JP4402867B2

JP4402867B2 - Reformer

Info

Publication number: JP4402867B2
Application number: JP2002217449A
Authority: JP
Inventors: 浩一楠村; 幹夫品川
Original assignee: Panasonic Corp; Matsushita Electric Industrial Co Ltd; Matsushita Electric Works Ltd
Current assignee: Panasonic Corp; Panasonic Electric Works Co Ltd; Panasonic Holdings Corp
Priority date: 2002-07-26
Filing date: 2002-07-26
Publication date: 2010-01-20
Anticipated expiration: 2022-07-26
Also published as: JP2004063170A

Description

【０００１】
【発明の属する技術分野】
本発明は、液化石油ガスを原燃料として水素を主成分とする改質ガスを生成させる燃料電池用の改質装置に関するものである。
【０００２】
【従来の技術】
従来より、液化石油ガスを原燃料として水蒸気改質反応により改質して水素を主成分とする改質ガスを生成させる改質装置が知られているが、現在、この改質ガスの有望な利用用途の一つとして、燃料電池用の発電燃料を挙げることができる。この改質装置は、改質触媒が充填された改質反応部と、一酸化炭素変成触媒が充填されたシフト反応部と、一酸化炭素酸化触媒が充填された一酸化炭素酸化部とを具備して形成されるもので、前記改質触媒をバーナーで加熱しながら原燃料と水蒸気とを改質部に通すことにより水蒸気改質反応を進行せしめ、水素を主成分とする改質ガスを得るというものである。
【０００３】
一方、この改質ガス中に一酸化炭素が含まれていると、これにより、燃料電池が被毒して電極触媒性能が低下するので、まず、生成直後の改質ガスをシフト反応部に通し、一酸化炭素変成触媒によって、改質ガス中の一酸化炭素含有量をシフト反応により低減せしめた後、さらに、これを一酸化炭素酸化部に通し、一酸化炭素酸化触媒によって系内に残留する一酸化炭素を酸化、除去して改質ガス中の一酸化炭素含有量を燃料電池の被毒を回避できる程度まで低減できるようにしている。
【０００４】
ところで、かかる水蒸気改質反応における原燃料供給量および水蒸気供給量の適正範囲は、原燃料の組成に応じて規定することができる。即ち、これらが適正範囲外になると、燃料電池に供給される改質ガス中の水素量が不足する、あるいは一酸化炭素濃度が上昇する等の不具合の発生により、燃料電池の発電出力が低下したり、燃料電池を損傷したりするおそれがあるので、例えば、特開平６−２６０２０３号公報等に見られるように、改質装置の運転前に原燃料の組成を測定し、測定した組成に応じて改質装置の運転条件を定めるという方法が採用されていた。
【０００５】
しかし、原燃料として液化石油ガスを用いる場合、液化石油ガスはプロパン、ブタン等の蒸気圧の異なる混合成分よりなるため、原燃料の消費に伴い、容器内の原燃料残液中の組成が順次、変動することにより、改質装置に供給される原燃料の組成も変動し、改質装置を常に最適な条件で運転することが難しいという問題があった。
【０００６】
【発明が解決しようとする課題】
本発明は、かかる事由に鑑み、なされたもので、本発明の目的は、液化石油ガスの組成が運転中に変動した場合でも、最適な条件で運転を行うことを可能とする改質装置を提供することにある。
【０００７】
【課題を解決するための手段】
上記課題を解決するために、請求項１記載の改質装置の発明にあっては、少なくとも、液化石油ガスを貯蔵する液化石油ガス貯蔵タンクと、前記液化石油ガス貯蔵タンクから出された液化石油ガスの圧力調整を行なう圧力調整器と、前記圧力調整器により圧力調整された液化石油ガスを水蒸気を用いて水蒸気改質して改質ガスを生成する改質触媒を有する改質反応部と、前記圧力調整器により圧力調整された液化石油ガスの一部を燃焼させることにより、前記改質反応部における反応を加熱により促進せしめる燃焼部と、を備えた燃料電池用の改質装置において、前記改質反応部に供給される液化石油ガスの組成を連続的に測定する組成測定手段と、前記組成測定手段で測定した組成に応じて前記改質反応部に供給される液化石油ガスの量と水蒸気の量とを連続的に制御する流量制御手段を備え、前記組成測定手段が、前記液化石油ガス貯蔵タンクから出され、前記圧力調整器により圧力調整される前の液化石油ガスの圧力および温度を測定することにより前記改質反応部に供給される液化石油ガスの組成を求める手段であることを特徴とするものである。
【０００８】
請求項２記載の改質装置の発明にあっては、少なくとも、液化石油ガスを貯蔵する液化石油ガス貯蔵タンクと、前記液化石油ガス貯蔵タンクから出された液化石油ガスの圧力調整を行なう圧力調整器と、前記圧力調整器により圧力調整された液化石油ガスを水蒸気を用いて水蒸気改質して改質ガスを生成する改質触媒を有する改質反応部と、前記圧力調整器により圧力調整された液化石油ガスの一部を燃焼させることにより、前記改質反応部における反応を加熱により促進せしめる燃焼部と、を備えた燃料電池用の改質装置において、前記改質反応部に供給される液化石油ガスの組成を連続的に測定する組成測定手段と、前記組成測定手段で測定した組成に応じて前記改質反応部に供給される液化石油ガスの量と水蒸気の量とを連続的に制御する流量制御手段と、前記燃焼部に供給される液化石油ガスの流量を均一化する流量均一化手段とを備え、前記組成測定手段が、前記燃焼部の燃焼ガス温度を測定することにより前記改質反応部に供給される液化石油ガスの組成を求める手段であることを特徴とするものである。
【０００９】
請求項３記載の改質装置の発明にあっては、少なくとも、液化石油ガスを貯蔵する液化石油ガス貯蔵タンクと、前記液化石油ガス貯蔵タンクから出された液化石油ガスの圧力調整を行なう圧力調整器と、前記圧力調整器により圧力調整された液化石油ガスを水蒸気を用いて水蒸気改質して改質ガスを生成する改質触媒を有する改質反応部と、前記圧力調整器により圧力調整された液化石油ガスの一部を燃焼させることにより、前記改質反応部における反応を加熱により促進せしめる燃焼部と、を備えた燃料電池用の改質装置において、前記改質反応部に供給される液化石油ガスの組成を連続的に測定する組成測定手段と、前記組成測定手段で測定した組成に応じて前記改質反応部に供給される液化石油ガスの量と水蒸気の量とを連続的に制御する流量制御手段と、前記燃焼部に供給される液化石油ガスの流量を均一化する流量均一化手段とを備え、前記組成測定手段が、前記燃焼部の燃焼排気ガス中の酸素または二酸化炭素濃度を測定することにより前記改質反応部に供給される液化石油ガスの組成を求める手段であることを特徴とするものである。
【００１２】
【発明の実施の形態】
以下、本発明の実施形態を図面に基づき説明する。
【００１３】
[第１の実施形態]
図１は本発明の第１の実施形態における改質装置の概略を示す図、図２は貯蔵タンク１０から取り出され、圧力調整される前の液化石油ガスの組成と液化石油ガスの圧力および温度の関係の一例を示す特性図である。
【００１４】
即ち、本実施形態の改質装置は、図１に示すように、原燃料の液化石油ガスを水蒸気を用いて水蒸気改質して水素を主成分とする改質ガスを生成する改質触媒を有する改質反応部１、改質反応部１にて生成した改質ガス中の一酸化炭素濃度を低減するシフト反応部２、シフト反応部２にて一酸化炭素濃度が低減された改質ガス中に未だ残留する一酸化炭素ガスを一酸化炭素酸化反応により酸化、除去する一酸化炭素酸化部３、及び、これら各反応部、特に、改質反応部１を加熱してその反応を促進せしめる燃焼部４を備えている。
【００１５】
また、改質反応部１に供給される液化石油ガスの圧力調整を行う圧力調整器５、改質反応部１に供給される原燃料である液化石油ガスの流量を調節する原燃料液化ガス流量調節弁６、改質反応部１に供給される水蒸気の流量を調節する水蒸気流量調節弁７、燃焼部４に供給される燃焼用液化石油ガスの流量を調節する燃焼用液化石油ガス流量調節弁８、燃焼部４に供給される燃焼用空気１６の流量を調節する燃焼用空気流量調節弁９とを設け、さらに、液化石油ガス貯蔵タンク１０から取り出され、圧力調整器５で圧力調整される前の液化石油ガスの組成を測定する組成測定手段１１ａと、該組成測定手段１１ａによって得られた液化石油ガスの組成に関する情報に基づいて、原燃料液化ガス流量調節弁６、水蒸気流量調節弁７の開閉レベルを制御する流量制御手段１２を備えたものである。
【００１６】
即ち、本実施形態の改質器においては、組成測定手段１１ａは、液化石油ガス貯蔵タンク１０から取り出され、圧力調整器５で圧力調整される前の液化石油ガスの圧力および温度を測定する手段を有する一方、さらに、これらの圧力および温度の測定値を基礎として液化石油ガスの組成を算出し得るというものである。
例えば、改質器の原燃料として使用される液化石油ガスが、プロパンとｎ−ブタンの２成分のみからなると仮定できる場合には、その系内の温度（Ｔ）、圧力（Ｐ_GT）を測定し、これらを基礎として、比較的簡便にその系内の両成分の割合を算出することができる。即ち、Ｔ＝Ｔ１、Ｐ_GT＝Ｐ_GT1のとき、プロパンのモル分率をｘしたとき、ｎ−ブタンのモル分率は、１−ｘであり、Ｔ＝Ｔ１のときのプロパンの飽和蒸気圧をＰ_GT1（プロパン）、ｎ−ブタンの飽和蒸気圧をＰ_GT1（ｎ−ブタン）としたとき、Ｐ_GT1（プロパン）ｘ+Ｐ_GT1（ｎ−ブタン）（１−ｘ）＝Ｐ_GT1であり、Ｐ_GT1（プロパン）、Ｐ_GT1（ｎ−ブタン）は、別途、例えば、Ａｎｔｏｉｎｅ式（例えば、「化学工学便覧、改訂第５版」、第１８頁〜第２７頁または、「電子計算機による蒸気圧データ」大江修造、データブック出版社に記載されている。）等から求められるからである。
【００１７】
図２の特性図は、かかる手法により算出された、プロパンとｎ−ブタンのみからなる液化石油ガス中の各温度における両成分の存在比とこの液化石油ガスの圧力の関係を示すものである。即ち、この特性図を基礎とすれば、液化石油ガスの貯蔵タンク１０から取り出された圧力調整される前の液化石油ガスの圧力および温度を測定するのみで、液化石油ガスの組成（成分比）が特定でき、さらには、この液化石油ガスの組成に関する情報に基づいて、液化石油ガスの組成に応じて改質反応部１に供給される液化石油ガスと水蒸気の量に関する最適条件を特定することが可能となるというものである。
【００１８】
この結果、液化石油ガスの貯蔵タンク１０から取り出され、圧力調整器５で圧力調整される前の液化石油ガスの圧力および温度を前記組成測定手段１１ａにおいて、連続的に測定し、これを基礎として算出される液化石油ガスの成分組成に対応して、流量制御手段１２において、改質反応部１に供給される液化石油ガスと水蒸気の量を連続的に制御することにより、改質反応部１に供給される液化石油ガスの成分組成が運転中に変動した場合においても、原燃料液化石油ガスと水蒸気の量が流量調節弁６、７によって適正に調節され、改質装置を常に最適な条件で運転を行うことが可能となる。
【００１９】
なお、流量制御手段１２は、例えば、組成測定手段１１ａからの上記液化石油ガスの成分組成に対応した出力信号を受け、上記流量調節弁６、７の開閉レベルを制御する信号を出力するように構成できる。制御方法は、特に制限されないが、ＰＩＤ制御、ファジィ制御、ニューラルネットワーク等公知の技術を利用できる。
【００２０】
[第２の実施形態]
図３は本発明の第２の実施形態における改質装置の概略を示す図、図４は本発明の第２の実施形態における液化石油ガス中のプロパンの割合と燃焼ガス温度の関係を示す特性図である。
【００２１】
即ち、本実施形態の改質装置は、図３に示すように、燃焼部４に組成測定手段１１ｂを有するものであり、この組成測定手段１１ｂは、燃焼部４の燃焼ガス温度を測定することにより、液化石油ガスの組成の概略値を算出し得るというものである。
【００２２】
図３において、燃焼用液化石油ガス流量調節弁８の開閉レベルを一定にした場合、液化石油ガスの組成が変動すると、燃焼部４に供給される液化石油ガスは、その流量においても変化し、その結果、燃焼部４の燃焼ガス温度は、かかる液化石油ガスの組成および流量の変化に対応して変化することとなる。図４の特性図は、プロパンとｎ−ブタンのみからなる液化石油ガスにおいて、燃焼用液化石油ガス流量調節弁８および燃焼用空気流量調節弁９の開閉レベルを一定にした場合の、両成分の組成の変化に対応した燃焼部４の燃焼ガス温度の相関関係の一例を示すものである。かかる特性図に示される液化石油ガスの組成と燃焼ガス温度の相関関係は、例えば、実際に燃焼部４において所定の組成を有する液化石油ガスを燃焼せしめてその燃焼ガス温度を実測する方法、或いは、理論火炎温度（断熱火炎温度）（例えば、「ガス燃焼の理論と実際〔吉田邦夫監修〕」仲町一郎、庄司不二雄共著、（財）省エネルギーセンター発行 [１９９２年１０月１３日第１版第１刷発行]、第１７頁〜第２１頁等に記載されている。）を液化石油ガスを構成する各成分ガスについて算出し、これを基礎として混合ガスについて各成分ガスの分圧に応じた比例配分でその混合ガスについての燃焼ガス温度を導出する方法等により求めることができる。
【００２３】
図４の特性図は、実測により算出された液化石油ガスの組成と燃焼ガス温度の相関関係を示すものである。即ち、このような相関関係を利用すれば、液化石油ガス中の成分比からその液化石油ガスの燃焼ガス温度の概略を算出し得る一方、逆に、液化石油ガスの燃焼ガス温度を測定することにより、液化石油ガス中の成分比の概略を算出し得ることとなる。具体的には、燃焼用液化石油ガス流量調節弁８および燃焼用空気流量調節弁９の開閉レベルを一定にしておき、組成測定手段１１ｂにおいて、燃焼部４の燃焼ガス温度を測定するのみで、液化石油ガスの組成の概略値を算出でき、これを基礎として、改質反応部１に供給される液化石油ガスと水蒸気の割合を原燃料液化石油ガスおよび水蒸気の流量制御手段１２において最適化できるというものである。
【００２４】
また、燃焼部４に供給される液化石油ガスの流量を均一化するためのオリフィス等の流量均一化手段１３を設けることにより、液化石油ガスの組成がより正確に把握することが可能となる。さらには、燃焼部４に供給される液化石油ガスの圧力を測定する圧力測定手段１４を設け、液化石油ガスの流量をこの圧力測定値により補正することにより、燃焼部に供給される液化石油ガスの流量をより正確に把握することも可能となる。
【００２５】
即ち、以上のような構成を採用することにより、燃焼部の燃焼ガス温度を連続的に測定して、この燃焼ガス温度から液化石油ガスの組成を求めることができ、この組成に応じて改質反応部１に供給される液化石油ガスと水蒸気の量を連続的に最適値に制御するようにしたので、液化石油ガスの組成が運転中に変動した場合でも、原燃料液化石油ガスと水蒸気の量が流量調節弁６、７によって適正に調節され、改質装置を最適な条件で運転を行うことができることとなる。
【００２６】
なお、流量制御手段１２は、例えば、組成測定手段１１ｂからの上記液化石油ガスの成分組成に対応した出力信号を受け、上記流量調節弁６、７の開閉レベルを制御する信号を出力するように構成できる。制御方法は、特に制限されないが、ＰＩＤ制御、ファジィ制御、ニューラルネットワーク等公知の技術を利用できる。
【００２７】
一方、本実施形態の改質装置では、燃焼部４の燃焼ガス温度を測定する構成としたが、別途、液化石油ガスの組成を測定するための専用燃焼部（図示せず）を設け、この専用燃焼部の燃焼ガス温度を測定する実施形態も当然に可能であり、上記課題解決に寄与する限りにおいて何ら制約のないことはいうまでもない。また、この場合において、かかる液化石油ガスの組成を測定するための燃焼部を、改質反応部１の改質触媒を加熱するよう配置することにより、より高効率の改質装置を提供できることとなる。
【００２８】
さらに、本実施形態の改質装置では、液化石油ガスの組成を求めるために、燃焼部４の燃焼ガス温度を測定する構成としたが、算出する液化石油ガスの組成の精度を、さらに向上するために、第１の実施形態で示した液化石油ガスの圧力および温度を測定し、これらの圧力および温度の測定値を基礎として液化石油ガスの組成を算出し得る組成測定手段１１ａを併用する実施形態も当然に可能である。
【００２９】
[第３の実施形態]
図５は本発明の第３の実施形態における改質装置の概略を示す図、図６は本発明の第３の実施形態における液化石油ガス中のプロパンの割合と燃焼排気ガス中の酸素濃度の関係を示す特性図、図７は本発明の第３の実施形態における液化石油ガス中のプロパンの割合と燃焼排気ガス中の二酸化炭素濃度の関係を示す特性図である。
【００３０】
即ち、本実施形態の改質装置は、図５に示すように、燃焼部４に組成測定手段１１ｃを有するものであり、この組成測定手段１１ｃは、燃焼部４の燃焼排気ガス中の残留酸素または二酸化炭素濃度を測定することにより、液化石油ガスの組成の概略値を算出し得るというものである。図５において、燃焼用液化石油ガス流量調節弁８の開閉レベルを一定にした場合、液化石油ガスの組成が変動すると、燃焼部４に供給される液化石油ガスは、その流量においても変化し、その結果、燃焼部４の燃焼排気ガス中の残留酸素または二酸化炭素濃度は、かかる液化石油ガスの組成および流量の変化に対応して変化することとなる。
【００３１】
図６の特性図は、プロパンとｎ−ブタンのみからなる液化石油ガスにおいて、燃焼用液化石油ガス流量調節弁８および燃焼用空気流量調節弁９の開閉レベルを一定にした場合の、両成分の組成の変化に対応した燃焼部４の燃焼排気ガス中の残留酸素濃度の推移の一例を示すものである。これは、液化石油ガスを構成する各成分の燃焼に係る化学反応式から化学量論的に求めることができるものである。即ち、このような液化石油ガスの組成と燃焼排気ガス中の残留酸素濃度の相関関係を利用することにより、液化石油ガス中の成分比からその液化石油ガスの燃焼排気ガス中の残留酸素濃度の概略を算出し得る一方、逆に、液化石油ガスの燃焼排気ガス中の残留酸素濃度を測定することにより、液化石油ガス中の成分比の概略を算出し得ることとなる。
【００３２】
具体的には、燃焼用液化石油ガス流量調節弁８および燃焼用空気流量調節弁９の開閉レベルを一定にしておき、組成測定手段１１ｃにおいて、燃焼部４の燃焼排気ガス中の残留酸素濃度を測定するのみで、液化石油ガスの組成の概略値を算出でき、これを基礎として、改質反応部１に供給される液化石油ガスと水蒸気の割合を原燃料液化石油ガスおよび水蒸気の流量制御手段１２において最適化できるというものである。
【００３３】
一方、図７の特性図は、プロパンとｎ−ブタンのみからなる液化石油ガスにおいて、燃焼用液化石油ガス流量調節弁８および燃焼用空気流量調節弁９の開閉レベルを一定にした場合の、両成分の組成の変化に対応した燃焼部４の燃焼排気ガス中の二酸化炭素濃度の推移の一例を示すものであり、上記図６に示した燃焼部４の燃焼排気ガス中の残留酸素濃度の場合と同様に、液化石油ガスを構成する各成分の燃焼に係る化学反応式から化学量論的に求めることができる。したがって、この場合、上記図６に示した燃焼部４の燃焼排気ガス中の残留酸素濃度の場合と同様に、液化石油ガスの燃焼排気ガス中の二酸化炭素濃度を測定することにより、液化石油ガス中の成分比の概略を算出し得ることとなる。
【００３４】
具体的には、上記流量調節弁８、９の開閉レベルを一定にしておき、組成測定手段１１ｃにおいて、燃焼部４の燃焼排気ガス中の二酸化炭素濃度を測定するのみで、液化石油ガスの組成の概略値を算出でき、これを基礎として、改質反応部１に供給される液化石油ガスと水蒸気の割合を原燃料液化石油ガスおよび水蒸気の流量制御手段１２において最適化できるというものである。
【００３５】
なお、上記図６、図７は、表１に示す燃焼条件に基づいて算出したものである。即ち、燃焼用液化石油ガス流量調節弁８に純プロパンを流したとき、０℃換算で、１.０リットル/分（１.０ＮＬＰＭ）となるようにその開閉レベルを設定する一方、燃焼用空気流量調節弁９の開閉レベルを空気過剰率（空気比）λが１.５となるように固定する。（プロパンの燃焼の化学反応式が、Ｃ₃Ｈ₈+５Ｏ₂→３ＣＯ₂+４Ｈ₂Ｏなので、具体的には、プロパン１モルに対して、酸素７.５モル[λ＝１.５]の流量となり、体積換算では、プロパン１.０体積部に対して、酸素７.５体積部、即ち空気換算では、空気３５.７[＝７.５×１/０.２１]体積部となる。）以下、順次プロパン/ｎ−ブタン比を変更しても流量調節弁８、９の開閉レベルは変更しないので、燃焼空気は、０℃換算で、３５.７リットル/分（１.０ＮＬＰＭ）で一定であるのに対し、液化石油ガス流量は、ｎ−ブタンのモル分率の増加（即ち、プロパンのモル分率の減少）とともに減少し、表１に示すようにプロパンのモル分率が０.５のとき、０.９２４ＮＬＰＭ、プロパンのモル分率が０（即ち、純ｎ−ブタン）のとき、０.８６３ＮＬＰＭとなる。以下、それぞれの液化石油ガス流量と成分比に対応する燃焼生成物の組成（体積％）を上記プロパン燃焼の化学反応式とｎ−ブタン燃焼の化学反応式（２Ｃ₄Ｈ₁₀+１３Ｏ₂→８ＣＯ₂+１０Ｈ₂Ｏ）に従って、算出すると表１及び上記図６、図７を得ることができる。
【００３６】
【表１】

また、本実施形態においても、燃焼部４に供給される液化石油ガスの流量を均一化するためのオリフィス等の流量均一化手段１３を設けることにより、液化石油ガスの組成がより正確に把握することが可能となる。さらには、燃焼部４に供給される液化石油ガスの圧力を測定する圧力測定手段１４を設け、液化石油ガスの流量をこの圧力測定値により補正することにより、燃焼部に供給される液化石油ガスの流量をより正確に把握することも可能となる。
【００３７】
即ち、以上のような構成を採用することにより、燃焼部の燃焼排気ガス中の残留酸素または二酸化炭素濃度を連続的に測定して、この燃焼排気ガス中の残留酸素または二酸化炭素濃度から液化石油ガスの組成を求めることができ、この組成に応じて改質反応部１に供給される液化石油ガスと水蒸気の量を連続的に最適値に制御するようにしたので、液化石油ガスの組成が運転中に変動した場合でも、原燃料液化石油ガスと水蒸気の量が流量調節弁６、７によって適正に調節され、改質装置を最適な条件で運転を行うことができることとなる。
【００３８】
なお、流量制御手段１２は、例えば、組成測定手段１１ｃからの上記液化石油ガスの成分組成に対応した出力信号を受け、上記流量調節弁６、７の開閉レベルを制御する信号を出力するように構成できる。制御方法は、特に制限されないが、ＰＩＤ制御、ファジィ制御、ニューラルネットワーク等公知の技術を利用できる。
【００３９】
一方、本実施形態の改質装置では、燃焼部４の燃焼排気ガス中の残留酸素または二酸化炭素濃度を測定する構成としたが、別途、液化石油ガスの組成を測定するための専用燃焼部（図示せず）を設け、この専用燃焼部の燃焼排気ガス中の残留酸素または二酸化炭素濃度を測定する実施形態も当然に可能であり、上記課題解決に寄与する限りにおいて何ら制約のないことはいうまでもない。また、この場合において、かかる液化石油ガスの組成を測定するための専用燃焼部を、改質反応部１の改質触媒を加熱するよう配置することにより、より高効率の改質装置を提供できることとなる。
【００４０】
さらに、本実施形態の改質装置では、液化石油ガスの組成を求めるために、燃焼部４の燃焼排気ガス中の二酸化炭素濃度或いは残留酸素濃度を測定する構成としたが、算出する液化石油ガスの組成の精度を、さらに向上するために、第１の実施形態で示した液化石油ガスの圧力および温度を測定し、これらの圧力および温度の測定値を基礎として液化石油ガスの組成を算出し得る組成測定手段１１ａ、或いは第２の実施形態で示した燃焼部４の燃焼ガス温度を測定し、これを基礎として液化石油ガスの組成を算出し得る組成測定手段１１ｂのいずれかを併用する実施形態、さらには、組成測定手段１１ａ、１１ｂ、１１ｃの三者を総て併用する実施形態も当然に可能である。
【００４１】
【発明の効果】
以上のように、請求項１〜請求項３記載の改質装置の発明にあっては、液化石油ガスの組成が運転中に変動した場合でも、最適な条件で運転を行うことができるという優れた効果を奏する。
【００４２】
請求項２または請求項３記載の改質装置の発明にあっては、上記効果に加えて、燃焼部に供給される液化石油ガスの流量を均一化することができるので、液化石油ガスの組成の測定をより正確に行うことができるという優れた効果を奏する。
【図面の簡単な説明】
【図１】本発明の第１の実施形態における改質装置の概略を示す図である。
【図２】貯蔵タンクから取り出され、圧力調整される前の液化石油ガスの組成と液化石油ガスの圧力および温度の関係の一例を示す特性図である。
【図３】本発明の第２の実施形態における改質装置の概略を示す図である。
【図４】本発明の第２の実施形態における液化石油ガス中のプロパンの割合と燃焼ガス温度の関係を示す特性図である。
【図５】本発明の第３の実施形態における改質装置の概略を示す図である。
【図６】本発明の第３の実施形態における液化石油ガス中のプロパンの割合と燃焼排気ガス中の酸素濃度の関係を示す特性図である。
【図７】本発明の第３の実施形態における液化石油ガス中のプロパンの割合と燃焼排気ガス中の二酸化炭素濃度の関係を示す特性図である。
【符号の説明】
１改質反応部
２シフト反応部
３一酸化炭素酸化部
４燃焼部
５圧力調整器
６原燃料液化ガス流量調節弁
７水蒸気流量調節弁
８燃焼用液化石油ガス流量調節弁
９燃焼用空気流量調節弁
１０液化石油ガス貯蔵タンク
１１組成測定手段
１１ａ組成測定手段
１１ｂ組成測定手段
１１ｃ組成測定手段
１２流量制御手段
１３流量均一化手段
１４圧力測定手段
１５水蒸気
１６空気[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a reformer for a fuel cell that generates a reformed gas mainly composed of hydrogen using liquefied petroleum gas as a raw fuel.
[0002]
[Prior art]
Conventionally, a reformer that generates a reformed gas mainly composed of hydrogen by reforming a liquefied petroleum gas as a raw fuel by a steam reforming reaction has been known. As one of the uses, a power generation fuel for a fuel cell can be mentioned. This reformer comprises a reforming reaction section filled with a reforming catalyst, a shift reaction section filled with a carbon monoxide conversion catalyst, and a carbon monoxide oxidation section filled with a carbon monoxide oxidation catalyst. The reforming catalyst is formed by passing the raw fuel and steam through the reforming part while heating the reforming catalyst with a burner to obtain a reformed gas mainly composed of hydrogen. That's it.
[0003]
On the other hand, if carbon monoxide is contained in the reformed gas, this causes poisoning of the fuel cell and lowers the electrocatalytic performance. First, the reformed gas immediately after generation is passed through the shift reaction section. The carbon monoxide conversion catalyst reduces the carbon monoxide content in the reformed gas by a shift reaction, and then passes this through the carbon monoxide oxidation section and remains in the system by the carbon monoxide oxidation catalyst. Carbon monoxide is oxidized and removed so that the content of carbon monoxide in the reformed gas can be reduced to such an extent that poisoning of the fuel cell can be avoided.
[0004]
By the way, the appropriate range of the raw fuel supply amount and the water vapor supply amount in the steam reforming reaction can be defined according to the composition of the raw fuel. In other words, if they are outside the proper range, the power generation output of the fuel cell decreases due to the occurrence of problems such as insufficient hydrogen in the reformed gas supplied to the fuel cell or an increase in the concentration of carbon monoxide. Or the fuel cell may be damaged. For example, as seen in JP-A-6-260203, the composition of the raw fuel is measured before the operation of the reformer, and the fuel composition is determined according to the measured composition. The method of determining the operating conditions of the reformer has been adopted.
[0005]
However, when liquefied petroleum gas is used as the raw fuel, the liquefied petroleum gas is composed of mixed components having different vapor pressures such as propane and butane. Therefore, as the raw fuel is consumed, the composition of the raw fuel residual liquid in the container is sequentially increased. Due to the fluctuation, the composition of the raw fuel supplied to the reformer also fluctuates, and it is difficult to always operate the reformer under the optimum conditions.
[0006]
[Problems to be solved by the invention]
The present invention has been made in view of such reasons, and an object of the present invention is to provide a reformer that enables operation under optimum conditions even when the composition of liquefied petroleum gas fluctuates during operation. It is to provide.
[0007]
[Means for Solving the Problems]
In order to solve the above problems, in the invention of the reformer according to claim 1, at least a liquefied petroleum gas storage tank for storing liquefied petroleum gas, and a liquefied petroleum discharged from the liquefied petroleum gas storage tank. A pressure regulator for adjusting the pressure of the gas; and a reforming reaction section having a reforming catalyst for generating a reformed gas by steam reforming the liquefied petroleum gas pressure-adjusted by the pressure regulator using steam; In a reformer for a fuel cell, comprising: a combustion part that promotes a reaction in the reforming reaction part by heating by burning part of the liquefied petroleum gas pressure-adjusted by the pressure regulator, A composition measuring means for continuously measuring the composition of the liquefied petroleum gas supplied to the reforming reaction section; and an amount of the liquefied petroleum gas supplied to the reforming reaction section according to the composition measured by the composition measuring means; Comprises a flow control means for continuously controlling the amount of steam, the composition measuring means ,in front Means for obtaining the composition of the liquefied petroleum gas supplied from the liquefied petroleum gas storage tank and supplied to the reforming reaction section by measuring the pressure and temperature of the liquefied petroleum gas before the pressure is adjusted by the pressure regulator. It is characterized by being.
[0008]
In the invention of the reformer according to claim 2, At least a liquefied petroleum gas storage tank for storing liquefied petroleum gas, a pressure regulator for adjusting the pressure of the liquefied petroleum gas discharged from the liquefied petroleum gas storage tank, and a liquefied petroleum gas pressure-adjusted by the pressure regulator The reforming reaction section having a reforming catalyst for steam reforming using steam to generate reformed gas, and burning the part of the liquefied petroleum gas pressure-adjusted by the pressure regulator A reforming device for a fuel cell comprising: a combustion section that promotes the reaction in the quality reaction section by heating; and a composition measuring means for continuously measuring the composition of the liquefied petroleum gas supplied to the reforming reaction section; A flow rate control means for continuously controlling the amount of liquefied petroleum gas and the amount of water vapor supplied to the reforming reaction section in accordance with the composition measured by the composition measuring means, and is supplied to the combustion section. And a flow uniformizing means for uniformizing the flow rate of the liquefied petroleum gas, the composition measuring means, by measuring the combustion gas temperature of the combustion portion It is a means for obtaining the composition of the liquefied petroleum gas supplied to the reforming reaction section.
[0009]
In the invention of the reformer according to claim 3, At least a liquefied petroleum gas storage tank for storing liquefied petroleum gas, a pressure regulator for adjusting the pressure of the liquefied petroleum gas discharged from the liquefied petroleum gas storage tank, and a liquefied petroleum gas pressure-adjusted by the pressure regulator The reforming reaction section having a reforming catalyst for steam reforming using steam to generate reformed gas, and burning the part of the liquefied petroleum gas pressure-adjusted by the pressure regulator A reforming device for a fuel cell comprising: a combustion section that promotes the reaction in the quality reaction section by heating; and a composition measuring means for continuously measuring the composition of the liquefied petroleum gas supplied to the reforming reaction section; A flow rate control means for continuously controlling the amount of liquefied petroleum gas and the amount of water vapor supplied to the reforming reaction section in accordance with the composition measured by the composition measuring means, and is supplied to the combustion section. And a flow uniformizing means for uniformizing the flow rate of the liquefied petroleum gas, by the composition measuring means measures the oxygen or carbon dioxide concentration in the combustion exhaust gas of the combustion portion It is a means for obtaining the composition of the liquefied petroleum gas supplied to the reforming reaction section.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0013]
[First embodiment]
FIG. 1 is a diagram showing an outline of a reforming apparatus according to a first embodiment of the present invention, and FIG. 2 is a composition of a liquefied petroleum gas taken out of a storage tank 10 and pressure-adjusted, and a pressure and temperature of the liquefied petroleum gas. It is a characteristic view which shows an example of the relationship.
[0014]
That is, as shown in FIG. 1, the reforming apparatus of this embodiment includes a reforming catalyst that generates a reformed gas mainly composed of hydrogen by steam reforming the liquefied petroleum gas of the raw fuel using steam. The reforming reaction part 1 having, the shift reaction part 2 for reducing the carbon monoxide concentration in the reformed gas generated in the reforming reaction part 1, and the reformed gas in which the carbon monoxide concentration is reduced in the shift reaction part 2 The carbon monoxide oxidation unit 3 that oxidizes and removes the carbon monoxide gas still remaining in the carbon monoxide oxidation reaction, and each of these reaction units, particularly the reforming reaction unit 1, is heated to promote the reaction. A combustion unit 4 is provided.
[0015]
Further, a pressure regulator 5 that adjusts the pressure of the liquefied petroleum gas supplied to the reforming reaction unit 1, and a raw fuel liquefied gas flow rate that adjusts the flow rate of the liquefied petroleum gas that is the raw fuel supplied to the reforming reaction unit 1. Control valve 6, steam flow rate control valve 7 for adjusting the flow rate of steam supplied to the reforming reaction unit 1, and combustion liquefied petroleum gas flow rate control valve for adjusting the flow rate of combustion liquefied petroleum gas supplied to the combustion unit 4 8. A combustion air flow rate adjustment valve 9 for adjusting the flow rate of the combustion air 16 supplied to the combustion unit 4 is provided, and is further taken out from the liquefied petroleum gas storage tank 10 and pressure-adjusted by the pressure regulator 5. Based on the information on the composition of the liquefied petroleum gas obtained by the composition measuring means 11a obtained from the composition measuring means 11a for measuring the composition of the previous liquefied petroleum gas, the raw fuel liquefied gas flow control valve 6 and the steam flow control valve 7 Opening and closing level Those having a flow rate control means 12 for controlling.
[0016]
That is, in the reformer of the present embodiment, the composition measuring unit 11 a is a unit that measures the pressure and temperature of the liquefied petroleum gas taken out from the liquefied petroleum gas storage tank 10 and pressure-adjusted by the pressure regulator 5. In addition, the composition of the liquefied petroleum gas can be calculated based on the measured values of pressure and temperature.
For example, when it can be assumed that the liquefied petroleum gas used as the raw fuel for the reformer consists of only two components, propane and n-butane, the temperature (T) and pressure (P _GT ), And based on these, the ratio of both components in the system can be calculated relatively easily. That is, T = T1, P _GT = P _GT1 Where x is the molar fraction of propane, the molar fraction of n-butane is 1-x, and the saturated vapor pressure of propane when T = T1 is P _GT1 (Propane), the saturated vapor pressure of n-butane is P _GT1 (N-butane), P _GT1 (Propane) x + P _GT1 (N-butane) (1-x) = P _GT1 And P _GT1 (Propane), P _GT1 (N-butane) is separately available, for example, using the Antoine formula (for example, “Chemical Engineering Handbook, Rev. 5th Edition”, pages 18-27 or “Vapor Pressure Data by Electronic Computer”, Shuzo Oe, Data Book Publishing This is because it is obtained from the company.
[0017]
The characteristic diagram of FIG. 2 shows the relationship between the abundance ratio of both components at each temperature in the liquefied petroleum gas consisting only of propane and n-butane and the pressure of the liquefied petroleum gas, calculated by this method. That is, on the basis of this characteristic diagram, the composition (component ratio) of the liquefied petroleum gas can be obtained simply by measuring the pressure and temperature of the liquefied petroleum gas taken out from the liquefied petroleum gas storage tank 10 before the pressure adjustment. Further, based on the information on the composition of the liquefied petroleum gas, the optimum conditions regarding the amount of the liquefied petroleum gas and the steam supplied to the reforming reaction unit 1 according to the composition of the liquefied petroleum gas are identified. Is possible.
[0018]
As a result, the pressure and temperature of the liquefied petroleum gas taken out from the liquefied petroleum gas storage tank 10 and pressure-adjusted by the pressure regulator 5 are continuously measured in the composition measuring means 11a. Corresponding to the calculated component composition of the liquefied petroleum gas, the flow rate control means 12 continuously controls the amount of the liquefied petroleum gas and water vapor supplied to the reforming reaction unit 1, whereby the reforming reaction unit 1. Even when the component composition of the liquefied petroleum gas supplied to the engine fluctuates during operation, the amounts of the raw fuel liquefied petroleum gas and water vapor are appropriately adjusted by the

flow control valves

6 and 7, and the reformer is always in the optimum condition. It becomes possible to drive with.
[0019]
The flow rate control means 12 receives, for example, an output signal corresponding to the component composition of the liquefied petroleum gas from the composition measurement means 11a, and outputs a signal for controlling the open / close level of the flow

rate control valves

6 and 7. Can be configured. The control method is not particularly limited, but known techniques such as PID control, fuzzy control, and neural network can be used.
[0020]
[Second Embodiment]
FIG. 3 is a diagram showing an outline of the reforming apparatus in the second embodiment of the present invention, and FIG. 4 is a characteristic showing the relationship between the proportion of propane in the liquefied petroleum gas and the combustion gas temperature in the second embodiment of the present invention. FIG.
[0021]
That is, as shown in FIG. 3, the reforming apparatus of this embodiment has a composition measuring means 11b in the combustion section 4, and this composition measuring means 11b measures the combustion gas temperature of the combustion section 4. Thus, the approximate value of the composition of the liquefied petroleum gas can be calculated.
[0022]
In FIG. 3, when the open / close level of the liquefied petroleum gas flow rate regulating valve 8 for combustion is made constant, when the composition of the liquefied petroleum gas varies, the liquefied petroleum gas supplied to the combustion unit 4 also changes in its flow rate. As a result, the combustion gas temperature of the combustion section 4 changes in response to changes in the composition and flow rate of the liquefied petroleum gas. The characteristic diagram of FIG. 4 shows that in the case of liquefied petroleum gas consisting only of propane and n-butane, the opening and closing levels of the combustion liquefied petroleum gas flow rate control valve 8 and the combustion air flow rate control valve 9 are constant. An example of the correlation of the combustion gas temperature of the combustion part 4 corresponding to the change of a composition is shown. The correlation between the composition of the liquefied petroleum gas and the combustion gas temperature shown in the characteristic diagram is, for example, a method of actually burning the liquefied petroleum gas having a predetermined composition in the combustion section 4 and actually measuring the combustion gas temperature, or , Theoretical flame temperature (adiabatic flame temperature) (for example, “Theory and practice of gas combustion [supervised by Kunio Yoshida]” published by Ichiro Nakamachi and Fujio Shoji, Energy Conservation Center, October 13, 1992, 1st edition, 1st edition Printed on page 17 to page 21 etc.) is calculated for each component gas constituting the liquefied petroleum gas, and based on this, the mixed gas is proportional to the partial pressure of each component gas. The distribution can be determined by a method of deriving the combustion gas temperature for the mixed gas.
[0023]
The characteristic diagram of FIG. 4 shows the correlation between the composition of liquefied petroleum gas and the combustion gas temperature calculated by actual measurement. That is, if such a correlation is used, the outline of the combustion gas temperature of the liquefied petroleum gas can be calculated from the component ratio in the liquefied petroleum gas, while conversely, the combustion gas temperature of the liquefied petroleum gas can be measured. Thus, an outline of the component ratio in the liquefied petroleum gas can be calculated. Specifically, the open / close levels of the combustion liquefied petroleum gas flow rate control valve 8 and the combustion air flow rate control valve 9 are kept constant, and the composition measuring means 11b only measures the combustion gas temperature of the combustion unit 4, A rough value of the composition of the liquefied petroleum gas can be calculated, and based on this, the ratio of the liquefied petroleum gas and steam supplied to the reforming reaction section 1 can be optimized in the raw fuel liquefied petroleum gas and steam flow rate control means 12. That's it.
[0024]
In addition, by providing the flow rate equalizing means 13 such as an orifice for equalizing the flow rate of the liquefied petroleum gas supplied to the combustion unit 4, the composition of the liquefied petroleum gas can be grasped more accurately. Furthermore, the pressure measurement means 14 which measures the pressure of the liquefied petroleum gas supplied to the combustion part 4 is provided, and the liquefied petroleum gas supplied to the combustion part is corrected by correcting the flow rate of the liquefied petroleum gas by this pressure measurement value. It is also possible to grasp the flow rate of the gas more accurately.
[0025]
That is, by adopting the configuration as described above, the combustion gas temperature in the combustion section can be continuously measured, and the composition of the liquefied petroleum gas can be obtained from the combustion gas temperature. Since the amount of liquefied petroleum gas and water vapor supplied to the reaction section 1 is continuously controlled to the optimum values, even if the composition of the liquefied petroleum gas changes during operation, the raw fuel liquefied petroleum gas and water vapor The amount is appropriately adjusted by the flow

rate control valves

6 and 7, and the reformer can be operated under the optimum conditions.
[0026]
The flow control means 12 receives, for example, an output signal corresponding to the component composition of the liquefied petroleum gas from the composition measurement means 11b, and outputs a signal for controlling the open / close level of the

flow control valves

6 and 7. Can be configured. The control method is not particularly limited, but known techniques such as PID control, fuzzy control, and neural network can be used.
[0027]
On the other hand, in the reformer of the present embodiment, the combustion gas temperature of the combustion unit 4 is measured, but a dedicated combustion unit (not shown) for measuring the composition of the liquefied petroleum gas is separately provided. Naturally, an embodiment for measuring the combustion gas temperature of the dedicated combustion section is also possible, and it goes without saying that there is no restriction as long as it contributes to the solution of the above problems. Further, in this case, a combustion unit for measuring the composition of the liquefied petroleum gas can be provided so as to heat the reforming catalyst of the reforming reaction unit 1, thereby providing a more efficient reformer. Become.
[0028]
Further, in the reformer of this embodiment, the combustion gas temperature of the combustion unit 4 is measured in order to obtain the composition of the liquefied petroleum gas, but the accuracy of the calculated composition of the liquefied petroleum gas is further improved. For this purpose, the pressure and temperature of the liquefied petroleum gas shown in the first embodiment are measured, and the composition measuring means 11a capable of calculating the composition of the liquefied petroleum gas based on the measured values of the pressure and temperature is used in combination. Naturally, the form is also possible.
[0029]
[Third embodiment]
FIG. 5 is a diagram showing an outline of the reformer in the third embodiment of the present invention, and FIG. 6 shows the ratio of propane in the liquefied petroleum gas and the oxygen concentration in the combustion exhaust gas in the third embodiment of the present invention. FIG. 7 is a characteristic diagram showing the relationship between the proportion of propane in the liquefied petroleum gas and the carbon dioxide concentration in the combustion exhaust gas in the third embodiment of the present invention.
[0030]
That is, as shown in FIG. 5, the reformer of the present embodiment has a composition measuring unit 11 c in the combustion unit 4, and this composition measuring unit 11 c is a residual oxygen in the combustion exhaust gas of the combustion unit 4. Alternatively, the approximate value of the composition of the liquefied petroleum gas can be calculated by measuring the carbon dioxide concentration. In FIG. 5, when the open / close level of the liquefied petroleum gas flow rate control valve 8 for combustion is made constant, when the composition of the liquefied petroleum gas varies, the liquefied petroleum gas supplied to the combustion unit 4 also changes in its flow rate. As a result, the residual oxygen or carbon dioxide concentration in the combustion exhaust gas of the combustion section 4 changes corresponding to the change in the composition and flow rate of the liquefied petroleum gas.
[0031]
The characteristic diagram of FIG. 6 shows that in the case of liquefied petroleum gas consisting only of propane and n-butane, the opening and closing levels of the combustion liquefied petroleum gas flow rate control valve 8 and the combustion air flow rate control valve 9 are constant. An example of transition of the residual oxygen concentration in the combustion exhaust gas of the combustion part 4 corresponding to the change of the composition is shown. This can be obtained stoichiometrically from the chemical reaction formula relating to the combustion of each component constituting the liquefied petroleum gas. That is, by utilizing the correlation between the composition of the liquefied petroleum gas and the residual oxygen concentration in the combustion exhaust gas, the residual oxygen concentration in the combustion exhaust gas of the liquefied petroleum gas can be calculated from the component ratio in the liquefied petroleum gas. On the contrary, by measuring the residual oxygen concentration in the combustion exhaust gas of the liquefied petroleum gas, the outline of the component ratio in the liquefied petroleum gas can be calculated.
[0032]
Specifically, the open / close levels of the combustion liquefied petroleum gas flow rate control valve 8 and the combustion air flow rate control valve 9 are kept constant, and the residual oxygen concentration in the combustion exhaust gas of the combustion unit 4 is determined by the composition measuring means 11c. By simply measuring, the approximate value of the composition of the liquefied petroleum gas can be calculated, and based on this, the ratio of the liquefied petroleum gas and the steam supplied to the reforming reaction unit 1 can be determined to control the flow rate of the raw fuel liquefied petroleum gas and steam. 12 can be optimized.
[0033]
On the other hand, the characteristic diagram of FIG. 7 shows that in the case of liquefied petroleum gas consisting only of propane and n-butane, both open and closed levels of the combustion liquefied petroleum gas flow rate control valve 8 and the combustion air flow rate control valve 9 are constant. FIG. 7 shows an example of the transition of the carbon dioxide concentration in the combustion exhaust gas of the combustion section 4 corresponding to the change in the composition of the components, and the case of the residual oxygen concentration in the combustion exhaust gas of the combustion section 4 shown in FIG. Similarly to the above, it can be obtained stoichiometrically from the chemical reaction formula relating to the combustion of each component constituting the liquefied petroleum gas. Therefore, in this case, the liquefied petroleum gas is measured by measuring the carbon dioxide concentration in the combustion exhaust gas of the liquefied petroleum gas as in the case of the residual oxygen concentration in the combustion exhaust gas of the combustion section 4 shown in FIG. It is possible to calculate the outline of the component ratio in the medium.
[0034]
Specifically, the composition of the liquefied petroleum gas can be obtained only by measuring the carbon dioxide concentration in the combustion exhaust gas of the combustion section 4 in the composition measuring means 11c while keeping the flow rate control valves 8 and 9 constant. Based on this, the ratio of the liquefied petroleum gas and water vapor supplied to the reforming reaction section 1 can be optimized by the flow control means 12 for the raw fuel liquefied petroleum gas and water vapor.
[0035]
6 and 7 are calculated based on the combustion conditions shown in Table 1. That is, when pure propane is passed through the liquefied petroleum gas flow rate control valve 8 for combustion, its open / close level is set to 1.0 liter / minute (1.0 NLPM) in terms of 0 ° C., while combustion air is set. The open / close level of the flow rate control valve 9 is fixed so that the excess air ratio (air ratio) λ is 1.5. (The chemical reaction formula of propane combustion is C _Three H ₈ + 5O ₂ → 3CO ₂ + 4H ₂ Since it is O, specifically, the flow rate of oxygen is 7.5 mol [λ = 1.5] with respect to 1 mol of propane, and in terms of volume, 7.5 volumes of oxygen with respect to 1.0 volume part of propane. Part, that is, in terms of air, it is 35.7 [= 7.5 × 1 / 0.21] volume part of air. ) Since the open / close levels of the flow control valves 8 and 9 are not changed even if the propane / n-butane ratio is changed successively, the combustion air is converted to 0 ° C at 35.7 liters / minute (1.0NLPM) Whereas it is constant, the liquefied petroleum gas flow rate decreases with increasing n-butane mole fraction (ie, decreasing propane mole fraction) and the propane mole fraction is zero as shown in Table 1. When 0.5, 0.924 NLPM, and when the propane molar fraction is 0 (ie, pure n-butane), 0.863 NLPM. Hereinafter, the composition (volume%) of the combustion product corresponding to each liquefied petroleum gas flow rate and component ratio is expressed by the chemical reaction formula for propane combustion and the chemical reaction formula for n-butane combustion (2C _Four H _Ten + 13O ₂ → 8CO ₂ + 10H ₂ Table 1 and FIGS. 6 and 7 can be obtained by calculation according to O).
[0036]
[Table 1]

Also in the present embodiment, the composition of the liquefied petroleum gas can be grasped more accurately by providing the flow rate equalizing means 13 such as an orifice for equalizing the flow rate of the liquefied petroleum gas supplied to the combustion unit 4. It becomes possible. Furthermore, the pressure measurement means 14 which measures the pressure of the liquefied petroleum gas supplied to the combustion part 4 is provided, and the liquefied petroleum gas supplied to the combustion part is corrected by correcting the flow rate of the liquefied petroleum gas by this pressure measurement value. It is also possible to grasp the flow rate of the gas more accurately.
[0037]
That is, by adopting the configuration as described above, the residual oxygen or carbon dioxide concentration in the combustion exhaust gas of the combustion section is continuously measured, and the liquefied petroleum is determined from the residual oxygen or carbon dioxide concentration in the combustion exhaust gas. The composition of the gas can be obtained, and the amount of the liquefied petroleum gas and water vapor supplied to the reforming reaction section 1 is continuously controlled to the optimum values according to this composition. Even if it fluctuates during operation, the amounts of the raw fuel liquefied petroleum gas and water vapor are appropriately adjusted by the

flow control valves

6 and 7, and the reformer can be operated under optimum conditions.
[0038]
The flow rate control means 12 receives, for example, an output signal corresponding to the component composition of the liquefied petroleum gas from the composition measurement means 11c, and outputs a signal for controlling the open / close level of the flow

rate control valves

6 and 7. Can be configured. The control method is not particularly limited, but known techniques such as PID control, fuzzy control, and neural network can be used.
[0039]
On the other hand, in the reformer of the present embodiment, the residual oxygen or carbon dioxide concentration in the combustion exhaust gas of the combustion section 4 is measured, but separately, a dedicated combustion section for measuring the composition of liquefied petroleum gas ( An embodiment in which the concentration of residual oxygen or carbon dioxide in the combustion exhaust gas of this dedicated combustion section is measured is naturally possible, and there is no limitation as long as it contributes to the solution of the above problem. Not too long. Further, in this case, it is possible to provide a more efficient reformer by disposing the dedicated combustion unit for measuring the composition of the liquefied petroleum gas so as to heat the reforming catalyst of the reforming reaction unit 1. It becomes.
[0040]
Furthermore, in the reformer of this embodiment, in order to obtain the composition of the liquefied petroleum gas, the carbon dioxide concentration or the residual oxygen concentration in the combustion exhaust gas of the combustion unit 4 is measured. In order to further improve the accuracy of the composition, the pressure and temperature of the liquefied petroleum gas shown in the first embodiment are measured, and the composition of the liquefied petroleum gas is calculated based on the measured values of the pressure and temperature. The composition measuring means 11a to be obtained or the composition measuring means 11b capable of measuring the combustion gas temperature of the combustion section 4 shown in the second embodiment and calculating the composition of the liquefied petroleum gas based on this is used in combination. Naturally, an embodiment in which all three of the form and the composition measuring means 11a, 11b, and 11c are used together is naturally possible.
[0041]
【The invention's effect】
As described above, in the invention of the reformer according to claims 1 to 3, ,liquid Even when the composition of the liquefied petroleum gas fluctuates during operation, it has an excellent effect that it can be operated under optimum conditions.
[0042]
In the invention of the reformer according to claim 2 or claim 3, In addition to the above effects, Since the flow rate of the liquefied petroleum gas supplied to the combustion section can be made uniform, an excellent effect is obtained that the composition of the liquefied petroleum gas can be measured more accurately.
[Brief description of the drawings]
FIG. 1 is a diagram showing an outline of a reforming apparatus in a first embodiment of the present invention.
FIG. 2 is a characteristic diagram showing an example of the relationship between the composition of the liquefied petroleum gas and the pressure and temperature of the liquefied petroleum gas before being pressure-adjusted from the storage tank.
FIG. 3 is a diagram showing an outline of a reforming apparatus in a second embodiment of the present invention.
FIG. 4 is a characteristic diagram showing the relationship between the proportion of propane in liquefied petroleum gas and the combustion gas temperature in the second embodiment of the present invention.
FIG. 5 is a diagram showing an outline of a reforming apparatus in a third embodiment of the present invention.
FIG. 6 is a characteristic diagram showing the relationship between the ratio of propane in liquefied petroleum gas and the oxygen concentration in combustion exhaust gas in the third embodiment of the present invention.
FIG. 7 is a characteristic diagram showing the relationship between the proportion of propane in liquefied petroleum gas and the concentration of carbon dioxide in combustion exhaust gas in the third embodiment of the present invention.
[Explanation of symbols]
1 Reforming reaction section
2 Shift reaction section
3 Carbon monoxide oxidation section
4 Combustion section
5 Pressure regulator
6 Raw fuel liquefied gas flow control valve
7 Steam flow control valve
8 Combustion liquefied petroleum gas flow control valve
9 Combustion air flow control valve
10 Liquefied petroleum gas storage tank
11 Composition measuring means
11a Composition measuring means
11b Composition measuring means
11c Composition measuring means
12 Flow control means
13 Flow equalization means
14 Pressure measuring means
15 Water vapor
16 Air

Claims

At least a liquefied petroleum gas storage tank for storing liquefied petroleum gas, a pressure regulator for adjusting the pressure of the liquefied petroleum gas discharged from the liquefied petroleum gas storage tank, and a liquefied petroleum gas pressure-adjusted by the pressure regulator The reforming reaction section having a reforming catalyst for steam reforming using steam to generate reformed gas, and burning the part of the liquefied petroleum gas pressure-adjusted by the pressure regulator A reforming device for a fuel cell, comprising: a combustion section that promotes the reaction in the quality reaction section by heating;
Composition measuring means for continuously measuring the composition of the liquefied petroleum gas supplied to the reforming reaction section;
Flow rate control means for continuously controlling the amount of liquefied petroleum gas and the amount of water vapor supplied to the reforming reaction section according to the composition measured by the composition measuring means,
Liquefying said composition measuring means is out of the previous SL liquefied petroleum gas storage tank, it is supplied to the reforming reactor by measuring the pressure and temperature of the liquefied petroleum gas before being pressure regulated by the pressure regulator A reformer characterized by being a means for obtaining the composition of petroleum gas.

At least a liquefied petroleum gas storage tank for storing liquefied petroleum gas, a pressure regulator for adjusting the pressure of the liquefied petroleum gas discharged from the liquefied petroleum gas storage tank, and a liquefied petroleum gas pressure-adjusted by the pressure regulator The reforming reaction section having a reforming catalyst for steam reforming using steam to generate reformed gas, and burning the part of the liquefied petroleum gas pressure-adjusted by the pressure regulator A reforming device for a fuel cell, comprising: a combustion section that promotes the reaction in the quality reaction section by heating;
Composition measuring means for continuously measuring the composition of the liquefied petroleum gas supplied to the reforming reaction section;
Flow rate control means for continuously controlling the amount of liquefied petroleum gas and the amount of water vapor supplied to the reforming reaction section according to the composition measured by the composition measuring means;
A flow rate equalizing means for equalizing the flow rate of the liquefied petroleum gas supplied to the combustion section,
The reforming apparatus, wherein the composition measuring means is a means for obtaining a composition of liquefied petroleum gas supplied to the reforming reaction section by measuring a combustion gas temperature in the combustion section .

At least a liquefied petroleum gas storage tank for storing liquefied petroleum gas, a pressure regulator for adjusting the pressure of the liquefied petroleum gas discharged from the liquefied petroleum gas storage tank, and a liquefied petroleum gas pressure-adjusted by the pressure regulator The reforming reaction section having a reforming catalyst for steam reforming using steam to generate reformed gas, and burning the part of the liquefied petroleum gas pressure-adjusted by the pressure regulator A reforming device for a fuel cell, comprising: a combustion section that promotes the reaction in the quality reaction section by heating;
Composition measuring means for continuously measuring the composition of the liquefied petroleum gas supplied to the reforming reaction section;
Flow rate control means for continuously controlling the amount of liquefied petroleum gas and the amount of water vapor supplied to the reforming reaction section according to the composition measured by the composition measuring means;
A flow rate equalizing means for equalizing the flow rate of the liquefied petroleum gas supplied to the combustion section,
The composition measuring means is means for determining the composition of liquefied petroleum gas supplied to the reforming reaction section by measuring oxygen or carbon dioxide concentration in the combustion exhaust gas of the combustion section. Quality equipment.