201105907 六、發明說明： 【發明所屬之技術領域】 本發明槪括而言相關於用來實施燃燒作用以產生動力 的工業燃燒器裝置的領域。 【先前技術】 此處所用的術語「生物質（biomass )」係描述從多 種不同的活的、或最近還活的有機體，例如草及木材產物 所得來的廣泛範圍的有機物質。生物質的來源包括樹木、 灌木（shrubs)、矮樹叢（bushes)、來自收割穀物（ harvesting grains)的殘餘植被（residual vegetation)、 及蔬菜。生物質通常是被收割以產生電力或產生熱的植物 素材。生物質也可包含可充當燃料而被燃燒的有機來源（ organic origin )的可生物降解的廢料（biodegradable waste ) ° 生物質與化石（fossil)燃料不同，因爲化石燃料爲 在地球的地殼的頂層內所發現的碳氫化合物。化石燃料的 一般例子包括煤及油。不像化石燃料，生物質燃料一般被 視爲 C〇2(二氧化碳）中和（neutral)及再生（ renewable)資源，因爲產生自生物質燃燒的C〇2可藉著 提供生物質的植物而從大氣被移去。 因爲生物質的物理性質及化學成分與煤顯著地不同， 所以用於動力的產生的生物質燃料在歷史上向來被作爲加 煤機（stoker )及流體化床（fluid bed )類型的鍋爐中的 201105907 主要或輔助燃料。此種鍋爐不依賴燃燒器，因而可有顯著 較闻的用於燃燒的爐膛滯留時間（furnace residence time )’因此具有較不嚴苛的燃料準備要求。 與溫室氣體排放相關的全球暖化的關注已提高對於開 發新技術以可普及地使用再生資源來產生動力的興趣。此 種興趣的一個領域便是於懸空燃燒（suspension firing) 使用生物質燃料，在懸空燃燒中的短的爐膛滯留時間使得 必須以細微粒子來進行有效率的燃燒。 粉煤引燃是動力產生工業中懸空燃燒的主要機制。在 第一步驟中，煤被機械式地粉碎成爲細微粒子。然後，粒 子隨後經由在主空氣流（pri mary air stream)中懸浮而被 運送至燃燒器，其中燃燒器將空氣/燃料混合物噴射至爐 膛內以進行燃燒。滯留時間公稱爲1至2秒，此在常態下 足以將適當的粒子尺寸進行完全的粉煤燃燒。 在粉煤引燃的鍋爐中的生物質引燃正更普及地成爲用 來減少溫室氣體的策略》爲使此策略可行，有需要開發可 於懸空燃燒有效地使用生物質燃料的燃燒器。 引燃生物質燃料面對許多技術性挑戰。與煙煤（ bituminous coal)相比，生物質燃料具有顯著較低的熱値 (heating value)及較高的揮發性物質濃度。熱値與水分 含量成反比，使得生物質熱値總計爲典型的煙煤的熱値的 25%至75%。爲了材料處理的理由以及用以增進過程的 效率及產能，生物質的水分經常會在引燃之前被減少。然 而，引燃取代煤的生物質需要顯著較多的燃料質量以達成 -6- 201105907 相當的熱輸出。另外，雖然生物質的高度揮發性本質使得 燃料先天性地易於燃燒，但是高的水分含量可能會延遲點 火。延遲的點火在懸空燃燒中是特別不想要的。 對生物質的另一顧慮爲生物質並未被處理至與粉煤相 同的粒子尺寸。經驗顯示成功的懸空燃燒可在尺寸爲 0.062 5英吋的木材粒子之下達成，而相較之下粉煤的最大 尺寸爲0.012英吋。粒子體積依直徑的立方而變，因而木 材粒子所具有的體積爲用於懸空燃燒的較大煤粒子的體積 的幾近1 50倍。因此，生物質的較大體積需要快速的點火 及迅速的燃燒，以可在被設計用於粉煤引燃的爐膛中使用 生物質。 一種於懸空燃燒使用生物質的已知技術爲生物質混燃 (co-firing)。在此技術中，生物質顆粒與粉煤及主空氣 結合成單一氣流。然後，結合的氣流被引入爐膛內。然而 ，由於保持兩種類型的粒子懸浮所必須有的合成燃燒器噴 嘴速度，此技術在實用性上受限制。過度的燃燒器噴嘴速 度導致火焰的不穩定、延遲的點火及不良的燃燒性能。 因此，對於開發用於有效率及有效的替代燃燒煤以產 生動力的方案的機構或手段以及用來對於動力產生的應用 達成普及的碳中和燃料（carbon-neutral fuel)的燃燒的 機構或手段仍然有需求。 【發明內容】 本發明的實施例提供新穎的燃燒裝置。更明確地說， 201105907 本發明的實施例提供一種燃燒裝置，其可引燃生物質燃料 且可依需要在生物質的引燃與煤的引燃之間交替，且/或 可同時燃燒煤與生物質燃料的組合。 本發明的實施例擴大習知技術燃燒器的能力。LaRue 等人的美國專利第7，430,970號（‘970專利）藉著參考而 整個結合於此。 本發明藉著提供用來燃燒包括，但是不限於生物質， 的再生燃料的新穎裝置而對習知技術燃燒器進行改良。 本發明的實施例提供用來將與粉煤結合的生物質混燃 的優越方法及裝置。 可引燃生物質燃料的燃燒裝置包含燃燒器總成，而燃 燒器總成包含被核心空氣區同心地環繞且沿著核心空氣區 的長度軸向延伸的生物質噴嘴，燃燒器總成存在於風箱內 ，而風箱附著於鍋爐的爐膛，且燃燒器總成藉著燃燒器喉 道而連接於爐膛，而被供應至燃燒器總成的空氣及燃料經 由燃燒器喉道而被放射至爐膛內。 在本發明的實施例中，裝置包含強制通風扇，其提供 第一空氣供應至風箱；核心空氣導管，其圍封核心空氣區 ，用來接收第一空氣供應的核心部份，核心空氣導管具有 用來調節進入核心空氣導管的上述核心部份的核心氣流調 節器（core damper );核心噴嘴’用來接收來自該核心 空氣導管的核心部份，核心噴嘴將該核心部份遞送至該燃 燒器喉道；燃燒器彎管，用來接收粉煤及第二空氣供應， 粉煤及該第二空氣供應在核心噴嘴與煤噴嘴之間所形成的 -8 - 201105907 環帶（annulus )中繼續通過煤噴嘴，上述核心部份用來 藉著接觸離開煤噴嘴的煤噴射流（coal jet )的內圓柱面 C inner cylinder )而加速粉煤的引燃，核心部份也用來加 速燃燒。 本發明的特性所在的各種不同的新穎特徵在附隨成爲 本揭示的一部份的申請專利範圍中被具體地指出。爲更佳 地瞭解本發明、本發明的操作的有利點，及藉著利用本發 明而達成的特定目的，可參考舉例說明本發明的較佳實施 例的所附圖式及敘述。 【實施方式】 現在參考圖式’其中相同的參考數字在所有的數個圖 中標示相同或功能上類似的元件，圖1顯示常駐在風箱2 內的燃燒器總成1，而風箱2附著於鍋爐（未顯示）的爐 膛3。次級空氣（secondary air ) 22由強制通風扇（未顯 示）提供至風箱2’且由空氣預熱器（未顯示）加熱。燃 燒器總成1藉著燃燒器喉道4而連接於爐膛3，而被供應 至燃燒器總成1的空氣及燃料經由燃燒器喉道4而被放射 至爐膛3內。次級空氣22的一部份構成核心空氣5。核 心空氣5進入核心空氣導管6且由核心空氣氣流調節器7 調節。核心空氣5經由核心噴嘴8而繼續通過燃燒器總成 1，而經由燃燒器喉道4排出。 次級空氣2 2也被供應至燃燒器總成（由至燃燒器總 成9的次級空氣所示）。次級空氣22進入燃燒器總成1 -9 - 201105907 ，且行進通過內空氣區10及外空氣區11的平行流動路徑 。這些空氣區中的旋流葉片（swirl vane )用來使次級空 氣22產生旋流，以利接觸粉煤流的次級空氣22的點火及 燃燒。在外空氣區11的出口處的空氣分離葉片12用來增 加由合成空氣動力學所形成的內部再循環區（internal recirculation zone, IRZ)的大小。粉煤及主空氣13進入 燃燒器彎管1 4，且在核心噴嘴8與煤噴嘴1 5之間所形成 的環帶中繼續通過煤噴嘴15。核心空氣5用來藉著接觸 離開煤噴嘴I 5的煤噴射流（未顯示）的內圓柱面而加速 粉煤的點火，並且用來藉著以「伸縮囊效應（bellows effect )」供應空氣至火焰的中心而加速燃燒。LaRue的 ‘9*70專利提供對於與核心空氣相關的加速點火的詳細討 論。 根據本發明的實施例，燃燒器總成1可與火上空氣（ over-fire-air，OFA )系統（未顯示）結合操作。被供應至 爐膛用於燃燒的次級空氣22的一部份被供應至OFA系統 ，使得被供應至燃燒器總成1的空氣的總量小於理論上的 空氣要求。此在OFA被供應之前於爐膛內產生還原（ reducing)環境。加速的燃燒、較高溫度的火焰，及較大 的IRZ均用來在還原情況下更有效地還原NOx。 在本發明的實施例中，生物質可使用切碎機（ shredder)、鍵磨機（hammer mill)、及類似者（未顯示 )而被製備用於懸空燃燒，可藉著螺旋進給器（screw feeder )或等效裝置（未顯示）而被收集並在進給率上被 -10- 201105907 調節，並且可經由適當的導管而被氣動式地運送至燃燒器 總成1。導管通過出口位在燃燒器總成1的軸線處的彎管 供應生物質及運輸空氣16。 在一些實施例中，漸縮管（reducer) 17可被用來在 生物質噴嘴1 8橫過燃燒器彎管1 4且繼續經過核心空氣導 管6時，縮減生物質噴嘴18的截面面積。漸縮管17係用 來在生物質噴嘴18延伸通過燃燒器總成1的長度方向時 ，減少流動障礙。靠近燃燒器總成1的爐膛端，生物質噴 嘴尖端1 9的直徑可被擴張，如圖1所示，以將生物質出 口速度降低至用於燃燒的最佳値。在某些實施例中，此出 口速度是在大約2500英尺/分鐘與大約5000英尺/分鐘之 間，且較佳地在大約3000英尺/分鐘與4000英尺/分鐘之 間。 在另外的實施例中，環繞生物質噴嘴尖端19的核心 空氣5作用來在生物質進入燃燒器喉道4時，加速生物質 的點火，並且在生物質繼續進入爐膛內時，供應空氣以滋 長燃燒。環繞生物質噴嘴的次級核心空氣提供熱，以可從 生物質燃料額外地移除水分，同時對燃料供應氧化劑以便 利點火及燃燒。此解決相關於與在習知技術燃燒器中，引 燃與生物質相關聯的延遲點火及燃燒的問題。核心空氣氣 流調節器7被調整成以可在引燃與粉煤結合的生物質之時 將NOx排放減至最少的量來供應核心空氣5。對於生物質 未被引燃的時間，供應燃燒器總成1的生物質供應系統（ 未顯示）停止運轉，且閥2 3被關閉。屆時，閥21被打開 -11 - 201105907 且與核心氣流調節器7共同被調整，以供應在引燃粒狀煤 時將ΝΟχ減至最少所需要之核心空氣5的最佳量。當生 物質要被引燃時，閥21被關閉且閥23被打開，以供給生 物質及運輸空氣16。 現在參考圖4，圖中顯示本發明的燃燒器總成1的示 意剖面圖，其中可識別燃燒器總成1的五個分開的區域。 由生物質噴嘴18所界定的生物質區32被界定生物質噴嘴 1 8與核心噴嘴8之間的區域的核心空氣區44同心地環繞 。煤噴嘴1 5同心地環繞核心噴嘴8以界定第一環狀區47 ，而PC/PA (粉煤及主空氣）13在第一環狀區47中流動 。套筒42同心地環繞煤噴嘴15，且界定在套筒42的內 部的內空氣區10及在套筒42的外部的外空氣區11。 雖然已經顯示較佳實施例，但是在不離開本發明的範 疇之前提下，也可達成另外替代的實施例。 —種替代實施例包含筆直管件，其不具有漸縮管17 (圖2)且/或在生物質噴嘴18的爐膛端處不擴大。在此 實施例中，也顯示較短的或凹入的生物質噴嘴18的替代 物’其中生物質噴嘴尖端1 9終止在核心噴嘴8內靠近核 心空氣導管6之處。此實施例提供將生物質預加熱且將生 物質與核心空氣預混合的額外效益，因而可進一步從生物 質燃料額外地移除水分。 漸縮錐體（reducing taper)可被使用在生物質噴嘴 18的出口處（圖3)，以在生物質燃料進入爐膛3時加速 生物質燃料，以防止逆燃至生物質噴嘴1 8內。雖然生物 -12- 201105907 質噴嘴18在圖中被顯示成爲開端式（open-ended)的噴 嘴，但是生物質噴嘴18可容易地在靠近出口處裝配有偏 轉器（deflector)或旋流器（swirler)，以增加生物質與 核心空氣的混合率。 在其他實施例中，可包含調整機構，以便利生物質噴 嘴1 8的端部相對於核心管件的位置的微量的前後調整， 以可進一步使燃燒最佳化。雖然生物質噴嘴18在圖1中 被顯示成與核心管件的端部齊平，但是生物質噴嘴18也 可被定位成稍微進一步向後或進一步向前。在某些實施例 中，閥21可被使用來供給小量的空氣（熱的次級空氣或 未經加熱的空氣），以在引燃生物質的同時添加空氣於火 焰的中心。此目的在於以最低的N0X，增大中心化學計量 (center stoichiometry )(作爲增加運輸空氣量的替代方 案）。 本發明的實施例提供眾多的有利點。根據本發明的實 施例之生物質混燃的噴氣燃燒器提供新穎的優越結構，且 可達成優越的引燃生物質燃料的方法。 大型核心區可在不改變燃燒器尺寸之情況下容納生物 質噴嘴’因而省下通常與建立不同尺寸的燃燒器以順應生 物質引燃相關之工程及製造成本。 大型生物質噴嘴使得在選定的燃燒器中引燃較大量的 生物質’而必須被供應以引燃生物質的燃燒器較少成爲可 能。筒達額定的燃燒器輸入（rated burner input)的40% 的生物質引燃率在只使用半數的燃燒器之情況下達成2 〇 -13- 201105907 %的鍋爐生物質引燃率。 生物質燃料的可獲得性（availability )經常隨著季節 而變化，使得生物質的燃燒可能無法被連續地實施。在替 代實施例中，生物質噴嘴可在不引燃生物質時被供應以次 級空氣，使得生物質噴嘴18及核心噴嘴8二者提供用於 粉煤的燃燒之結合核心空氣噴射流。 並且，與生物質一起的運輸空氣在引燃與煤結合的生 物質時促成燃燒器的較佳的中心化學計量。在此情況中， 煤流被減少，使得較高的PA/PC比被供應至燃燒器。來 自生物質的運輸空氣將此增大而提供對於非常低的NOx 排放有助益的中心化學計量。 另外，生物質噴嘴在核心區內的定位提供用來將生物 質燃料點火及滋長生物質燃料的燃燒的熱的次級空氣源， 防止習知技術中所經驗過的延遲的點火，並且滋長混燃的 生物質燃料的燃燒。 雖然已經顯示及詳細敘述本發明的特定實施例以舉例 說明本發明的原理的應用，但是應可瞭解本發明可在不離 開此種原理之下以其他方式實施。 【圖式簡單說明】 在圖式中： 圖1爲本發明的實施例的示意側視圖。 圖2爲本發明的另一實施例的示意側視圖。 圖3爲本發明的另一實施例的示意側視圖。 -14 - 201105907 圖4爲識別本發明的各同心區的本發明的實施例的示 意剖面圖。 【主要元件符號說明】 1 :燃燒器總成 2 :風箱 3 :爐膛 4 :燃燒器喉道 5 :核心空氣 6 :核心空氣導管 7 :核心空氣氣流調節器 8 :核心噴嘴 9 :至燃燒器總成的次級空氣 1 〇 :內空氣區 1 1 :外空氣區 1 2 :空氣分離葉片 1 3 :粉煤及主空氣 1 4 :燃燒器彎管 1 5 :煤噴嘴 16:生物質及運輸空氣 1 7 ‘·漸縮管 1 8 :生物質噴嘴 1 9 :生物質噴嘴尖端 21 :閥 -15- 201105907 2 2 :次級空氣 23 :閥 3 2 :生物質區 42 :套筒 4 4 :核心空氣區 4 7 :第一環狀區201105907 VI. Description of the Invention: TECHNICAL FIELD OF THE INVENTION The present invention relates to the field of industrial burner devices for performing combustion to generate power. [Prior Art] The term "biomass" as used herein describes a wide range of organic materials derived from a variety of different living or recently living organisms, such as grass and wood products. Sources of biomass include trees, shrubs, bushes, residual vegetation from harvesting grains, and vegetables. Biomass is usually a plant material that is harvested to produce electricity or produce heat. Biomass can also contain biodegradable waste that can be used as a fuel to burn organic sources. Biomass is different from fossil fuel because fossil fuels are in the top layer of the earth's crust. Hydrocarbons found. Common examples of fossil fuels include coal and oil. Unlike fossil fuels, biomass fuels are generally considered to be C〇2 (carbon dioxide) neutral and renewable resources, since C〇2 produced from biomass combustion can be extracted from the atmosphere by plants that provide biomass. Was removed. Because the physical properties and chemical composition of biomass are significantly different from those of coal, biomass fuels used for power generation have historically been used as boilers of the type of stoker and fluid bed. 201105907 Primary or auxiliary fuel. Such a boiler does not rely on a burner and thus has a significantly better furnace residence time for combustion, thus having less stringent fuel preparation requirements. Concerns about global warming associated with greenhouse gas emissions have increased interest in developing new technologies to generate power using universally available renewable resources. One area of interest is the use of biomass fuels for suspension firing, and the short residence time in suspended combustion necessitates efficient combustion with fine particles. Pulverized coal ignition is the main mechanism for suspended combustion in power generation industries. In the first step, the coal is mechanically pulverized into fine particles. The particles are then transported to the burner via suspension in a primary air stream, wherein the burner injects the air/fuel mixture into the furnace for combustion. The residence time is known as 1 to 2 seconds, which is sufficient to carry out full pulverized coal combustion at the appropriate particle size. Biomass igniting in pulverized coal-fired boilers is becoming more popular as a strategy for reducing greenhouse gases. To make this strategy feasible, there is a need to develop burners that can effectively use biomass fuels for suspended combustion. Ignition of biomass fuels faces many technical challenges. Biomass fuels have significantly lower heating values and higher volatile matter concentrations than bituminous coal. The enthalpy is inversely proportional to the moisture content, making the biomass enthalpy totaling between 25% and 75% of the typical enthalpy of bituminous coal. For reasons of material handling and to increase the efficiency and productivity of the process, the moisture of the biomass is often reduced before ignition. However, igniting biomass that replaces coal requires significantly more fuel quality to achieve a comparable heat output of -6-201105907. In addition, although the highly volatile nature of biomass makes the fuel inherently easy to burn, high moisture content may delay ignition. Delayed ignition is particularly undesirable in suspended combustion. Another concern with biomass is that the biomass is not treated to the same particle size as the pulverized coal. Experience has shown that successful suspended combustion can be achieved under wood particles of size 0.062 5 inches, compared to a maximum size of 0.012 inches for pulverized coal. The volume of the particles varies depending on the cube of the diameter, so that the volume of the wood particles is approximately 150 times the volume of the larger coal particles used for suspended combustion. Therefore, the larger volume of biomass requires rapid ignition and rapid combustion to use biomass in furnaces designed for pulverized coal ignition. One known technique for using biomass in suspended combustion is biomass co-firing. In this technique, biomass particles combine with pulverized coal and primary air to form a single gas stream. The combined gas stream is then introduced into the furnace. However, this technique is limited in practicality due to the synthetic burner nozzle speed necessary to maintain both types of particle suspension. Excessive burner nozzle speeds result in flame instability, delayed ignition, and poor combustion performance. Therefore, an institution or means for developing an efficient and effective alternative to burning coal to generate power and a mechanism or means for achieving universal carbon-neutral fuel combustion for power generation applications There is still demand. SUMMARY OF THE INVENTION Embodiments of the present invention provide novel combustion apparatus. More specifically, 201105907 embodiments of the present invention provide a combustion apparatus that ignites biomass fuel and can alternate between ignition of biomass and ignition of coal as needed, and/or can simultaneously burn coal and A combination of biomass fuels. Embodiments of the present invention extend the capabilities of prior art burners. U.S. Patent No. 7,430,970 (the '970 patent) to La. The present invention improves upon conventional art burners by providing novel means for burning regenerative fuel including, but not limited to, biomass. Embodiments of the present invention provide superior methods and apparatus for co-firing biomass coupled with pulverized coal. A combustible apparatus for igniting a biomass fuel includes a combustor assembly including a biomass nozzle concentrically surrounded by a core air zone and extending axially along a length of the core air zone, the combustor assembly being present Inside the bellows, the bellows is attached to the furnace of the boiler, and the burner assembly is connected to the furnace by the burner throat, and the air and fuel supplied to the burner assembly are radiated to the throat of the burner to Inside the furnace. In an embodiment of the invention, the apparatus includes a forced ventilation fan that provides a first air supply to the windbox; a core air conduit that encloses the core air zone for receiving a core portion of the first air supply, the core air conduit a core damper for regulating the core portion of the core air conduit; a core nozzle 'for receiving a core portion from the core air conduit, the core nozzle delivering the core portion to the combustion The throat of the burner; the burner elbow is used to receive the pulverized coal and the second air supply, and the pulverized coal and the second air supply continue in the -8 - 201105907 annulus formed between the core nozzle and the coal nozzle Through the coal nozzle, the core portion is used to accelerate the ignition of the pulverized coal by contacting the inner cylinder C of the coal jet leaving the coal nozzle, and the core portion is also used to accelerate the combustion. The various features of the invention are set forth with particularity in the scope of the appended claims. For a better understanding of the present invention, the advantages of the present invention, and the specific objects of the present invention, reference to the preferred embodiments of the invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawings, wherein like reference numerals refer to the same or functionally similar elements in the various figures, FIG. 1 shows the burner assembly 1 resident in the bellows 2, while the bellows 2 Furnace 3 attached to a boiler (not shown). Secondary air 22 is supplied to the bellows 2' by a forced ventilation fan (not shown) and is heated by an air preheater (not shown). The burner assembly 1 is connected to the furnace 3 by the burner throat 4, and the air and fuel supplied to the burner assembly 1 are radiated into the furnace chamber 3 via the burner throat 4. A portion of the secondary air 22 constitutes the core air 5. The core air 5 enters the core air duct 6 and is regulated by the core air damper 7. The core air 5 continues to pass through the burner assembly 1 via the core nozzle 8 and exits via the burner throat 4. Secondary air 2 2 is also supplied to the combustor assembly (shown by secondary air to combustor assembly 9). Secondary air 22 enters the combustor assembly 1 -9 - 201105907 and travels through the parallel flow paths of the inner air zone 10 and the outer air zone 11. Swirl vanes in these air zones are used to create a swirling flow of the secondary air 22 to facilitate ignition and combustion of the secondary air 22 contacting the pulverized coal stream. The air separation vanes 12 at the outlet of the outer air zone 11 serve to increase the size of the internal recirculation zone (IRZ) formed by synthetic aerodynamics. The pulverized coal and primary air 13 enters the burner elbow 14 and continues through the coal nozzle 15 in the annulus formed between the core nozzle 8 and the coal nozzle 15. The core air 5 is used to accelerate the ignition of the pulverized coal by contacting the inner cylindrical surface of the coal jet (not shown) exiting the coal nozzle I 5 and is used to supply air by "bellows effect" Accelerate combustion at the center of the flame. LaRue's '9*70 patent provides a detailed discussion of accelerated ignition associated with core air. According to an embodiment of the invention, the burner assembly 1 can be operated in conjunction with an over-fire-air (OFA) system (not shown). A portion of the secondary air 22 supplied to the furnace for combustion is supplied to the OFA system such that the total amount of air supplied to the burner assembly 1 is less than the theoretical air requirement. This creates a reducing environment in the furnace before the OFA is supplied. Accelerated combustion, higher temperature flames, and larger IRZ are used to reduce NOx more efficiently in the case of reduction. In an embodiment of the invention, the biomass may be prepared for suspended combustion using a shredder, a hammer mill, and the like (not shown), by means of a screw feeder ( Screw feeder ) or an equivalent device (not shown) is collected and adjusted at feed rate by -10- 201105907 and can be pneumatically transported to the burner assembly 1 via a suitable conduit. The conduit supplies biomass and transports air 16 through an elbow at the outlet of the burner assembly 1. In some embodiments, a reducer 17 can be used to reduce the cross-sectional area of the biomass nozzle 18 as the biomass nozzle 18 traverses the burner elbow 14 and continues through the core air conduit 6. The reducer 17 is used to reduce flow impediments as the biomass nozzle 18 extends through the length of the burner assembly 1. Near the furnace end of the burner assembly 1, the diameter of the biomass nozzle tip 19 can be expanded, as shown in Figure 1, to reduce the biomass outlet velocity to the optimum enthalpy for combustion. In some embodiments, the exit speed is between about 2,500 feet per minute and about 5,000 feet per minute, and preferably between about 3,000 feet per minute and about 4,000 feet per minute. In a further embodiment, the core air 5 surrounding the biomass nozzle tip 19 acts to accelerate the ignition of the biomass as it enters the burner throat 4, and to supply air as the biomass continues to enter the furnace. combustion. The secondary core air surrounding the biomass nozzle provides heat to additionally remove moisture from the biomass fuel while supplying oxidant to the fuel for ignition and combustion. This solution relates to the problem of delayed ignition and combustion associated with ignition and biomass in prior art burners. The core air flow regulator 7 is adjusted to supply the core air 5 in an amount that minimizes NOx emissions at the time of ignition of the biomass associated with the pulverized coal. For the time when the biomass is not ignited, the biomass supply system (not shown) supplying the burner assembly 1 is stopped and the valve 23 is closed. At that time, the valve 21 is opened -11 - 201105907 and is adjusted together with the core damper 7 to supply an optimum amount of core air 5 required to minimize enthalpy when igniting the granulated coal. When the biomass is to be ignited, the valve 21 is closed and the valve 23 is opened to supply the biomass and transport the air 16. Referring now to Figure 4, there is shown a schematic cross-sectional view of the burner assembly 1 of the present invention in which five separate regions of the burner assembly 1 are identified. The biomass zone 32 defined by the biomass nozzle 18 is concentrically surrounded by a core air zone 44 that defines a region between the biomass nozzle 18 and the core nozzle 8. The coal nozzle 15 concentrically surrounds the core nozzle 8 to define a first annular zone 47, while PC/PA (puff and primary air) 13 flows in the first annular zone 47. The sleeve 42 concentrically surrounds the coal nozzle 15 and defines an inner air zone 10 within the interior of the sleeve 42 and an outer air zone 11 external to the sleeve 42. While the preferred embodiment has been shown, additional alternative embodiments may be implemented without departing from the scope of the invention. An alternative embodiment includes a straight tubular member that does not have a tapered tube 17 (Fig. 2) and/or that does not expand at the furnace end of the biomass nozzle 18. In this embodiment, an alternative to the shorter or recessed biomass nozzle 18 is also shown where the biomass nozzle tip 19 terminates within the core nozzle 8 near the core air conduit 6. This embodiment provides the added benefit of preheating the biomass and premixing the biomass with core air, thereby further removing moisture from the biomass fuel. A reducing taper can be used at the outlet of the biomass nozzle 18 (Fig. 3) to accelerate the biomass fuel as it enters the furnace 3 to prevent flashback into the biomass nozzle 18. Although the Bio-12-201105907 mass nozzle 18 is shown as an open-ended nozzle in the figure, the biomass nozzle 18 can be easily fitted with a deflector or swirler near the outlet. ) to increase the mixing rate of biomass and core air. In other embodiments, an adjustment mechanism can be included to facilitate a slight back and forth adjustment of the position of the end of the biomass nozzle 18 relative to the core tube to further optimize combustion. While the biomass nozzle 18 is shown flush with the ends of the core tubular member in Figure 1, the biomass nozzle 18 can also be positioned slightly further rearward or further forward. In certain embodiments, valve 21 can be used to supply a small amount of air (hot secondary or unheated air) to add air to the center of the flame while igniting the biomass. The goal is to increase the center stoichiometry (as an alternative to increasing the amount of transport air) with the lowest N0X. Embodiments of the present invention provide numerous advantages. The biomass co-firing jet burner according to the embodiment of the present invention provides a novel superior structure and a superior method of igniting biomass fuel can be achieved. The large core zone accommodates the biomass nozzles without changing the size of the burner' thus eliminating the engineering and manufacturing costs typically associated with establishing burners of different sizes to accommodate biomass ignition. Large biomass nozzles make it possible to ignite larger amounts of biomass in selected burners, while burners that must be supplied to ignite biomass are less likely. The 40% biomass ignition rate of the rated burner input achieves a boiler biomass ignition rate of 2 〇 -13 - 201105907% with only half of the burners. The availability of biomass fuels often varies with the seasons, so that the combustion of biomass may not be continuously implemented. In an alternate embodiment, the biomass nozzle can be supplied with secondary air when the biomass is not ignited, such that both the biomass nozzle 18 and the core nozzle 8 provide a combined core air jet for combustion of the pulverized coal. Moreover, the transport air with the biomass contributes to a better central stoichiometry of the burner when igniting the biomass associated with the coal. In this case, the coal flow is reduced such that a higher PA/PC ratio is supplied to the combustor. This transport air from biomass increases this to provide a central stoichiometry that is beneficial for very low NOx emissions. In addition, the positioning of the biomass nozzle in the core region provides a hot secondary air source for igniting the biomass fuel and stimulating the combustion of the biomass fuel, preventing delayed ignition experienced in the prior art, and stimulating mixing Combustion of fueled biomass fuel. While the invention has been shown and described with reference to the embodiments of the embodiments of the present invention, it is understood that the invention may be practiced otherwise. BRIEF DESCRIPTION OF THE DRAWINGS In the drawings: FIG. 1 is a schematic side view of an embodiment of the present invention. Figure 2 is a schematic side view of another embodiment of the present invention. Figure 3 is a schematic side view of another embodiment of the present invention. -14 - 201105907 Figure 4 is a schematic cross-sectional view showing an embodiment of the present invention for identifying concentric regions of the present invention. [Main component symbol description] 1 : Burner assembly 2 : Bellows 3 : Furnace 4 : Burner throat 5 : Core air 6 : Core air duct 7 : Core air flow regulator 8 : Core nozzle 9 : to burner Secondary air of assembly 1 〇: inner air zone 1 1 : outer air zone 1 2 : air separation blade 1 3 : pulverized coal and main air 1 4 : burner elbow 1 5 : coal nozzle 16: biomass and transportation Air 1 7 '·Reducing tube 1 8 : Biomass nozzle 1 9 : Biomass nozzle tip 21 : Valve -15- 201105907 2 2 : Secondary air 23 : Valve 3 2 : Biomass area 42 : Sleeve 4 4 : Core air zone 4 7 : first annular zone