass velocity.In view of EGR Gas includes about 15% O2, it should use 15% flow velocity for being equal to the optimization flow velocity through temperature adjustmemt.This causes for rising The dynamic and stable state firepower stage is respectively 6.7 and 9.4SLPM pure O2Spray flow velocity.Second, the O of injection2Speed should class The speed of the EGR gases of injection is similar to, to simulate the spray penetration that gas enters combustion chamber.For the speed between matching test The diameter in the hole that gas effusion is passed through is modified such that new hole area is decreased to foramen primum area in degree, side injection nozzle 15%.Three cold start WBT are completed to replicate, wherein, pure O2It is injected into stove.

In order to replicate and isolate CO2Chemical action, pure CO2It is injected into stove.Due to CO2Including about 5% EGR gas Body, it should use 5% flow velocity for being equal to the optimization flow velocity through temperature adjustmemt.This causes for starting and stable state firepower rank Section is respectively 2.2 and 3.1SLPM pure CO2Spray flow velocity.Because these flow velocitys are substantially less than the total air flow by stove, it is difficult to make Spray penetration is matched with side injection nozzle.In order to reconcile this problem, diffusion injection setting is used.Which ensure that the natural gas of stove Flow CO2It is carried in the combustion chamber of flame central position.Three WBT are completed to replicate.

Because simulation includes 5%CO2EGR gases CO2Flow velocity is extremely low, therefore utilizes higher CO2Flow velocity operating is extra Test, to cause the effect of any chemical/physical more obvious.It followed by and in pure O2The identical mistake used in injection test Journey, includes 15%CO instead of replicating2EGR gases in CO2Chemical action.Three WBT are completed to replicate.

Mix, dilute and temperature reduction as caused by circulating nitrogen gas

In order to complete this research, argon gas is sprayed by side injection nozzle to optimize EGR rate.In a word, execution three is cold Start WBT.

Initially, it is intended to operate these tests, mixing, dilution and the temperature reduction of accurate replication cycle nitrogen using pure nitrogen gas Effect.But, the thermal capacity of nitrogen make it that flame can not be maintained.Therefore, it is these test selection argon gas, because its thermal capacity It is the half of nitrogen.The low heat capacity of argon gas allows to more fully understand the effect of flame cooling, without making flame cooled many So that burning can not be maintained.

In addition, its inert nature allow by by intrinsic chemical action from equation remove and to mixing, dilution and cool down Effect is isolated.

Firepower

The effect for the increase firepower observed to be isolated in part 4.4.3 to be tested using EGR, will surveyed in EGR stoves The expection PM discharges under firepower are measured compared with being discharged using the basic M5000 of identical fuel feedstock method.

In addition, using the relation between basic ingle power described above and PM discharges, will complete in this section All tests contrasted with the expected basis discharge based on measurement firepower.This allows more accurately to isolate the mechanism each tested Effect.

As a result/discuss

All tests are all completed using the configuration of side injection nozzle, and it is excellent to 70SLPM to quote determined above 50 Change flow velocity.Therefore, each mechanism to the importance of the PM effects discharged should with using side injection nozzle EGR test in It was observed that PM emission reductions (seen in table 3-1) compare.As the prompting to reader, configure real using the EGR of this optimization Existing average cold start boiling water test PM discharges are 150mg/MJd.

Increased particle residence time

In EGR stoves, a part of particle thing cycles through flame.This will cause the net PM of discharge2.5Mass lost, it is assumed that Oxidation is the net domination mechanism along particle path.As indicated above, synthesis speed and oxidation rate are at a temperature of about 800 DEG C Start confrontation.Fortunately, the Temperature Distribution measured in flame bend pipe road is in the major part of combustion chamber more than 800 DEG C.This Synthesis speed can be exceeded and can be in PM by the circulation of the particle of flame by meaning oxidation2.5Device great role in emission reduction.

Used by performing one group without particle EGR duplication gases (by 80%N2, 15%O2And 5%CO2Constitute) cold start WBT, isolation cycle PM2.5With therefore increase the effect of its oxidization time.Hereinafter, the visible knot that these are tested in table 5 Really.

Table 5.EGR replicates gas test result

In test described above, it is determined that firepower cuts much ice in PM discharges, and proposes for basis M5000PM2.5The model of discharge.In order to preferably isolate the effect of particle circulation, based on the measurement firepower of these tests, by Fig. 5 The test of detailed description is discharged with expected basic M5000.What this test being allowed under identical firepower in contrast table 5 was produced Discharge and basis discharge, and firepower is no longer influence factor and is allowed more accurately experimentally to isolate machine interested System.Describe this contrast in detail in table 6.

Table 6. replicates test result with the EGR that the basis through firepower amendment compares

EGR replicates the average PM of gas test2.5(mg/MJd) 180 Average measurement FP (kW) 3.4 Estimated basis PM under measurement FP2.5(mg/MJd) 440

It is visible in table 6, realize that (mg/MJd) subtracts from 440 (mg/MJd) to 180 using gas is replicated without particle EGR It is few.This instruction, the most of PM observed in EGR stoves2.5Emission reduction is not caused by particle circulation, but by cycle gas Caused by the chemically and physically effect of the gas component of product.But, the gained discharge capacity that no particle EGR replicates gas test is omited Optimization EGR fire grates higher than 150 (mg/MJd) are high-volume.This might mean that particle circulation is to from 180 (mg/MJd) to 150 (mg/ MJd some emission reductions) are responsible for.

CO2/O2The chemical action of circulation

Measurement result before recyclegas indicates that it is average by about 15% during EGR stove cold starts WBT is optimized O2, 5% CO2With 80% N2Constitute.Other gas componants may include carbon monoxide and argon gas, but their concentration is sufficiently low, It is negligible so that their effect to be taken as.In view of N2That is undergone during due to the biomass combustion in rocket bend pipe stove is relative Low ignition temperature and as relative inertness gas, it will be assumed that main chemical action is O2/CO2The result of circulation.

It is visible by O in table 72And CO2Chemical action isolation test result.Note, " to optimize 15% spray of flow velocity Penetrate pure O2" and " to optimize the 5% pure CO of injection of flow velocity2" test and directly replicate each of which by 15%O2And 5%CO2Constitute EGR gases in chemical action.Complete to optimize the 15% pure CO of injection of flow velocity2" test, so that CO2It is any potential Chemical action is more obvious.Must always 80%N in view of recyclegas2, 15%CO2Composition will indicate stove almost close to total gas Operate the stoichiometric levels of stream.Because rocket bend pipe stove is generally operated with a fairly low fuel concentration, therefore replicate 15% CO2Composition can be considered as CO2The potential chemical action of absolute maximum estimate.

Table 7.CO2And O2Effect test result

Based on the measurement firepower of these tests, the test result for describing table 7 in detail in table 8 and expected basis M5000 Discharge capacity compares.This allow by so that firepower change be no longer influence factor, more accurately isolate chemistry interested Effect.

The CO compared with the basis through firepower amendment of table 8.2And O2Effect test result

It is visible in table 8, spray pure O2The PM mass of discharge can be caused drastically to reduce.Visually seen through these tests The immixture observed can be neglected, and may be assumed that the O near fuel2Concentration is unaffected.But, visually observe O2 In the flame for being injected into lower combustion chamber near top, so that the injection O on the either side of combustion chamber2Stream enters at them Assembled during M5000 chimney.Therefore, it can it is concluded that, occur PM2.5Quality is substantially reduced, and main by raising fuel O in the flame region of top2Chemical action caused by concentration causes.

CO2The chemical action of isolation seem that the PM of discharge will not be caused2.5Any remarkable effect of quality.This is indicated, horizontal Across potential concentration range CO2Chemical action have remarkable effect to PM discharge capacitys.

Mixing, dilution and temperature reduction

Make various effects of the nitrogen circulation by side injection nozzle to more fully understand, to optimize the spray of EGR stoves flow velocity Penetrate argon gas.Utilize and spray three cold start WBT of completion to optimize the argon gas of flow velocity air inlet, below its visible result in table 9.

Table 9. mixes, dilute and temperature reduction effect test result

As forward part described in, based on these test measurement firepower, the test knot for describing table 9 in detail in table 10 Fruit compares with expected basis M5000 discharges.This allow by so that firepower change be no longer influence factor, more accurately every From mechanism interested.

Table 10. mixes compared with the basis through firepower amendment, dilute and temperature reduction effect test result

Visible in table 10, the effect of injection argon gas causes less PM2.5Discharge increase.This smaller increase of discharge It is the net result of the combination of the mixing through raising, reacted constituent dilution and temperature reduction.

In order to more fully understand each self-applying of these three mechanism, it will consider to mix first.For this test group, it will optimize EGR stoves mass velocity matches with argon gas.Each cycle gas molecule is replaced by the argon molecules sprayed with identical speed.Examine Consider the function that mixing is particle momentum, and be 40 (kg/ kilomols) in view of argon molecules amount, and cycle gas molecular weight It is about 29 (kg/ kilomols).Because argon molecules amount is larger, therefore its momentum and immixture will approximate greatly 38%.

The effect of the mixing through raising has been demonstrated to reduce the row of carbonaceous particles in the combustion process of solid biomass Put.The discharge of coal smoke and soot precursor is aggravated because of undermixing, wherein, small quantities of unburned steam and particle may exit off Combustion zone.Thus, it is supposed that the buffer action mixed as caused by argon gas reduces PM2.5Discharge.

But, the resultant action of argon gas injection actually results in PM2.5Discharge increase.Therefore, the argon gas that dilution and temperature are reduced Combination actually causes PM2.5Discharge increase.In order to more fully understand effect of the cooling to flame, the EGR in optimization is contrasted The cooling capacity of the cooling capacity of circulating nitrogen gas in stove and the argon gas of injection.The thermal capacity of argon gas is 0.52 (kJ/ (kg-K)), And N2 thermal capacity is 1.04 (kJ/ (kg-K)).In addition, calculating quality stream is for argon gas during steady state phase 114g/ minutes and for circulation N2 be 83g/ minutes.In view of two kinds of gas initial injection temperation still close to surrounding ring Border, it can be deduced that conclusion, circulates N2Cooling effect (it is multiplied by the thermal capacity of two kinds of gas to estimate by using mass velocity) Cooling effect than argon gas is big by approximate 45%.This indicates that effects of the circulation N2 in EGR stoves to discharge is bigger.Finally, document refers to Show, the effect of cooling flame will increase the mass discharge of particle in small biomass combustion application.This can be by below about 800 DEG C The expansions of cooler regions explain, wherein, particles generation tends to be more than particle oxidation.

It is not easy to find out the buffer action of diluting reaction component in solid biomass burning from this test data.In addition, this Effect is not recorded well in the literature.Therefore, the combination that dilution and temperature are reduced is grouped together as being seen Observe and cause PM2.5Discharge an increased emission mechanism.

Firepower

Utilizing to optimize in test of the flow velocity by the EGR of side injection nozzle, it was observed that firepower surprisingly increases.This is Because the positive action of the oxidant near biological surface.In order to be isolated in what is observed in the case that the EGR of optimization is tested The effect of firepower increase, by the expection PM discharges in EGR stoves under measurement firepower and the base using equal fuel feeding method Plinth M5000 discharges compare.

The effect of firepower increase caused by the application of table 11. EGR

Result seen in table indicates that the effect that the segregate firepower as caused by application EGR increases causes PM discharges slightly Increase.

Understand the common conclusions of EGR emission reduction mechanism

The optimum experimental of EGR stoves causes PM2.5Mass discharge is reduced.Optimized configuration is by discharge capacity from basic value 280mg/MJd is reduced to optimal value 150mg/MJd.Optimized stove uses side injection nozzle, and side injection nozzle will be circulated Exhaust blast is to the zoneofoxidation of flame, and the increase of Forced Mixing and fuel consumption rate.In order to more fully understand net emission reduction The driving force of behind, identification can influence PM2.5Quality potential mechanism and the effect for experimentally isolating them.

According to determination, for reducing PM2.5The mechanism of mass discharge is included by spraying optimization O above flame fuel2Concentration And the chemical action produced, the particle realized via circulation increased residence time in flame, and the mixing through raising. Reduce PM2.5In the mechanism of discharge, injection optimization O2The chemical action of concentration is shown to be most prominent.CO2The isolation of circulation is made With being determined to be to PM2.5Discharge no remarkable effect.In addition, the combination of temperature reduction and dilution is made as caused by circulating nitrogen gas PM is likely resulted in and as the increased buffer action of fuel consumption rate caused by application EGR2.5Discharge increase.But, when When the effect of these mechanism is combined, it was observed that the PM of discharge2.5The only reduces of quality.

The contrast that example IV-EGR sprays with air

It has been found that one of primary mechanism of emission reduction is O when in the zoneofoxidation for being injected into flame in EGR stoves2Change Act on.These results are indicated, can be caused using the stove of air injection with configuring similar mode with EGR furnace sides face injection nozzle Similar or bigger emission reduction.Studied, to confirm that this assumes and understood the pressure air flow system of two fundamental differences Between relative effect.

Method of testing

M5000 is used for these tests.For forcing stream air spraying system, adjusted by Alicat mass flow controllers Compressed air be routed through side injection nozzle.Side injection nozzle is identical with those being used above, with phase A diameter of 4.9 millimeters of 12 holes of air are vertically sprayed for the stove natural gas flow at top of combustion chamber.

In order to liberally contrast EGR and air injection, configured for side injection nozzle, it is determined that each forcing air flow system Minimum PM discharge.The combustion with minimal of this configuration using EGR before identified above.In order to determine with air injection Minimum emissions, it then follows with the identical process summarized in the 4.4.3 of part.Once it is determined that each pressure air flow system is most Small emission, with regard to being contrasted.

As a result/discuss

Below in Figure 19 visible air velocity optimal inspection result.Compared with 50 and 70SLPM optimization EGR rate, For starting and steady state phase, the optimization flow velocity sprayed using air is confirmed as 40 and 80SLPM.Below in table 12 It can be seen that the knot limited before tested using the result for three cold start WBT for optimizing air velocity and the EGR rate of optimization Really.

The air of table 12. and EGR contrasts

Result in table 12 indicates that the performance of air jeting furnace is better than EGR stoves, with 70% total CER (with 44% Compared to).As being illustrated above, the O in flame oxidation region is improved2Concentration is to the contributive principal element of emission reduction.Air sprays Penetrating stove can force to improve O2Concentration, without being diluted or cooling flame as EGR stoves, wherein, cycle gas partly by CO2Constitute, therefore add O2Bulk chemical effect.

These results prove that air injection is probably feasible for the pressure air flow system in rocket bend pipe cooking furnace Scheme.Therefore, the remainder of this research pays close attention to the further optimization of air injection method.

In certain embodiments, the configuration of different nozzles may be particularly suited for EGR and non-air is sprayed, and vice versa.

Example V- optimizes the air injection nozzle diameter of side injection nozzle

Finding to force the performance of stream air system to be better than or equivalent for the situation of pencil rocket bend pipe stove After the performance of egr system, determine that research will continue with air and be injected into one-step optimization nozzle.In part 7, inquire into Change the effect of the bore dia of side injection nozzle while the hole using fixed eject position and fixed qty.

Method of testing

M5000 is used for these tests.For forcing stream air spraying system, the pressure adjusted by Alicat stream controllers Contracting air is routed through side injection nozzle.Side injection nozzle is located at top of combustion chamber, in parallel orientation, often 6 holes of individual nozzle.

Test four different diameters, including 2.3,3.2,4.9 and 5.7mm.For each diameter, such as institute above is completed The flowing rate of description.Then three cold start WBT are completed to optimize flow velocity for each diameter.

As a result/discuss

Nozzle diameter and the flow velocity of optimization

The main result of the visible flowing rate for each diameter in table 13.Flow velocity scanning can be found at Figure 30-36 The detailed results of test.

The nozzle diameter optimum results of the side injection nozzle of table 13.

Present relative to basic M5000PM2.5The PM of emissions data2.5CER, for contrast.It can be seen that, for tested Each nozzle diameter, realize relative to basis about 70% notable PM2.5Emission reduction is (for 5.7,4.9,3.2 and 2.3mm's Diameter, respectively p=0.03,0.02,0.02 and 0.02).

It can be seen that the flow velocity optimized between start-up period and steady state phase is quite different.This indicates such as aobvious above Show, flow velocity can be associated with vigor.

It should also be noted that the stable state flow velocity of optimization tends to be slightly reduced with the reduction of diameter.This can be by seeing The tendency of this raising that the flue gas observed is burst out with higher pressure air velocity from the front portion of combustion chamber is explained.This effect The flow velocity that limitation passes through minor diameter high speed nozzle.

Nozzle diameter and PM discharge capacitys

Figure 20 is by the PM of optimization2.5Discharge capacity is rendered as the function of nozzle diameter.What error line represented every group of test 80% puts Letter is interval.

It is seen that, the PM optimized in entirely tested diameter range2.5Discharge capacity is similar, is used if indicated The flow velocity of optimization, then various diameters will the similar CER of generation.

Figure 21 shows the speed of the air sprayed for each diameter with stable state flow velocity.Again, error line represents every 80% confidential interval of group test.Data point from left to right represents 5.7,4.9,3.2 and 2.3mm diameters.Injection nozzle mesopore The diameter of mouth can be greater than about 0.5mm and less than about 3.5mm.In many examples, the diameter in aperture is smaller than in injection nozzle About 9.0mm, 8.0mm, 7.0mm, 6.0mm, 5.0mm, 4.5mm, 4.0mm, 3.5mm, 3.0mm, 2.9mm, 2.8mm, 2.7mm, 2.6mm、2.5mm、2.4mm、2.3mm、2.2mm、2.1mm、2.0mm、1.9mm、1.8mm、1.7mm、1.6mm、1.5mm、 1.4mm, 1.3mm, 1.2mm, 1.0mm, 0.9mm, 0.8mm, 0.7mm, 0.6mm or 0.5mm, and greater than about 0.4mm, 0.5mm, 0.6mm、0.7mm、0.8mm、0.9mm、1.0mm、1.1mm、1.2mm、1.3mm、1.4mm、1.5mm、1.6mm、1.7mm、 1.8mm、1.9mm、2.0mm、2.1mm、2.2mm、2.3mm、2.4mm、2.4mm、2.5mm、2.6mm、2.7mm、2.8mm、 2.9mm, 3.0mm, 3.5mm, 4.0mm, 5.0mm, 6.0mm, 7.0mm, 8.0mm or 9.0mm.

In figure 21, it is seen that injection air speed dramatically increased with the reduction of side injection nozzle bore dia, but It is the PM discharge capacitys still relative constancy of optimization.If this implies the flow velocity using optimization for the diameter range tested, Speed can change.In many examples, the speed for leaving the gas of injection nozzle can be from about 5m/s to 20m/s.At some In embodiment, the speed of gas can be greater than about 1m/s, 2m/s, 3m/s, 4m/s, 5m/s, 6m/s, 7m/s, 8m/s, 9m/s, 10m/ S, 11m/s, 12m/s, 13m/s, 14m/s, 15m/s, 16m/s, 17m/s, 18m/s, 19m/s, 20m/s or 25m/s, and be less than About 30m/s, 25m/s, 20m/s, 19m/s, 18m/s, 17m/s, 16m/s, 15m/s, 14m/s, 13m/s, 12m/s, 11m/s, 10m/s, 9m/s, 8m/s, 7m/s, 6m/s, 5m/s, 4m/s, 3m/s or 2m/s.When speed is too low (because injection orifices are excessive And/or the gas volume of transmission is too small), gas may not cross flame, take extra oxidant to flame kernel.

Another that can be drawn from Figure 21 is it was concluded that the diffusion of optimization discharge can increase with the increase of speed.Such as it Before refer to, this this raising that can be burst out by the flue gas observed with higher pressure air velocity from the front portion of combustion chamber It is inclined to explain.

The behavior of local peaking's discharge

During flow velocity is tested, interesting local peaking's discharge behavior is observed in several instances.This local peaking See at the 40SLPM that the example of behavior can be in 30SLPM and Figure 23 below in Figure 22, wherein, Figure 22 displayings are for starting The result of the pressure air-flow velocity scope of the nozzle of stage 3.2mm diameter, and Figure 23 displayings are for steady state phase 5.7mm The result of the pressure air-flow velocity scope of the nozzle of diameter.

The Visual Observations Observations of flame and fluid flow characteristics are helped to provide defense for these local peakings in discharge capacity.Figure 24 depict the stream mode observed.

The flow distribution that right side is drawn is the rough description to the stream by combustion chamber, and side injection nozzle is in black arrow Locate to supplement for curve 1 to 3 and flow.

Point 0 represents the undisturbed natural gas flow by combustion chamber in the case of no pressure air-flow.At point 1 (its about 20SLPM at) in fig 23, supplements the oxide regions of flame, therefore reduces PM discharges, but in side injection nozzle Lower section is not mixed.At point 2 (its about 40SLPM place) in fig 23, force air-flow sufficiently strong and concentration, it is sufficient to extinguish The oxide regions of flame at nozzle height, but be not strong enough to below nozzle trigger mixing.The zoneofoxidation of knock down the flame Domain can cause the local increase of PM discharges.Point 3 at (its correspond to Figure 23 in flow velocity 60SLPM and more than), force air-flow it is enough By force, it is sufficient to overcome the natural gas flow of stove and trigger mixing in whole combustion chamber.This is more uniformly distributed pressure air-flow, allows Air-flow velocity is preferably forced without therefore knock down the flame, and finally cause significant PM emission reductions.

This effect is not all observed in all flow rates.It is possible on condition that, if using finer flow velocity model If enclosing resolution ratio, then all it will be observed that this effect in all flow rates.

The optimization of example VI- air injection posts

In order to further investigate air injection method, eject position is estimated.In in this section, visited in G3300 Beg for various eject positions.

Method of testing

The contrast of G3300 and M5000 PM discharge performance

The G3300 used in these tests is similar to M5000 in design, there are some differences.G3300 is in combustion chamber week Insulation is enclosed, and M5000 uses aluminium radiation shielding structure.Compared with M5000, G3300 has bigger combustion chamber, combustion chamber has Wider opening.Finally, G3300 ceramic bases are less than M5000 ceramic bases.In other respects, two stoves have similar cigarette Chimney size.It has been found that these differences cause the basic PM between two stoves2.5Discharge capacity difference.But, when air-flow is forced in application When, to carrying out additional comparison between the performance of stove.This second contrast is completed, is obtained with to ensure the work before to M5000 Air-flow knowledge is forced to may extend into the work to G3300.

The minimum PM of each stove is completed using a diameter of 2.3mm side injection nozzle2.5Between discharge capacity and optimization flow velocity Contrast.The minimum PM of each stove is determined using identical process outlined above2.5Discharge capacity and optimization flow velocity.

Eject position

Test is for 4 eject position minimum PM2.5Contrast between discharge capacity and optimization flow velocity, including top of combustion chamber And bottom, the middle and top of chimney part.The sectional view of G3300 rockets bent-tube boiler design is presented in Figure 25, has marked general Eject position.Marked away from the distance at the top of ceramic bases (bottom surface), by centimetre in units of.

In order to test the top of combustion chamber eject position, side injection nozzle is used.In order to test the spray in chimney part Position is penetrated, " chimney ring " nozzle is manufactured.Figure 26 shows the chimney ring spray mouth for chimney foot.Chimney ring type shown in Figure 26 Nozzle level towards chimney vertical axis gas injection.

For all nozzles in this part, a diameter of 1.5mm 12 holes are used.Selection 1.5mm is because tentatively grinding Study carefully instruction, flame can be reduced with slow flow velocity with larger-diameter chimney ring type nozzle.In some cases, this can draw Play smog and flame is discharged into outside combustor head.1.5mm diameters reduce this effect and allow to use higher pressure Air-flow velocity.It is provided below and 1.5mm diameters is discussed further for eject position research.Finally, using 12 holes, it is used to Help across flame distribution pressure air-flow and the uniformity to keep Yu work before.In certain embodiments, spray-hole The quantity of mouth (hole) can be more than 12 or less than 12.In certain embodiments, injection orifices can be uniformly spaced open in nozzle or Person can and unevenly, to help oxygen being sent to flame inside.

As a result/discuss

The contrast of G3300 and M5000 PM discharge performance

The optimization PM between G3300 and M5000 when using a diameter of 2.3mm side injection nozzle is presented in table 142.5Row The main result of contrast high-volume.Average value represent 3 test be averaged.

The contrast of table 14.G3300 and M5000 PM discharge performance and the optimization flow velocity with similar configuration

It can be seen that, the flow velocity optimized for two stoves is similar.Geometry between this instruction, two combustion chambers Difference will not cause the significance difference XOR limitation of the pressure air-flow velocity for optimization.This is also implied for two stoves and other sprays The pressure air-flow velocity optimized for mouth configuration will be similar.

In addition, it is seen that the PM for two stoves2.5Discharge capacity is similar (p=0.82).This is indicated, is utilizing M5000 Before work in the optimization PM that measures2.5Discharge performance can be comparable to the PM of the optimization using G33002.5Discharge performance, and And the difference when the flow velocity of optimizing application between two stove performances is less obvious.

Eject position

The main result of eject position research is presented in table 15.The more detailed of flow rates test can be found in Figure 30-36 Thin result.

The eject position optimum results of table 15.

It can be seen that, across bottom three, eject position optimization flow velocity is similar.But, in top jet position, optimization stream Speed drops to 10SLPM.Figure 27 by during flow rates for top jet position shoot image construction.

Disclosed device, method and system can help to reduce the pollutant from biomass stove.As above and below What example was proved, the present invention can help to reduce the granular mass discharge from biomass stove, such as PM2.5Discharge, relative to gas Body is not ejected into flame actively for the identical stove of (that is, fan or air blower are closed, or do not install spraying system). In some cases, the present invention provides the PM between about 20% to about 95%2.5Emission reduction.In many examples, PM2.5Emission reduction exists Between about 25% and 85%.In certain embodiments, PM2.5Emission reduction is greater than about 20%, 25%, 30,35%, 40%, 45%, 50%th, 55%, 60%, 65%, 70%, 75%, 80%, 85% or 90%, and less than about 100%, 95%, 90%, 85%, 80%th, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30% and 25%.

Under 0SLPM flow velocity, the flame that chimney top comes out is high and very thin.Under 10SLPM flow velocity, flame is shorter And more concentrate.When the flow velocity using 20SLPM, extinguish completely at eject position at the top of flame.This causes the gas by stove Stream is substantially reduced, and causes many smog and flame to leave stokehold portion.Finally, this is by the optimization stream at the top of chimney eject position Speed limit system limits the PM of this configuration to 10SLPM2.5Emission reduction potential.But this phenomenon is located in combustion chamber for ring spray mouth The embodiment of lower is less important, because flame is stronger at lower position, less easily by the effect seen in Figure 27 Influence.On the contrary, at reduced levels, gas injection enters the oxide regions (rather than extinguishing it) of flame to transmit oxygen, and Promote extra oxidation and PM reductions.

Contrasting the discharges of the optimization PM from the eject position of bottom three can show that chimney bottom is the knot for optimizing eject position By.But, progress injection also results in good performance at top of combustion chamber.It can be assumed that these positions cause maximum to subtract It is few, because they spray in flame most strength and supplement the oxidation of particle, without causing flame to cool down or extinguishing.

Another important observation is the effect of the firepower of boiling time and each eject position.Chimney bottom eject position Seem to cause that firepower is dramatically increased and boiling time is greatly shortened, the two features are all quite valuable for consumer.

Finally, injection forces air-flow to be probably desired at chimney bottom.This placement can be helped relative to basis (p =emission reduction 0.001) and relatively unnoticed compared with side injection nozzle (it is invaded in combustion chamber) set can be provided Meter.In many examples, the placement of injection nozzle promotes the injection gas of the top of solid biomass level in a combustion chamber Body.In most embodiments, gas is sprayed at solid fuel (such as the firewood seen in Figure 26) top 0.5 to 30.0cm Body.In most embodiments, gas is ejected into flame with following height, the height be greater than about 0.5cm, 1.0cm, 1.5cm、2.0cm、2.5cm、3.0cm、3.5cm、4.0cm、4.5cm、5.0cm、5.5cm、6.0cm、6.5cm、7.0cm、 7.5cm、8.0cm、8.5cm、9.0cm、9.5cm、10cm、11cm、12cm、13cm、14cm、15cm、16cm、17cm、18cm、 19cm, 20cm or 25cm, and less than about 30cm, 25cm, 20cm, 19cm, 18cm, 17cm, 16cm, 15cm, 14cm, 13cm, 12cm、11cm、10cm、9.5cm、9.0cm、8.5cm、8.0cm、7.5cm、7.0cm、6.5cm、6.0cm、5.5cm、5.0cm、 4.5cm, 4.0cm, 3.5cm, 3.0cm, 2.5cm, 2.0cm, 1.5cm or 1.0cm.

Example VII- optimizes the air injection nozzle diameter of chimney ring spray mouth

Hereinbefore, it was found that when eject position is at the top of combustion chamber with side injection nozzle, nozzle diameter is not It is the strong determinant for minimizing PM discharges.But, configured for other eject positions and nozzle, the PM discharges of minimum may It is not the minorant of diameter.Therefore, in this section, the diameter for the chimney ring type nozzle at chimney bottom is inquired into Effect to discharge capacity.

Method of testing

Work of the sprayed fiber concrete to discharge capacity for the chimney ring type nozzle at chimney bottom is tested in G3300 With.Test 1.5 and 3.0mm bore dia.For each diameter, flowing rate as described above is completed.Then, for each Diameter completes three cold start WBT to optimize flow velocity.Then optimization discharge capacity and flow velocity obtained by contrasting.

As a result/discuss

The diameter optimum results of chimney ring type nozzle are shown in table 16 below.

The diameter optimum results of the chimney bottom eject position of table 16.

It can be seen that, 1.5mm diameter nozzles have larger optimization stable state flow velocity.Because 3.0mm diameter nozzles are drawn Polot flame extinguishes under the flow velocity more than 20SLPM, causes smog and flame to be discharged from combustor head.It is also shown, with 3.0mm Diameter (p=0.04) is compared, the PM optimized for 1.5mm diameters2.5Discharge capacity is significantly lower.Gas is forced in the extinguishing limitation of flame Flow velocity is flowed, therefore this limit PM2.5CER.

This data indicates that, for chimney ring type nozzle, diameter is smaller than about 3mm.

Example VIII- optimizes the air injection angle degree of chimney ring spray mouth

Hereinbefore, except the external survey eject position of diameter.Sprayed here, inquiring into and changing for eject position and diameter The effect of firing angle degree.

Method of testing

In order to understand the effect of spray angle, the minimum emissions of two configurations are contrasted.The injection position that these tests are used Put at chimney bottom, optimal eject position is found in part 8.The spray angle of test is 30 ° above horizontal or level. Figure 28 shows the position of two nozzles used in this research.In addition, in this research two nozzles using have it is a diameter of 1.5mm 12 holes.Figure 28 shows the spray angle being tested at chimney bottom.Figure 29 show relative to horizontal direction with The chimney ring spray mouth of 30 ° of angle injections.

As a result/discuss

The result of the displaying spray angle research of table 17.The more detailed result of flow rates test can be found in Figure 30-36.

The spray angle test result of table 17.

It can be seen that, for 30 ° of spray angles, optimum flow rate is restricted to 10SLPM.In addition, being realized using horizontal-jet angle Emission reduction be more than the emission reduction (p=0.02) realized using 30 ° of spray angles.

Less emission reduction is realized in angled injection, because forcing the angle of air-flow to promote to pass through the high total air flow of stove.Increase Plus by the total air flow of stove can notable cooling flame, particularly if in the absence of if high-caliber mixing.Cooling flame can increase Plus particles generation region volume and reduce particle oxide regions.

Although preferred levels spray angle, spray angle can at about -50 ° (relative to horizontal direction, 0 °, i.e., from spray Mouth is downward towards fuel) to the anaplasia of about+50 ° (relative to horizontal direction, 0 °, i.e., upward towards the top of top combustion chamber) Change, preferably from about -30 ° to about+30 °.In many examples, spray angle can greater than about -55 °, -45 °, -40 °, -45 °, - 30 °, -25 °, -20 °, -15 °, -10 °, -9 °, -8 °, -7 °, -6 °, -5 °, -4 °, -3 °, -2 °, -1 °, 0 ° (level), 1 °, 2 °, 3°、4°、5°、6°、7°、8°、9°、10°、11°、12°、13°、14°、15°、16°、17°、18°、19°、20°、25°、30°、35°、 40 °, 45 ° or 50 °, and less than 55 °, 50 °, 45 °, 40 °, 35 °, 30 °, 25 °, 20 °, 19 °, 18 °, 17 °, 16 °, 15 °, 14 °, 13°、12°、11°、10°、9°、8°、7°、6°、5°、4°、3°、2°、1°、0°、-1°、-2°、-3°、-4°、-5°、-6°、-7°、- 8°、-9°、-10°、-11°、-12°、-13°、-14°、-15°、-16°、-17°、-18°、-19°、-20°、-25°、-30°、- 35 °, -40 °, -45 °, -50 ° or -55 °.

Claims (20)

1. a kind of device for being used to reduce the emission of biomass stove, described device includes:
Fluid intake aperture;
Entry conductor with outer surface and inner surface, the inner surface limits inlet, and the inlet is via the entrance Aperture and the appearance fluid communication, interior chamber are used to direct fluid;
In the inlet and positioned at the fan of the entrance aperture distal end, the fan is used to fluid being aspirated through The entrance aperture is simultaneously drawn into the room, and enter;
Delivery channel, the delivery channel has the inner surface for limiting downstream chamber, and the downstream chamber connects with inlet's fluid It is logical;
One or more nozzles with the inside being in fluid communication with the downstream chamber, the nozzle is used to direct fluid to life In the combustion chamber of material stove;And
Multiple exit apertures on the surface of the nozzle are limited at, the exit aperture is designed to allow that fluid leaves institute State the inside of nozzle.
2. device as claimed in claim 1, wherein, the nozzle is located at or near the top of lower combustion chamber.
3. the device as described in any one in claims 1 to 3, wherein, the exit aperture have 0.5 and 3.5mm it Between average diameter.
4. the device as described in any one in claims 1 to 3, wherein, the exit aperture limits circular, square, three Angular or ellipse, the average diameter is measured by the center of the circular, square, triangle or ellipse.
5. the device as described in any one in Claims 1-4, wherein, from one or more of nozzle escaping gas Volume be greater than about 10 Standard Liters per Minutes and less than about 100 Standard Liters per Minutes.
6. the device as described in any one in claim 1 to 5, wherein, gas is escaped from one or more of nozzles Speed is greater than about 5 metre per second (m/s)s and less than about 20 metre per second (m/s)s.
7. the device as described in any one in claim 1 to 6, wherein, the nozzle is selected from linear nozzle or round nozzle.
8. device as claimed in claim 7, wherein, the nozzle is annulus, its be located above the lower combustion chamber and In the lower half of top combustion chamber, and it is designed to allow burning gases directly through jeting area.
9. device as claimed in any of claims 1 to 8 in one of claims, wherein, the fluid is gas, and it includes greater than about 15% O2, oxygen.
10. a kind of method for the emission for reducing biomass stove, methods described includes:
Gas is placed into the interior chamber of nozzle, the nozzle is located at or near flame;
Increase the pressure of the gas in the nozzle;
The multiple outer apertures limited by the outer surface by the nozzle discharge a certain amount of gas from the nozzle;And
The gas sprayed is guided into the flame in the combustion chamber of the biomass stove, wherein, the gas is reduced and left The amount of at least one pollutant of the biomass stove.
11. method as claimed in claim 10, wherein, the amount of gas is in about 10 Standard Liters per Minutes and 100 standard liters per minutes Between clock.
12. the method as described in any one in claim 10 to 11, wherein, the nozzle limits ring, and exit aperture In the inner surface of the ring, to help gas injection to the center of the ring.
13. the method as described in any one in claim 10 to 12, wherein, the exit aperture is limited to 0.5 and 6.0mm Between diameter.
14. the method as described in any one in claim 10 to 13, wherein, the exit aperture and the bottom of the combustion chamber Face is an equal distance away.
15. the method as described in any one in claim 10 to 14, wherein, by electric fan or air blower by the gas Body is advanced in the nozzle.
16. the method as described in any one in claim 10 to 15, wherein, by one or more apertures with 5 and 25 Speed between metre per second (m/s) discharges the gas.
17. the method as described in any one in claim 10 to 16, wherein, the emission of reduction is less than about 2.5 microns Particulate matter.
18. the method as described in any one in claim 10 to 17, wherein, from being less than that the fire grate is put during burning The amount fewer than the amount discharged when the gas pressure in the nozzle does not increase about 25% and 90% of about 2.5 microns of particulate matter it Between.
19. the method as described in any one in claim 10 to 18, wherein, with about -10 degree to the angle between about+30 degree Degree is by the gas injection into flame.
20. a kind of method for the granular material discharged thing for reducing biomass stove, methods described includes:
Gas is drawn into room, the gas includes greater than about 15% O2
The gas is directed into the nozzle with inner surface and outer surface from the room, the nozzle limits round tube, institute Stating round tube has multiple exit apertures on round inner surface, wherein, the exit aperture allows gas from the pipe Advance at the internal center towards circle;
Increase the pressure of the gas in the inside of the nozzle;
A certain amount of gas-pressurized is discharged from the nozzle with the speed between about 5 metre per second (m/s)s and 20 metre per second (m/s)s;And
The gas sprayed is guided into the flame in the combustion chamber of the biomass stove, wherein, with lacking nozzle or described The stove for lacking gas-pressurized in nozzle is compared, and the gas reduces the amount at least one pollutant for leaving the biomass stove More than about 25%.
CN201580056465.1A 2014-09-11 2015-09-11 Side feed forced ventilation formula biomass combustion cooking furnace CN107110492A (en)

Priority Applications (3)

Application Number Priority Date Filing Date Title
US201462048884P true 2014-09-11 2014-09-11
US62/048,884 2014-09-11
PCT/US2015/049760 WO2016040851A1 (en) 2014-09-11 2015-09-11 Side-feed forced-air biomass burning cookstove

Publications (1)

Publication Number Publication Date
CN107110492A true CN107110492A (en) 2017-08-29

Family

ID=54249584

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201580056465.1A CN107110492A (en) 2014-09-11 2015-09-11 Side feed forced ventilation formula biomass combustion cooking furnace

Country Status (3)

Country Link
US (1) US20160076774A1 (en)
CN (1) CN107110492A (en)
WO (1) WO2016040851A1 (en)

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2015112606A1 (en) * 2014-01-21 2015-07-30 Biolite Llc Portable combustion device utilizing thermoelectrical generatiion
US9955819B2 (en) * 2016-02-23 2018-05-01 Terraoak, Inc. Cooker with thermoelectric generation
WO2018002387A1 (en) * 2016-06-30 2018-01-04 Powerspot, S.L. Auxiliary device for electric generator and system

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4335660A (en) * 1980-06-02 1982-06-22 Research Cottrell Technologies, Inc. Apparatus and method for flue gas recirculation in a solid fuel boiler
CN2396288Y (en) * 1999-10-18 2000-09-13 荣文清 Forced circulation smoke prevention and dust control energy-saver for boiler smoke
CN202040970U (en) * 2011-04-10 2011-11-16 赵玉良 Boiler with smoke returning pipes
CN102625821A (en) * 2009-09-03 2012-08-01 特茨拉夫·卡尔-海因茨 Method and device for using oxygen in the steam reforming of biomass

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB1126981A (en) * 1965-03-03 1968-09-11 Aeropur S R L Process and apparatus for insuring complete combustion of exhaust gases
US4438756A (en) * 1982-12-13 1984-03-27 Joseph G. Chamberlain Apparatus and method for accomplishing efficient burning of biomass fuel materials
US4655705A (en) * 1986-02-28 1987-04-07 Shute Alan B Power gas burner for wood stove
JP2009541710A (en) * 2006-06-26 2009-11-26 コーニンクレッカ フィリップス エレクトロニクス エヌ ヴィ Fixed fuel stove with improved combustion
ITMI20072292A1 (en) * 2007-12-06 2009-06-07 Itea Spa Combustion Process
US9739389B2 (en) * 2011-04-08 2017-08-22 David Deng Heating system
CN105051459A (en) * 2012-11-06 2015-11-11 恩威罗菲特国际股份有限公司 High efficiency wood-burning griddle cook stove

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4335660A (en) * 1980-06-02 1982-06-22 Research Cottrell Technologies, Inc. Apparatus and method for flue gas recirculation in a solid fuel boiler
CN2396288Y (en) * 1999-10-18 2000-09-13 荣文清 Forced circulation smoke prevention and dust control energy-saver for boiler smoke
CN102625821A (en) * 2009-09-03 2012-08-01 特茨拉夫·卡尔-海因茨 Method and device for using oxygen in the steam reforming of biomass
CN202040970U (en) * 2011-04-10 2011-11-16 赵玉良 Boiler with smoke returning pipes

Also Published As

Publication number Publication date
WO2016040851A1 (en) 2016-03-17
US20160076774A1 (en) 2016-03-17

Similar Documents

Publication Publication Date Title
Hosseini et al. Development of biogas combustion in combined heat and power generation
MacCarty et al. Fuel use and emissions performance of fifty cooking stoves in the laboratory and related benchmarks of performance
CN105960565B (en) Low NOxMultitubular boiler
US5542840A (en) Burner for combusting gas and/or liquid fuel with low NOx production
Costa et al. Experimental characterization of an industrial pulverized coal-fired furnace under deep staging conditions
US7631499B2 (en) Axially staged combustion system for a gas turbine engine
Micka Combustion stabilization, structure, and spreading in a laboratory dual-mode scramjet combustor
CA2464490C (en) Combustion apparatus for solid fuel
CA2016972C (en) Apparatus for burning gas in the combustion chamber of a fireplace
Dally et al. On the burning of sawdust in a MILD combustion furnace
CA2530236C (en) High efficiency cyclone gasifying combustion burner to produce thermal energy and devices and method of operation
CN102192508B (en) The premixed combustor of classification vertically
Flamme New combustion systems for gas turbines (NGT)
US7261046B1 (en) System and method of reducing pulverizer flammability hazard and boiler nitrous oxide output
Smyth et al. Greatly enhanced soot scattering in flickering CH4/air diffusion flames
CN101040149B (en) Burner for combustion of a low-calorific fuel gas and method for operating a burner
CN103277811B (en) Single cavity standing vortex burning chamber
KR101574367B1 (en) Method and device for igniting and operating burners when gasifying carbon-containing fuels
WO2004065848A8 (en) Method and apparatus to facilitate flameless combustion absent catalyst or high temperature oxident
Chakraborty et al. Measurement of CO2, CO, SO2, and NO emissions from coal-based thermal power plants in India
BR0314741A (en) Method and apparatus for heat treatment
WO2004097299A3 (en) An apparatus and method for selecting a flow mixture
ElKady et al. Exhaust gas recirculation in DLN F-class gas turbines for post-combustion CO2 capture
RU2009113620A (en) Method of gas supply for burning, and also furnace installation
CA2541122A1 (en) Gas-fired portable unvented infrared heater

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
WD01 Invention patent application deemed withdrawn after publication

Application publication date: 20170829

WD01 Invention patent application deemed withdrawn after publication