JP3716577B2

JP3716577B2 - Exhaust gas water recovery device

Info

Publication number: JP3716577B2
Application number: JP28485697A
Authority: JP
Inventors: 重雄幡宮; 務奥沢; 雅彦山岸
Original assignee: Hitachi Ltd
Current assignee: Hitachi Ltd
Priority date: 1997-10-17
Filing date: 1997-10-17
Publication date: 2005-11-16
Anticipated expiration: 2017-10-17
Also published as: JPH11117764A

Description

【０００１】
【発明の属する技術分野】
本発明は、排ガスの水回収装置に係り、ガスタービン等の燃焼排ガスから水分を回収し、水資源の有効活用をはかるとともに、環境への水蒸気の放出量を低減させる排ガスからの水回収装置に関する。
【０００２】
【従来の技術】
湿分を多く含んだ排ガスから水を回収する方法については燃料電池発電プラントにおける排ガスからの水回収、あるいはガスタービン排ガスからの水回収といった分野で考えられており、例えば燃料電池発電プラントに関しては特開平8− 31443 号公報やガスタービン排ガスからの水回収では特開昭56−12006 号公報といった例がある。
【０００３】
【発明が解決しようとする課題】
湿分を多く含んだ排ガスは、その露点以下に温度を下げるならば、水蒸気が凝縮して水を回収することができる。従来の水回収装置では回収水の温度には充分な関心が払われていなかった。しかし、外部に取り出すことのできる有効エネルギー（エクセルギー）をできるだけ有効に回収するためには、回収水を混合して同一温度にするより、温度の高い回収水は温度の高いままで回収するのが望ましい。従来の排ガスからの水回収装置はこの点が充分ではない。
【０００４】
そこで、本発明は、湿分を含んだ排ガスから水を回収する際に温度レベルの異なる回収水を簡易なシステムで回収できる水回収装置を提供する。
【０００５】
【課題を解決するための手段】
本発明は、排ガスから水分を回収する際に複数の水回収部に分け、燃焼排ガスの温度が低くなっている出口側の液回収部回収水の一部を、燃焼排ガスの温度の高い入口側の冷却水散布部に供給し、その領域で得られた回収水を更に、燃焼排ガスの入口側に位置する冷却水散布部に供給するようにする。
【０００６】
例えば、排ガスに水滴を散布する冷却水散布部と、散布水および排ガス中の水分の凝縮水を回収する回収部とを備えた水回収手段を、排ガスの流れ方向に対して直列に複数配置した排ガスの水回収装置であって、第１の水回収手段の回収部で回収した回収水の少なくとも一部を、該第１の水回収手段より排ガス流れの上流側に位置する他の水回収手段の冷却水散布部から散布するよう構成し、排ガス下流側の水回収手段で得られた回収水を排ガス上流側の水回収手段の冷却水として用いるプロセスを繰り返すように複数の水回収手段を配置したことを特徴とする。
【０００７】
又は、排ガスに水滴を散布する冷却水散布部と、散布水及び排ガス中の水分の凝縮水を回収する回収部とを備えた水回収手段を、排ガスの流れ方向に対して直列に複数配置した排ガスの水回収装置であって、第１の水回収手段の回収部で回収した回収水の少なくとも一部を、該第１の水回収手段より排ガス流れの上流側に位置する第２の水回収手段の冷却水散布部から散布するよう構成し、排ガス下流側の水回収手段で得られた回収水を排ガス上流側の水回収手段の冷却水として用いるプロセスを繰り返すように複数の水回収手段を配置すると共に、前記第１の水回収手段の冷却水散布部から散布される水滴の平均粒径は、前記第１の水回収手段の排ガス流れの下流側に位置する第２の水回収手段の冷却水散布部から散布される水滴の平均粒径より小さくなるよう構成されていることを特徴とする。
【０００８】
又は、排ガスに水滴を散布する冷却水散布部と、散布水及び排ガス中の水分の凝縮水を回収する回収部とを備えた水回収手段を、排ガスの流れ方向に対して直列に複数配置した排ガスの水回収装置であって、第１の水回収手段の回収部で回収した回収水の少なくとも一部を、該第１の水回収手段より排ガス流れの上流側に位置する第２の水回収手段の冷却水散布部から散布するよう構成し、排ガス下流側の水回収手段で得られた回収水を排ガス上流側の水回収手段の冷却水として用いるプロセスを繰り返すように複数の水回収手段を配置すると共に、前記冷却水散布部と回収部とを備えた水回収手段を排ガスの流れ方向に沿って直列に多数配置され、第１の水回収手段の冷却水散布部と回収部との間の距離は、前記第１の冷却水回収手段の排ガス流れの下流側に位置する第２の水回収手段の冷却水散布部と回収部との間の距離より長くなるよう構成されていることを特徴とする。
【０００９】
又は、圧縮機と、圧縮機から吐出される圧縮空気に蒸気を混入させる蒸気混入手段と、蒸気を含む圧縮空気と燃料と蒸気が供給される燃焼器と、燃焼器の排ガスが供給され駆動するタービンとを備えたガスタービンにおいて、タービンから出た排ガスが供給され、排ガスに水滴を散布する冷却水散布部と散布水及び排ガスの凝縮水を回収する回収部とを備えた水回収手段を排ガスの流れ方向に沿って直列に多数配置し、第１の水回収手段の回収部で回収した回収水の少なくとも一部を、該第１の水回収手段より排ガス流れの上流側に位置する他の水回収手段の冷却水散布部から散布するよう構成し、排ガス下流側の水回収手段で得られた回収水を排ガス上流側の水回収手段の冷却水として用いるプロセスを繰り返すように複数の水回収手段を配置した水回収装置と、前記複数の水回収手段のうち、排ガス流れの最上流側に位置する水回収手段から回収された回収水を蒸気混入手段に供給する連絡経路とを有することを特徴とする。又は、圧縮機と、圧縮機から吐出される圧縮空気と燃料と蒸気が供給される燃焼器と、燃焼器の排ガスが供給され駆動するタービンとを備えたガスタービンにおいて、タービンから出た排ガスが供給され、排ガスに水滴を散布する冷却水散布部と散布水及び排ガスの凝縮水を回収する回収部とを備えた水回収手段を排ガスの流れ方向に沿って直列に多数配置し、第１の水回収手段の回収部で回収した回収水の少なくとも一部を、該第１の水回収手段より排ガス流れの上流側に位置する他の水回収手段の冷却水散布部から散布するよう構成し、排ガス下流側の水回収手段で得られた回収水を排ガス上流側の水回収手段の冷却水として用いるプロセスを繰り返すように複数の水回収手段を配置した水回収装置と、前記複数の水回収手段のうち、排ガス流れの最上流側に位置する水回収手段から回収された回収水を前記燃焼器に供給する連絡経路とを有することを特徴とする。
【００１０】
【発明の実施の形態】
以下図面を参照して本発明の実施の形態について説明する。
【００１１】
図１は本発明の一実施例の構成説明図である。空気圧縮機２で圧縮され燃焼器４に送られる。燃焼器４では燃料、蒸気発生器５で発生した蒸気とともに燃焼し高温の燃焼ガスとなってガスタービン１に送られる。ガスタービン１は発電機３を駆動したあと、高温の排気ガスを放出する。この排ガスは蒸気発生器５で熱回収されたあと、破線で囲んだ本発明の排ガスからの水回収領域に導かれる。
【００１２】
水蒸気を多く含んだ燃焼排ガスは、熱交換器６で冷却された後、水回収装置７に流入し、そこで冷却水と直接接触して冷却されて湿り蒸気となり、一部は凝縮し回収される。残りの排ガスは熱交換器６で加熱された後、煙突を経由して大気に放出される。水回収装置７は、ガス流れに対して直列に複数の水回収手段が配置されており、各水回収手段は、冷却水を流れる排ガスに散布する冷却水散布部と、散布水及び凝縮水を回収する回収部を備える。冷却水散布部と回収部との間を排ガスが流れるよう構成される。また、回収された水の少なくとも一部はガス流れの上流側に位置する水回収手段の冷却水散布部の冷却水として用いられる。具体的には以下に示す。
【００１３】
水回収装置７では冷却水は冷却水管４１を通り、冷却水散布部７１ａで排ガス中に散布され、散布水と凝縮水は回収水部７１ｂに回収される。回収水は戻り水管４３を通り冷却水冷却器８で冷却された後、冷却水管４１を通って冷却水として循環使用される。ところで、７１ｂで回収された回収水の内一部は冷却水分岐管４４，冷却水管４５を経由して、冷却水散布部７２ａに送られる。７２ａに送られた散布水は凝縮潜熱を吸収しているので、７１ａの散布水より温度が高くなっている。７２ａの散布水は７２ｂで回収され回収水管４６，冷却水管４７を通して冷却水散布部７３ａに送られる。このプロセスを繰り返すことにより、水回収装置出口の回収水管５０における回収水は回収水管４２の回収水よりも高温の回収水が得られる。最も上流側の水回収手段の水回収部７９ｂから出る回収水管５０における回収水は水処理装置１０を経由して、圧縮機から出た圧縮空気へ蒸気を混入させる蒸気混入手段に供給される。具体的には、蒸気発生器５に送られ補給水として利用され、圧縮機吐出空気に蒸気が混入される。余剰分は回収水タンク１２に蓄えられる。なお、熱交換器６は水回収した後の排ガスを加熱するためのものであり、この例では、水回収する前の排ガスを熱源としたガス−ガス熱交換器となっているが、別に熱源が得られる場合はそれを利用しても良い。
【００１４】
これにより、温度の異なる回収水が得られる。また、高温の回収水が容易に得られる。このため、排ガスの保有する熱エネルギーをエネルギーの高い状態で回収できる。
【００１５】
図２には、この散布と回収を繰り返し実施するプロセスにおける回収水温度の分布変化を概念図で示してある。ここでは、一例として４段の回収手段を設けた回収装置について示している。水回収装置７の出口側では回収水管４２の回収水の水温は温度Ｔ４２であるが、散布と回収を繰り返す度に回収水の温度は回収水管４６でＴ４６，配管４８でＴ４８に上昇し、水回収装置の入口側では回収水管５０で温度Ｔ５０になる。回収水を混合した場合の平均温度はＴｏであり、本実施例の水回収装置では循環水としてＴｏよりも温度の低いＴ４２の回収水が冷却水冷却器８に送られる。このため、散布水と回収水の温度差を１０℃と想定すると、冷却水冷却器８の熱負荷が約２％低減される。これにより、熱負荷の低減量に相当するだけ、冷却水冷却器８の伝熱面積を減らすことが可能になる。これにより、水回収装置を小型化する事もできる。
【００１６】
あるいは、冷却水量を同一とした場合には回収水量の増加をはかることができる。これは排ガス中の湿分含有率の低下につながり、白煙発生の防止効果が大きくなるという効果もある。いずれかの回収手段において回収される回収水が、他の機器へ供給するのに適するものであれば、複数ある回収手段のうち中間段の回収手段から他の機器への補給水として導いても良い。
【００１７】
また、水回収装置７の入口側ではＴｏよりも温度の高いＴ５０の回収水が補給水として蒸気発生器５に送られる。これにより、例えば図１の例では発電効率を約１％向上させることができる。
【００１８】
図３および図４は多数の水回収手段を備えた水回収装置の具体例で、図３は隔壁１７１，１７２等を設置し各水回収手段の回収水が混合しないようにしたもの、図４は各水回収手段の底面に傾斜を持たせて凹状を形成し、各水回収手段の回収水が混合しないようにした実施例である。
【００１９】
図５は水蒸気を含む排ガス中に冷却水を噴霧した場合の噴霧液滴径と回収時の液滴平均温度の関係を示したものである。液滴径が大きな場合には冷却水と水蒸気の直接接触により液表面の温度は上昇するがその影響は液滴内部には及んでいないため平均温度は低いが、液滴径が小さな場合には、液表面での温度上昇が内部まで及ぶため、平均温度が高くなる。この現象を利用すると、本発明の回収水の温度差を更に大きくすることができる。図６はその実施例で、水回収手段の冷却水散布部の散布水滴はその排ガス下流側に位置する第１の水回収手段の散布水滴より小さくなるようにする。例えば、水回収装置の排ガス流入側の最も排ガス上流側の冷却水散布部７９ａに最も微小な液滴が発生するスプレイノズルを使用し、流出側の最も排ガス下流側の冷却水散布部７１ａに最も大きな液滴が発生するスプレイノズルを使用している。このような構成にすることにより、冷却水散布時の液滴径が排ガスの入口側ほど小さくすることができ、入口側の温度を更に高くできる。この場合の水回収装置内回収水の温度分布推定例を図８に示す。実線が液滴径が一様な場合、破線が液滴径を上記のように変化させた場合である。
回収水の温度差を大きくする別な実施例を図７に示す。この例では水回収装置の入口側に行くほど冷却水散布部と回収部の距離を大きくしてある。このような構造にすることにより水回収装置の入口側ほど、液滴と排ガスの接触時間が長く、凝縮量も増えるため液滴温度が高くなる。
【００２０】
図９は本発明の更に別な実施例を示し、流量検出装置１３の値に基づき流量制御装置９が作動し、蒸気発生器５の蒸発量に相当する量を冷却水散布部７２ａに分岐させている。これにより蒸気量が安定し、出力変動の少ない発電設備の運転が可能になる。
【００２１】
図１０は本発明の装置を燃焼器の圧縮空気に水蒸気を含ませる水蒸気添加型のガスタービン発電システムに適用したシステム構成例である。回収水を補給水として再利用することにより、水蒸気添加型のガスタービン発電システムにおいて課題とされることの多い、補給水の確保が容易になる。また、高温の補給水が得られるので熱効率の良好なシステムを構成することができる。回収条件によっては、外部からの補給水をほとんど不要とするシステム構成も可能となる。
【００２２】
【発明の効果】
本発明によれば、排ガスから複数の温度レベルの回収水を得ることができ、外部に仕事として取り出し可能な有効エネルギーを効率良く回収することができる。また、この装置を水蒸気添加型のガスタービン発電システムに適用し、高温の回収水を補給水として利用すれば、プラント熱効率の向上に効果がある。
【図面の簡単な説明】
【図１】本発明の一実施例を示す概要図。
【図２】水回収装置内回収水の温度分布概念図。
【図３】水回収装置内の一実施例を示す概要図。
【図４】水回収装置内の一実施例を示す概要図。
【図５】液滴径と液滴温度の関係を説明する図。
【図６】本発明の一実施例を示す概要図。
【図７】本発明の一実施例を示す概要図。
【図８】水回収装置内回収水の温度分布説明図。
【図９】本発明の一実施例を示す概要図。
【図１０】本発明の一実施例を示す概要図。
【符号の説明】
１…ガスタービン、２…空気圧縮機、３…発電機、４…燃焼器、５…蒸気発生器、６…熱交換器、７…水回収装置、８…冷却水冷却器、９…流量制御装置、
１０…水処理装置、１１…ミスト除去装置、１２…回収水タンク、１３…流量検出装置、２０…燃料管、２１…空気吸入管、２２…空気吐出管、２３…管、２４…高温排気管、２５…蒸気供給管、２６…補給水供給管、２７，２８，２９…排ガス吐出管、３０…排気管、４１，４５，４７…冷却水管、４２，４６，５０…回収水管、４３…戻り水管、４４…冷却水分岐管、７１ａ…冷却水散布部、71ｂ…回収水部。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a water recovery device for exhaust gas, and relates to a water recovery device for exhaust gas that recovers moisture from combustion exhaust gas such as a gas turbine to effectively use water resources and reduces the amount of water vapor released to the environment. .
[0002]
[Prior art]
A method for recovering water from exhaust gas containing a lot of moisture is considered in the field of water recovery from exhaust gas in a fuel cell power plant or water recovery from gas turbine exhaust gas. Examples of Kaihei 8-31443 and water recovery from gas turbine exhaust gas include Japanese Unexamined Patent Publication No. 56-12006.
[0003]
[Problems to be solved by the invention]
If the temperature of the exhaust gas containing a lot of moisture is lowered below its dew point, water vapor can be condensed and water can be recovered. Conventional water recovery devices have not paid sufficient attention to the temperature of the recovered water. However, in order to recover the effective energy (exergy) that can be extracted to the outside as effectively as possible, the recovered water is recovered at a high temperature rather than mixing the recovered water to the same temperature. Is desirable. This is not sufficient for conventional water recovery devices from exhaust gas.
[0004]
Therefore, the present invention provides a water recovery apparatus that can recover recovered water having different temperature levels with a simple system when recovering water from exhaust gas containing moisture.
[0005]
[Means for Solving the Problems]
The present invention is divided into a plurality of water recovery sections when recovering moisture from exhaust gas, and a part of the liquid recovery section recovery water on the outlet side where the temperature of the combustion exhaust gas is low is used as the inlet side where the temperature of the combustion exhaust gas is high The recovered water obtained in that region is further supplied to the cooling water spraying portion located on the inlet side of the combustion exhaust gas.
[0006]
For example, a plurality of water recovery means provided in series with respect to the flow direction of the exhaust gas, including a cooling water spray unit that sprays water droplets on the exhaust gas and a recovery unit that recovers the condensed water of the spray water and the moisture in the exhaust gas. a water recovery device exhaust gas, at least a portion of the recovered recovered water in the recovery portion of the first water collection means, other water recovery means positioned on the upstream side of the exhaust gas flow from the water collecting means of said first configured to scatter from the cooling water spraying unit, arranging a plurality of water collecting means so as to repeat the process using the recovered water obtained by the water recovery means of an exhaust gas downstream side as cooling water for the water recovery means on the exhaust gas upstream side characterized in that it was.
[0007]
Alternatively, a plurality of water recovery means including a cooling water spraying unit for spraying water droplets on the exhaust gas and a recovery unit for collecting the condensed water of the sprayed water and moisture in the exhaust gas are arranged in series with respect to the flow direction of the exhaust gas. A second water recovery device for exhaust gas water recovery , wherein at least a part of the recovered water recovered by the recovery part of the first water recovery means is located upstream of the exhaust gas flow from the first water recovery means. A plurality of water recovery means is configured to repeat the process of using the recovered water obtained by the water recovery means downstream of the exhaust gas as the cooling water of the water recovery means upstream of the exhaust gas. And the average particle diameter of the water droplets sprayed from the cooling water spraying portion of the first water recovery means is that of the second water recovery means located downstream of the exhaust gas flow of the first water recovery means. Average grain size of water droplets sprayed from the cooling water spray section Characterized in that it is configured to be smaller.
[0008]
Alternatively, a plurality of water recovery means including a cooling water spraying unit for spraying water droplets on the exhaust gas and a recovery unit for collecting the condensed water of the sprayed water and moisture in the exhaust gas are arranged in series with respect to the flow direction of the exhaust gas. A second water recovery device for exhaust gas water recovery , wherein at least a part of the recovered water recovered by the recovery part of the first water recovery means is located upstream of the exhaust gas flow from the first water recovery means. A plurality of water recovery means is configured to repeat the process of using the recovered water obtained by the water recovery means downstream of the exhaust gas as the cooling water of the water recovery means upstream of the exhaust gas. A plurality of water recovery means including the cooling water spraying part and the recovery part arranged in series along the flow direction of the exhaust gas, and between the cooling water spraying part and the recovery part of the first water recovery means Is the drainage of the first cooling water recovery means. Characterized in that it is configured to be longer than the distance between the cooling water spraying unit of the second water collection means located downstream of the scan flows and the collecting unit.
[0009]
Or, a compressor, a steam mixing means for mixing steam into compressed air discharged from the compressor, a combustor to which compressed air containing steam, fuel and steam are supplied, and exhaust gas from the combustor are supplied and driven. In a gas turbine having a turbine, exhaust gas discharged from the turbine is supplied with a cooling water spraying unit that sprays water droplets on the exhaust gas and a recovery unit that collects sprayed water and condensed water of the exhaust gas. A number of the collected water collected in series in the flow direction of the first water recovery means , and at least a part of the recovered water recovered by the recovery part of the first water recovery means is located upstream of the first water recovery means . It is configured to spray from the cooling water spraying part of the water recovery means, and multiple water recovery is performed so that the process of using the recovered water obtained by the water recovery means downstream of the exhaust gas as the cooling water of the water recovery means upstream of the exhaust gas is repeated. Means A water recovery apparatus location, among the plurality of water collecting means, and wherein a recovered water recovered from the water recovery means positioned on the most upstream side of the exhaust gas flow and a contact path for supplying the steam mixing means To do. Alternatively, in a gas turbine including a compressor, a combustor to which compressed air discharged from the compressor, fuel and steam are supplied, and a turbine to which the exhaust gas of the combustor is supplied and driven, the exhaust gas emitted from the turbine is A number of water recovery means including a cooling water spraying unit that sprays water droplets on the exhaust gas and a recovery unit that collects the spray water and the condensed water of the exhaust gas are arranged in series along the flow direction of the exhaust gas. at least a portion of the recovered recovered water in the recovery portion of the water recovery means, and configured to spread the cooling water spraying unit of the other water collecting means positioned on the upstream side of the exhaust gas flow from the water collecting means of said first, A water recovery apparatus in which a plurality of water recovery means are arranged so as to repeat the process of using the recovered water obtained by the water recovery means downstream of the exhaust gas as cooling water for the water recovery means upstream of the exhaust gas, and the plurality of water recovery means Out of And having scan the recovered water recovered from the water recovery means positioned on the most upstream side of the flow and a contact path for supplying to said combustor.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0011]
FIG. 1 is a diagram illustrating the configuration of an embodiment of the present invention. It is compressed by the air compressor 2 and sent to the combustor 4. In the combustor 4, the fuel is combusted together with the fuel and the steam generated in the steam generator 5, and is sent to the gas turbine 1 as a high-temperature combustion gas. The gas turbine 1 drives the generator 3 and then releases high-temperature exhaust gas. This exhaust gas is heat-recovered by the steam generator 5 and then guided to a water recovery region from the exhaust gas of the present invention surrounded by a broken line.
[0012]
The flue gas containing a large amount of water vapor is cooled by the heat exchanger 6 and then flows into the water recovery device 7 where it is cooled by direct contact with the cooling water to become wet steam, and a part is condensed and recovered. . The remaining exhaust gas is heated by the heat exchanger 6 and then released to the atmosphere via the chimney. In the water recovery device 7, a plurality of water recovery means are arranged in series with respect to the gas flow, and each water recovery means has a cooling water spraying part for spraying the exhaust gas flowing through the cooling water, sprayed water and condensed water. A collection unit for collecting is provided. An exhaust gas is configured to flow between the cooling water spraying unit and the recovery unit. Further, at least a part of the recovered water is used as cooling water for the cooling water spraying portion of the water recovery means located on the upstream side of the gas flow. Specifically, it is shown below.
[0013]
In the water recovery device 7, the cooling water passes through the cooling water pipe 41 and is sprayed into the exhaust gas by the cooling water spraying part 71a, and the sprayed water and the condensed water are recovered in the recovery water part 71b. The recovered water passes through the return water pipe 43 and is cooled by the cooling water cooler 8, and then circulated and used as cooling water through the cooling water pipe 41. By the way, a part of the recovered water recovered by 71 b is sent to the cooling water spraying part 72 a via the cooling water branch pipe 44 and the cooling water pipe 45. Since the spray water sent to 72a has absorbed condensation latent heat, temperature is higher than the spray water of 71a. The spray water 72a is collected at 72b and sent to the cooling water spray section 73a through the recovery water pipe 46 and the cooling water pipe 47. By repeating this process, the recovered water in the recovered water pipe 50 at the outlet of the water recovery apparatus can be recovered at a higher temperature than the recovered water in the recovered water pipe 42. The recovered water in the recovered water pipe 50 exiting from the water recovery section 79b of the most upstream water recovery means is supplied via the water treatment device 10 to the steam mixing means that mixes the steam into the compressed air output from the compressor. Specifically, it is sent to the steam generator 5 and used as makeup water, and steam is mixed into the compressor discharge air. The surplus is stored in the recovered water tank 12. The heat exchanger 6 is for heating the exhaust gas after water recovery. In this example, the heat exchanger 6 is a gas-gas heat exchanger using the exhaust gas before water recovery as a heat source. If you can get it, you may use it.
[0014]
Thereby, recovered water having different temperatures is obtained. Moreover, high temperature recovered water can be easily obtained. For this reason, the thermal energy possessed by the exhaust gas can be recovered in a high energy state.
[0015]
FIG. 2 is a conceptual diagram showing the distribution change of the recovered water temperature in the process of repeatedly performing the spraying and recovery. Here, as an example, a collection apparatus provided with four stages of collection means is shown. At the outlet side of the water recovery device 7, the temperature of the recovered water in the recovered water pipe 42 is the temperature T42. However, each time spraying and recovery are repeated, the temperature of the recovered water rises to T46 in the recovered water pipe 46 and T48 in the pipe 48. At the inlet side of the recovery device, the temperature of the recovery water pipe 50 reaches T50. The average temperature when the recovered water is mixed is To, and in the water recovery apparatus of this embodiment, the recovered water of T42 having a temperature lower than To is sent to the cooling water cooler 8 as circulating water. For this reason, assuming that the temperature difference between the spray water and the recovered water is 10 ° C., the heat load of the cooling water cooler 8 is reduced by about 2%. Thereby, the heat transfer area of the cooling water cooler 8 can be reduced by an amount corresponding to the reduction amount of the heat load. Thereby, a water recovery apparatus can also be reduced in size.
[0016]
Or when the amount of cooling water is made the same, the amount of recovered water can be increased. This leads to a decrease in the moisture content in the exhaust gas, and also has the effect of increasing the effect of preventing white smoke generation. If the recovered water recovered by any of the recovery means is suitable for supply to other equipment, it can be led as makeup water from the intermediate recovery means to the other equipment among the multiple recovery means. good.
[0017]
In addition, on the inlet side of the water recovery device 7, recovered water of T50 having a temperature higher than To is sent to the steam generator 5 as makeup water. Thereby, in the example of FIG. 1, for example, the power generation efficiency can be improved by about 1%.
[0018]
3 and 4 are specific examples of a water recovery apparatus provided with a large number of water recovery means. FIG. 3 shows a structure in which partition walls 171, 172 and the like are installed so that the recovered water of each water recovery means is not mixed. Is an embodiment in which the bottom surface of each water recovery means is inclined to form a concave shape so that the recovered water of each water recovery means is not mixed.
[0019]
FIG. 5 shows the relationship between the spray droplet diameter when the cooling water is sprayed into the exhaust gas containing water vapor and the average droplet temperature during recovery. When the droplet size is large, the temperature of the liquid surface rises due to direct contact between cooling water and water vapor, but the effect does not reach the inside of the droplet, so the average temperature is low, but when the droplet size is small Since the temperature rise at the liquid surface reaches the inside, the average temperature becomes high. By utilizing this phenomenon, the temperature difference of the recovered water of the present invention can be further increased. FIG. 6 shows an embodiment, in which the sprayed water droplets of the cooling water spraying portion of the water recovery means are made smaller than the sprayed water droplets of the first water recovery means located on the downstream side of the exhaust gas. For example, a spray nozzle that generates the most minute droplets is used in the cooling water spraying portion 79a on the exhaust gas inflow side of the water recovery device, and the cooling water spraying portion 71a on the outflow side is the most downstream of the exhaust gas. A spray nozzle that generates large droplets is used. By adopting such a configuration, the droplet diameter when spraying the cooling water can be made smaller toward the exhaust gas inlet side, and the temperature on the inlet side can be further increased. An example of estimating the temperature distribution of the recovered water in the water recovery apparatus in this case is shown in FIG. A solid line indicates a case where the droplet diameter is uniform, and a broken line indicates a case where the droplet diameter is changed as described above.
Another embodiment for increasing the temperature difference of the recovered water is shown in FIG. In this example, the distance between the cooling water spraying portion and the recovery portion is increased toward the inlet side of the water recovery device. With this structure, the contact time between the droplets and the exhaust gas is longer and the amount of condensation increases toward the inlet side of the water recovery device, so that the droplet temperature becomes higher.
[0020]
FIG. 9 shows still another embodiment of the present invention. The flow rate control device 9 is operated based on the value of the flow rate detection device 13, and an amount corresponding to the evaporation amount of the steam generator 5 is branched to the cooling water spraying portion 72a. ing. This stabilizes the amount of steam and enables operation of the power generation facility with little fluctuation in output.
[0021]
FIG. 10 shows a system configuration example in which the apparatus of the present invention is applied to a steam addition type gas turbine power generation system in which steam is included in the compressed air of the combustor. By reusing the recovered water as make-up water, it becomes easy to secure make-up water, which is often a problem in a steam addition type gas turbine power generation system. In addition, since hot makeup water can be obtained, a system with good thermal efficiency can be configured. Depending on the collection conditions, a system configuration that requires almost no external makeup water is also possible.
[0022]
【The invention's effect】
According to the present invention, recovered water having a plurality of temperature levels can be obtained from exhaust gas, and effective energy that can be taken out as work can be efficiently recovered. Moreover, if this apparatus is applied to a steam addition type gas turbine power generation system and high-temperature recovered water is used as makeup water, there is an effect in improving plant thermal efficiency.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an embodiment of the present invention.
FIG. 2 is a conceptual diagram of the temperature distribution of recovered water in the water recovery apparatus.
FIG. 3 is a schematic diagram showing an embodiment in the water recovery apparatus.
FIG. 4 is a schematic diagram showing an embodiment in the water recovery apparatus.
FIG. 5 is a diagram for explaining a relationship between a droplet diameter and a droplet temperature.
FIG. 6 is a schematic diagram showing an embodiment of the present invention.
FIG. 7 is a schematic diagram showing an embodiment of the present invention.
FIG. 8 is an explanatory diagram of temperature distribution of recovered water in the water recovery apparatus.
FIG. 9 is a schematic diagram showing an embodiment of the present invention.
FIG. 10 is a schematic diagram showing an embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Gas turbine, 2 ... Air compressor, 3 ... Generator, 4 ... Combustor, 5 ... Steam generator, 6 ... Heat exchanger, 7 ... Water recovery apparatus, 8 ... Cooling water cooler, 9 ... Flow control apparatus,
DESCRIPTION OF SYMBOLS 10 ... Water treatment apparatus, 11 ... Mist removal apparatus, 12 ... Recovery water tank, 13 ... Flow rate detection apparatus, 20 ... Fuel pipe, 21 ... Air intake pipe, 22 ... Air discharge pipe, 23 ... Pipe, 24 ... High temperature exhaust pipe 25 ... steam supply pipe, 26 ... makeup water supply pipe, 27, 28, 29 ... exhaust gas discharge pipe, 30 ... exhaust pipe, 41, 45, 47 ... cooling water pipe, 42, 46, 50 ... recovery water pipe, 43 ... return Water pipe, 44 ... cooling water branch pipe, 71a ... cooling water spraying section, 71b ... recovered water section.

Claims

An exhaust gas system comprising a plurality of water recovery means arranged in series with respect to the flow direction of the exhaust gas, including a cooling water spray unit that sprays water droplets on the exhaust gas and a recovery unit that recovers the condensed water of the spray water and the moisture in the exhaust gas. A water recovery device,
At least a portion of the recovered recovered water in the recovery portion of the first water collecting means, so as to spread from the cooling water spraying unit of the other water collecting means positioned on the upstream side of the exhaust gas flow from the water collecting means of said first Exhaust water characterized in that a plurality of water recovery means are arranged so as to repeat the process of using the recovered water obtained by the water recovery means downstream of the exhaust gas as cooling water for the water recovery means upstream of the exhaust gas Recovery device.

An exhaust gas system comprising a plurality of water recovery means arranged in series with respect to the flow direction of the exhaust gas, comprising a cooling water spray unit for spraying water droplets on the exhaust gas, and a recovery unit for recovering the condensed water of the dispersed water and moisture in the exhaust gas. A water recovery device,
At least a part of the recovered water recovered by the recovery part of the first water recovery means is sprayed from the cooling water spraying part of the second water recovery means located on the upstream side of the exhaust gas flow from the first water recovery means. And arranging a plurality of water recovery means so as to repeat the process of using the recovered water obtained by the water recovery means downstream of the exhaust gas as the cooling water of the water recovery means upstream of the exhaust gas,
The average particle size of water droplets being sprayed from the cooling water spraying unit of the first water collection means, the cooling water spraying unit of the second water collection means located downstream of the exhaust gas flow of the first water collection means An exhaust gas water recovery device configured to be smaller than an average particle diameter of water droplets sprayed from

An exhaust gas system comprising a plurality of water recovery means arranged in series with respect to the flow direction of the exhaust gas, comprising a cooling water spray unit for spraying water droplets on the exhaust gas, and a recovery unit for recovering the condensed water of the dispersed water and moisture in the exhaust gas. A water recovery device,
At least a part of the recovered water recovered by the recovery part of the first water recovery means is sprayed from the cooling water spraying part of the second water recovery means located on the upstream side of the exhaust gas flow from the first water recovery means. And arranging a plurality of water recovery means so as to repeat the process of using the recovered water obtained by the water recovery means downstream of the exhaust gas as the cooling water of the water recovery means upstream of the exhaust gas,
The distance between the cooling water spraying unit and the collecting portion of the first water collecting means includes a cooling water spraying unit of the second water collection means located downstream of the exhaust gas flow of the first water collection means An exhaust gas water recovery apparatus, characterized in that it is longer than the distance between the recovery section.

A compressor,
Steam mixing means for mixing steam into the compressed air discharged from the compressor;
A combustor supplied with compressed air containing steam, fuel and steam;
In a gas turbine having a turbine driven by being supplied with exhaust gas from a combustor,
A large number of water recovery means are provided in series along the flow direction of the exhaust gas, which is provided with a cooling water spraying unit that supplies exhaust gas from the turbine and sprays water droplets on the exhaust gas, and a recovery unit that collects the sprayed water and condensed water of the exhaust gas. arranged to, at least a portion of the recovered recovered water in the recovery portion of the first water collection means, from the cooling water spraying unit of the other water collecting means positioned on the upstream side of the exhaust gas flow from the water collecting means of said first A water recovery apparatus that is configured to spray and has a plurality of water recovery means arranged so as to repeat the process of using the recovered water obtained by the water recovery means downstream of the exhaust gas as cooling water of the water recovery means upstream of the exhaust gas ;
A gas turbine, comprising: a communication path for supplying, to the steam mixing means, recovered water recovered from a water recovery means located on the most upstream side of the exhaust gas flow among the plurality of water recovery means.

A compressor,
A combustor supplied with compressed air, fuel, and steam discharged from the compressor;
In a gas turbine having a turbine driven by being supplied with exhaust gas from a combustor,
A large number of water recovery means are provided in series along the flow direction of the exhaust gas, which is provided with a cooling water spraying unit that supplies exhaust gas from the turbine and sprays water droplets on the exhaust gas, and a recovery unit that collects the sprayed water and condensed water of the exhaust gas. arranged to, at least a portion of the recovered recovered water in the recovery portion of the first water collection means, from the cooling water spraying unit of the other water collecting means positioned on the upstream side of the exhaust gas flow from the water collecting means of said first A water recovery apparatus that is configured to spray and has a plurality of water recovery means arranged so as to repeat the process of using the recovered water obtained by the water recovery means downstream of the exhaust gas as cooling water of the water recovery means upstream of the exhaust gas ;
A gas turbine comprising: a communication path for supplying, to the combustor, recovered water recovered from a water recovery means located on the most upstream side of the exhaust gas flow among the plurality of water recovery means.