JP2022021409A - Concentration difference power generation system - Google Patents

Abstract

To provide a concentration difference power generation system capable of supplying sea water to an osmosis device even without providing a seat water pump only for supplying sea water to the osmosis device including a semipermeable membrane.SOLUTION: A concentration difference power generation system 1 includes a condenser 15 for cooling water vapor by sea water. The concentration difference power generation system 1 includes an osmosis device 50 including a semipermeable membrane 51 defining a first space 52 through which the sea water supplied from the condenser 15 passes, and a second space 53 through which fresh water passes, and disposed on a position lower than the condenser 15. Power is generated by the sea water passing through the first space 52.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to an osmotic power generation system.

Osmotic power generation is known in which power is generated by utilizing the difference in salt concentration between seawater and freshwater. Unlike thermal power generation, concentration difference power generation does not use fossil fuels, and unlike solar power generation, the amount of power generation does not fluctuate significantly, so it is attracting attention as a new renewable energy.

As a concentration difference power generation method, Patent Document 1 describes that by contacting low-concentration salt water and high-concentration salt water through a semipermeable membrane, water flows from low-concentration salt water to high-concentration salt water. A method of driving a generator using flow is disclosed.

International Publication No. 2013/172330

As described above, the concentration difference power generation is generated by the concentration difference between seawater and river water. Therefore, it is necessary to supply seawater from the sea in order to bring the seawater into contact with the semipermeable membrane. However, there are many cases where the distance from the sea to the semipermeable membrane that causes concentration difference power generation is long. In such a case, the piping for supplying seawater tends to be long. If the piping for supplying seawater is long, the energy for supplying seawater to the semipermeable membrane increases. Therefore, if a seawater pump is provided only for supplying seawater to the permeation device including the semipermeable membrane, the power generation efficiency of the entire concentration difference power generation system may decrease.

Therefore, it is an object of the present disclosure to provide a concentration difference power generation system capable of supplying seawater to an infiltration device without having a seawater pump only for supplying seawater to the infiltration device including a semipermeable membrane.

The concentration difference power generation system according to the present disclosure includes a condenser that cools water vapor with seawater. The osmotic power generation system includes a semipermeable membrane that separates the first space through which seawater supplied from the condenser passes and the second space through which freshwater passes, and is placed at a position lower than the condenser. Equipped with a penetration device. The concentration difference power generation system generates power by seawater passing through the first space.

The concentration difference power generation system may further include a turbine rotated by seawater passing through the first space and a generator generated by the rotation of the turbine. The concentration difference power generation system includes a boiler that generates steam from water cooled by the condenser, and generates electricity by the steam generated by the boiler, and the steam generated by the boiler may be cooled by the condenser.

According to the present disclosure, it is possible to provide a concentration difference power generation system capable of supplying seawater to an infiltration device without having a seawater pump only for supplying seawater to the infiltration device including a semipermeable membrane.

It is a schematic diagram which shows the concentration difference power generation system which concerns on one Embodiment.

Hereinafter, some exemplary embodiments will be described with reference to the drawings. The dimensional ratios in the drawings are exaggerated for convenience of explanation and may differ from the actual ratios.

The concentration difference power generation system 1 according to the present embodiment generates power by utilizing the osmotic pressure difference between seawater and freshwater. FIG. 1 is a schematic diagram showing a concentration difference power generation system 1 according to an embodiment. As shown in FIG. 1, the concentration difference power generation system 1 includes a condenser 15, a permeation device 50, a turbine 60, and a generator 70. Further, the concentration difference power generation system 1 includes a steam power generation device 10.

The steam power generation device 10 includes a circulation pipe 11, a water supply pump 12, a boiler 13, a turbine 14, a condenser 15, and a generator 16. The circulation pipe 11 is provided with a water supply pump 12, a boiler 13, a turbine 14, and a condenser 15.

Liquid water is supplied to the boiler 13 by the water supply pump 12. The water supplied to the boiler 13 is heated, and the heated water becomes steam. The steam whose volume has expanded as steam passes through the turbine 14 and is used as power to rotate the turbine 14. The turbine 14 is mechanically connected to the generator 16 and is provided so that the generator 16 generates electricity by the rotation of the turbine 14. The steam discharged from the turbine 14 is supplied to the condenser 15.

The condenser 15 cools the steam generated by the boiler 13 with seawater. As the condenser 15, for example, a surface condenser can be used. Since seawater is supplied from the sea S to the condenser 15, the heat of the water vapor passing through the condenser 15 is exchanged with the heat of the seawater passing through the condenser 15. The steam cooled by the condenser 15 is condensed, and the condensed water is supplied to the boiler 13 again by the water supply pump 12.

In this way, the boiler 13 produces steam from the water cooled by the condenser 15. The generator 16 generates electricity from the steam generated by the boiler 13. The steam generated by the boiler 13 is cooled by the condenser 15. A supply pipe 17 and a discharge pipe 18 are connected to the condenser 15, seawater for cooling steam is supplied to the condenser 15 through the supply pipe 17, and heat exchange with the heat of the steam through the discharge pipe 18. The steamed and heated seawater is discharged from the condenser 15.

One end of the supply pipe 17 is connected to the inlet of the seawater of the condenser 15, and the other end of the supply pipe 17 is arranged in the sea S. The supply pipe 17 is provided with a circulating water pump 19 and a discharge valve 20. The circulating water pump 19 pumps seawater from the sea S to the condenser 15. The discharge valve 20 can adjust the discharge amount of the seawater pumped by the circulating water pump 19 by opening and closing the passage of the seawater pumped by the circulating water pump 19. Further, the supply pipe 17 is provided with an inlet valve 21 capable of opening and closing the seawater passage on the inlet side of the condenser 15. The inlet valve 21 can regulate the amount of seawater flowing into the condenser 15.

One end of the discharge pipe 18 is connected to the seawater outlet of the condenser 15, and the other end of the discharge pipe 18 is led to the sea S. The discharge pipe 18 is provided with an outlet valve 22 that can open and close the seawater passage. Since the condenser 15 is provided at a position higher than the sea surface, even if a pump for discharging seawater from the condenser 15 is not provided, the seawater can be weighted by simply opening and closing the outlet valve 22. Can be discharged from the condenser 15 to the sea S.

A connection pipe 31 is connected to the downstream side of the condenser 15 in the discharge pipe 18. One end of the connecting pipe 31 is connected to the discharge pipe 18, and the other end of the connecting pipe 31 is connected to the infiltration device 50. The connection pipe 31 is provided between the condenser 15 and the outlet valve 22 in the discharge pipe 18. However, the connection pipe 31 may be provided in the discharge pipe 18 on the side opposite to the condenser 15 with respect to the outlet valve 22. The discharge pipe 18 is provided with a flow rate control valve 32, a water pressure gauge 33, a booster pump 34, and a pretreatment device 35.

The flow rate control valve 32 can open and close the passage of seawater supplied from the condenser 15 to the infiltration device 50. Since the condenser 15 is provided at a position higher than the sea surface and the infiltration device 50 as described above, the seawater can move from the condenser 15 to the infiltration device 50 by its own weight. Therefore, even if a pump for supplying seawater from the condenser 15 is not provided, the amount of seawater flowing from the condenser 15 to the infiltration device 50 can be adjusted simply by opening and closing the flow rate control valve 32. can.

The water pressure gauge 33 can measure the water pressure of the seawater flowing in the connecting pipe 31. By measuring the water pressure with the water pressure gauge 33, it is possible to grasp the amount of seawater flowing in the connecting pipe 31. Therefore, for example, the opening degree of the flow rate control valve 32 can be adjusted to supply the optimum flow rate of seawater to the infiltration device 50. The signal regarding the water pressure obtained by the water pressure gauge 33 may be sent to the control unit 80, and the control unit 80 may adjust the opening degree of the flow rate control valve 32 based on the above signal.

The booster pump 34 is provided in the connection pipe 31 on the downstream side of the flow rate control valve 32, and boosts the seawater flowing in the connection pipe 31. As described above, seawater can flow from the condenser 15 to the infiltration device 50 by its own weight. Therefore, although the booster pump 34 is not essential, the water pressure of the seawater flowing in the connecting pipe 31 can be increased as needed.

The pretreatment device 35 is provided on the upstream side of the infiltration device 50. The pretreatment device 35 includes a filter, and foreign matter such as dust in water can be removed by the filter. When the seawater passes through the pretreatment device 35, the treated water from which foreign substances have been removed and cleaned can be supplied to the infiltration device 50. Therefore, it is possible to prevent the semipermeable membrane 51 of the permeation device 50 from being clogged with foreign matter. As the filter, a known filter such as an ultrafilter membrane can be used. The pretreatment device 35 may include a backflow washer capable of backflow cleaning. Since the backflow washer can flow water from the downstream side to the upstream side with respect to the filter, it is possible to remove the foreign matter caught by the filter and clean the filter. The backflow washing may be carried out at any timing, or may be carried out at predetermined intervals.

The permeation device 50 includes a semipermeable membrane 51. The permeation device 50 has a first space 52 and a second space 53, and the first space 52 and the second space 53 are partitioned by a semipermeable membrane 51. Seawater passes through the first space 52, and freshwater passes through the second space 53.

The seawater passing through the first space 52 is supplied from the condenser 15 as described above. Since the semipermeable membrane 51 is arranged at a position lower than that of the condenser 15, seawater is supplied from the condenser 15 to the infiltration device 50 by its own weight. Further, the fresh water passing through the second space 53 is supplied from the river R. Fresh water is supplied to the infiltration device 50 via the water supply pipe 40. One end of the water supply pipe 40 is connected to the second space 53 of the infiltration device 50, and the other end of the water supply pipe 40 is arranged in the river R. The water supply pipe 40 is provided with a pump 41 and a pretreatment device 42, and the pump 41 can pump fresh water from the river R and supply the fresh water to the second space 53 of the infiltration device 50 through the water supply pipe 40. ..

The pretreatment device 42 is provided on the upstream side of the infiltration device 50. The pretreatment device 42 includes a filter, and foreign matter such as dust in water can be removed by the filter. By passing the fresh water through the pretreatment device 42, the treated water from which foreign substances have been removed and cleaned can be supplied to the infiltration device 50. Therefore, it is possible to prevent the semipermeable membrane 51 of the permeation device 50 from being clogged with foreign matter. As the filter, a known filter such as an ultrafilter membrane can be used. The pretreatment device 42 may include a backflow washer similar to the pretreatment device 35. Although the pretreatment device 35 and the pretreatment device 42 are provided in the connection pipe 31 and the water supply pipe 40 as different configurations, they may be provided in the connection pipe 31 and the water supply pipe 40 as one pretreatment device.

As described above, the semipermeable membrane 51 partitions the first space 52 through which the seawater supplied from the condenser 15 passes and the second space 53 through which the fresh water passes. That is, one surface of the semipermeable membrane 51 is in contact with seawater, and the other surface is in contact with fresh water. The semipermeable membrane 51 permeates water molecules, but does not permeate sodium ions or the like in seawater. Therefore, water molecules in fresh water permeate through the semipermeable membrane 51 and merge with seawater. Since the flow rate of seawater in the first space 52 increases according to the amount of permeated water molecules, the flow of seawater in the first space 52 accelerates.

The shape and film thickness of the semipermeable membrane 51 are not particularly limited, and can be appropriately changed as needed. The semipermeable membrane 51 may be provided on the surface of a support or the like in order to impart rigidity. The pore size of the semipermeable membrane 51 may be such that it allows water molecules to permeate and does not permeate sodium ions or the like in seawater, and is, for example, 1 nm to 10 nm. As the semipermeable membrane 51, known materials such as cellulose acetate, polyacrylonitrile, polysulfone, polyethersulfone, polyethylene, polypropylene, polyvinylidene fluoride and ceramic can be used.

A pipe 54 is connected to the infiltration device 50. One end of the pipe 54 is connected to the first space 52 of the infiltration device 50, and the other end of the pipe 54 is connected to the turbine 60. A water pressure gauge 55 is provided in the pipe 54, and the water pressure of the seawater flowing in the pipe 54 can be measured. The opening degree of the flow rate control valve 32 may be adjusted based on the water pressure measured by the water pressure gauge 55. A signal relating to the water pressure obtained by the water pressure gauge 33 may be sent to the control unit 80, and the control unit 80 may adjust the opening degree of the flow rate control valve 32 based on the above signal.

The seawater discharged from the first space 52 of the semipermeable membrane 51 is supplied to the turbine 60. The turbine 60 is rotated by the passage of seawater flowing through the first space 52 of the semipermeable membrane 51. The turbine 60 is mechanically connected to the generator 70 and is provided so as to interlock with the generator 70. Therefore, the generator 70 generates electricity by the rotation of the turbine 60. That is, the concentration difference power generation system 1 generates power by seawater passing through the first space 52.

The turbine 60 is connected to the pipe 61. One end of the pipe 61 is connected to the outlet of the turbine 60, and the other end of the pipe 61 is led to the sea S. The seawater that has passed through the turbine 60 is discharged to the sea S via the pipe 61.

The permeation device 50 is connected to the pipe 56. One end of the pipe 56 is connected to the second space 53 of the infiltration device 50, and the other end of the pipe 56 is led to the river R. The fresh water in the second space 53 is discharged from the infiltration device 50 into the river R.

The fresh water discharged from the infiltration device 50 may be transferred to a factory P or the like and used as industrial water. The fresh water supplied to the infiltration device 50 can be used as water used in the factory because foreign substances are removed and purified by the pretreatment device 42.

The control unit 80 may receive a signal regarding the water pressure from the water pressure gauge 33, a signal regarding the water pressure from the water pressure gauge 55, a signal regarding the rotation speed from the generator 70, and the like. Then, the control unit 80 may adjust the opening / closing of the flow rate control valve 32, the discharge amount of the booster pump 34, and the discharge amount of the pump 41 based on these signals.

As described above, the concentration difference power generation system 1 according to the present embodiment includes a condenser 15 for cooling water vapor with seawater. The concentration difference power generation system 1 partitions a first space 52 through which seawater supplied from the condenser 15 passes and a second space 53 through which fresh water passes, and is arranged at a position lower than the condenser 15. A permeation device 50 including a semipermeable membrane 51 is provided. Power is generated by seawater passing through the first space 52.

In order to generate osmotic power generation, it is necessary to supply seawater from the sea S to the infiltration device 50. However, if the pipe for supplying seawater to the infiltration device 50 is long, the energy for supplying seawater to the infiltration device 50 becomes large, and the power generation efficiency of the concentration difference power generation system 1 as a whole may decrease.

On the other hand, the condenser 15 cools the steam generated in a thermal power plant or the like with seawater. In the concentration difference power generation system 1 according to the present embodiment, the seawater used for cooling the water vapor in the condenser 15 can also be used in the infiltration device 50. Therefore, seawater can be supplied to the infiltration device 50 even if the seawater pump for supplying seawater to the infiltration device 50 including the semipermeable membrane 51 is not provided. Therefore, the energy for supplying seawater from the sea S to the infiltration device 50 can be reduced. In addition, the equipment cost and maintenance cost required for the pump can be reduced.

Further, the seawater supplied from the condenser 15 to the infiltration device 50 is heated by exchanging heat with the heat of steam. Since the osmotic pressure increases as the temperature rises, the heated seawater is supplied to the osmotic device 50, so that water molecules in fresh water passing through the second space 53 pass through the first space 52. It becomes easy to penetrate to. Therefore, the flow rate of seawater passing through the first space 52 increases, and the amount of power generated by the concentration difference power generation system 1 increases.

The concentration difference power generation system 1 may further include a turbine 60 rotated by seawater passing through the first space 52, and a generator 70 generated by the rotation of the turbine 60. As a result, the seawater passing through the first space 52 of the infiltration device 50 can generate electricity more reliably.

The concentration difference power generation system 1 includes a boiler 13 that generates steam from the water cooled by the condenser 15, and generates electricity by the steam generated by the boiler 13, and the steam generated by the boiler 13 is generated by the condenser 15. It may be cooled. As a result, not only the generator 70 but also the generator 16 can generate electric power, so that more electric power can be generated.

In the concentration difference power generation system 1 according to the present embodiment, an example in which the condenser 15 is used for thermal power generation has been described. However, if the steam is cooled by seawater, not only thermal power generation but also a condenser used in, for example, nuclear power generation can be used in the same manner.

Further, in the concentration difference power generation system 1 according to the present embodiment, the seawater of the condenser 15 was supplied to the infiltration device 50. However, the concentrated water of the condenser 15 may be supplied to the infiltration device 50. By supplying such water to the infiltration device 50, the concentration difference from fresh water becomes large, so that the osmotic pressure can be increased and the amount of power generated by the generator 70 can be increased. Examples of the method for concentrating the seawater in the condenser 15 include a desalination apparatus using a semipermeable membrane. The desalination apparatus can extrude fresh water to the other surface side of the semipermeable membrane by pressurizing the seawater on one surface side of the semipermeable membrane above the osmotic pressure. By providing such a device, fresh water is generated from seawater, and the concentration difference from freshwater is large because the water on the seawater side is concentrated, so that the amount of power generation due to the concentration difference can be increased.

Although some embodiments have been described, it is possible to modify or modify the embodiments based on the above disclosure contents. All the components of the embodiment and all the features described in the claims may be individually extracted and combined as long as they do not contradict each other.

1 Osmotic power generation system 13 Boiler 15 Condenser 50 Penetration device 51 Semipermeable membrane 52 First space 53 Second space 60 Turbine 70 Generator

Claims (3)

A condenser that cools water vapor with seawater,
An infiltration device including a semipermeable membrane that separates a first space through which seawater supplied from the condenser passes and a second space through which fresh water passes, and is arranged at a position lower than the condenser.
Equipped with
A concentration difference power generation system that generates electricity by seawater passing through the first space. A turbine rotated by seawater passing through the first space,
A generator that generates electricity by the rotation of the turbine,
The concentration difference power generation system according to claim 1. It is equipped with a boiler that generates steam from the water cooled by the condenser.
Power is generated by the steam generated by the boiler,
The concentration difference power generation system according to claim 1 or 2, wherein the steam generated by the boiler is cooled by the condenser.

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