JP5708926B2 - Seawater desalination system and method - Google Patents

Seawater desalination system and method Download PDF

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JP5708926B2
JP5708926B2 JP2011111451A JP2011111451A JP5708926B2 JP 5708926 B2 JP5708926 B2 JP 5708926B2 JP 2011111451 A JP2011111451 A JP 2011111451A JP 2011111451 A JP2011111451 A JP 2011111451A JP 5708926 B2 JP5708926 B2 JP 5708926B2
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seawater
evaporator
flow path
saturation temperature
distilled water
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JP2012239968A (en
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裕一 西山
裕一 西山
知哉 村本
知哉 村本
真也 奥野
真也 奥野
至高 中村
至高 中村
克明 松澤
克明 松澤
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IHI Corp
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
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    • Y02A20/124Water desalination

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Description

本発明は、海水を淡水化するための淡水化システム及びその方法に関するものである。   The present invention relates to a desalination system and method for desalinating seawater.

海水を淡水化する方法としては、多段フラッシュ法やRO膜法等が用いられている。多段フラッシュ法は、加熱された海水を減圧された蒸発器で沸騰蒸発させ、その発生蒸気を凝縮して淡水を生産する海水の淡水化方法である。この多段フラッシュ法は、海水の品質を問わず使用でき、大量の淡水を作成できるが、熱効率が悪く、そのために多量のエネルギを必要とする。RO膜法は、半透膜を通して海水から淡水を得るものである。このRO膜法は、半透膜が海水中の微生物や析出物で目詰まりしないように入念に前処理をする必要があり、その整備にコストがかかり、さらには製造した淡水の塩濃度が高いこと等の難点がある。   As a method for desalinating seawater, a multistage flash method, an RO membrane method, or the like is used. The multistage flash method is a desalination method of seawater in which heated seawater is boiled and evaporated in a decompressed evaporator, and the generated steam is condensed to produce fresh water. This multi-stage flash method can be used regardless of the quality of seawater, and can produce a large amount of fresh water, but it has poor thermal efficiency, and therefore requires a large amount of energy. The RO membrane method obtains fresh water from seawater through a semipermeable membrane. This RO membrane method requires careful pretreatment so that the semipermeable membrane is not clogged with microorganisms and precipitates in seawater, which is expensive to maintain and also has a high salt concentration in the fresh water produced. There are difficulties.

一方で、蒸発器での蒸気を圧縮させる蒸気圧縮法による海水の淡水化方法が実用化されている。一般的な蒸気圧縮法は例えば特許文献1に記載されている。すなわち、蒸気を圧縮して断熱温度上昇させ、この温度をもって熱交換に用いるための温度差を得るものである。この蒸気圧縮法は上述した多段フラッシュ法と同様、蒸発法に属するが、多段フラッシュ法に比して半分程度のエネルギで運転が可能である。   On the other hand, a seawater desalination method by a vapor compression method in which the vapor in the evaporator is compressed has been put into practical use. A general vapor compression method is described in Patent Document 1, for example. That is, the vapor is compressed to increase the adiabatic temperature, and a temperature difference for use in heat exchange is obtained at this temperature. This vapor compression method belongs to the evaporation method as in the above-described multistage flash method, but can be operated with about half the energy of the multistage flash method.

特開2008−188514号公報JP 2008-188514 A

しかしながら、上述した蒸気圧縮法で海水を淡水化する方法は、一般的にシステム全体としての熱効率が悪いため、そのシェアが5%程度である。そのため、システム全体として熱交換率を高めて運転効率を向上させる技術が望まれている。   However, since the method of desalinating seawater by the above-described vapor compression method generally has poor thermal efficiency as a whole system, its share is about 5%. Therefore, there is a demand for a technique for improving the operation efficiency by increasing the heat exchange rate as a whole system.

本発明は、上記従来技術を考慮したものであり、システム全体として熱効率を高め、海水の淡水化に要するための無駄なエネルギが極力使用されないようにするための海水の淡水化システム及びその方法を提供することを目的とする。   The present invention takes the above-mentioned conventional technology into consideration, and provides a seawater desalination system and method for improving thermal efficiency as a whole system and preventing wasteful energy required for seawater desalination from being used as much as possible. The purpose is to provide.

前記目的を達成するため、本発明では、供給された海水が流通する海水供給流路と、前記海水供給流路に配設された分離器及び混合器と、前記海水供給流路の一部を形成し、前記分離器及び混合器の間に架け渡された第1の流路及び第2の流路と、該第1及び第2の流路に配設された第1及び第2の熱交換器と、前記海水供給流路の終端に形成され、前記海水の飽和温度である第1の飽和温度で前記海水を蒸発する蒸発器と、該蒸発器によって発生した蒸気前記蒸発器及び前記第1の熱交換器の順番で通過し、該蒸気と前記蒸発器及び前記第1の熱交換器で前記海水と熱交換され発生した液状の蒸留水とが蒸気を含む蒸留水として流通する蒸留水還り流路と、前記蒸発器によって発生した濃縮水が流通し、前記第2の熱交換器を通過する濃縮水還り流路と、前記蒸留水還り流路に前記蒸発器の上流に位置して配設され、前記蒸気を圧縮するための圧縮機とを備えた海水の淡水化システムにおいて、前記海水のうち前記蒸気となる割合を前記第1の流路に、前記濃縮水となる割合を前記第2の流路にそれぞれ流通させるために前記分離器での前記海水の分離率を調整する分離率調整部と、前記蒸発器内での蒸発による前記海水の沸点上昇を認識し、沸点上昇後の前記海水の飽和温度である第2の飽和温度を認識するための沸点上昇認識部と、該沸点上昇認識部にて認識された前記第2の飽和温度に予め定めた熱交換温度差の値を加算して前記蒸留水の飽和温度である第3の飽和温度を求め、前記蒸留水が前記第3の飽和温度となるような圧力を決定して前記圧縮機での圧縮率を定める圧縮率演算部と、前記第1の熱交換器を通過した前記海水の温度が前記第1の飽和温度となるように調整する温度差調整部とを有する制御装置と、前記第2の熱交換器を通過した前記海水の温度を前記第1の飽和温度まで上昇させるための加熱手段とをさらに備えたことを特徴とする海水の淡水化システムを提供する。 In order to achieve the object, in the present invention, a seawater supply channel through which the supplied seawater flows, a separator and a mixer disposed in the seawater supply channel, and a part of the seawater supply channel are provided. A first flow path and a second flow path formed between the separator and the mixer, and a first heat and a second heat disposed in the first flow path and the second flow path. and exchangers, is formed at the end of the seawater supply passage, a first evaporator for evaporating the sea water at saturation temperature, the evaporator and the steam generated by the evaporator is a saturation temperature of the seawater Distillation that passes in the order of the first heat exchanger, and that the steam and liquid distilled water generated by heat exchange with the seawater in the evaporator and the first heat exchanger circulate as distilled water containing steam. Concentrated water generated by the water return flow path and the evaporator circulates and passes through the second heat exchanger. And water went back channel is arranged positioned upstream of the evaporator in the distilled water went back channel, in seawater desalination system that includes a compressor for compressing the vapor, of the seawater A separation rate adjusting unit that adjusts the separation rate of the seawater in the separator so that the proportion of the steam becomes the first flow channel and the proportion of the concentrated water flows to the second flow channel. A boiling point increase recognition unit for recognizing a rise in boiling point of the seawater due to evaporation in the evaporator and recognizing a second saturation temperature that is a saturation temperature of the seawater after the boiling point rises, A value of a predetermined heat exchange temperature difference is added to the second saturation temperature recognized in the section to obtain a third saturation temperature which is a saturation temperature of the distilled water, and the distilled water is the third saturation temperature. Determine the pressure at which the saturation temperature is reached and determine the compression ratio in the compressor A control device having a compression ratio calculation unit, and a temperature difference adjustment unit that adjusts the temperature of the seawater that has passed through the first heat exchanger to be the first saturation temperature, and the second heat exchange. The seawater desalination system further comprising heating means for raising the temperature of the seawater that has passed through the vessel to the first saturation temperature.

好ましくは、前記加熱手段は、前記蒸留水還り流路における前記蒸発器と前記第1の熱交換器との間に配設され、且つ前記第2の流路における前記第2の熱交換器と前記蒸発器との間に配設された第3の熱交換器である。   Preferably, the heating means is disposed between the evaporator and the first heat exchanger in the distilled water return flow path, and the second heat exchanger in the second flow path. It is a 3rd heat exchanger arrange | positioned between the said evaporators.

また、本発明では、海水を蒸発させるべき蒸発器まで通じ、且つ分離器にて分岐された第1の流路及び第2の流路を有する海水供給流路に海水を供給し、前記分離器にて、前記第1の流路に流す前記海水と前記第2の流路に流す前記海水との分離率を前記蒸発器における前記海水の蒸発率と濃縮率との比率と一致させて前記第1及び第2の流路にそれぞれ流し、前記海水供給流路に配設され、且つ前記第1及び第2の流路が合流する混合器に前記第1及び第2の流路からそれぞれ海水を流入するに際し、前記第1及び第2の流路にそれぞれ配設された第1及び第2の熱交換器を用いて前記海水の温度を海水の飽和温度である第1の飽和温度まで加熱し、前記海水を前記蒸発器にて蒸発させて発生した蒸気を蒸留水還り流路に流通させ、前記蒸発器及び前記第1の熱交換器の順番で通過させることで該蒸気と前記蒸発器及び前記第1の熱交換器で前記海水と熱交換され発生した液状の蒸留水とからなる蒸気を含む蒸留水を生成し、前記蒸発器内での蒸発によって沸点上昇を生じた後の前記海水の飽和温度である第2の飽和温度を認識し、前記第2の飽和温度に予め定めた熱交換温度差の値を加算して前記蒸留水の飽和温度である第3の飽和温度を求め、前記蒸留水還り流路に前記蒸発器の上流に位置して配設された圧縮機にて前記蒸留水を前記第3の飽和温度となるまで圧縮し、前記第3の飽和温度の前記蒸留水を前記蒸留水還り流路における前記蒸発器及び前記第1の熱交換器での前記海水の蒸発及び加熱に用い、前記蒸発器にて発生した濃縮水を濃縮水還り流路に流通させて前記第2の熱交換器での前記海水の加熱に用いることを特徴とする海水の淡水化方法を提供する。 Further, in the present invention, seawater is supplied to a seawater supply flow path that has a first flow path and a second flow path that lead to an evaporator to evaporate seawater and that is branched by the separator, and the separator The separation rate between the seawater flowing through the first flow path and the seawater flowing through the second flow path is made to coincide with the ratio of the evaporation rate and the concentration rate of the seawater in the evaporator. The seawater flows from the first and second flow paths to the mixers that flow through the first and second flow paths, respectively, are disposed in the seawater supply flow path, and the first and second flow paths merge. When flowing in, the temperature of the seawater is heated to a first saturation temperature, which is a saturation temperature of seawater, using first and second heat exchangers disposed in the first and second flow paths, respectively. the seawater was passed through distilled water went back passage of steam generated by evaporation in said evaporator, said vapor Distillation containing vessel and steam comprising a distilled water liquid that the seawater by heat exchange occurs the a steam evaporator and in the first heat exchanger by passing in the first order of the heat exchanger to produce water, the recognizes a second saturation temperature is the saturation temperature of the seawater after the rise to the boiling point rise by evaporation in the evaporator, the predetermined heat exchange temperature difference to a second saturation temperature seeking a third saturation temperature value is the saturation temperature of the distilled water by adding the distilled at front Ki蒸 distilled water went back channel disposed positioned upstream of the evaporator to the compressor water compresses until the third saturation temperature, evaporated and the seawater of the distilled water of the third saturation temperature in the evaporator and the first heat exchanger in the distilled water went back channel Used for heating, circulating the concentrated water generated in the evaporator through the concentrated water return flow path, and It provides a desalination process for seawater, which comprises using the heat of the sea water in the second heat exchanger.

本発明では、第1の流路を通った海水は第1の熱交換器により海水の飽和温度である第1の飽和温度まで上昇され、第2の流路を通った海水は第2の熱交換器及び加熱手段により海水の飽和温度である第1の飽和温度まで上昇される。したがって、これらの海水は混合器にて同一の温度で混合される。したがって、第1の流路と第2の流路を通った海水の温度がともに飽和温度で揃った状態で海水は蒸発器にて蒸発される。これにより、蒸発器での蒸発に際して最低限の熱量で海水を蒸発させることができる。また、分離率調整部は、海水の濃縮率(蒸発率)に応じてそれぞれ海水を分離させる。したがって、蒸留水及び濃縮水の顕熱をそれぞれの割合に応じた海水と熱交換させることができ、効率よく回収することができる。また、予め熱交換温度差を定め、沸点上昇を起こした海水の第2の飽和温度に対して熱交換温度差を加算した第3の飽和温度を求め、蒸留水がこの第3の飽和温度となるように蒸気の圧縮率を定める。この熱交換温度差は、各熱交換器で最も効率よく熱交換できる温度差である。第1の熱交換器では、第3の飽和温度の蒸留水と海水とが熱交換されるため、海水を第1の飽和温度まで上昇させることができ、無駄なく蒸留水の顕熱を回収することができる。   In the present invention, the seawater that has passed through the first flow path is raised to the first saturation temperature that is the saturation temperature of the seawater by the first heat exchanger, and the seawater that has passed through the second flow path has the second heat. The temperature is raised to the first saturation temperature which is the saturation temperature of seawater by the exchanger and the heating means. Therefore, these seawaters are mixed at the same temperature in the mixer. Accordingly, the seawater is evaporated by the evaporator in a state where the temperatures of the seawater passing through the first flow path and the second flow path are all equal to the saturation temperature. Thereby, seawater can be evaporated with the minimum heat quantity at the time of evaporation in an evaporator. Moreover, a separation rate adjustment part isolate | separates seawater according to the concentration rate (evaporation rate) of seawater, respectively. Therefore, the sensible heat of distilled water and concentrated water can be heat exchanged with seawater corresponding to each ratio, and can be efficiently recovered. In addition, a heat exchange temperature difference is determined in advance, a third saturation temperature obtained by adding the heat exchange temperature difference to the second saturation temperature of the seawater that has risen in boiling point is obtained, and distilled water is obtained from the third saturation temperature. The compressibility of steam is determined so that This heat exchange temperature difference is a temperature difference at which heat exchange can be performed most efficiently in each heat exchanger. In the first heat exchanger, the distilled water having the third saturation temperature is exchanged with seawater, so that the seawater can be raised to the first saturation temperature, and the sensible heat of the distilled water can be recovered without waste. be able to.

本発明に係る海水淡水化システムの概念を示した概略図である。It is the schematic which showed the concept of the seawater desalination system which concerns on this invention. 本発明に係る海水淡水化システムの装置構成を示した概略図である。It is the schematic which showed the apparatus structure of the seawater desalination system which concerns on this invention. 海水を50%濃縮したときの温度と熱量との関係を示したグラフである。It is the graph which showed the relationship between temperature and calorie | heat amount when seawater was concentrated 50%.

本発明が適用される淡水化システムについて説明する。
図1に示すように、このシステムSは、熱交換器1〜4と圧縮機5とを備えている。熱交換器は、それぞれ第1の熱交換器1〜3及び蒸発器4からなる。蒸発器4は海水供給端6と海水供給流路7を介して接続されている。システムSは、海水供給端6から供給される海水を淡水にするためのものである。海水供給流路7には、第1〜3の熱交換器1、2、3が配設されている。具体的には、海水供給流路7には分離器8が設けられていて、ここで流路7は第1の流路11及び第2の流路12に分岐される。第1の流路11には上述した第1の熱交換器1が配設され、第2の流路12には上述した第2の熱交換器2及び第3の熱交換器3がそれぞれ第2の流路12の上流側から順番に配設されている。そして、第1及び第2の流路11、12は混合器9にて再び一つの流路となり、蒸発器4に接続される。
A desalination system to which the present invention is applied will be described.
As shown in FIG. 1, the system S includes heat exchangers 1 to 4 and a compressor 5. The heat exchanger includes first heat exchangers 1 to 3 and an evaporator 4, respectively. The evaporator 4 is connected to the seawater supply end 6 via a seawater supply channel 7. The system S is for making the seawater supplied from the seawater supply end 6 into fresh water. First to third heat exchangers 1, 2, and 3 are disposed in the seawater supply channel 7. Specifically, the seawater supply flow path 7 is provided with a separator 8, where the flow path 7 is branched into a first flow path 11 and a second flow path 12. The first heat exchanger 1 described above is disposed in the first flow path 11, and the second heat exchanger 2 and the third heat exchanger 3 described above are respectively provided in the second flow path 12. The two flow paths 12 are arranged in order from the upstream side. The first and second flow paths 11 and 12 become one flow path again in the mixer 9 and are connected to the evaporator 4.

蒸発器4は、供給された海水を蒸発させるものである。蒸発器4は気液分離器10に接続されている。蒸発器4で生じた蒸気及び濃縮水は、気液分離器10にてそれぞれ分離され、蒸気は蒸留水還り流路13に、濃縮水は濃縮水還り流路14に導かれる。蒸留水還り流路13には上述した圧縮機5が配設され、この圧縮機5で蒸気は圧縮される。圧縮機5の下流には、上述した蒸発器4、第3の熱交換器3、第1の熱交換器1がそれぞれ順番に配設されている。すなわち、蒸留水は蒸発器4、第3の熱交換器3、第1の熱交換器1の順番でそれぞれ海水と熱交換される。なお、蒸発器4で熱交換されるまでは、蒸留水は蒸発した状態で流通している。蒸留水還り流路13における第1の熱交換器1のさらに下流には、熱交換器16が配設されていて、この熱交換器16にて蒸留水はさらに冷却水によって冷却される。蒸留水還り流路13は蒸留水回収端18を出口としている。蒸留水は十分に冷却されてから蒸留水回収端18より回収される。   The evaporator 4 evaporates the supplied seawater. The evaporator 4 is connected to the gas-liquid separator 10. The vapor and concentrated water generated in the evaporator 4 are separated by the gas-liquid separator 10, and the vapor is guided to the distilled water return channel 13 and the concentrated water is guided to the concentrated water return channel 14. The above-described compressor 5 is disposed in the distilled water return flow path 13, and the steam is compressed by the compressor 5. Downstream of the compressor 5, the evaporator 4, the third heat exchanger 3, and the first heat exchanger 1 described above are arranged in order. That is, distilled water is heat-exchanged with seawater in the order of the evaporator 4, the third heat exchanger 3, and the first heat exchanger 1. In addition, until it heat-exchanges with the evaporator 4, distilled water is distribute | circulating in the state evaporated. A heat exchanger 16 is disposed further downstream of the first heat exchanger 1 in the distilled water return flow path 13, and the distilled water is further cooled by cooling water in the heat exchanger 16. The distilled water return channel 13 has a distilled water recovery end 18 as an outlet. Distilled water is recovered from the distilled water recovery end 18 after sufficiently cooled.

一方、濃縮水還り流路14には上述した第2の熱交換器2が配設されている。すなわち、濃縮水は第2の熱交換器2で海水と熱交換される。濃縮水還り流路14における第2の熱交換器2のさらに下流には、熱交換器17が配設されていて、この熱交換器17にて濃縮水はさらに冷却水によって冷却される。濃縮水還り流路14は濃縮水回収端19を出口としている。濃縮水は十分に冷却されてから濃縮水回収端19より回収される。   On the other hand, the second heat exchanger 2 described above is disposed in the concentrated water return flow path 14. That is, the concentrated water is heat-exchanged with seawater in the second heat exchanger 2. A heat exchanger 17 is disposed further downstream of the second heat exchanger 2 in the concentrated water return flow path 14, and the concentrated water is further cooled by cooling water in the heat exchanger 17. The concentrated water return channel 14 has the concentrated water recovery end 19 as an outlet. The concentrated water is recovered from the concentrated water recovery end 19 after being sufficiently cooled.

また、図2に示すように、第1〜第3の熱交換器1〜3は例えば熱交換ユニット15として一体化されている。図2を参照して海水から淡水化への流れを概説すると、海水供給端6から供給された海水は、海水供給流路7にある熱交換ユニット15を通って蒸発器4に導かれ、この蒸発器4で蒸発される。蒸発された海水は蒸気状態の蒸留水と濃縮水に分離される。蒸気は圧縮機5によって圧縮されて蒸発器4での熱交換により液状の蒸留水となる。蒸留水は蒸留水還り流路13にある蒸発器4及び熱交換ユニット15を通って蒸留水回収端18から回収される。一方で濃縮水は濃縮水還り流路14にある熱交換ユニット15を通って濃縮水回収端19から回収される。   Further, as shown in FIG. 2, the first to third heat exchangers 1 to 3 are integrated as, for example, a heat exchange unit 15. The flow from seawater to desalination will be outlined with reference to FIG. 2. Seawater supplied from the seawater supply end 6 is guided to the evaporator 4 through the heat exchange unit 15 in the seawater supply flow path 7, and It is evaporated by the evaporator 4. The evaporated seawater is separated into distilled water and concentrated water in the vapor state. The steam is compressed by the compressor 5 and becomes liquid distilled water by heat exchange in the evaporator 4. Distilled water is recovered from the distilled water recovery end 18 through the evaporator 4 and the heat exchange unit 15 in the distilled water return flow path 13. On the other hand, the concentrated water is recovered from the concentrated water recovery end 19 through the heat exchange unit 15 in the concentrated water return flow path 14.

さらに、このシステムSには制御装置20が備わっている。この制御装置20は、システム全体としての熱効率を高め、海水の淡水化に要するための無駄なエネルギが極力使用されないようにするためのものである。そのために、制御装置20は、蒸発器4、圧縮機5、熱交換ユニット15に接続されている。制御装置20には、分離器8での海水の分離率を調整するための分離率調整部21が備わっている。また、圧縮機5による蒸気の圧縮率を定めるための圧縮率演算部22も備わっている。また、各熱交換器での熱交換温度差を状況に応じて変更するための温度差調整部23も備わっている。また、蒸発器4内での蒸発による海水の沸点上昇を認識するための沸点上昇認識部24も備わっている。   Further, the system S includes a control device 20. This control device 20 is intended to increase the thermal efficiency of the entire system and prevent the wasteful energy required for seawater desalination from being used as much as possible. For this purpose, the control device 20 is connected to the evaporator 4, the compressor 5, and the heat exchange unit 15. The control device 20 includes a separation rate adjusting unit 21 for adjusting the separation rate of seawater in the separator 8. Moreover, the compression rate calculating part 22 for determining the compression rate of the vapor | steam by the compressor 5 is also provided. Moreover, the temperature difference adjustment part 23 for changing the heat exchange temperature difference in each heat exchanger according to a condition is also provided. Moreover, the boiling point rise recognition part 24 for recognizing the boiling point rise of seawater by the evaporation in the evaporator 4 is also provided.

上述したシステムSを用いて海水を淡水化させる方法を以下に説明する。なお、図1では各流路における海水、蒸留水、濃縮水の温度及び圧力を記載している。
まず、海水供給端6から海水(例えば20℃)を供給する。ここで、分離率に応じて海水は分離率調整部21によって調整された分離器8で分離される。この分離率は、蒸発器4での海水の濃縮率(蒸発率)に応じて定められるものであり、作業者が予め決定する。濃縮率としては、25%〜75%の範囲が適しているが、濃縮率が高いとスケールが発生しそれが蒸発器4内の機器等に付着するため、あるいは濃縮率が低いと熱交換率が低下してしまうため、50%が最も適している。濃縮率が50%であれば、分離器8での分離率は、50:50となる。濃縮率が25%であれば、第1の流路11と第2の流路12への分離率は、75:25となる。分離器8によってそれぞれ第1の流路11と第2の流路12に流通するように分離された海水は、熱交換ユニット15にて温度が上昇される。具体的には、第1の流路11内の海水は、第1の熱交換器1内を通って後述する蒸留水と熱交換される。熱交換後、海水は飽和温度(101℃)まで上昇される。
A method for desalinating seawater using the system S described above will be described below. FIG. 1 shows the temperature and pressure of seawater, distilled water, and concentrated water in each flow path.
First, seawater (for example, 20 ° C.) is supplied from the seawater supply end 6. Here, the seawater is separated by the separator 8 adjusted by the separation rate adjusting unit 21 according to the separation rate. This separation rate is determined according to the concentration rate (evaporation rate) of seawater in the evaporator 4 and is determined in advance by the operator. As the concentration rate, a range of 25% to 75% is suitable. However, if the concentration rate is high, scale is generated and adheres to equipment in the evaporator 4, or if the concentration rate is low, the heat exchange rate. 50% is most suitable. If the concentration rate is 50%, the separation rate in the separator 8 is 50:50. If the concentration rate is 25%, the separation rate into the first channel 11 and the second channel 12 is 75:25. The temperature of the seawater separated by the separator 8 so as to flow through the first flow path 11 and the second flow path 12 is raised by the heat exchange unit 15. Specifically, the seawater in the first flow path 11 passes through the first heat exchanger 1 and exchanges heat with distilled water described later. After heat exchange, the seawater is raised to the saturation temperature (101 ° C.).

第2の流路12内の海水は、まず第2の熱交換器2内を通って後述する濃縮水と熱交換される。そして、第3の熱交換器3内を通って後述する蒸留水と熱交換される。第2及び第3の熱交換器2、3での熱交換後、海水は飽和温度(101℃)まで上昇される。第1の流路11及び第2の流路12は混合器9で一つにまとめられる。すなわち、第1及び第2の流路11、12を流通してきた海水は、それぞれ同一の飽和温度の状態で混合される。そして、飽和温度のまま蒸発器4内に導かれ、後述する蒸気(蒸留水)と熱交換されて蒸発される。   Seawater in the second flow path 12 first passes through the second heat exchanger 2 and exchanges heat with concentrated water described later. Then, heat exchange is performed with distilled water described later through the third heat exchanger 3. After the heat exchange in the second and third heat exchangers 2 and 3, the seawater is raised to the saturation temperature (101 ° C.). The first flow path 11 and the second flow path 12 are combined into one by the mixer 9. That is, the seawater that has circulated through the first and second flow paths 11 and 12 is mixed at the same saturation temperature. And it is guide | induced in the evaporator 4 with saturation temperature, is heat-exchanged with the vapor | steam (distilled water) mentioned later, and is evaporated.

蒸発器4で生じた濃縮水は、気液分離器10にて濃縮水のみが流通する濃縮水還り流路14に導かれる。このとき、蒸発器4での蒸発により濃縮水は沸点上昇を起こしている。濃縮率が50%のときは飽和温度101℃の海水が濃縮水となって102℃になっている。濃縮水はこの状態で第2の熱交換器2で海水と熱交換される。具体的には、濃縮水の入口温度と海水の出口温度が予め定めた熱交換温度差となるように熱交換される。すなわち、102℃で濃縮水が入ってくるので、海水は97℃となる。このようにして、濃縮率50%で得られた濃縮水の顕熱は第2の熱交換器2で回収される(例えば濃縮水は25.4℃となる)。そのため、上述した分離器8での分離率は50%になっている。濃縮水はさらに熱交換器17で冷却され、濃縮水回収端19から回収される。   The concentrated water generated in the evaporator 4 is guided to the concentrated water return channel 14 through which only the concentrated water flows in the gas-liquid separator 10. At this time, the boiling point of the concentrated water is raised by evaporation in the evaporator 4. When the concentration rate is 50%, seawater at a saturation temperature of 101 ° C. becomes concentrated water and becomes 102 ° C. Concentrated water is heat-exchanged with seawater in the second heat exchanger 2 in this state. Specifically, heat exchange is performed so that the inlet temperature of the concentrated water and the outlet temperature of the seawater have a predetermined heat exchange temperature difference. That is, since concentrated water enters at 102 ° C., seawater reaches 97 ° C. In this way, the sensible heat of the concentrated water obtained at a concentration rate of 50% is recovered by the second heat exchanger 2 (for example, the concentrated water becomes 25.4 ° C.). Therefore, the separation rate in the separator 8 described above is 50%. The concentrated water is further cooled by the heat exchanger 17 and recovered from the concentrated water recovery end 19.

蒸発器4で生じた蒸気(蒸気状態の蒸留水)は、気液分離器10にて蒸気のみが流通する蒸留水還り流路13に導かれる。ここで蒸気は圧縮率演算部22の結果に基づいて動作する圧縮機5により圧縮され、温度上昇される。この蒸気は、圧縮機5での圧縮に伴い蒸発潜熱を有している。この状態の蒸気が蒸発器4にて海水の蒸発に用いられる。すなわち、飽和温度で蒸発器4に供給された海水は、蒸気の潜熱を用いて熱交換されて蒸発されるため、潜熱はここで回収される。このとき蒸気は凝縮されて蒸留水となる。上述した圧縮機5での圧縮率は、蒸発器4にて熱交換した後の蒸留水の飽和温度を基準にして定められる。この蒸留水の飽和温度は、蒸発器4を通過した後の海水の飽和温度(海水濃縮(蒸発)後の飽和温度)に対して予め定めた熱交換温度差だけ高く設定される。蒸留水の飽和温度がこの高く設定された温度となるように、蒸気は圧縮機5にて圧縮される。例えば、濃縮率50%の場合、飽和温度101℃で蒸発器4に流入した海水は、蒸気の潜熱を用いて蒸発されて蒸気となるが、このとき濃縮により沸点上昇が起こり、飽和温度は102℃となる。予め設定された熱交換温度差が5℃であれば、海水蒸発のために用いられた蒸気は熱交換後107℃になって凝縮されるように設定される。飽和温度が107℃に相当する蒸留水となるような圧力は飽和蒸気圧表を用いて求められる。例えば、飽和温度が107℃の蒸留水を得るためには、圧縮機5で蒸気を28PaGまで圧縮すればよい。なお、沸点上昇の幅は濃縮率によって異なるため、この沸点上昇後の飽和温度の値は、上述した沸点上昇認識部24に予め入力するか、あるいはセンサ等によって計測した結果を入力してもよい。 The vapor generated in the evaporator 4 (distilled water in the vapor state) is guided to the distilled water return channel 13 through which only the vapor flows in the gas-liquid separator 10. Here, the steam is compressed by the compressor 5 that operates based on the result of the compressibility calculation unit 22, and the temperature is increased. This steam has latent heat of vaporization as it is compressed by the compressor 5. The steam in this state is used for evaporation of seawater in the evaporator 4. That is, since the seawater supplied to the evaporator 4 at the saturation temperature is heat-exchanged using the latent heat of steam and evaporated, the latent heat is recovered here. At this time, the steam is condensed into distilled water. The compression rate in the compressor 5 described above is determined based on the saturation temperature of distilled water after heat exchange in the evaporator 4. The saturation temperature of the distilled water is set higher by a predetermined heat exchange temperature difference than the saturation temperature of seawater after passing through the evaporator 4 (saturation temperature after seawater concentration (evaporation)). The steam is compressed by the compressor 5 so that the saturation temperature of the distilled water becomes the set temperature. For example, when the concentration rate is 50%, seawater that has flowed into the evaporator 4 at a saturation temperature of 101 ° C. is evaporated using the latent heat of the steam to become steam. At this time, the boiling point rises due to concentration, and the saturation temperature is 102 It becomes ℃. If the preset heat exchange temperature difference is 5 ° C., the steam used for seawater evaporation is set to be condensed at 107 ° C. after heat exchange. The pressure at which the saturated temperature becomes distilled water corresponding to 107 ° C. is obtained using a saturated vapor pressure table. For example, in the saturation temperature to obtain a distilled water 107 ° C. may be compressed steam until 28 k PAG in the compressor 5. Since the range of the boiling point rise varies depending on the concentration rate, the saturation temperature value after the boiling point rise may be input in advance to the above-described boiling point increase recognition unit 24 or may be the result measured by a sensor or the like. .

蒸発器4を通過した蒸留水は、わずかに蒸気が包含された状態である。この蒸気が有する潜熱は第3の熱交換器3にて回収される。具体的には、第2の熱交換器2で温度上昇された海水をさらに飽和温度まで高めるために用いられる。ここでは海水の顕熱と蒸留水が有する蒸気の潜熱とが熱交換される。これにより、第2の熱交換器2で97℃まで上昇した海水の温度は、飽和温度である101℃までさらに上昇される。したがって、上述したように、第1の流路11又は第2の流路12を経て混合器9にて混合された海水はともに飽和温度の101℃であるため、蒸発器4内での海水の温度低下を防止でき、蒸発に関するエネルギのロスを防止することができる。   Distilled water that has passed through the evaporator 4 is in a state in which steam is slightly contained. The latent heat of the steam is recovered by the third heat exchanger 3. Specifically, it is used to further raise the seawater whose temperature has been raised by the second heat exchanger 2 to the saturation temperature. Here, the sensible heat of seawater and the latent heat of steam of distilled water are exchanged. Thereby, the temperature of the seawater which rose to 97 ° C. in the second heat exchanger 2 is further raised to 101 ° C. which is the saturation temperature. Therefore, as described above, since the seawater mixed in the mixer 9 via the first flow path 11 or the second flow path 12 has a saturation temperature of 101 ° C., the seawater in the evaporator 4 A temperature drop can be prevented, and energy loss related to evaporation can be prevented.

第3の熱交換器3を通過した蒸留水は、第1の熱交換器1で海水と熱交換される。具体的には、蒸留水の入口温度が107℃である場合に、海水の出口温度は101℃となる。上述では、熱交換温度差を5℃としたが、このような値にすると、海水の出口温度が102℃となってしまい、海水が飽和温度よりも高くなってしまうので蒸発してしまう。したがって、海水の出口温度が飽和温度となることを限度として、予め定めた熱交換温度差以上の最小値を新たな熱交換温度差として定める。この例では新たな熱交換温度差は6℃になり、海水は飽和温度の101℃まで上昇される。なお、この判断は上述した温度差調整部23にて行われる。このようにして、濃縮率50%で得られた蒸留水の顕熱は、第1の熱交換器1で回収される(例えば蒸留水は28℃となる)。そのため、上述した分離器8での分離率は50%になっている。蒸留水はさらに熱交換器16で冷却され、濃縮水回収端18から回収される。 Distilled water that has passed through the third heat exchanger 3 is heat-exchanged with seawater in the first heat exchanger 1. Specifically, when the inlet temperature of distilled water is 107 ° C, the outlet temperature of seawater is 101 ° C. In the above description, the heat exchange temperature difference is set to 5 ° C. However, when such a value is set, the outlet temperature of the seawater becomes 102 ° C., and the seawater becomes higher than the saturation temperature, so that it evaporates. Therefore, a minimum value not less than a predetermined heat exchange temperature difference is determined as a new heat exchange temperature difference, with the limit that the outlet temperature of the seawater becomes the saturation temperature. In this example, the new heat exchange temperature difference is 6 ° C., and the seawater is raised to the saturation temperature of 101 ° C. This determination is made by the temperature difference adjusting unit 23 described above. In this way, the sensible heat of distilled water obtained at a concentration rate of 50% is recovered by the first heat exchanger 1 (for example, distilled water becomes 28 ° C.). Therefore, the separation rate in the separator 8 described above is 50%. The distilled water is further cooled by the heat exchanger 16 and recovered from the concentrated water recovery end 18.

まとめると、第1〜第3の熱交換器1〜3及び蒸発器4における熱交換温度差は、蒸留水又は濃縮水が有する顕熱の入口温度と海水の出口温度が予め定めた一定の値となるように制御され、このうち海水の出口温度が飽和温度を超える熱交換器においては予め定めた熱交換温度差以上の最小値を新たな熱交換温度差とする。また、蒸発器4に流入する海水の温度は、一定の飽和温度とする。   In summary, the heat exchange temperature difference between the first to third heat exchangers 1 to 3 and the evaporator 4 is a constant value determined in advance by the sensible heat inlet temperature and the seawater outlet temperature of distilled water or concentrated water. In the heat exchanger in which the seawater outlet temperature exceeds the saturation temperature, a minimum value equal to or greater than a predetermined heat exchange temperature difference is set as a new heat exchange temperature difference. Further, the temperature of the seawater flowing into the evaporator 4 is set to a constant saturation temperature.

このような制御を行うことで、熱効率は向上する。例えば、図3を参照すれば明らかなように、温度と熱量とを示すグラフ(いわゆるT−Q線図)においても、熱交換温度差を一定にすることで、要した熱はほぼ回収できることになり、熱効率は向上することになる。図3について説明すると、グラフのA部分は、蒸留水からの顕熱の回収と海水の温度上昇を示している。グラフのB部分は、濃縮水からの顕熱の回収と海水の温度上昇を示している。グラフのC部分は、海水の蒸発と蒸留水(蒸気)の潜熱の回収とを示している。なお、C部分の上側のグラフで128℃まで立ち上がっている部分は、蒸気を圧縮させて断熱温度上昇をさせたときの状態を示している。このT−Q線図を見れば、海水の温度を上昇させるときと蒸留水又は濃縮水の温度を下降させるときの温度を一定(グラフとしては平行)にすることで、効率が高まっていることがわかる。このグラフの平行の幅が開くと、その分無駄な熱が必要になるので、温度差は可能な限り小さい方がよい。現状の装置等の性能を考慮すれば、理想の熱交換温度差は5℃であることがわかっている。なお、グラフのD部分は、第3の熱交換器3での蒸留水に含まれる蒸気の潜熱の回収を示している。このように、システムS全体としてみると第3の熱交換器3による熱回収は少量であるため、ここでの海水の温度上昇は蒸留水の潜熱を用いずに他の加熱手段を用いてもよい。   By performing such control, the thermal efficiency is improved. For example, as is clear from FIG. 3, even in a graph (so-called TQ diagram) showing the temperature and the amount of heat, the required heat can be almost recovered by making the heat exchange temperature difference constant. As a result, thermal efficiency is improved. If FIG. 3 is demonstrated, the A part of a graph has shown the collection | recovery of the sensible heat from distilled water, and the temperature rise of seawater. Part B of the graph shows the recovery of sensible heat from the concentrated water and the temperature rise of the seawater. Part C of the graph shows the evaporation of seawater and the recovery of latent heat of distilled water (steam). In addition, the part which has risen to 128 ° C. in the upper graph of the C part shows a state when the vapor is compressed to increase the adiabatic temperature. If you look at this TQ diagram, efficiency will increase by keeping the temperature when raising the temperature of seawater and lowering the temperature of distilled water or concentrated water constant (parallel as a graph) I understand. When the parallel width of this graph is widened, unnecessary heat is required, so the temperature difference should be as small as possible. Considering the performance of current devices and the like, it is known that the ideal heat exchange temperature difference is 5 ° C. In addition, D part of a graph has shown collection | recovery of the latent heat of the vapor | steam contained in the distilled water in the 3rd heat exchanger 3. FIG. Thus, since the heat recovery by the third heat exchanger 3 is small when viewed as the entire system S, the temperature rise of the seawater here can be achieved by using other heating means without using the latent heat of distilled water. Good.

上記と重複する部分もあるが、本発明についてさらに説明する。
システムSの構成は上述したとおりであるが、簡単に説明すると、供給されるべき海水は海水供給流路7を流れる。海水供給路7には分離器8と混合器9が配設されている。海水供給流路7は分離器8で第1の流路11及び第2の流路12に分岐され、これら第1及び第2の流路11、12は混合器9で一つにまとまっている。すなわち、第1の流路11及び第2の流路12は分離器8及び混合器9の間に架け渡されている。第1の流路11及び第2の流路12にはそれぞれ第1の熱交換器1及び第2の熱交換器2が配設されている。海水供給流路7の終端には、蒸発器4が配設されている。この蒸発器4は、海水の飽和温度である第1の飽和温度で海水を蒸発するためのものである。蒸発器4は気液分離器10に接続され、それぞれ蒸留水(蒸気)と濃縮水に分離される。蒸留水は蒸留水還り流路13を通る。この蒸留水還り流路13にはそれぞれ上述した蒸発器4及び第1の熱交換器1が配設されている。すなわち、蒸発器4及び第1の熱交換器1では、海水と蒸留水が熱交換される。一方濃縮水は濃縮水還り流路14を通る。この濃縮水還り流路14には第2の熱交換器が配設されている。すなわち、第2の熱交換器2では、海水と濃縮水が熱交換される。蒸留水還り流路13における蒸発器4の上流側には、蒸気の状態の蒸留水を圧縮するための圧縮機5が配設されている。
Although there are portions that overlap the above, the present invention will be further described.
The configuration of the system S is as described above, but simply described, seawater to be supplied flows through the seawater supply channel 7. A separator 8 and a mixer 9 are disposed in the seawater supply path 7. The seawater supply flow path 7 is branched into a first flow path 11 and a second flow path 12 by a separator 8, and the first and second flow paths 11 and 12 are combined together by a mixer 9. . That is, the first flow path 11 and the second flow path 12 are bridged between the separator 8 and the mixer 9. A first heat exchanger 1 and a second heat exchanger 2 are disposed in the first flow path 11 and the second flow path 12, respectively. An evaporator 4 is disposed at the end of the seawater supply channel 7. The evaporator 4 is for evaporating seawater at a first saturation temperature that is the saturation temperature of seawater. The evaporator 4 is connected to a gas-liquid separator 10 and is separated into distilled water (steam) and concentrated water, respectively. Distilled water passes through the distilled water return channel 13. The evaporator 4 and the first heat exchanger 1 described above are disposed in the distilled water return flow path 13. That is, in the evaporator 4 and the first heat exchanger 1, seawater and distilled water are heat-exchanged. On the other hand, the concentrated water passes through the concentrated water return channel 14. A second heat exchanger is disposed in the concentrated water return channel 14. That is, in the second heat exchanger 2, the seawater and the concentrated water are heat-exchanged. On the upstream side of the evaporator 4 in the distilled water return flow path 13, a compressor 5 for compressing distilled water in a vapor state is disposed.

このようなシステムSにおいて、制御装置20が備わっている。制御装置20は分離率調整部21、圧縮率演算部22、温度差調整部23、沸点上昇認識部24を有している。分離率調整部21は、海水のうち蒸気となる割合を第1の流路11に、濃縮水となる割合を第2の流路12にそれぞれ流通させるために分離器8での海水の分離率を調整するためのものである。この結果に基づいて、海水は分離器8で分離される。沸点上昇認識部24は、蒸発器4内での蒸発による海水の沸点上昇を認識し、沸点上昇後の海水の飽和温度である第2の飽和温度を認識するためのものである。圧縮率演算部22は、沸点上昇認識部24にて認識された第2の飽和温度に予め定めた熱交換温度差の値を加算して蒸留水の飽和温度である第3の飽和温度を求め、蒸留水が第3の飽和温度となるような圧力を決定して圧縮機5での圧縮率を定めるものである。温度差調整部23は、第1の熱交換器1を通過した海水の温度が第1の飽和温度となるように調整するものである。そして、システム1はさらに、第2の熱交換器2を通過した海水の温度を第1の飽和温度まで上昇させるための加熱手段を備えている。この加熱手段は、具体的には第3の熱交換器3であるが、他の加熱作用を有する装置を用いてもよい。   In such a system S, a control device 20 is provided. The control device 20 includes a separation rate adjustment unit 21, a compression rate calculation unit 22, a temperature difference adjustment unit 23, and a boiling point increase recognition unit 24. The separation rate adjusting unit 21 separates the ratio of seawater in the separator 8 in order to distribute the ratio of steam to the first flow path 11 and the ratio of concentrated water to the second flow path 12. It is for adjusting. Based on this result, the seawater is separated by the separator 8. The boiling point increase recognition unit 24 is for recognizing a boiling point increase of seawater due to evaporation in the evaporator 4 and recognizing a second saturation temperature which is a saturation temperature of seawater after the boiling point increase. The compression ratio calculation unit 22 adds the value of the predetermined heat exchange temperature difference to the second saturation temperature recognized by the boiling point increase recognition unit 24 to obtain a third saturation temperature that is the saturation temperature of distilled water. The pressure at which the distilled water reaches the third saturation temperature is determined to determine the compression rate in the compressor 5. The temperature difference adjusting unit 23 adjusts the temperature of the seawater that has passed through the first heat exchanger 1 to be the first saturation temperature. And the system 1 is further provided with the heating means for raising the temperature of the seawater which passed the 2nd heat exchanger 2 to the 1st saturation temperature. This heating means is specifically the third heat exchanger 3, but another apparatus having a heating action may be used.

このようなシステムSでは、第1の流路11を通った海水は第1の熱交換器1により海水の飽和温度である第1の飽和温度まで上昇され、第2の流路12を通った海水は第2の熱交換器2及び加熱手段(第3の熱交換器3)により海水の飽和温度である第1の飽和温度まで上昇される。したがって、これらの海水は混合器9にて同一の温度で混合される。したがって、第1の流路11と第2の流路12を通った海水の温度がともに飽和温度で揃った状態で海水は蒸発器4にて蒸発される。これにより、蒸発器4での蒸発に際して最低限の熱量で海水を蒸発させることができる。また、分離率調整部21は、海水の濃縮率(蒸発率)に応じてそれぞれ海水を分離させる。したがって、蒸留水及び濃縮水の顕熱をそれぞれの割合に応じた海水と熱交換させることができ、効率よく回収することができる。また、予め熱交換温度差を定め、沸点上昇を起こした海水の第2の飽和温度に対して熱交換温度差を加算した第3の飽和温度を求め、蒸留水がこの第3の飽和温度となるように蒸気の圧縮率を定める。この熱交換温度差は、各熱交換器で最も効率よく熱交換できる温度差である。現状一般的に用いられている熱交換器では、5℃が好ましい。第1の熱交換器1では、第3の飽和温度の蒸留水と海水とが熱交換されるため、海水を第1の飽和温度まで上昇させることができ、無駄なく蒸留水の顕熱を回収することができる。   In such a system S, the seawater that has passed through the first flow path 11 is raised to the first saturation temperature that is the saturation temperature of the seawater by the first heat exchanger 1, and has passed through the second flow path 12. Seawater is raised to the first saturation temperature, which is the saturation temperature of seawater, by the second heat exchanger 2 and the heating means (third heat exchanger 3). Therefore, these seawaters are mixed at the same temperature in the mixer 9. Therefore, the seawater is evaporated by the evaporator 4 in a state where the temperatures of the seawater that has passed through the first flow path 11 and the second flow path 12 are all equal to the saturation temperature. Thereby, seawater can be evaporated with a minimum amount of heat when the evaporator 4 evaporates. Moreover, the separation rate adjusting unit 21 separates the seawater according to the concentration rate (evaporation rate) of the seawater. Therefore, the sensible heat of distilled water and concentrated water can be heat exchanged with seawater corresponding to each ratio, and can be efficiently recovered. In addition, a heat exchange temperature difference is determined in advance, a third saturation temperature obtained by adding the heat exchange temperature difference to the second saturation temperature of the seawater that has risen in boiling point is obtained, and distilled water is obtained from the third saturation temperature. The compressibility of steam is determined so that This heat exchange temperature difference is a temperature difference at which heat exchange can be performed most efficiently in each heat exchanger. In the heat exchanger generally used at present, 5 ° C. is preferable. In the first heat exchanger 1, the distilled water having the third saturation temperature is exchanged with seawater, so that the seawater can be raised to the first saturation temperature, and the sensible heat of the distilled water can be recovered without waste. can do.

また、濃縮水は沸点上昇を起こした後の第2の飽和温度であるため、第1の飽和温度に比べてわずかに高い温度のままである。この第2の飽和温度の濃縮水と海水とを第2の熱交換器2で熱交換しても海水は第1の飽和温度まで上昇しない。一方、蒸発器4では圧縮された蒸気と第1の飽和温度の海水が熱交換され、蒸気は蒸留水となる。このとき、蒸留水にはわずかに蒸気が含まれているため、わずかに潜熱を有している。上述した第2の熱交換器2を通過して温度上昇している海水と潜熱を有する蒸留水とを第3の熱交換器3にて熱交換することで、第2の流路12を通過した海水を第1の飽和温度まで上昇させることができる。したがって、上述した加熱手段として第3の熱交換器3を用いることで、蒸留水の潜熱を利用してシステムS全体として熱量を効率よく利用することができる。   Further, since the concentrated water is the second saturation temperature after the boiling point rises, it remains at a slightly higher temperature than the first saturation temperature. Even if the concentrated water having the second saturation temperature and seawater are heat-exchanged by the second heat exchanger 2, the seawater does not rise to the first saturation temperature. On the other hand, in the evaporator 4, the compressed steam and the seawater having the first saturation temperature are subjected to heat exchange, and the steam becomes distilled water. At this time, since the distilled water contains a slight amount of steam, it has a slight latent heat. The second heat exchanger 2 passes through the second flow path 12 by exchanging heat between the seawater rising in temperature and the distilled water having latent heat in the third heat exchanger 3. The seawater that has been removed can be raised to the first saturation temperature. Therefore, by using the third heat exchanger 3 as the heating means described above, it is possible to efficiently use the amount of heat as the entire system S using the latent heat of distilled water.

本発明でシステムS全体としての熱効率を高めるためには、分離器8にて、第1の流路11に流す海水の流量と第2の流路12に流す海水の流量との比率を蒸発器4における海水の蒸発率と濃縮率との比率と合致させ、混合器9に流入する第1の流路11及び第2の流路12からの海水の温度を第1の飽和温度に揃え、第2の飽和温度に熱交換温度差を加算して第3の飽和温度を求め、蒸留水が第3の飽和温度となるように蒸気を圧縮すればよい。   In order to increase the thermal efficiency of the system S as a whole in the present invention, the separator 8 uses the ratio of the flow rate of seawater flowing in the first flow path 11 and the flow rate of seawater flowed in the second flow path 12 to the evaporator. 4, the seawater temperature from the first flow path 11 and the second flow path 12 flowing into the mixer 9 is matched with the first saturation temperature, and the ratio of the evaporation rate and the concentration rate of seawater in FIG. The third saturation temperature may be obtained by adding the heat exchange temperature difference to the saturation temperature of 2, and the vapor may be compressed so that the distilled water becomes the third saturation temperature.

1 第1の熱交換器
2 第2の熱交換器
4 蒸発器
5 圧縮機
7 海水供給流路
8 分離器
9 混合器
11 第1の流路
12 第2の流路
13 蒸留水還り流路
14 濃縮水還り流路
20 制御装置
21 分離率調整部
22 圧縮率演算部
23 温度差調整部
24 沸点上昇認識部
DESCRIPTION OF SYMBOLS 1 1st heat exchanger 2 2nd heat exchanger 4 Evaporator 5 Compressor 7 Seawater supply flow path 8 Separator 9 Mixer 11 First flow path 12 Second flow path 13 Distilled water return flow path 14 Concentrated water return flow path 20 Controller 21 Separation rate adjustment unit 22 Compression rate calculation unit 23 Temperature difference adjustment unit 24 Boiling point rise recognition unit

Claims (3)

供給された海水が流通する海水供給流路と、
前記海水供給流路に配設された分離器及び混合器と、
前記海水供給流路の一部を形成し、前記分離器及び混合器の間に架け渡された第1の流路及び第2の流路と、
該第1及び第2の流路に配設された第1及び第2の熱交換器と、
前記海水供給流路の終端に形成され、前記海水の飽和温度である第1の飽和温度で前記海水を蒸発する蒸発器と、
該蒸発器によって発生した蒸気前記蒸発器及び前記第1の熱交換器の順番で通過し、該蒸気と前記蒸発器及び前記第1の熱交換器で前記海水と熱交換され発生した液状の蒸留水とが蒸気を含む蒸留水として流通する蒸留水還り流路と、
前記蒸発器によって発生した濃縮水が流通し、前記第2の熱交換器を通過する濃縮水還り流路と、
前記蒸留水還り流路に前記蒸発器の上流に位置して配設され、前記蒸気を圧縮するための圧縮機と
を備えた海水の淡水化システムにおいて、
前記海水のうち前記蒸気となる割合を前記第1の流路に、前記濃縮水となる割合を前記第2の流路にそれぞれ流通させるために前記分離器での前記海水の分離率を調整する分離率調整部と、
前記蒸発器内での蒸発による前記海水の沸点上昇を認識し、沸点上昇後の前記海水の飽和温度である第2の飽和温度を認識するための沸点上昇認識部と、
該沸点上昇認識部にて認識された前記第2の飽和温度に予め定めた熱交換温度差の値を加算して前記蒸留水の飽和温度である第3の飽和温度を求め、前記蒸留水が前記第3の飽和温度となるような圧力を決定して前記圧縮機での圧縮率を定める圧縮率演算部と、
前記第1の熱交換器を通過した前記海水の温度が前記第1の飽和温度となるように調整する温度差調整部と
を有する制御装置と、
前記第2の熱交換器を通過した前記海水の温度を前記第1の飽和温度まで上昇させるための加熱手段とをさらに備えたことを特徴とする海水の淡水化システム。
A seawater supply channel through which the supplied seawater circulates;
A separator and a mixer disposed in the seawater supply channel;
Forming a part of the seawater supply flow path, and a first flow path and a second flow path spanned between the separator and the mixer;
First and second heat exchangers disposed in the first and second flow paths;
An evaporator that is formed at the end of the seawater supply channel and evaporates the seawater at a first saturation temperature that is a saturation temperature of the seawater;
The steam generated by the evaporator passes through the evaporator and the first heat exchanger in this order, and the steam , the evaporator, and the first heat exchanger exchange heat with the seawater to generate a liquid state. A distilled water return flow path through which distilled water circulates as distilled water containing steam ;
A concentrated water return flow path through which the concentrated water generated by the evaporator flows and passes through the second heat exchanger;
In the seawater desalination system provided in the distilled water return flow path and located upstream of the evaporator , and comprising a compressor for compressing the steam,
The separation rate of the seawater in the separator is adjusted in order to distribute the ratio of the seawater to the first flow path and the ratio of the concentrated water to the second flow path. A separation rate adjustment unit;
A boiling point increase recognition unit for recognizing a rise in boiling point of the seawater due to evaporation in the evaporator and recognizing a second saturation temperature that is a saturation temperature of the seawater after the boiling point rise;
A value of a predetermined heat exchange temperature difference is added to the second saturation temperature recognized by the boiling point increase recognition unit to obtain a third saturation temperature that is a saturation temperature of the distilled water, A compression ratio calculation unit for determining a pressure at which the third saturation temperature is reached and determining a compression ratio in the compressor;
A control device having a temperature difference adjustment unit that adjusts the temperature of the seawater that has passed through the first heat exchanger to be the first saturation temperature;
A seawater desalination system, further comprising heating means for raising the temperature of the seawater that has passed through the second heat exchanger to the first saturation temperature.
前記加熱手段は、前記蒸留水還り流路における前記蒸発器と前記第1の熱交換器との間に配設され、且つ前記第2の流路における前記第2の熱交換器と前記蒸発器との間に配設された第3の熱交換器であることを特徴とする請求項1に記載の海水の淡水化システム。   The heating means is disposed between the evaporator and the first heat exchanger in the distilled water return channel, and the second heat exchanger and the evaporator in the second channel. The seawater desalination system according to claim 1, wherein the system is a third heat exchanger disposed between the two. 海水を蒸発させるべき蒸発器まで通じ、且つ分離器にて分岐された第1の流路及び第2の流路を有する海水供給流路に海水を供給し、
前記分離器にて、前記第1の流路に流す前記海水と前記第2の流路に流す前記海水との分離率を前記蒸発器における前記海水の蒸発率と濃縮率との比率と一致させて前記第1及び第2の流路にそれぞれ流し、
前記海水供給流路に配設され、且つ前記第1及び第2の流路が合流する混合器に前記第1及び第2の流路からそれぞれ海水を流入するに際し、前記第1及び第2の流路にそれぞれ配設された第1及び第2の熱交換器を用いて前記海水の温度を海水の飽和温度である第1の飽和温度まで加熱し、
前記海水を前記蒸発器にて蒸発させて発生した蒸気を蒸留水還り流路に流通させ、前記蒸発器及び前記第1の熱交換器の順番で通過させることで該蒸気と前記蒸発器及び前記第1の熱交換器で前記海水と熱交換され発生した液状の蒸留水とからなる蒸気を含む蒸留水を生成し、
前記蒸発器内での蒸発によって沸点上昇を生じた後の前記海水の飽和温度である第2の飽和温度を認識し、
前記第2の飽和温度に予め定めた熱交換温度差の値を加算して前記蒸留水の飽和温度である第3の飽和温度を求め、
記蒸留水還り流路に前記蒸発器の上流に位置して配設された圧縮機にて前記蒸留水を前記第3の飽和温度となるまで圧縮し、
前記第3の飽和温度の前記蒸留水を前記蒸留水還り流路における前記蒸発器及び前記第1の熱交換器での前記海水の蒸発及び加熱に用い、
前記蒸発器にて発生した濃縮水を濃縮水還り流路に流通させて前記第2の熱交換器での前記海水の加熱に用いることを特徴とする海水の淡水化方法。
Seawater is supplied to the seawater supply flow path that has a first flow path and a second flow path that lead to an evaporator to evaporate the seawater and is branched by a separator,
In the separator, the separation rate between the seawater flowing through the first flow path and the seawater flowing through the second flow path is made to coincide with a ratio between the evaporation rate and the concentration rate of the seawater in the evaporator. Flowing through the first and second flow paths,
When the seawater flows from the first and second flow paths into the mixer that is disposed in the seawater supply flow path and the first and second flow paths merge, Heating the temperature of the seawater to a first saturation temperature, which is the saturation temperature of seawater, using first and second heat exchangers respectively disposed in the flow path;
Steam generated by evaporating the seawater in the evaporator is circulated through the distilled water return flow path, and the steam, the evaporator, and the first heat exchanger are passed through in this order. Producing distilled water containing steam composed of liquid distilled water generated by heat exchange with the seawater in the first heat exchanger ;
Recognizing a second saturation temperature, which is the saturation temperature of the seawater after raising the boiling point by evaporation in the evaporator;
Adding a value of a predetermined heat exchange temperature difference to the second saturation temperature to obtain a third saturation temperature which is a saturation temperature of the distilled water;
Compressing the distilled water at pre Ki蒸 distilled water went back channel disposed positioned upstream of the evaporator to the compressor until the third saturation temperature,
Using the distilled water of the third saturation temperature to the evaporation and heating of the seawater in the evaporator and the first heat exchanger in the distilled water went back channel,
A seawater desalination method, wherein concentrated water generated in the evaporator is circulated through a concentrated water return flow path and used for heating the seawater in the second heat exchanger.
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