JP6092284B2 - Seawater desalination equipment - Google Patents

Description

  Embodiments of the present invention relate to a seawater desalination apparatus that desalinates seawater.

  Seawater desalination apparatuses using reverse osmosis membranes are known. This seawater desalination apparatus conveys seawater with a seawater pump and causes it to flow into a pretreatment membrane. The pretreatment membrane is, for example, a hollow fiber membrane, and seawater becomes filtered water from which solid substances have been removed by filtration. The filtered water is pressurized by, for example, an osmotic pressure pump exceeding 6 MPa, becomes high-pressure seawater, and flows into the reverse osmosis membrane. The high pressure seawater is separated into fresh water that passes through the membrane and concentrated seawater that does not pass through the reverse osmosis membrane. In this way, fresh water for use in drinking water is obtained.

  In a steam turbine plant, water is transferred to a boiler by a feed water pump, and is converted into steam by being heated there. The boiler heats water by combustion exhaust gas generated using, for example, coal as fuel. Steam flows into the steam turbine, expands inside the steam turbine, and decreases in pressure and temperature.

Turbine exhaust flows into the condenser. The turbine exhaust is cooled by seawater in a condenser to become water and circulates. Seawater is conveyed to the condenser by a seawater pump. The rotating shaft of the steam turbine rotated by the expanding steam is connected to a generator, and power is generated by the generator using the generated shaft power.

JP 52-27067 A Japanese Patent No. 4475925

  Electricity demand varies depending on the time of day, and there is surplus electricity at night. Some power plants do not need to generate electricity at night, but the boiler cannot be stopped or started easily and wants to continue operating. Therefore, at some power plants, the amount of power generation is reduced by operating the boilers and steam turbines partially at night.

  I want to use the energy of the steam turbine plant left over at night for seawater desalination. If surplus energy can be used, the energy consumption of seawater desalination can be reduced. Furthermore, if heat can be used as surplus energy, the amount of chemical injection used for cleaning can be reduced by heating the cleaning water used for reverse cleaning. In addition, by reducing daytime power, power leveling is achieved. The steam turbine plant and the seawater desalination device both use seawater and are therefore installed near the sea.

  The problem to be solved by the present invention is to provide a seawater desalination apparatus that can utilize surplus energy of a steam turbine plant for seawater desalination according to electric power demand.

Seawater desalination apparatus according to one embodiment, complex with a steam turbine, and a seawater desalination apparatus for carrying out the desalination using a reverse osmosis membrane, wherein the steam turbine or we extracted gas vapors, said reverse osmosis A seawater heater for heating seawater flowing into the membrane, a branching means for branching the steam extracted from the steam turbine into the extraction steam for the feed water heater and the extraction steam for the seawater heater, and the branching means Stopping means for stopping the circulation of the extraction steam for the feed water heater and the extraction steam for the seawater heater, respectively, can be provided, and the seawater flowing into the reverse osmosis membrane can be heated.

The block diagram which shows the whole seawater desalination apparatus concerning 1st Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 2nd Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 3rd Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 4th Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 5th Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 6th Embodiment. The block diagram which shows the whole seawater desalination apparatus concerning 7th Embodiment. The schematic diagram showing the steam turbine plant concerning the 1st technique. The schematic diagram showing the steam turbine plant concerning the 2nd technique. Schematic which shows the seawater desalination apparatus concerning 3rd technique. Schematic which shows the seawater desalination apparatus concerning a 4th technique. Schematic which shows the seawater desalination apparatus concerning a 5th technique. Schematic which shows the seawater desalination apparatus concerning a 6th technique. Schematic which shows the seawater desalination apparatus concerning a 7th technique.

<First technology>
Hereinafter, in describing the present embodiment, first to seventh techniques which are the premise of each embodiment will be described with reference to the drawings. A steam turbine plant according to the first technique will be described with reference to FIG. In the steam turbine plant according to the first technique, the water 6 is transferred to the boiler 3 by the feed water pump 7, and is changed to steam 2 by being heated there. The boiler 3 heats the water 6 with combustion exhaust gas generated using, for example, coal as fuel. The steam 2 flows into the steam turbine 1, expands inside the steam turbine 1, and decreases in pressure and temperature.

  The turbine exhaust 4 flows into the condenser 5. The turbine exhaust 4 is cooled by seawater in a condenser 5 to become water 6 and circulates. Although not shown, seawater is conveyed to the condenser 5 by a seawater pump. The rotating shaft of the steam turbine 1 rotated by the expanding steam 2 is connected to a generator (not shown) and is generated by the generator using the generated shaft power.

<Second technology>
A steam turbine plant as the second technique will be described with reference to FIG. Only parts different from the first technique will be described. This extracts the extracted steam 8 in the middle stage of the steam turbine 1 and flows it into the feed water heater 9. The turbine exhaust 4 is cooled by seawater in the condenser 5 to become condensed water 10 and flows into the feed water heater 9 where it is heated by the heat of the extracted steam 8.

  The extracted steam 8 is cooled by the feed water heater 9 to become the drain 11, conveyed by the drain pump 12, and merged with the condensed water 10 that has passed through the feed water heater 9. The merged water flows into the boiler 3 as water 6. Compared to the first technology, it is closer to the Carnot cycle and the turbine cycle efficiency is higher.

<Third technology>
A seawater desalination apparatus as a third technique will be described with reference to FIG. This conveys the seawater 13 by the seawater pump 14 and flows it into the pretreatment membrane 15. The pretreatment membrane 15 is, for example, a hollow fiber membrane, and the seawater 13 becomes seawater 16 after the pretreatment membrane from which solid matter has been removed by filtration. The seawater 16 after the pretreatment membrane is pressurized by, for example, an osmotic pressure pump 17 exceeding 6 MPa to become high-pressure seawater 22 and flows into the reverse osmosis membrane 18. The reverse osmosis membrane 18 separates the high-pressure seawater 22 into fresh water 19 that passes through the membrane and concentrated seawater 24 that does not pass through. Thus, the fresh water 19 for utilizing for drinking water is obtained.

<Fourth technology>
A seawater desalination apparatus as a fourth technique will be described with reference to FIG. Only portions different from the third technique will be described. This is because the seawater 16 after the pretreatment membrane is branched into the second filtered water 21 and the third filtered water 25, and the pressure is increased by the osmotic pressure pump 17 and the second osmotic pressure pump 23, respectively. Seawater 22 is used. Since the concentrated seawater 24 is at a high pressure, when it flows into the impeller 26, the impeller 26 is driven to rotate to a low pressure. The rotation shafts of the second osmotic pump 23 and the impeller 26 are connected directly or indirectly, and the second osmotic pump 23 is driven to rotate by the rotation of the impeller 26. Therefore, compared with the third technique, the required power of the osmotic pressure pump 17, that is, power consumption is reduced.

<Fifth technology>
A seawater desalination apparatus as the fifth technique will be described with reference to FIG. Only portions different from the third technique will be described. In normal operation, the on-off valves 27, 28 are opened, and the on-off valves 76, 78, 34 are closed. Hereinafter, the on-off valve 27 and the like open and close the flow path and function as a branching means or a stopping means for the flow path. The backwash pump 77 is stopped and all other pumps are operated.

  The seawater 16 after the pretreatment membrane once enters the filtered water tank 75 and is conveyed while being pressurized by the osmotic pressure pump 17 from there. Since the removed solid matter is deposited on the pretreatment membrane 15, the membrane is clogged and the seawater 13 becomes difficult to flow. Therefore, when the membrane differential pressure increases to some extent or when a certain amount of time has elapsed, the backwash operation is performed as follows.

  The seawater pump 14 is stopped and the on-off valves 27 and 28 are closed. Then, the on-off valves 76, 78, and 34 are opened, the backwash pump 77 is operated, and the wash water 79 from the filtered water tank 75 is passed through the pretreatment film 15. Since the washing water 79 flows in the opposite direction to the seawater 13, the solid matter deposited on the membrane rides on the washing water 79 and is discharged to a washing drain tank (not shown). In this way, the pretreatment film 15 can be backwashed with a water flow. Even if the backwashing is repeated, the differential pressure of the pretreatment film 15 increases at a certain rate. If the differential pressure sufficiently increases, cleaning using chemicals is also performed. In addition, the osmotic pressure pump 17 is operated even during the backwashing operation, and the pretreated membrane-sealed seawater 16 stored in the filtered water tank 75 is conveyed while being pressurized, and the desalination treatment is continued.

<Sixth technology>
A seawater desalination apparatus as a sixth technique will be described with reference to FIG. Only parts different from the fifth technique will be described. In normal operation, the on-off valves 27, 28 are opened, and the on-off valves 76, 78, 35, 36, 34 are closed. The backwash pump 77 and the second backwash pump 32 are stopped, and all other pumps are operated. The heater 80 is, for example, an electric heater and is not normally operated. The seawater 16 after the pretreatment membrane once enters the filtered water tank 75 and is conveyed while being pressurized by the osmotic pressure pump 17. Fresh water 19 flows into a fresh water tank 29, from which an appropriate amount is taken out as a second fresh water 31 by a fresh water pump 30. Since the removed solid matter is deposited on the pretreatment membrane 15, the membrane is clogged and the seawater 13 becomes difficult to flow. Therefore, when the membrane differential pressure increases to some extent or when a certain amount of time elapses, the backwash operation is performed as follows.

  The seawater pump 14 is stopped and the on-off valves 27 and 28 are closed. Then, the on-off valves 76, 78, and 34 are opened, the backwash pump 77 is operated, and the wash water 79 from the filtered water tank 75 is passed through the pretreatment film 15. Since the washing water 79 flows in the opposite direction to the seawater 13, the solid matter deposited on the membrane rides on the washing water 79 and is discharged to a washing drain tank (not shown). Now, some of the backwashing operations, for example, once every few times, are performed as follows.

  The seawater pump 14 is stopped, and the on-off valves 27, 28, 76, 78 are closed. Then, the on-off valves 34, 35, and 36 are opened, the second backwash pump 32 is operated, the heater 80 is operated, and the second wash water 33 is heated. The reason for heating the second wash water 33 from the fresh water tank 29 without heating the wash water 79 from the filtered water tank 75 is to prevent corrosion of the heater 80 due to seawater components. The cleaning water 79 may be heated by disposing it between the on-off valve 76 and the on-off valve 78.

  The second wash water 33 from the fresh water tank 29 is passed through the pretreatment film 15, but is hot water when it flows into the pretreatment film 15. Since the second washing water 33 flows in the opposite direction to the seawater 13, the solid matter deposited on the membrane rides on the second washing water 33 and is discharged to a washing drain tank (not shown).

  In this way, the pretreatment film 15 can be backwashed with a water flow. Even if the backwashing is repeated, the differential pressure of the pretreatment film 15 increases at a certain rate. If the differential pressure sufficiently increases, cleaning with chemicals is also performed. Since the pretreatment film 15 has a large cleaning effect when backwashed with warm water, the use of the heated second cleaning water 33 extends the time for increasing the film differential pressure to a value that requires cleaning with chemicals. .

  Therefore, the time interval for performing cleaning using chemicals is longer than that in the fifth technique, and the amount of chemical injection per day is reduced. Note that the osmotic pressure pump 17 is operated even during the backwash operation regardless of whether it is based on warm water, and the seawater 16 after the pretreatment membrane stored in the filtered water tank 75 is conveyed while being pressurized, and the desalination treatment is continued. .

<Seventh technology>
A seawater desalination apparatus as a seventh technique will be described with reference to FIG. Only parts different from the third to sixth techniques will be described. During normal operation, the on-off valves 27, 28, 47 are opened, the on-off valves 76, 78, 34, 35, 36 are closed, the backwash pump 77 and the second backwash pump 32 are stopped, and the heater 80 Do not operate. The seawater 13 flows into the sand basin 39 by the second seawater pump 40, and a part of the sand is removed. Then, it flows into the sand filter 37 with the 3rd seawater pump 38, and the remaining sand is removed. Then, it becomes the 2nd seawater 41, and flows into the adjustment water tank 42. FIG.

  The fresh water 19 is slightly pressurized to a high pressure by the third osmotic pressure pump 44 and flows into the second reverse osmosis membrane 45. The fresh water 19 is separated by the second reverse osmosis membrane 45 into a third fresh water 46 that passes through the membrane and a second concentrated seawater 20 that does not pass through. The third fresh water 46 flows into the fresh water tank 29, and the second concentrated seawater 20 flows into the adjusted water tank 42.

  The backwashing operation is performed as in the sixth technique, and the osmotic pressure pump 17 and the third osmotic pressure pump 44 are also operated during the backwashing operation, and the pretreated membrane post-seawater 16 stored in the filtered water tank 75, Alternatively, the fresh water 19 in the fresh water tank 29 is conveyed while being pressurized, and the desalination treatment is continued. Note that a bactericide, a flocculant, a scale inhibitor, a reducing agent, and a pH adjuster are respectively injected at appropriate locations in the flow of FIG. Thus, the 2nd fresh water 31 for utilizing for drinking water is obtained.

  Next, an embodiment of a seawater desalination apparatus will be described.

<First Embodiment>
The seawater desalination apparatus concerning 1st Embodiment is demonstrated using FIG. Only parts different from the first to third techniques will be described. The first embodiment corresponds to claims 1, 12, and 13.

  The seawater desalination apparatus according to the first embodiment is operated at night as follows. Open the on-off valves 48, 53, 54. It should be noted that a system configuration in which the on-off valves 51 and 52 are closed and the osmotic pump 17 is stopped, or a system configuration in which the on-off valves 51 and 52 are opened and the osmotic pump 17 is operated at night as in the daytime. .

  The extracted steam 8 is caused to flow into the small steam turbine 49. The extracted steam 8 expands inside the small steam turbine 49 and decreases in pressure and temperature, and the small turbine exhaust 50 flows into the condenser 5. The rotary shafts of the second osmotic pump 23 and the small steam turbine 49 are connected directly or indirectly, and the second osmotic pump 23 is rotationally driven by the rotation of the small steam turbine 49.

  In the fourth technique, the second osmotic pump 23 is driven by the rotation of the impeller 26. However, in the first embodiment, the second osmotic pump 23 is driven by the rotation of the small steam turbine 49. In addition, there is a technique for driving the feed water pump 7 by the rotation of the small steam turbine 49 as a technique not described.

  At night, the steam flow of the steam turbine 1 decreases after the stage where the extracted steam 8 is extracted by flowing the extracted steam 8 into the small steam turbine 49, and the extracted steam 8 heats the water 6. Since it is not implemented, the power generation output and power generation efficiency of the steam turbine cycle are reduced, but there is no problem because the power is surplus. Compared with the third technique, the seawater desalination apparatus according to the first embodiment reduces or eliminates the required power of the osmotic pressure pump 17, that is, power consumption.

  The seawater desalination apparatus according to the first embodiment closes the on-off valves 48, 53, and 54 in the daytime, and does not drive the small steam turbine 49 and the second osmotic pressure pump 23. Both devices perform normal operation, but neither causes problems.

  The fourth to seventh techniques may be applied to the first embodiment. In the first embodiment, the second osmotic pump 23 is in parallel with the osmotic pump 17, but may be in parallel with any osmotic pump, and in parallel with the third osmotic pump 44 in the seventh technique. You may make it. Alternatively, the extraction steam 8 may be branched by a branching means for the feed water heater 9 and the small steam turbine 49, and switched to flow only to the latter during the night and only to the former during the day.

Second Embodiment
A second embodiment will be described with reference to FIG. Only parts different from the first to third techniques will be described. The second embodiment corresponds to claims 2, 3, 12, and 13.

  The seawater desalination apparatus according to the second embodiment operates as follows at night. The on-off valves 48 and 54 are opened and the fourth seawater pump 67 is operated. It should be noted that the system configuration may be such that the on-off valve 53 is closed and the second seawater pump 40 is stopped, or the on-off valve 53 is opened and the second seawater pump 40 is operated at night as in the daytime. .

  The seawater 13 and the fourth seawater 55 merge to become the second seawater 41 and flow into the adjusted water tank 42. Then, it is conveyed to the pretreatment membrane 15 by the seawater pump 14. The rotation axis of the fourth seawater pump 67 and the small steam turbine 49 is connected directly or indirectly, and the fourth seawater pump 67 is rotationally driven by the rotation of the small steam turbine 49.

  At night, the steam flow rate of the steam turbine 1 decreases after the stage where the extracted steam 8 is extracted, and the extracted steam 8 does not heat the water 6, so the power output of the steam turbine cycle is also generated. Although efficiency is reduced, there is no problem because it is a surplus of power. As the seawater desalination apparatus, the necessary power of the second seawater pump 40, that is, power consumption is reduced or unnecessary.

  In the daytime, the on-off valves 48 and 54 are closed, and the small steam turbine 49 and the fourth seawater pump 67 are not driven. In the case of a system configuration in which the opening / closing valve 53 is closed and the second seawater pump 40 is stopped at night, the opening / closing valve 53 is opened and the second seawater pump 40 is operated during the daytime. Both the steam turbine plant and the seawater desalination unit will operate normally, but neither will cause problems.

  The fourth to seventh techniques may be applied to the second embodiment. The extraction steam 8 may be branched to the feed water heater 9 and the small steam turbine 49 and switched to flow only to the latter at night and only to the former during the day. Further, the seawater desalination method need not be a method using a reverse osmosis membrane.

<Third Embodiment>
A third embodiment will be described with reference to FIG. Only parts different from the first to third techniques will be described. The third embodiment corresponds to claims 2, 4, 5, 12, and 13.

  The seawater desalination apparatus according to the third embodiment operates as follows at night. Open the on-off valves 48, 53, 54. It should be noted that the system configuration may be such that the on-off valves 51 and 52 are closed and the seawater pump 14 is stopped, or at night, the on-off valves 51 and 52 are opened and the seawater pump 14 is operated as in the daytime. The seawater 13 flows into the adjusted water tank 42 by the second seawater pump 40. The fifth seawater 56 that has flowed out of the adjustment water tank 42 branches into a sixth seawater 57 that is transported by the seawater pump 14 and a seventh seawater 58 that is transported by the fourth seawater pump 67. 8 seawater 68 flows into the pretreatment membrane 15.

The rotation shafts of the fourth seawater pump 67 and the small steam turbine 49 are connected directly or indirectly, and the fourth seawater pump 67 is rotationally driven by the rotation of the small steam turbine 49. At night, the steam flow rate of the steam turbine 1 decreases after the stage where the extracted steam 8 is extracted, and the extracted steam 8 does not heat the water 6, so the power output of the steam turbine cycle is also generated. Although efficiency is reduced, there is no problem because it is a surplus of power. Compared with the third technique, the seawater desalination apparatus reduces or eliminates the required power of the osmotic pump 17, that is, power consumption.

  In the daytime, the on-off valves 48, 53, 54 are closed, and the steam turbine plant and the seawater desalination device are operated normally without driving the small steam turbine 49 and the fourth seawater pump 67. Does not occur. The extraction steam 8 may be branched to the feed water heater 9 and the small steam turbine 49 and switched to flow only to the latter at night and only to the former during the day.

  The fourth to seventh techniques and the techniques of the first and second embodiments may be applied to the third embodiment. In the third embodiment, the fourth seawater pump 67 is in parallel with the seawater pump 14, but may be in parallel with any pump as long as it pumps seawater or fresh water. The second seawater pump referred to in the seventh technology 40, the third seawater pump 38, and the fresh water pump 30 may be arranged in parallel. The case where it is in parallel with the fresh water pump 30 corresponds to claim 5. Further, the seawater desalination method need not be a method using a reverse osmosis membrane.

<Fourth embodiment>
A fourth embodiment will be described with reference to FIG. Only the parts different from the first, second and fifth techniques will be described. The fourth embodiment corresponds to claims 6, 9, 12, and 13.

  When performing the backwash operation of the pretreatment membrane 15 at night, the seawater desalination apparatus according to the fourth embodiment operates as follows. The on-off valves 27, 28, 48 are closed, the on-off valves 34, 61, 70, 74 are opened, and the seawater pump 14 and the drain pump 12 are stopped. Even in a system configuration in which the on-off valves 76 and 78 are closed and the backwash pump 77 is stopped, the backwash operation at night is also performed by opening the on-off valves 76 and 78 in the same way as the daytime backwash operation. A system configuration for operation may be used. The rotation shafts of the third backwash pump 71 and the small steam turbine 49 are connected directly or indirectly, and the third backwash pump 71 rotates by the rotation of the small steam turbine 49 by the extraction steam 60 for the small turbine. The second cleaning water 33 from the fresh water tank 29 is driven to flow through the pretreatment film 15.

  At night, the steam flow rate of the steam turbine 1 decreases after the stage where the extracted steam 8 is extracted, and the extracted steam 8 does not heat the water 6, so the power output of the steam turbine cycle is also generated. Although efficiency is reduced, there is no problem because it is a surplus of power. Compared with the fifth technology, the seawater desalination apparatus reduces or eliminates the necessary power, that is, power consumption, of the second backwash pump 32.

  When performing the backwash operation of the pretreatment film 15 during the daytime, the operation is performed as follows. The on-off valves 27, 28, 70, 74, 61 are closed, the on-off valves 34, 76, 78, 48 are opened, and the backwash pump 77, the seawater pump 14, and the drain pump 12 are operated. Although the small steam turbine 49 and the third backwash pump 71 are not driven, the steam turbine plant performs a normal operation and the seawater desalination apparatus performs a normal backwash operation. At this time, the condensed water 10 is heated by the feed water heater 9 by the extraction steam 59 for the heater.

  When the backwash operation of the pretreatment film 15 is not performed at night or in the daytime, the operation is performed as follows. The on-off valves 27, 28, 48 are opened, the on-off valves 34, 76, 78, 70, 74, 61 are closed, the second backwash pump 32 is stopped, and the seawater pump 14 and the drain pump 12 are operated. Although the small steam turbine 49 and the third backwash pump 71 are not driven, both the steam turbine plant and the seawater desalination apparatus are operated normally, but neither of them causes a problem.

  At this time, the condensed water 10 is heated by the feed water heater 9 by the extraction steam 59 for the heater. The osmotic pressure pump 17 is operated during backwashing operation at night or in the day regardless of whether it is based on hot water, and the pretreated membrane-sealed seawater 16 stored in the filtered water tank 75 is conveyed while being pressurized to be desalinated. Continue processing.

  In the fourth embodiment, the extraction steam 8 is branched into the extraction steam 59 for the heater and the extraction steam 61 for the small turbine. However, the entire amount is extracted into the extraction steam 61 for the small turbine without branching, and the extraction steam 59 for the heater is changed. It may be eliminated.

  However, since the time until the start and end of the backwash operation is short, whether or not the extracted steam 8 is distributed is switched in a short time. At that time, since the state change of the steam turbine 1 and the steam turbine cycle becomes severe, in order to avoid this, in the fourth embodiment, the extraction steam 8 and the extraction steam 59 for the heater are maintained while the extraction steam 8 continues to flow. Is switched by switching means. Further, the on-off valves 48 and 61 may be used as flow rate control valves, and may be switched while adjusting the flow rates of the extraction steam 59 for the heater and the extraction steam 60 for the small turbine.

  The fourth, sixth, and seventh technologies and the first to third embodiments may be applied to the fourth embodiment. For example, the second backwash pump 32 and the small steam turbine according to the sixth and seventh technologies. You may connect 49 rotating shafts directly or indirectly. Further, the seawater desalination method need not be a method using a reverse osmosis membrane.

<Fifth Embodiment>
A fifth embodiment will be described with reference to FIG. Only parts different from the first to third techniques will be described. The fifth embodiment corresponds to claims 7 and 12.

  The seawater desalination apparatus according to the fifth embodiment operates as follows at night. The on-off valve 48 is opened, and the extracted steam 8 flows into the seawater heater 62. The seawater 16 after the pretreatment membrane is heated by the extraction steam 8 by the seawater heater 62. After the temperature of the extraction steam 8 is lowered by the seawater heater 62, the extraction steam 8 flows into the condenser 5. Since the viscosity of the seawater 16 after the pretreatment membrane decreases due to an increase in water temperature and the membrane permeability of the reverse osmosis membrane 18 increases, the required power of the osmotic pressure pump 17, that is, power consumption, is reduced. For example, when the temperature of the seawater 16 after the pretreatment membrane is increased from 20 ° C. to 25 ° C., it is reduced by 0.2 kWh / m 3. However, since the membrane blocking rate is lowered and the treated water quality deteriorates due to an increase in the water temperature, the higher the water temperature is, the better. Therefore, the water temperature is increased by an appropriate amount.

  At night, the extraction steam 8 flows into the seawater heater 62, so that the steam flow of the steam turbine 1 decreases after the stage where the extraction steam 8 is extracted and the extraction steam 8 heats the water 6. Since it is not implemented, the power generation output and power generation efficiency of the steam turbine cycle are reduced, but there is no problem because the power is surplus. Compared with the third technology, the seawater desalination apparatus reduces the required power, that is, power consumption, of the osmotic pump 17. During the daytime, the on-off valve 48 is closed and normal operation is carried out for both the steam turbine plant and the seawater desalination apparatus, but neither of them causes a problem.

  The fourth to seventh techniques and the techniques of the first to fourth embodiments may be applied to the fifth embodiment. The extraction steam 8 may be branched to the feed water heater 9 and the seawater heater 62 and switched to flow only to the latter at night and only to the former during the day.

<Sixth Embodiment>
A sixth embodiment will be described with reference to FIG. Only the parts different from the first, second and fifth techniques will be described. The sixth embodiment corresponds to claims 8, 9, and 12.

  The seawater desalination apparatus according to the sixth embodiment operates as follows when hot water cleaning is performed as a backwash operation of the pretreatment membrane 15 at night. The on-off valves 27, 28, 76 and 78 are closed, the on-off valves 34, 35, 36 and 48 are opened, the seawater pump 14 and the backwash pump 77 are stopped, the second backwash pump 32 is operated, and the heater 80 is turned on. Do not operate. The extraction steam 8 is caused to flow into the cleaning water heater 63, and the second cleaning water 33 is heated by the extraction steam 8. The extraction steam 8 is lowered in temperature by the washing water heater 63 and then flows into the condenser 5. When the pretreatment film 15 is backwashed with warm water, the cleaning effect is large. Therefore, by using the heated second cleaning water 33, the time during which the film differential pressure rises to a value that requires cleaning with a chemical is used. Extend.

  At night, the steam flow of the steam turbine 1 decreases after the stage where the extraction steam 8 is extracted by flowing the extraction steam 8 into the washing water heater 63, and the extraction steam 8 heats the water 6. Is not implemented, the power generation output and power generation efficiency of the steam turbine cycle are reduced, but there is no problem because the power is surplus. Similar to the fifth technology, the seawater desalination apparatus extends the time interval for cleaning with chemicals and reduces the total amount of chemicals injected at night. Compared with the fifth technique, the energy consumption at night of the heater 80, for example, the power consumption of the electric heater is eliminated. The reason for heating the second wash water 33 from the fresh water tank 29 without heating the wash water 79 from the filtered water tank 75 is to prevent corrosion of the wash water heater 63 due to seawater components. The vessel 63 may be disposed between the opening / closing valve 76 and the opening / closing valve 78 to heat the washing water 79.

  When hot water cleaning is performed as a backwash operation of the pretreatment film 15 during the daytime, the opening / closing valve 48 is closed and the heater 80 is operated from the state of backwash operation at night. The steam turbine plant performs a normal operation, and the seawater desalination apparatus performs a backwash operation using hot water heated by a normal heater 80, but neither of them causes a problem.

  When warm water washing is not performed as a back washing operation of the pretreatment film 15 at night or in the daytime, the on / off valves 35 and 36 are closed and the on / off valves 76 and 78 are opened from the state of back washing operation with warm water in the daytime. 2, the backwash pump 32 is stopped, the backwash pump 77 is operated, and the heater 80 is not operated. The steam turbine plant performs normal operation and the seawater desalination device performs normal backwash operation, but neither of them causes a problem. The osmotic pressure pump 17 is operated during backwashing operation at night or in the day regardless of whether it is based on hot water, and the pretreated membrane-sealed seawater 16 stored in the filtered water tank 75 is conveyed while being pressurized to be desalinated. Continue processing.

  When the backwash operation of the pretreatment film 15 is not performed at night or in the daytime, the operation is performed as follows. The on-off valves 27 and 28 are opened, the on-off valves 34, 35, 36, 76, 78 and 48 are closed, the second backwash pump 32 and the backwash pump 77 are stopped, the seawater pump 14 is operated, and the heater 80 is operated. I won't let you. Both the steam turbine plant and the seawater desalination unit will operate normally, but neither will cause problems.

  In 6th Embodiment, although it is set as the structure which can perform the backwash operation using warm water in the daytime, without installing the heater 80, you may make it the structure which cannot perform the backwash operation using warm water in the daytime. Compared to the fourth technique, there is an effect similar to the fifth technique at night. The fourth to seventh techniques and the techniques of the first to fifth embodiments may be applied to the sixth embodiment. The extraction steam 8 may be branched to the feed water heater 9 and the seawater heater 62 and switched to flow only to the latter at night and only to the former during the day. Further, the seawater desalination method need not be a method using a reverse osmosis membrane.

<Seventh embodiment>
A seventh embodiment will be described with reference to FIG. The seventh embodiment corresponds to the seventh, eighth, ninth, tenth, eleventh, and twelfth aspects. In the seawater desalination apparatus according to the seventh embodiment, the extraction steam 8 is branched into the extraction steam 59 for the heater, the second extraction steam 66, and the third extraction steam 69. When heating with the feed water heater 9, the seawater heater 62, and the washing water heater 63, the on-off valves 48, 64, and 65 are opened, respectively. The reason for heating the second washing water 33 from the fresh water tank 29 without heating the washing water 79 from the filtered water tank 75 by the washing water heater 63 is to prevent corrosion of the washing water heater 63 due to seawater components. The cleaning water heater 63 may be disposed between the on-off valve 76 and the on-off valve 78 to heat the cleaning water 79.

  Since the time until the start and end of the backwash operation is short, the flow of the third extraction steam 69 passing through the wash water heater 63 is switched in a short time. At that time, since the state change of the steam turbine or the steam turbine cycle becomes severe, in order to avoid this, in the seventh embodiment, the circulation of the extracted steam 8 is continued.

  That is, the circulation of the third extraction steam 69 is eliminated in a state where at least one of the extraction steam 59 for heater and the second extraction steam 66 exists. Alternatively, the on-off valves 48, 64, and 65 may be used as flow rate adjusting valves, and may be switched while adjusting the flow rates of the extraction steam 59 for the heater, the second extraction steam 66, and the third extraction steam 69, respectively. The effects of the technology of the fifth embodiment and the technology of the sixth embodiment are both provided. The fourth to seventh techniques and the techniques of the first to fourth embodiments may be applied to the seventh embodiment.

<Eighth Embodiment>
An eighth embodiment will be described. The eighth embodiment corresponds to claim 14. In the first to seventh embodiments, the seawater desalination apparatus according to the eighth embodiment performs system operation as follows. When the electric power demand is larger than the first predetermined value, an operation is performed in which the entire amount or a part of the extracted steam 8 is not used except for the feed water heater 9. The on-off valve 48 may be closed and the extracted steam 8 may not be circulated. When the electric power demand is smaller than the second predetermined value, the system operation in which the entire amount or part of the extracted steam 8 is distributed to the small steam turbine 49, the seawater heater 62, or the washing water heater 63 is continuously or intermittently performed. To implement. The second predetermined value is less than or equal to the first predetermined value. A predetermined value for power demand is provided as a guide for switching operation patterns.

<Ninth Embodiment>
A ninth embodiment will be described. The ninth embodiment corresponds to claim 15. In the first to seventh embodiments, the seawater desalination apparatus according to the ninth embodiment performs system operation as follows. When the amount of power generated by the steam turbine 1 is smaller than the fourth predetermined value, an operation is performed in which the entire amount or part of the extracted steam 8 is not used except for the feed water heater 9. The on-off valve 48 may be closed and the extracted steam 8 may not be circulated. When the power generation amount is larger than the third predetermined value, the total amount of the extraction steam 8 is
Alternatively, the system operation in which a part is distributed to the small steam turbine 49, the seawater heater 62, or the washing water heater 63 is performed continuously or intermittently. The fourth predetermined value is less than or equal to the third predetermined value. A predetermined value for the amount of power generation is provided as a guide for switching operation patterns.

<Tenth Embodiment>
A tenth embodiment will be described. The tenth embodiment corresponds to the sixteenth aspect. In the second embodiment, the seawater desalination apparatus according to the tenth embodiment performs system operation as follows.

  When the power demand is larger than the first predetermined value, the on-off valves 48 and 54 are closed and the fourth seawater pump 67 is not driven. Furthermore, the on-off valve 53 is closed, the second seawater pump 40 is also stopped, and only the seawater stored in the adjustment water tank 42 is desalinated.

  When the power demand is smaller than the second predetermined value, the on-off valves 48 and 54 are opened, the fourth seawater pump 67 is driven, and the fourth seawater 55 conveyed from the sea is desalinated. Even if the system configuration is such that the on-off valve 53 is closed and the second seawater pump 40 is stopped, the on-off valve 53 is opened to operate the second seawater pump 40, and the seawater 13 is also desalinated. Also good. The second predetermined value is less than or equal to the first predetermined value. In the tenth embodiment, the second seawater pump 40 may not be provided. However, when the temporary steam turbine cycle cannot be operated due to maintenance or the like, the fourth seawater 55 cannot be conveyed. It is good to install. In addition to the effect of the second embodiment, power consumption when there is a large amount of power demand can be reduced and power leveling can be achieved.

<Eleventh embodiment>
An eleventh embodiment will be described. The eleventh embodiment corresponds to claim 17. In the second embodiment, the seawater desalination apparatus according to the eleventh embodiment performs system operation as follows.

  When the amount of power generated by the steam turbine 1 is smaller than the fourth predetermined value, the on-off valves 48 and 54 are closed and the fourth seawater pump 67 is not driven. Furthermore, the on-off valve 53 is closed, the second seawater pump 40 is also stopped, and only the seawater stored in the adjustment water tank 42 is desalinated.

  When the power generation amount is larger than the third predetermined value, the on-off valves 48 and 54 are opened, the fourth seawater pump 67 is driven, and the fourth seawater 55 conveyed from the sea is desalinated. Even if the system configuration is such that the on-off valve 53 is closed and the second seawater pump 40 is stopped, the on-off valve 53 is opened to operate the second seawater pump 40, and the seawater 13 is also desalinated. Also good. The fourth predetermined value is less than or equal to the third predetermined value. In the eleventh embodiment, the second seawater pump 40 may not be provided. However, when the temporary steam turbine cycle cannot be operated due to maintenance or the like, the fourth seawater 55 cannot be conveyed. It is good to install. In addition to the effect of the second embodiment, power consumption when there is a large amount of power demand can be reduced and power leveling can be achieved.

As described above, according to the present embodiment, it is possible to provide a seawater desalination apparatus that can use surplus energy of a steam turbine plant for seawater desalination according to electric power demand. In the embodiment, the reverse osmosis membrane 18 and the pretreatment membrane 15 are provided. However, these include a reverse osmosis membrane or a pretreatment membrane, and the inside is partitioned by these to utilize the osmotic pressure by these membranes. Refers to equipment. In addition, the present embodiment may be provided with a control device and operated according to an instruction from the control device. Hereinafter, the invention described in the scope of claims of the present application will be appended.
[1]
A seawater desalination device that combines with a steam turbine and desalinates seawater using a reverse osmosis membrane,
A second steam turbine driven by extracted steam from the steam turbine;
An osmotic pump for increasing the pressure of seawater flowing into the reverse osmosis membrane,
The seawater desalination apparatus characterized in that the osmotic pressure pump can be driven by the power generated by the second steam turbine.
[2]
A seawater desalination unit combined with a steam turbine,
A second steam turbine driven by extracted steam from the steam turbine;
A pump for conveying seawater or fresh water,
A seawater desalination apparatus characterized in that the pump can be driven by the power generated by the second steam turbine.
[3]
The seawater desalination apparatus according to [2], wherein the pump is a pump that takes in seawater.
[4]
The seawater desalination apparatus according to [2], wherein the pump is a pump that conveys seawater to a pretreatment membrane that removes solid matter from seawater.
[5]
The said pump is a pump which conveys the water which desalinated seawater, The seawater desalination apparatus as described in [2] characterized by the above-mentioned.
[6]
A seawater desalination unit combined with a steam turbine,
A second steam turbine driven by extracted steam from the steam turbine;
A pump for transporting washing water used for backwashing the pretreatment membrane that removes solid matter from seawater,
A seawater desalination apparatus characterized in that a pump for transporting the wash water can be driven by power generated by the second steam turbine.
[7]
A seawater desalination device that combines with a steam turbine and performs desalination using a reverse osmosis membrane,
A seawater desalination system comprising a seawater heater that heats seawater flowing into the reverse osmosis membrane with the extracted steam from the steam turbine, and capable of heating the seawater flowing into the reverse osmosis membrane apparatus.
[8]
A seawater desalination unit combined with a steam turbine,
A washing water heater for heating washing water used for backwashing a pretreatment membrane that removes solid matter from seawater by the extracted steam from the steam turbine is provided, and the washing water can be heated. Seawater desalination equipment.
[9]
A seawater desalination unit combined with a steam turbine,
Branching means for branching steam extracted from the steam turbine into extracted steam for a feed water heater and extracted steam for driving the second steam turbine;
[1] to [1], further comprising extraction steam for driving the second steam turbine branched by the branching means, and stopping means for stopping the circulation of the extraction steam for the feed water heater. 6] The seawater desalination apparatus according to any one of [6].
[10]
A seawater desalination unit combined with a steam turbine,
Branching means for branching steam extracted from the steam turbine into extracted steam for a feed water heater and extracted steam for the seawater heater;
[7] The seawater desalination according to [7], further comprising stop means for stopping the flow of the extraction steam for the feed water heater and the extraction steam for the seawater heater branched by the branching means. apparatus.
[11]
A seawater desalination unit combined with a steam turbine,
Branching means for branching steam extracted from the steam turbine into extracted steam for a feed water heater and extracted steam for the washing water heater;
[6] The seawater fresh water according to [8], further comprising stop means for stopping the flow of the extraction steam for the feed water heater and the extraction steam for the washing water heater branched by the branching means. Device.
[12]
The seawater desalination apparatus according to any one of [1] to [11], wherein the circulation of the extracted steam can be stopped.
[13]
Any one of [1] to [6], wherein the circulation of the extracted steam is stopped and the second steam turbine is not driven, and the osmotic pressure pump or the pump can be driven by a different power source. Or the seawater desalination apparatus according to [9].
[14]
When the power demand is greater than a first predetermined value, the second steam turbine, the seawater heater or the washing water heater is operated in an operation pattern in which the extracted steam is not circulated, and the power demand is the second When it is smaller than a predetermined value, the seawater desalination apparatus according to [12] or [13], wherein the operation is performed in an operation pattern in which the extracted steam is circulated.
[15]
When the amount of power generated by the steam turbine is smaller than a fourth predetermined value, the power generation is performed in an operation pattern in which the extracted steam is not circulated to the second steam turbine, the seawater heater, or the washing water heater. When the amount is larger than a third predetermined value, the seawater desalination apparatus according to [12] or [13], which is operated in an operation pattern in which the extracted steam is circulated.
[16]
The pump is one or more of the pumps that transport seawater to the aquarium, and when the power demand is greater than a first predetermined value, the extracted steam is not circulated through the second steam turbine, It operates with the operation pattern which desalinates the seawater in the aquarium, and when the power demand is smaller than the second predetermined value, it operates with the operation pattern of desalination while circulating the extracted steam [2] The seawater desalination apparatus according to 1.
[17]
The pump is one or more pumps that transport seawater to the water tank, and when the amount of power generated by the steam turbine is smaller than a fourth predetermined value, the extracted steam is circulated to the second steam turbine. Without operating, the operation is performed with an operation pattern of desalinating seawater in the aquarium, and when the power generation amount is greater than a third predetermined value, the operation is performed with an operation pattern of desalination while circulating the extracted steam. The seawater desalination apparatus according to claim 2.

  DESCRIPTION OF SYMBOLS 1 ... Steam turbine, 2 ... Steam, 3 ... Boiler, 4 ... Turbine exhaust, 5 ... Condenser, 6 ... Water, 7 ... Feed water pump, 8 ... Extraction steam, 9 ... Feed water heater, 10 ... Condensate, 11 ... Drain, 12 ... Drain pump, 13 ... Seawater, 14 ... Seawater pump, 15 ... Pretreatment membrane, 16 ... Seawater after pretreatment membrane, 17 ... Osmotic pressure pump, 18 ... Reverse osmosis membrane, 19 ... Fresh water, 20th 2 concentrated seawater, 21 ... second filtered water, 22 ... high pressure seawater, 23 ... second osmotic pump, 24 ... concentrated seawater, 25 ... third filtered water, 26 ... impeller, 27 ... open / close valve, 28 ... Open / close valve, 29 ... Fresh water tank, 30 ... Fresh water pump, 31 ... Second fresh water, 32 ... Second backwash pump, 33 ... Second wash water, 34 ... Open / close valve, 35 ... Open / close valve, 36 Open / close valve 37 Sand filter 38 Third seawater pump 39 Sand basin 40 Second seawater pump 4 2nd seawater, 42 ... regulated water tank, 43 ... 3rd seawater, 44 ... 3rd osmotic pressure pump, 45 ... 2nd reverse osmosis membrane, 46 ... 3rd fresh water, 47 ... open / close valve, 48 ... On-off valve, 49 ... small steam turbine, 50 ... small turbine exhaust, 51 ... on-off valve, 52 ... on-off valve, 53 ... on-off valve, 54 ... on-off valve, 55 ... fourth seawater, 56 ... fifth seawater, 57 ... Sixth seawater, 58 ... Seventh seawater, 59 ... Extraction steam for heater, 60 ... Extraction steam for small turbine, 61 ... Open / close valve, 62 ... Seawater heater, 63 ... Washing water heater, 64 ... Opening / closing Valve: 65 ... Open / close valve, 66 ... Second extraction steam, 67 ... Fourth seawater pump, 68 ... Eight seawater, 69 ... Third extraction steam, 70 ... Open / close valve, 71 ... Third backwash Pump, 72 ... third wash water, 73 ... fourth wash water, 74 ... open / close valve, 75 ... filtered water tank, 76 ... open / close valve, 7 ... backwash pump, 78 ... on-off valve, 79 ... washing water, 80 ... heater

Claims (8)

A seawater desalination device that combines with a steam turbine and performs desalination using a reverse osmosis membrane,
By the steam turbine or extracted gas vapors, and sea water heater for heating the sea water flowing into the reverse osmosis membrane,
Branching means for branching steam extracted from the steam turbine into extracted steam for a feed water heater and extracted steam for the seawater heater;
Stop means for stopping the circulation of the extracted steam for the feed water heater and the extracted steam for the seawater heater branched by the branch means ,
A seawater desalination apparatus characterized in that seawater flowing into the reverse osmosis membrane can be heated. A seawater desalination unit combined with a steam turbine,
By the steam turbine or extracted gas vapor, a washing water heater for heating the wash water used for backwash of the pretreatment film removing solids from sea water,
Branching means for branching steam extracted from the steam turbine into extracted steam for a feed water heater and extracted steam for the washing water heater;
Stop means for stopping the flow of the extraction steam for the feed water heater and the extraction steam for the wash water heater branched by the branch means, respectively ,
A seawater desalination apparatus, characterized in that the washing water can be heated. It is possible to stop the circulation of steam extracted from the steam turbine,
When the power demand is greater than a first predetermined value, the seawater heater or the washing water heater is operated in an operation pattern in which the steam extracted from the steam turbine is not circulated, and the power demand is greater than the second predetermined value. The seawater desalination apparatus according to claim 1 or 2 , wherein when it is small, the operation is performed in an operation pattern in which the steam extracted from the steam turbine is circulated. It is possible to stop the circulation of steam extracted from the steam turbine,
When the power generation amount by the steam turbine is smaller than a fourth predetermined value, the seawater heater or the washing water heater is operated in an operation pattern in which the steam extracted from the steam turbine is not circulated. third predetermined value when larger than seawater desalination apparatus according to claim 1 or 2, characterized by operating at operation pattern for circulating steam bled from the steam turbine. A seawater desalination device that combines with a steam turbine and performs desalination using a reverse osmosis membrane,
Wherein the steam turbine or we extracted air and steam, with a seawater heater for heating the sea water flowing into the reverse osmosis membrane, it is possible to heat the seawater flowing into the reverse osmosis membrane, extracted from the steam turbine It is possible to stop the distribution of steam,
When the power demand is larger than a first predetermined value, the seawater heater is operated in an operation pattern in which the steam extracted from the steam turbine is not circulated, and when the power demand is smaller than a second predetermined value, the steam turbine A seawater desalination apparatus that operates with an operation pattern for circulating steam extracted from the seawater. A seawater desalination unit combined with a steam turbine,
  The steam extracted from the steam turbine is equipped with a cleaning water heater that heats the cleaning water used for backwashing the pretreatment film that removes solid matter from seawater, and the cleaning water can be heated. It is possible to stop the flow of steam extracted from the turbine,
  When the electric power demand is larger than a first predetermined value, the washing water heater is operated in an operation pattern in which the steam extracted from the steam turbine is not circulated, and when the electric power demand is smaller than a second predetermined value, the steam A seawater desalination apparatus that operates with an operation pattern for circulating steam extracted from a turbine. A seawater desalination device that combines with a steam turbine and performs desalination using a reverse osmosis membrane,
  The steam extracted from the steam turbine includes a seawater heater that heats the seawater flowing into the reverse osmosis membrane with the steam extracted from the steam turbine, and can heat the seawater flowing into the reverse osmosis membrane. It is possible to stop the distribution of
  When the power generation amount by the steam turbine is smaller than a fourth predetermined value, the seawater heater is operated in an operation pattern in which the steam extracted from the steam turbine is not circulated, and the power generation amount is larger than a third predetermined value. The seawater desalination apparatus is characterized in that it is operated with an operation pattern for circulating the steam extracted from the steam turbine. A seawater desalination unit combined with a steam turbine,
  The steam extracted from the steam turbine is equipped with a cleaning water heater that heats the cleaning water used for backwashing the pretreatment film that removes solid matter from seawater, and the cleaning water can be heated. It is possible to stop the flow of steam extracted from the turbine,
  When the power generation amount by the steam turbine is smaller than a fourth predetermined value, the cleaning water heater is operated in an operation pattern in which the steam extracted from the steam turbine is not circulated, and the power generation amount is less than a third predetermined value. When it is large, the seawater desalination apparatus is operated in an operation pattern in which the steam extracted from the steam turbine is circulated.