JP3546313B2

JP3546313B2 - Spouted bed coal gasifier

Info

Publication number: JP3546313B2
Application number: JP22622394A
Authority: JP
Inventors: 孝規工藤; 淳森原; 俊太郎小山; 真二田中; 栄次木田
Original assignee: Babcock Hitachi KK
Current assignee: Mitsubishi Power Ltd
Priority date: 1994-09-21
Filing date: 1994-09-21
Publication date: 2004-07-28
Anticipated expiration: 2019-07-28
Also published as: JPH0892573A

Description

【０００１】
【産業上の利用分野】
本発明は、石炭ガス化炉に係り、特に石炭をガス化したガスをガスタービンに供給して発電を行う石炭発電プラントに適用するのに好適な石炭ガス化炉に関する。
【０００２】
【従来の技術】
石炭の持つエネルギーを電気エネルギーに変換する方法には、直接燃焼して熱エネルギーからスチームを介してスチームタービンを用いて発電する方式、或いは一旦可燃性ガスに変換して、ガスタービンで燃焼して発電する方式がある。一般的に後者は前者に比べて効率が良く、次世代の発電システムとして有望視されている。石炭ガス化炉はこの次世代発電システムの中核となる技術である。
【０００３】
石炭ガス化炉とは、石炭等の燃料と酸素或いは空気などの酸化剤を高温で接触させ、水素，一酸化炭素，メタンなどで構成された可燃性ガスを生成する装置である。噴流層石炭ガス化炉は、この装置の中の形式の１つであり、高温で反応させることにより、反応を速やかに終了させて石炭のガス化効率を向上させると同時に、石炭中に存在する灰分を溶融分離した後回収するため、石炭中に存在する有害な金属成分を封じ込めることができ、かつ廃棄時の灰からの溶出も少なく、環境適合性に優れた反応炉形式である。
【０００４】
この形式の石炭ガス化炉では高温でガス化反応を行うため、石炭中の灰分が溶融し生成した粘着性の液滴や粒子が、ガス化ガスに同伴されガス化ガスを処理する装置の壁面等に付着する課題がある。
【０００５】
その対策として、特開平3−24195号公報においては、ガス化炉の内径より小さい内径のガス化炉出口とガス化ガスの冷却部との間にガスを噴出する機構を備え、生成ガスに同伴される粘着性粒子の粘着力を消失させ、熱回収部の粒子付着を抑制している。また、特開平3−239797 号公報においては、ガス化炉の内径より小さい内径のガス化炉出口とガス化ガスの冷却部との間に設置した内径が拡大していくディフューザー部にガスを噴出する機構を備え、熱回収部の粒子付着を抑制している。また、特開平2−38492号公報においては、ガス化炉の内径より小さい内径のガス化炉出口とガス化ガスの冷却部との間に、ガス噴出ノズルを半径方向に放射状に備えたガス注入リングを備え、熱回収部の粒子付着を抑制している。
【０００６】
【発明が解決しようとする課題】
前記従来の噴流層石炭ガス化炉においては、熱回収室の壁面への灰などの付着を問題とし、その対策について提案している。しかしながら、ガス化部と熱回収室の間の絞り部に灰が付着し、絞り部の閉塞につながることが明らかとなった。この課題に対して、前記従来技術では対策できない。すなわち、ガス化炉上部の絞り付近では何ら対策がとられておらず、このため、ガス化炉上部の絞り付近の灰付着が課題となる。
【０００７】
本発明の目的は、ガス化部から熱回収部に通じる絞り部に灰が付着することを抑制した噴流層石炭ガス化炉を提供することにある。
【０００８】
【課題を解決するための手段】
本発明の噴流層石炭ガス化炉は、石炭をガス化するガス化部と、該ガス化部の上部にあって内径が縮小する絞り部と、該絞り部の上部にありガスを排出する炉出口部と、前記ガス化部内の前記絞り部の下部にシール用のガスを噴出する手段とを備えることによって達成される。
【０００９】
【作用】
上記構成によれば、石炭バーナより供給された石炭等の燃料と酸素等の酸化剤は、円筒状のガス化部で反応し、熱回収部へ流れる。ガス化部の上部にあって内径がガス化部より順次縮小する絞り部に配置した、該絞り部の壁面を保護するガスを噴出するシールガス噴出ノズルから、シールガスを噴出すると、該シールガスはガス化部から流出するガスの流れにより、絞り部の壁面に沿って上昇し、絞り部の壁面にシール膜を形成する。ガス化部で生成した石炭灰等の粘着性の液滴を含む粒子は、ガス化部から流出するガスの流れに搬送される。絞り部では粒子の持つ慣性力により壁面に接近するが、絞り部の壁面に形成したシール膜により絞り部の壁面への粒子付着が抑制され、絞り部の閉塞の抑制が達成される。
【００１０】
また、石炭バーナを円筒状のガス化部に旋回流を形成するように配置し、石炭等の燃料と酸素等の酸化剤を供給すると、ガス化部で生成したガスは旋回しながら、熱回収部へ流れる。半径方向に放射状に設置した複数のシールガス噴出ノズルからシールガスを吹き込むと、該シールガスは生成ガスの持つ旋回力で壁面方向に移動し、絞り部の壁面に、ガス化部の旋回より弱旋回したシール膜を形成できる。粒子はガス化部から流出するガスの流れに搬送され、旋回する。遠心力により粒子は壁面に近づくが、絞り部の壁面に形成した弱旋回したシール膜により、遠心力が弱まり、粒子は絞り部の壁面に接近せず、絞り部の壁面への粒子付着が抑制され、絞り部の閉塞の抑制が達成される。
【００１１】
また、絞り部の壁面のシール用のガス噴出ノズルを斜め下向きに配置すると、シールガスは、シールガス噴出ノズルの下方に噴出され、ガス化部より旋回しながら流出するガスの旋回力により壁面へ移動し、絞り部の壁面に沿って流れ、シールガス噴出ノズルを覆うように、絞り部壁面を保護するシール膜を形成する。これによりシールガス噴出ノズル近傍の粒子付着が抑制され、シールガス噴出ノズルの閉塞の抑制が達成される。
【００１２】
また、絞り部の壁面のシール用のガス噴出ノズルから、粘着性粒子の粘着性が減衰或いは消失する温度のクエンチガスを吹き込むことにより、絞り部の粒子付着を抑制するとともに粘着性粒子の粘着性を減衰或いは消失される。
【００１３】
また、絞り部に複数段のガス噴出ノズルを配置し、一方からガス化部で生成したガスを冷却する前記クエンチガスを噴出し、他方から絞り部の壁面の保護用シールガスを噴出すると、該クエンチガスを噴出ノズル近傍に、シール膜が形成し、該クエンチガスの噴出ノズルに粘着性高い粒子が接近することを抑制し、該クエンチガスの噴出ノズル近傍で粘着性の高い粒子が冷却，固化し、堆積することを抑制し、該クエンチガスの噴出ノズルの閉塞の抑制が達成される。
【００１４】
さらに、ガスタービンの燃焼器に送る圧縮空気の一部をガス化炉の絞り部の壁面のシールガスとして吹き込むと、圧縮空気はガス化炉の絞り部にシール膜を形成し、ガス化炉の絞り部の灰付着を抑制する。それとともに、シールガス発生器とガスタービン用コンプレッサが一体化でき、システムを簡略化できる。
【００１５】
また、蒸気発生装置で生成した水蒸気を絞り部の壁面のシールガスとして吹き込むと、水蒸気はガス化部で生成した一酸化炭素及び活性化した炭素と反応し、水素に転化し、生成ガス中の水素濃度を高めることができるとともに、絞り部にシール膜を形成し、絞り部の灰付着を抑制する。
【００１６】
また、脱塵，冷却されたリサイクルガスを絞り部の壁面のシールガスとして吹き込むと、リサイクルガスの成分は生成ガスとほぼ同一であることから、生成ガスの成分をほとんど変化することなく、リサイクルガスは絞り部にシール膜を形成し、絞り部の灰付着を抑制する。
【００１７】
また、ガス噴出部の先端が最も縮小した複数のシールガス噴出ノズルを有し、該ガス噴出部先端の内径をすべて等しくした上記構成の装置は、圧力損失が最大となる先端部の影響が大きくなるため、等しい量のシールガスを供給することが可能となり、絞り部に均一な厚さのシール膜を形成することが達成される。
【００１８】
上記構成によれば、ガス化部において酸化剤と石炭等の燃料がガス化反応を起こし、高温の石炭ガス化ガスを生成するが、絞り部に配置したシールガス噴出ノズルは該石炭ガス化ガスにより熱せられ高温になることから、耐熱性の高い材料、例えばセラミックなどで構成する必要がある。
【００１９】
【実施例】
以下、本発明の実施例を説明する。
【００２０】
図１に本発明の実施例１のシステム構成図を示す。全体は石炭ガス化炉１，ガスタービン４０，スチームタービン４５などから構成される。石炭ガス化炉１で生成したガスは脱塵装置３０，脱硫装置３５を通過することで生成ガス中のダスト，硫黄分が除去され、ガスタービン４０で燃焼し発電する。この排ガスが排熱回収ボイラ４３を通過してスチームを生成してスチームタービン４５で発電する。ガスタービン４０のコンプレッサーで生成した圧縮空気は酸素製造装置５０に送られて窒素と酸素に分離され、窒素は石炭ホッパー１２での加圧用窒素として使われ、酸素はガス化用の酸化剤として使用される。圧縮空気の一部は、ガス化炉絞り部近傍に設置したシールガス噴出ノズル１５から噴出するシールガス２０として使用される。本実施例特有の効果は、ガスタービン４０のコンプレッサーで生成した圧縮空気を用いるため、シールガス生成用のコンプレッサーを省略し、システムが簡略化でき、システム全体のコストが削減できる点、或いは酸化剤や、加圧及びパージ用の窒素の昇圧のエネルギーが削減できるため、システム全体の効率が向上する点である。
【００２１】
図２に本発明の実施例１の噴流層石炭ガス化炉の縦方向断面図を示す。ガス化炉全体は容器２５に囲まれた耐火材２６により構成され、炉上部２とガス化部３と溶融灰急冷室４からなる。ガス化部３と炉上部２はガス化部３より炉径が縮小する絞り部７で連続している。
【００２２】
次に本実施例１の機能について説明する。石炭と酸素はバーナから供給する。上段バーナ１４と下段バーナ６はそれぞれ複数を、炉内に旋回流が生ずるように接線方向に配置し、石炭と酸素を所定の比率でガス化部３に噴出し、石炭をガス化する。ガス化部３内のガスの温度は１２００から１８００度になり、石炭中の灰分は溶融し、その大部分が重力によりガス化部３の下方に設置した溶融灰急冷室４内の冷却水５に流下し、急冷，固化，粉砕されたのち回収される。また、一部は、ガス化部３で生成したガスに搬送され、旋回しながら、絞り部７を通過し、炉上部２に到達する。炉上部２では、絞り部７によりガス化部３からの放射伝熱が遮られ、また、炉壁等に配置した伝熱管で熱回収され、生成ガス及び粒子の温度はガス化反応が殆ど進行しない温度まで低下する。絞り部７に設置したシールガス噴出ノズル１５からガスタービン４０のコンプレッサーで生成した圧縮空気をシールガス２０として噴出することにより、絞り部７の壁面にシール膜１０が形成される。ガス化部３で生成したガスに搬送され、絞り部７を通過する石炭中の灰分等の粒子は、シール膜１０により、絞り部７の壁面への接触が妨げられ、絞り部７への粒子付着が抑制される。さらに常温の圧縮空気をシールガス２０として噴出することにより、絞り部７を通過するガス及び粒子の温度は、ガス化反応が殆ど進行しない温度或いは粘着性粒子の粘着力が殆ど消失する温度まで低下する。粘着力を失った粒子は絞り部７の壁面への付着が抑制される。さらに、シールガス噴出ノズル１５を斜め下向きに設置することにより、シールガス２０はシールガス噴出ノズル１５の下方に噴出され、ガス化部３から旋回しながら流出するガスにより、絞り部７の壁面に沿って上昇する。これにより、シール膜１０の下端はシールガス噴出ノズル１５の下方に位置する。これによりシールガス噴出ノズル１５付近の壁面はシール膜１０に覆われ、シールガス噴出ノズル１５近傍の粒子付着が抑制され、シールガス噴出ノズル１５の閉塞の抑制が達成される。
【００２３】
図３に本発明の実施例１の噴流層石炭ガス化炉の横方向断面I−Iの断面図を示す。半径方向に放射状に複数のシールガス噴出ノズル１５を有することにより、絞り部７の壁面では、ガス化部３から流出するガスの外側に、シール膜１０が、円周方向にほぼ均一な厚みで形成する。ガス化部３で生成したガスに搬送され、絞り部７を通過する石炭中の灰分等の粒子は、ガス化部３で生成したガスから与えられる旋回力や壁面方向の慣性力により絞り部７付近の壁面に接近するが、シール膜１０により、旋回力や壁面方向の慣性力を弱められた粒子は、絞り部７の壁面に接触せず、絞り部７への粒子付着の抑制が達成される。
【００２４】
図４に本発明の実施例１の噴流層石炭ガス化炉の絞り部の断面図を示す。シールガス噴出ノズルはノズル先端のガス噴出部が最も細くなるように構成されている。このため、シールガス供給系の中で、この部分の圧力損失が最も高くなることから、ノズル先端のガス噴出部の内径を等しくすることで、いずれのシールガス噴出ノズルからの供給量も等しくすることができる。
【００２５】
図５に本発明の実施例１の噴流層石炭ガス化炉の絞り部７付近の半径方向距離と周方向速度分布の関係を示す。絞り部７に設置したシールガス噴出ノズル１５からシールガス２０として水蒸気を噴出したときは噴出しないときと比較して絞り部７の壁近傍の周方向速度が減少していることがわかる。
【００２６】
実施例２を以下説明する。図６に本発明の実施例２の噴流層石炭ガス化炉の横方向断面Ｉ−Ｉの断面図を示す。本実施例の特徴は旋回方向にシールガス２０を噴出するシールガス噴出ノズルを有することにより絞り部７の壁面にガス化部３から流出するガスより弱旋回したシール膜を形成できることである。
【００２７】
次に本実施例２の機能について説明する。旋回方向に複数のシールガス噴出ノズル１５を有することにより、絞り部７の壁面では、ガス化部３から流出するガスの旋回力と所定量で噴出するシールガス２０の旋回力が合成し、ガス化部より弱旋回したシール膜１０が形成される。ガス化部３で生成したガスに搬送され、絞り部７を通過する石炭中の灰分等の粒子は、ガス化部３で生成したガスから与えられる旋回力や壁面方向の慣性力により絞り部７付近の壁面に接近するが、シール膜１０により、旋回力や壁面方向の慣性力を弱められた粒子は、絞り部７の壁面に接触せず、絞り部７への粒子付着の抑制が達成される。
【００２８】
実施例３を以下説明する。図７に本発明の実施例３の噴流層石炭ガス化炉の縦方向断面図を示す。本実施例の特徴は半径方向に放射状にシールガス２０を噴出するシールガス噴出ノズル１５の先端部にスリット１７を有することにより、絞り部７の壁面に位置するガス化部３から流出するガスの外側に、シール膜１０を円周方向に均一な厚みで形成することができることと、シールガス噴出部を１つの部品で構成し、構造を簡略化できることである。
【００２９】
次に本実施例３の機能について説明する。石炭と酸素はバーナから供給する。上段バーナ１４と下段バーナ６はそれぞれ複数を、炉内に旋回流が生ずるように配置し、石炭と酸素を所定の比率でガス化部３に噴出し、石炭をガス化する。ガス化部３内のガスの温度は１２００から１８００度になり、石炭中の灰分は溶融し、その大部分が重力によりガス化部３の下方に設置した溶融灰急冷室４内の冷却水５に流下し、急冷，固化，粉砕されたのち回収される。また、一部は、ガス化部３で生成したガスに搬送され、旋回しながら、絞り部７を通過し、炉上部２に到達する。炉上部２では、絞り部７によりガス化部３からの放射伝熱が遮られ、また、炉壁等に配置した伝熱管で熱回収され、生成ガス及び粒子の温度はガス化反応が殆ど進行しない温度まで低下する。シールガス噴出スリット１７からガスタービン４０のコンプレッサーで生成した圧縮空気をシールガス２０として噴出することにより、絞り部７の壁面にシール膜１０が形成する。ガス化部３で生成したガスに搬送され、絞り部７を通過する石炭中の灰分等の粒子は、シール膜１０により、絞り部７の壁面への接触が妨げられ、絞り部７への粒子付着が抑制される。さらに常温の圧縮空気をシールガス２０として噴出することにより、絞り部７を通過するガス及び粒子の温度は、ガス化反応が殆ど進行しない温度或いは粘着性粒子の粘着力が殆ど消失する温度まで低下する。粘着力を失った粒子は絞り部７の壁面へ付着せず、絞り部７への付着が抑制される。また、斜め下向きにガスを噴出するシールガス噴出スリット１７を有することにより、シールガス２０はシールガス噴出スリット１７の斜め下方に噴出される。シールガス２０はガス化部３から旋回しながら流出するガスから受ける遠心力により壁面に移動した後、絞り部７の壁面に沿って上昇する。これにより、シール膜１０の下端はシールガス噴出スリット１７の下方に位置する。このためシールガス噴出スリット１７付近の壁面はシール膜１０に覆われ、シールガス噴出スリット１７先端の粒子付着が抑制され、シールガス噴出スリット１７の閉塞の抑制が達成される。
【００３０】
図８に本発明の実施例３の噴流層石炭ガス化炉の横方向断面Ｉ−Ｉの断面図を示す。シールガス噴出ノズル１５の先端部のシールガス噴出スリット１７の先端部には仕切り１８が設けてあり、半径方向に放射状にシールガス２０を噴出してシール膜１０を形成するようにできる。ガス化部３で生成したガスに搬送され、絞り部７を通過する石炭中の灰分等の粒子は、ガス化部３で生成したガスから与えられる旋回力や壁面方向の慣性力により絞り部７付近の壁面に接近するが、シール膜１０により、旋回力や壁面方向の慣性力を弱められた粒子は、絞り部７の壁面に接触せず、絞り部７への粒子付着の抑制が達成される。
【００３１】
実施例４を以下説明する。図９に本発明を実施した噴流層石炭ガス化炉の縦方向断面図を示す。本実施例の特徴は絞り部７にガス噴出ノズルを複数段配置し、絞り部７の壁面を保護するシール膜１０を形成させるためのシールガス２０を噴出するシールガス噴出ノズル１５の近傍に、シールガス噴出ノズル１５先端を保護するノズルシール用膜１１を形成させるためのノズルシール用ガス２３を噴出するノズルシール用ガス噴出ノズル１６を有し、ノズルの粒子付着が抑制されることである。
【００３２】
次に本実施例４の機能について説明する。石炭と酸素はバーナから供給する。上段バーナ１４と下段バーナ６はそれぞれ複数を、炉内に旋回流が生ずるように配置し、石炭と酸素を所定の比率でガス化部３に噴出し、石炭をガス化する。ガス化部３内のガスの温度は１２００から１８００度になり、石炭中の灰分は溶融し、その大部分が重力によりガス化部３の下方に設置した溶融灰急冷室４内の冷却水５に流下し、急冷，固化，粉砕されたのち回収される。また、一部は、ガス化部３で生成したガスに搬送され、旋回しながら、絞り部７を通過し、炉上部２に到達する。炉上部２では、絞り部７によりガス化部３からの放射伝熱が遮られ、また、炉壁等に配置した伝熱管で熱回収され、生成ガス及び粒子の温度はガス化反応が殆ど進行しない温度まで低下する。シールガス噴出ノズル１５からガスタービン４０のコンプレッサーで生成した圧縮空気をシールガス２０として噴出することにより、絞り部７の壁面にシール膜１０が形成する。ガス化部３で生成したガスに搬送され、絞り部７を通過する石炭中の灰分等の粒子は、シール膜
１０により、絞り部７の壁面への接触が妨げられ、絞り部７への粒子付着が抑制される。さらに常温の圧縮空気をシールガス２０として噴出することにより、絞り部７を通過するガス及び粒子の温度は、ガス化反応が殆ど進行しない温度或いは粘着性粒子の粘着力が殆ど消失する温度まで低下する。粘着力を失った粒子は絞り部７の壁面へ付着せず、絞り部７への付着が抑制される。また、絞り部壁面を保護するためのシールガス噴出ノズル１５の近傍に設置したノズルシール用ガス噴出ノズル１６から、ノズルシール用ガス２３をシールガス噴出ノズル１５の下方に噴出する。ノズルシール用ガス２３はガス化部３から旋回しながら流出するガスにより、絞り部７の壁面に沿って上昇する。これにより、ノズルシール用膜１１の下端はシールガス噴出ノズル１５の下方に位置する。これによりシールガス噴出ノズル１５付近の壁面はノズルシール用膜１１に覆われ、シールガス噴出ノズル１５近傍では粒子は壁面から離れた位置を通る。シールガス噴出ノズル１５から灰の粘着性が消失する所定の温度のシールガス２０を噴出することにより、粘着性粒子は壁面から離れた位置で急冷され、粘着性の消失した粒子になるため、粒子が絞り部７壁面及びシールガス噴出ノズル１５近傍の壁面に堆積し、絞り部を閉塞することが抑制される。
【００３３】
図１０に本発明の実施例５のシステム構成図を示す。全体は石炭ガス化炉１，ガスタービン４０，スチームタービン４５などから構成される。石炭ガス化炉１で生成したガスは脱塵装置３０，脱硫装置３５を通過することで生成ガス中のダスト，硫黄分が除去され、ガスタービン４０で燃焼し発電する。この排ガスが排熱回収ボイラ４３を通過してスチームを生成してスチームタービン４５で発電する。ガスタービン４０のコンプレッサーで生成した圧縮空気は酸素製造装置５０に送られて窒素と酸素に分離され、窒素は石炭ホッパー１２での加圧用窒素として使われ、酸素はガス化用の酸化剤として使用される。また、冷却されたのち、ダスト及び硫黄分が除去された生成ガスの一部は、リサイクルガスとして、ガス化炉絞り部の近傍に設置したシールガス噴出ノズル１５から噴出される。本実施例の特徴は、リサイクルガスの成分は生成ガスとほぼ同一であるから、リサイクルガスは生成ガスの成分をほとんど変化することなく、絞り部にシール膜を形成するとともに生成ガスを冷却し、絞り部の灰付着を抑制することである。
【００３４】
図１１に本発明の実施例６のシステム構成図を示す。全体は石炭ガス化炉１，ガスタービン４０，スチームタービン４５などから構成される。石炭ガス化炉１で生成したガスは脱塵装置３０，脱硫装置３５を通過することで生成ガス中のダスト，硫黄分が除去され、ガスタービン４０で燃焼し発電する。この排ガスが排熱回収ボイラ４３を通過してスチームを生成してスチームタービン４５で発電する。ガスタービン４０のコンプレッサーで生成した圧縮空気は酸素製造装置５０に送られて窒素と酸素に分離され、窒素は石炭ホッパー１２での加圧及びパージ用の窒素として使われ、酸素はガス化用の酸化剤として使用される。また、窒素の一部は、ガス化炉絞り部の近傍に設置したシールガス噴出ノズル１５から噴出される。本実施例の特徴は、不活性な窒素ガスを噴出するため、生成したガスと反応せず、生成ガスを消費することを抑制できること、また酸素製造装置で分離された窒素ガスを用いるため、窒素ガス製造用の装置が省略され、システムが簡略化されるところにある。
【００３５】
図１２に本発明の実施例７のシステム構成図を示す。全体は石炭ガス化炉１，ガスタービン４０，スチームタービン４５などから構成される。石炭ガス化炉１で生成したガスは脱塵装置３０，脱硫装置３５を通過することで生成ガス中のダスト，硫黄分が除去され、ガスタービン４０で燃焼し発電する。この排ガスが排熱回収ボイラ４３を通過してスチームを生成してスチームタービン４５で発電する。ガスタービン４０のコンプレッサーで生成した圧縮空気は酸素製造装置５０に送られて窒素と酸素に分離され、窒素は石炭ホッパー１２での加圧用窒素として使われ、酸素はガス化用の酸化剤として使用される。蒸気発生装置６０で生成した高圧の蒸気は、ガス化炉絞り部の近傍に設置したシールガス噴出ノズル１５から噴出される。本実施例の特徴は、シールガス水蒸気はガス化部で生成した一酸化炭素及び活性化した炭素と反応し、水素に転化し、生成ガス中の水素濃度を高めるとともに、絞り部にシール膜を形成し、生成したガス化ガスを冷却し、絞り部の灰付着を抑制することである。
【００３６】
【発明の効果】
本発明により、絞り部での粒子の付着を抑制し、該絞り部の閉塞を抑制し、長時間連続運転可能な噴流層石炭ガス化炉を供与できる。
【図面の簡単な説明】
【図１】本発明の実施例１のガス化発電システムの構成図。
【図２】本発明の実施例１のガス化炉の縦方向断面図。
【図３】本発明の実施例１のガス化炉のＩ−Ｉ断面図。
【図４】本発明の実施例１のガス化炉の絞り部の縦方向断面図。
【図５】本発明の実施例１のガス化炉の絞り部での周方向速度分布図。
【図６】本発明の実施例２のガス化炉のＩ−Ｉ断面図。
【図７】本発明の実施例３のガス化炉の縦方向断面図。
【図８】本発明の実施例３のガス化炉のＩＩ−ＩＩ断面図。
【図９】本発明の実施例４のガス化炉の縦方向断面図。
【図１０】リサイクルガスをシールガスとして吹き込む方式のガス化発電システムの構成図。
【図１１】窒素ガスをシールガスとして吹き込む方式のガス化発電システムの構成図。
【図１２】水蒸気をシールガスとして吹き込む方式のガス化発電システムの構成図。
【図１３】シールガスノズル本数／石炭バーナ本数と灰付着量の関係図。
【図１４】シールガス噴出角度と灰付着量の関係図。
【符号の説明】
１…石炭ガス化炉、２…炉上部、３…ガス化部、４…溶融灰急冷室、５…冷却水、６…下段石炭バーナ、７…絞り部、１０…シール膜、１１…ノズルシール用膜、１２…石炭ホッパー、１４…上段石炭バーナ、１５…シールガス噴出ノズル、１６…ノズルシール用ガス噴出ノズル、１７…シールガス噴出部、１８…仕切り、２０…シールガス、２１…石炭、２２…酸化剤、２３…ノズルシール用ガス、２５…容器、２６…耐火材、３０…脱塵装置、３５…脱硫装置、４０…ガスタービン、４３…排熱回収ボイラ、４５…スチームタービン、５０…酸素製造装置、６０…蒸気発生装置。[0001]
[Industrial applications]
The present invention relates to a coal gasifier, and more particularly to a coal gasifier suitable for being applied to a coal power plant that generates electric power by supplying gas obtained by gasifying coal to a gas turbine.
[0002]
[Prior art]
The method of converting the energy of coal into electric energy is a method of directly burning and generating electricity from heat energy using steam through a steam turbine, or once converting it to flammable gas and burning it with a gas turbine. There is a method of generating electricity. Generally, the latter is more efficient than the former, and is regarded as promising as a next-generation power generation system. Coal gasifier is the core technology of this next-generation power generation system.
[0003]
A coal gasifier is a device that brings a fuel such as coal into contact with an oxidizing agent such as oxygen or air at a high temperature to generate a combustible gas composed of hydrogen, carbon monoxide, methane, and the like. A spouted bed coal gasifier is one type of this device, which reacts at a high temperature to quickly terminate the reaction and improve the gasification efficiency of the coal, while at the same time being present in the coal. Since the ash is recovered after being melted and separated, harmful metal components present in the coal can be contained, and there is little elution from the ash at the time of disposal, and this is a reactor type with excellent environmental compatibility.
[0004]
In this type of coal gasifier, the gasification reaction is carried out at high temperatures, so the sticky droplets and particles generated by melting the ash in the coal are entrained by the gasification gas and the wall of the device that processes the gasification gas And the like.
[0005]
As a countermeasure, Japanese Unexamined Patent Publication No. 3-24195 discloses a mechanism in which a gas is blown out between a gasification furnace outlet having an inner diameter smaller than the inner diameter of the gasification furnace and a gasification gas cooling unit, and the mechanism is accompanied by the generated gas. The adhesive force of the adhered adhesive particles is eliminated, and the adhesion of the particles to the heat recovery section is suppressed. Also, in Japanese Patent Application Laid-Open No. 3-239797, gas is injected into a diffuser portion whose inner diameter is increased between a gasifier outlet having an inner diameter smaller than the inner diameter of the gasifier and a gasification gas cooling section. A mechanism to reduce the amount of particles attached to the heat recovery unit is provided. Also, in Japanese Patent Application Laid-Open No. 2-38492, a gas injection nozzle is provided radially in a radial direction between a gasification furnace outlet having an inner diameter smaller than the inner diameter of the gasification furnace and a gasification gas cooling unit. A ring is provided to prevent particles from adhering to the heat recovery section.
[0006]
[Problems to be solved by the invention]
In the conventional spouted bed coal gasifier described above, adhesion of ash and the like to the wall surface of the heat recovery chamber has been a problem, and measures have been proposed. However, it was found that ash adhered to the narrowed portion between the gasification section and the heat recovery chamber, which led to blockage of the narrowed portion. This problem cannot be solved by the conventional technology. That is, no countermeasures are taken in the vicinity of the restriction in the upper part of the gasification furnace, and therefore, ash adhesion in the vicinity of the restriction in the upper part of the gasification furnace becomes a problem.
[0007]
An object of the present invention is to provide a spouted bed coal gasification furnace in which ash is prevented from adhering to a throttle section communicating from a gasification section to a heat recovery section.
[0008]
[Means for Solving the Problems]
Of the present invention Spouted bed The coal gasifier includes a gasification unit for gasifying coal, a throttle unit at the top of the gasification unit, the inner diameter of which is reduced, a furnace outlet at the top of the throttle unit to discharge gas, The throttle section in the gasification section Bottom of Means for ejecting a gas for sealing.
[0009]
[Action]
According to the above configuration, the fuel such as coal and the oxidant such as oxygen supplied from the coal burner react in the cylindrical gasification unit and flow to the heat recovery unit. When the seal gas is ejected from a seal gas ejection nozzle that is located at an upper portion of the gasification section and has an inner diameter gradually reduced from the gasification section and that ejects a gas that protects a wall surface of the throttle section, the seal gas is discharged. Due to the flow of the gas flowing out of the gasification unit, the pressure rises along the wall surface of the throttle unit to form a seal film on the wall surface of the throttle unit. Particles including sticky droplets such as coal ash generated in the gasification section are conveyed to the gas flow flowing out of the gasification section. In the constricted portion, the particles approach the wall surface due to the inertial force of the particles. However, the adhesion of the particles to the wall surface of the constricted portion is suppressed by the seal film formed on the wall surface of the constricted portion, thereby suppressing the blockage of the constricted portion.
[0010]
In addition, a coal burner is arranged in a cylindrical gasification section to form a swirling flow, and when a fuel such as coal and an oxidizing agent such as oxygen are supplied, the gas generated in the gasification section turns while recovering heat. Flows to the department. When the seal gas is blown from a plurality of seal gas ejection nozzles radially installed in the radial direction, the seal gas moves in the wall direction by the swirling force of the generated gas, and is weaker than the gasification unit swirl on the wall of the throttle unit. A turned seal film can be formed. The particles are conveyed and swirled into the gas stream flowing out of the gasification section. Although the particles approach the wall surface due to centrifugal force, the centrifugal force is weakened by the weakly-turned seal film formed on the wall surface of the constricted portion, and the particles do not approach the wall surface of the constricted portion, preventing the particles from adhering to the wall surface of the constricted portion. Thus, suppression of blockage of the constricted portion is achieved.
[0011]
In addition, if the gas ejection nozzle for sealing the wall of the throttle portion is arranged obliquely downward, the seal gas is ejected below the seal gas ejection nozzle, and is swirled from the gasification section to the wall by the swirling force of the gas flowing out. The seal film that moves and flows along the wall surface of the throttle unit and covers the seal gas ejection nozzle is formed to protect the wall surface of the throttle unit. Thereby, adhesion of particles near the seal gas ejection nozzle is suppressed, and suppression of blockage of the seal gas ejection nozzle is achieved.
[0012]
In addition, by blowing a quench gas at a temperature at which the adhesiveness of the sticky particles is attenuated or eliminated from the gas ejection nozzle for sealing the wall surface of the narrowed portion, the adhesion of the particles at the narrowed portion is suppressed and the adhesiveness of the sticky particles is reduced. Is attenuated or lost.
[0013]
Further, when a plurality of gas ejection nozzles are arranged in the throttle unit, the quench gas for cooling the gas generated in the gasification unit is jetted from one side, and the sealing gas for protecting the wall surface of the throttle unit is jetted from the other side. A seal film is formed in the vicinity of the quench gas ejection nozzle to prevent the highly adhesive particles from approaching the quench gas ejection nozzle, and the highly adhesive particles are cooled and solidified in the vicinity of the quench gas ejection nozzle. In addition, the deposition is suppressed, and the blockage of the quench gas ejection nozzle is suppressed.
[0014]
Furthermore, when a part of the compressed air sent to the combustor of the gas turbine is blown as a seal gas on the wall of the gasification furnace throttle part, the compressed air forms a seal film on the gasification furnace throttle part, and the gasification furnace Suppresses ash adhesion at the throttle. At the same time, the seal gas generator and the gas turbine compressor can be integrated, and the system can be simplified.
[0015]
When the steam generated by the steam generator is blown in as a seal gas on the wall of the throttle, the steam reacts with the carbon monoxide and activated carbon generated in the gasification section, and is converted into hydrogen, and the The hydrogen concentration can be increased, and a seal film is formed on the narrowed portion to suppress ash adhesion on the narrowed portion.
[0016]
In addition, when the dust-removed and cooled recycle gas is blown in as a seal gas for the wall of the throttle section, the components of the recycle gas are almost the same as the product gas. Forms a seal film on the constricted portion and suppresses ash adhesion on the constricted portion.
[0017]
In addition, the apparatus having the above-described configuration having a plurality of seal gas ejection nozzles in which the tip of the gas ejection section is the smallest and having the same inner diameter of the tip of the gas ejection section is largely affected by the tip where the pressure loss is maximized. Therefore, it is possible to supply an equal amount of seal gas, and it is possible to form a seal film having a uniform thickness in the narrowed portion.
[0018]
According to the above configuration, the oxidizing agent and a fuel such as coal cause a gasification reaction in the gasification section to generate a high-temperature coal gasification gas. Therefore, it is necessary to be made of a material having high heat resistance, for example, ceramics.
[0019]
【Example】
Hereinafter, examples of the present invention will be described.
[0020]
FIG. 1 shows a system configuration diagram of Embodiment 1 of the present invention. The whole is composed of a coal gasifier 1, a gas turbine 40, a steam turbine 45 and the like. The gas generated in the coal gasifier 1 passes through a dust removing device 30 and a desulfurizing device 35 to remove dust and sulfur in the generated gas, and is burned by a gas turbine 40 to generate power. This exhaust gas passes through the exhaust heat recovery boiler 43 to generate steam, and the steam turbine 45 generates power. The compressed air generated by the compressor of the gas turbine 40 is sent to an oxygen production device 50 and separated into nitrogen and oxygen. Nitrogen is used as nitrogen for pressurization in the coal hopper 12, and oxygen is used as an oxidizing agent for gasification. Is done. Part of the compressed air is used as the seal gas 20 ejected from the seal gas ejection nozzle 15 installed near the gasification furnace throttle section. The effect peculiar to the present embodiment is that the compressed air generated by the compressor of the gas turbine 40 is used, so that the compressor for generating the seal gas can be omitted, the system can be simplified, the cost of the entire system can be reduced, or the oxidizing agent can be reduced. Another advantage is that the energy of pressurizing and purging nitrogen can be reduced, thereby improving the efficiency of the entire system.
[0021]
FIG. 2 is a vertical cross-sectional view of the spouted bed coal gasifier according to the first embodiment of the present invention. The entire gasification furnace is constituted by a refractory material 26 surrounded by a vessel 25, and comprises a furnace upper part 2, a gasification part 3, and a molten ash quenching chamber 4. The gasification unit 3 and the furnace upper part 2 are continuous with each other at a throttle unit 7 whose furnace diameter is smaller than that of the gasification unit 3.
[0022]
Next, the function of the first embodiment will be described. Coal and oxygen are supplied by burners. A plurality of upper burners 14 and lower burners 6 are arranged in a tangential direction such that a swirling flow is generated in the furnace, and coal and oxygen are injected into the gasification section 3 at a predetermined ratio to gasify the coal. The temperature of the gas in the gasification section 3 changes from 1200 to 1800 degrees, the ash in the coal is melted, and most of the ash is cooled by cooling water 5 in the molten ash quench chamber 4 installed below the gasification section 3 by gravity. , Quenched, solidified, pulverized and collected. Further, a part is conveyed by the gas generated in the gasification unit 3, passes through the throttle unit 7 while turning, and reaches the furnace upper part 2. In the furnace upper part 2, the radiant heat transfer from the gasification part 3 is blocked by the throttle part 7, and the heat is recovered by the heat transfer tube arranged on the furnace wall or the like. Do not drop to a temperature. The compressed air generated by the compressor of the gas turbine 40 is blown out as the seal gas 20 from the seal gas blow-out nozzle 15 installed in the narrowed portion 7, so that the seal film 10 is formed on the wall surface of the narrowed portion 7. Particles such as ash in coal which are conveyed by the gas generated in the gasification unit 3 and pass through the narrowing unit 7 are prevented from contacting the wall surface of the narrowing unit 7 by the seal film 10, and particles to the narrowing unit 7 Adhesion is suppressed. Further, by blowing compressed air at normal temperature as the seal gas 20, the temperature of the gas and particles passing through the throttle unit 7 is reduced to a temperature at which the gasification reaction hardly proceeds or a temperature at which the adhesive force of the sticky particles almost disappears. I do. Particles having lost the adhesive force are suppressed from adhering to the wall surface of the narrowed portion 7. Further, by disposing the seal gas ejection nozzle 15 obliquely downward, the seal gas 20 is ejected below the seal gas ejection nozzle 15 and is swirled out of the gasification unit 3 to flow out of the gasification unit 3 to the wall surface of the throttle unit 7. Rise along. As a result, the lower end of the seal film 10 is located below the seal gas ejection nozzle 15. As a result, the wall surface near the seal gas ejection nozzle 15 is covered with the seal film 10, particles are prevented from adhering near the seal gas ejection nozzle 15, and the blockage of the seal gas ejection nozzle 15 is suppressed.
[0023]
FIG. 3 shows a cross-sectional view taken along a horizontal section II of the spouted bed coal gasifier according to the first embodiment of the present invention. By having a plurality of seal gas jet nozzles 15 radially in the radial direction, the seal film 10 has a substantially uniform thickness in the circumferential direction on the wall surface of the throttle unit 7 outside the gas flowing out of the gasification unit 3. Form. Particles such as ash in the coal conveyed to the gas generated in the gasification section 3 and passing through the narrowing section 7 are turned by the swirling force or the inertial force in the wall direction provided by the gas generated in the gasification section 3 to reduce the size of the narrow section 7. Particles that approach the nearby wall surface but whose swirling force and inertial force in the wall direction direction are weakened by the seal film 10 do not come into contact with the wall surface of the throttle unit 7, thereby suppressing the particle adhesion to the throttle unit 7. You.
[0024]
FIG. 4 is a cross-sectional view of the throttle portion of the spouted bed coal gasifier according to the first embodiment of the present invention. The seal gas ejection nozzle is configured such that the gas ejection portion at the nozzle tip is the thinnest. For this reason, in the seal gas supply system, since the pressure loss at this portion is the highest, the supply amount from any of the seal gas ejection nozzles is equalized by equalizing the inner diameter of the gas ejection portion at the nozzle tip. be able to.
[0025]
FIG. 5 shows the relationship between the radial distance in the vicinity of the throttle portion 7 and the circumferential velocity distribution in the spouted bed coal gasifier of the first embodiment of the present invention. It can be seen that the circumferential velocity near the wall of the throttle unit 7 is reduced when steam is injected as the seal gas 20 from the seal gas injection nozzle 15 installed in the throttle unit 7 compared to when steam is not injected.
[0026]
Embodiment 2 will be described below. FIG. 6 is a cross-sectional view taken along a horizontal section II of a spouted bed coal gasifier according to a second embodiment of the present invention. A feature of the present embodiment is that a seal film that is slightly swirled from the gas flowing out of the gasification unit 3 can be formed on the wall surface of the throttle unit 7 by having the seal gas ejection nozzle that ejects the seal gas 20 in the swirling direction.
[0027]
Next, the function of the second embodiment will be described. By having a plurality of seal gas ejection nozzles 15 in the swirling direction, the swirl force of the gas flowing out of the gasification unit 3 and the swirl force of the seal gas 20 ejected at a predetermined amount are synthesized on the wall surface of the throttle unit 7, The seal film 10 that has turned slightly from the turning portion is formed. Particles such as ash in the coal conveyed to the gas generated in the gasification section 3 and passing through the narrowing section 7 are turned by the swirling force or the inertial force in the wall direction provided by the gas generated in the gasification section 3 to reduce the size of the narrow section 7. Particles that approach the nearby wall surface but whose swirling force and inertial force in the wall direction direction are weakened by the seal film 10 do not come into contact with the wall surface of the throttle unit 7, thereby suppressing the particle adhesion to the throttle unit 7. You.
[0028]
Embodiment 3 will be described below. FIG. 7 is a longitudinal sectional view of a spouted bed coal gasifier of Embodiment 3 of the present invention. The feature of the present embodiment is that a seal gas ejection nozzle 15 for ejecting the seal gas 20 radially in the radial direction has a slit 17 at the tip end, so that the gas flowing out of the gasification unit 3 located on the wall surface of the throttle unit 7 can be removed. On the outside, the seal film 10 can be formed with a uniform thickness in the circumferential direction, and the seal gas ejection portion can be formed of one component, and the structure can be simplified.
[0029]
Next, the function of the third embodiment will be described. Coal and oxygen are supplied by burners. A plurality of the upper burners 14 and the lower burners 6 are respectively arranged so as to generate a swirling flow in the furnace, and coal and oxygen are injected into the gasification section 3 at a predetermined ratio to gasify the coal. The temperature of the gas in the gasification section 3 changes from 1200 to 1800 degrees, the ash in the coal is melted, and most of the ash is cooled by cooling water 5 in the molten ash quench chamber 4 installed below the gasification section 3 by gravity. , Quenched, solidified, pulverized and collected. Further, a part is conveyed by the gas generated in the gasification unit 3, passes through the throttle unit 7 while turning, and reaches the furnace upper part 2. In the furnace upper part 2, the radiant heat transfer from the gasification part 3 is blocked by the throttle part 7, and the heat is recovered by the heat transfer tube arranged on the furnace wall or the like. Do not drop to a temperature. The compressed air generated by the compressor of the gas turbine 40 is jetted out as the seal gas 20 from the seal gas jet slit 17 to form the seal film 10 on the wall surface of the throttle unit 7. Particles such as ash in coal which are conveyed by the gas generated in the gasification unit 3 and pass through the narrowing unit 7 are prevented from contacting the wall surface of the narrowing unit 7 by the seal film 10, and particles to the narrowing unit 7 Adhesion is suppressed. Further, by blowing compressed air at normal temperature as the seal gas 20, the temperature of the gas and particles passing through the throttle unit 7 is reduced to a temperature at which the gasification reaction hardly proceeds or a temperature at which the adhesive force of the sticky particles almost disappears. I do. The particles having lost the adhesive force do not adhere to the wall surface of the narrowed portion 7, and the adhesion to the narrowed portion 7 is suppressed. Further, since the seal gas ejection slit 17 for ejecting the gas obliquely downward is provided, the seal gas 20 is ejected obliquely below the seal gas ejection slit 17. The seal gas 20 moves to the wall surface by the centrifugal force received from the gas flowing out while turning from the gasification unit 3, and then rises along the wall surface of the throttle unit 7. Thereby, the lower end of the seal film 10 is located below the seal gas ejection slit 17. For this reason, the wall surface near the seal gas ejection slit 17 is covered with the seal film 10, and the adhesion of particles at the tip of the seal gas ejection slit 17 is suppressed, so that the sealing of the seal gas ejection slit 17 is suppressed.
[0030]
FIG. 8 is a cross-sectional view taken along a horizontal section II of a spouted bed coal gasifier according to a third embodiment of the present invention. A partition 18 is provided at the tip of the seal gas ejection slit 17 at the tip of the seal gas ejection nozzle 15 so that the seal gas 20 can be ejected radially in the radial direction to form the seal film 10. Particles such as ash in the coal conveyed to the gas generated in the gasification section 3 and passing through the narrowing section 7 are turned by the swirling force or the inertial force in the wall direction provided by the gas generated in the gasification section 3 to reduce the size of the narrow section 7. Particles that approach the nearby wall surface but whose swirling force and inertial force in the wall direction direction are weakened by the seal film 10 do not come into contact with the wall surface of the throttle unit 7, thereby suppressing the particle adhesion to the throttle unit 7. You.
[0031]
Embodiment 4 will be described below. FIG. 9 is a longitudinal sectional view of a spouted bed coal gasifier embodying the present invention. The feature of the present embodiment is that a plurality of gas ejection nozzles are arranged in the throttle unit 7 and in the vicinity of a seal gas ejection nozzle 15 which ejects a seal gas 20 for forming a seal film 10 for protecting a wall surface of the throttle unit 7, A nozzle sealing gas ejection nozzle 16 for ejecting a nozzle sealing gas 23 for forming a nozzle sealing film 11 for protecting the tip of the sealing gas ejection nozzle 15 is provided, so that particle adhesion of the nozzle is suppressed.
[0032]
Next, the function of the fourth embodiment will be described. Coal and oxygen are supplied by burners. A plurality of the upper burners 14 and the lower burners 6 are respectively arranged so as to generate a swirling flow in the furnace, and coal and oxygen are injected into the gasification section 3 at a predetermined ratio to gasify the coal. The temperature of the gas in the gasification section 3 changes from 1200 to 1800 degrees, the ash in the coal is melted, and most of the ash is cooled by cooling water 5 in the molten ash quench chamber 4 installed below the gasification section 3 by gravity. , Quenched, solidified, pulverized and collected. Further, a part is conveyed by the gas generated in the gasification unit 3, passes through the throttle unit 7 while turning, and reaches the furnace upper part 2. In the furnace upper part 2, the radiant heat transfer from the gasification part 3 is blocked by the throttle part 7, and the heat is recovered by the heat transfer tube arranged on the furnace wall or the like. Do not drop to a temperature. Compressed air generated by the compressor of the gas turbine 40 is ejected from the seal gas ejection nozzle 15 as the seal gas 20 to form the seal film 10 on the wall surface of the throttle unit 7. Particles, such as ash, in the coal conveyed by the gas generated in the gasification section 3 and passing through the narrowing section 7 form a seal film.
By 10, the contact of the narrowed portion 7 with the wall surface is prevented, and the adhesion of particles to the narrowed portion 7 is suppressed. Further, by blowing compressed air at normal temperature as the seal gas 20, the temperature of the gas and particles passing through the throttle unit 7 is reduced to a temperature at which the gasification reaction hardly proceeds or a temperature at which the adhesive force of the sticky particles almost disappears. I do. The particles having lost the adhesive force do not adhere to the wall surface of the narrowed portion 7, and the adhesion to the narrowed portion 7 is suppressed. Further, a nozzle sealing gas 23 is blown out below the seal gas blowing nozzle 15 from a nozzle sealing gas blowing nozzle 16 installed near the seal gas blowing nozzle 15 for protecting the wall surface of the throttle portion. The nozzle sealing gas 23 rises along the wall surface of the throttle unit 7 due to the gas flowing out while turning from the gasification unit 3. Thus, the lower end of the nozzle sealing film 11 is located below the seal gas ejection nozzle 15. As a result, the wall surface near the seal gas ejection nozzle 15 is covered with the nozzle sealing film 11, and the particles pass near the seal gas ejection nozzle 15 at a position away from the wall surface. By ejecting the seal gas 20 at a predetermined temperature at which the stickiness of the ash disappears from the seal gas ejection nozzle 15, the sticky particles are rapidly cooled at a position away from the wall surface and become sticky particles. Accumulates on the wall surface of the throttle portion 7 and the wall surface in the vicinity of the seal gas ejection nozzle 15, and the blocking of the throttle portion is suppressed.
[0033]
FIG. 10 shows a system configuration diagram of Embodiment 5 of the present invention. The whole is composed of a coal gasifier 1, a gas turbine 40, a steam turbine 45 and the like. The gas generated in the coal gasifier 1 passes through a dust removing device 30 and a desulfurizing device 35 to remove dust and sulfur in the generated gas, and is burned by a gas turbine 40 to generate power. This exhaust gas passes through the exhaust heat recovery boiler 43 to generate steam, and the steam turbine 45 generates power. The compressed air generated by the compressor of the gas turbine 40 is sent to an oxygen production device 50 and separated into nitrogen and oxygen. Nitrogen is used as nitrogen for pressurization in the coal hopper 12, and oxygen is used as an oxidizing agent for gasification. Is done. Further, after cooling, a part of the generated gas from which dust and sulfur content have been removed is blown out as a recycle gas from the seal gas blowout nozzle 15 installed near the gasification furnace throttle section. The feature of this embodiment is that the components of the recycle gas are almost the same as the product gas, so that the recycle gas forms the seal film in the narrowed portion and cools the product gas without substantially changing the components of the product gas. The purpose is to suppress ash adhesion at the narrowed portion.
[0034]
FIG. 11 shows a system configuration diagram of Embodiment 6 of the present invention. The whole is composed of a coal gasifier 1, a gas turbine 40, a steam turbine 45 and the like. The gas generated in the coal gasifier 1 passes through a dust removing device 30 and a desulfurizing device 35 to remove dust and sulfur in the generated gas, and is burned by a gas turbine 40 to generate power. This exhaust gas passes through the exhaust heat recovery boiler 43 to generate steam, and the steam turbine 45 generates power. The compressed air generated by the compressor of the gas turbine 40 is sent to an oxygen production device 50 and separated into nitrogen and oxygen. Nitrogen is used as nitrogen for pressurization and purging in the coal hopper 12, and oxygen is used for gasification. Used as an oxidizing agent. Further, a part of the nitrogen is jetted from the seal gas jet nozzle 15 installed near the gasification furnace throttle section. The feature of the present embodiment is that since inert nitrogen gas is ejected, it does not react with the generated gas and consumption of the generated gas can be suppressed, and nitrogen gas separated by the oxygen production apparatus is used. The equipment for gas production is omitted and the system is simplified.
[0035]
FIG. 12 shows a system configuration diagram of Embodiment 7 of the present invention. The whole is composed of a coal gasifier 1, a gas turbine 40, a steam turbine 45 and the like. The gas generated in the coal gasifier 1 passes through a dust removing device 30 and a desulfurizing device 35 to remove dust and sulfur in the generated gas, and is burned by a gas turbine 40 to generate power. This exhaust gas passes through the exhaust heat recovery boiler 43 to generate steam, and the steam turbine 45 generates power. The compressed air generated by the compressor of the gas turbine 40 is sent to an oxygen production device 50 and separated into nitrogen and oxygen. Nitrogen is used as nitrogen for pressurization in the coal hopper 12, and oxygen is used as an oxidizing agent for gasification. Is done. The high-pressure steam generated by the steam generator 60 is jetted from a seal gas jet nozzle 15 installed near the gasification furnace throttle section. The feature of this embodiment is that the seal gas water vapor reacts with carbon monoxide and activated carbon generated in the gasification section, is converted to hydrogen, increases the hydrogen concentration in the generated gas, and forms a seal film on the throttle section. The purpose of the present invention is to cool the formed and generated gasified gas and suppress ash adhesion at the narrowed portion.
[0036]
【The invention's effect】
According to the present invention, it is possible to provide a spouted bed coal gasifier capable of suppressing the adhesion of particles in the narrowed portion, suppressing the blockage of the narrowed portion, and continuously operating for a long time.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a gasification power generation system according to a first embodiment of the present invention.
FIG. 2 is a longitudinal sectional view of the gasification furnace according to the first embodiment of the present invention.
FIG. 3 is a sectional view taken along line II of the gasification furnace according to the first embodiment of the present invention.
FIG. 4 is a vertical cross-sectional view of a narrowed portion of the gasification furnace according to the first embodiment of the present invention.
FIG. 5 is a diagram showing a circumferential velocity distribution at a throttle portion of the gasification furnace according to the first embodiment of the present invention.
FIG. 6 is a sectional view taken along the line II of the gasification furnace according to a second embodiment of the present invention.
FIG. 7 is a longitudinal sectional view of a gasification furnace according to a third embodiment of the present invention.
FIG. 8 is a sectional view taken along the line II-II of the gasification furnace according to the third embodiment of the present invention.
FIG. 9 is a longitudinal sectional view of a gasification furnace according to a fourth embodiment of the present invention.
FIG. 10 is a configuration diagram of a gasification power generation system in which a recycled gas is blown as a seal gas.
FIG. 11 is a configuration diagram of a gasification power generation system in which nitrogen gas is blown as a seal gas.
FIG. 12 is a configuration diagram of a gasification power generation system in which steam is blown as a seal gas.
FIG. 13 is a graph showing the relationship between the number of seal gas nozzles / the number of coal burners and the amount of deposited ash.
FIG. 14 is a diagram showing a relationship between a seal gas ejection angle and an ash adhesion amount.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Coal gasification furnace, 2 ... Furnace upper part, 3 ... Gasification part, 4 ... Molten ash quenching room, 5 ... Cooling water, 6 ... Lower coal burner, 7 ... Reducing part, 10 ... Seal film, 11 ... Nozzle seal Membrane 12, coal hopper 14 upper coal burner 15 seal gas jet nozzle 16 gas jet nozzle for nozzle sealing 17 seal gas jet part 18 partition 20 gas seal 21 coal Reference numeral 22: oxidizing agent, 23: gas for nozzle sealing, 25: container, 26: refractory material, 30: dust removing device, 35: desulfurizing device, 40: gas turbine, 43: exhaust heat recovery boiler, 45: steam turbine, 50 ... Oxygen generator, 60 ... Steam generator.

Claims

A gasification section for gasifying coal, a narrowing section having an inner diameter smaller than that of the gasification section, a furnace outlet section for drawing gas from the gasification section upward through the narrowing section and discharging the gas outside the furnace; spouted bed coal gasifier and having a mechanism for ejecting a gas for sealing the bottom of the narrowed portion of the reduction unit.

A supply unit for supplying coal and an oxidant is provided tangentially to the furnace wall, a gasification unit forming a swirling flow of the coal-producing gas, a narrowing unit having an inner diameter smaller than the gasification unit, and the gasification unit. A spouted bed coal gasifier comprising: a furnace outlet part for discharging gas to the outside of the furnace through the throttle part; and a mechanism for injecting a sealing gas into a lower part of the throttle part in the gasification part. .

A gasifying section for gasifying coal, a narrowing section above the gasifying section and having a reduced inner diameter, a furnace outlet section above the narrowing section for discharging gas, and the throttle in the gasifying section. Means for injecting a sealing gas in a radial direction at a lower portion of the portion .

A gasifying section for gasifying coal, a narrowing section above the gasifying section and having a reduced inner diameter, a furnace outlet section above the narrowing section for discharging gas, and the throttle in the gasifying section. And a nozzle for ejecting the quench gas of the throttle portion in a radial direction at a lower portion of the portion .

A gasifying section for gasifying coal, a narrowing section above the gasifying section and having a reduced inner diameter, a furnace outlet section above the narrowing section for discharging gas, and the throttle in the gasifying section. A mechanism for ejecting a swirling seal gas at a lower part of the section.

A gasifying section for gasifying coal, a narrowing section above the gasifying section and having a reduced inner diameter, a furnace outlet section above the narrowing section for discharging gas, and the throttle in the gasifying section. A spouted bed coal gasifier having a mechanism at a lower part of the part for injecting a sealing gas obliquely downward.

A plurality of gasification reaction sections, a throttle section having an inner diameter smaller than that of the gasification section, a furnace outlet section for discharging gas generated in the gasification section, and a sealing section below the throttle section in the gasification section . A spouted bed coal gasifier having a mechanism for ejecting gas.

The spouted bed coal gasifier according to any one of claims 1 to 7, wherein the gas ejection mechanism has a plurality of stages .

The spouted bed coal gasifier according to any one of claims 1 to 8, wherein the gas ejection mechanism has a nozzle that ejects gas radially in a radial direction.

The spouted bed coal gasifier according to any one of claims 1 to 8, wherein the gas ejection mechanism has a slit that ejects gas radially in a radial direction.

The gas ejection mechanism is spouted bed coal gas according to one of claims 1 to 10 in which the pressure loss in the gas ejection tip is characterized the structure der Turkey was reduced most tip portion such that the maximum Furnace.

The spouted bed coal gasifier according to any one of claims 1 to 11, wherein the gas ejecting mechanism is configured such that a tip portion of the gas ejecting mechanism that comes into contact with a high-temperature generated gas and becomes high in temperature is made of ceramic. .

The spouted bed coal gasifier according to any one of claims 1 to 11, wherein the gas ejection mechanism is made of ceramic as a whole in contact with a high-temperature generated gas and has a high temperature.

Spouted bed coal gas according to one of claims 1 to 13, characterized in that the nitrogen gas produced by the oxygen production equipment to produce an oxidant injected into the gasification unit and the gas of the gas ejection mechanism Furnace.

The spouted bed coal gasifier according to any one of claims 1 to 13, further comprising a steam generator, wherein steam generated by the steam generator is used as the gas of the gas ejection mechanism .

A heat recovery section for cooling the gas produced in the gasification unit, and a dust removing unit for dedusted the cooled gas at the heat recovery unit, of the product gas is dedusted in a dehydration dust The spouted bed coal gasifier according to any one of claims 1 to 13, wherein a part of the gas is used as the recycle gas by the gas ejection mechanism .