KR101239440B1 - Power generation system using salinity gradient of salt water and fresh water - Google Patents

Abstract

PURPOSE: A power-generating system using salinity difference energy between salty water and fresh water is provided to improve energy recovering efficiency by generating power using mechanical energy of piston reciprocation of a pressure exchange device. CONSTITUTION: A power-generating system using salinity difference energy between salty water and fresh water comprises a fresh water supply part(30), a salty water supply part(20), a osmosis part(10), and a pressure exchange part(50). The fresh water supply part supplies fresh water. The salty water supply part supplies salty water. The osmosis part includes a low centration area which is connected to the fresh water supply part and a high centration area which is connected to the salty water supply part along the semipermeable membrane boundary. The pressure exchange part comprises at least two cylinders(51,52) which includes an inlet port and an outlet port; pistons(58,59) which are installed at the inner part of the cylinders; and a piston rod(57) which connects to the pistons. The salty water in the high centration area which is delivered by the generated pressure at the osmosis part flows into one of the cylinders of the pressure exchange part, reciprocates the piston rod, and recovers the generated pressure at the osmosis part.

Description

Power generation system using salinity difference energy between brine and freshwater {POWER GENERATION SYSTEM USING SALINITY GRADIENT OF SALT WATER AND FRESH WATER}

The present invention relates to a power generation system using the salinity difference energy between salt water and fresh water, and more specifically, unlike the prior art, the high pressure salt water flow by osmotic pressure using a pressure exchange device with two pistons interlocked, It is possible to recover the salinity difference energy between brine and freshwater, which not only recovers and reuses, but also generates power by using mechanical energy of the piston reciprocating motion, which significantly improves energy recovery efficiency in the high pressure and low flow rate delay osmosis system. It relates to a power generation system used.

Due to the recent industrialization, fossil energy has been used indiscriminately. As a result, the concentration of greenhouse gases is gradually increased while the amount of fossil fuel is gradually reduced. In particular, increasing the concentration of greenhouse gases caused rises in temperature and sea level, resulting in abnormal climate events.

Therefore, the efficient use and saving of energy have some effects as the primary measures, but the energy combustion part, which accounts for 84% of the greenhouse gas emissions, must be reduced, which is a sustainable and carbon-free future energy source. It is time for research and development and commercialization of new energy.

At present, the renewable energy that is in the spotlight includes energy using solar light, wind power, and hydropower (hydropower), and the direction of development of renewable energy is concentrated on them. Such major renewable energy has problems such as high initial investment cost, output instability, and ecosystem disturbance.

On the other hand, the generation method of recovering the salinity difference between seawater and freshwater as energy, in addition to the advantages of renewable energy, can secure a stable output without disturbing the ecosystem, and utilizes the sea area in connection with the estuary weir and embankment. There is an advantage that can reduce the initial installation cost, the recent research has been conducted mainly in Europe.

This energy recovery technique using the difference in seawater and freshwater concentrations can be roughly classified into pressure delayed osmosis and reverse electrodialysis, first proposed by Professor Sidney Loeb of Israel in 1975. Each study is underway at the Sustainable Hydro Technology Center (Wetsus).

From this, energy recovery techniques using various concentrations of seawater and freshwater have been studied. However, each technology has a large number of complex devices, which are economically inefficient, or require additional energy to supply hydraulic pressure. There was a low problem.

In particular, pressure delay osmosis is a method of recovering the osmotic pressure by energy due to the difference in concentration between seawater and freshwater. In current pressure delay osmosis system in which seawater and freshwater are injected, diluted brine is released at high pressure and used to operate a turbine. do.

In this pressure delay osmosis power generation system, a turbine is operated by using high pressure brine discharged, which is high pressure but small due to the mechanical characteristics of the hydro turbine, which is advantageous to a flow having a large flow rate rather than a high pressure flow. There is a disadvantage in recovering energy for application to pressure delayed osmosis systems in which flow rates are released.

Therefore, there has been a demand for the development of a technology that can increase the energy recovery efficiency while significantly reducing the construction cost by simplifying the energy recovery system.

The present invention is to solve the above problems, unlike the conventional system for generating power by simply turning the turbine to osmotic pressure, using a pressure exchange device with two pistons linked to the high-pressure salt water flow by osmotic pressure, Not only can pressure be recovered and reused for system operation, but also power is generated using the mechanical energy of the piston reciprocating motion of the pressure exchanger, which significantly improves energy recovery efficiency in high pressure and low flow rate delay osmosis systems. It is an object of the present invention to provide a power generation system using salinity difference energy between salt water and fresh water.

In addition, by integrating a pressure recovery device and a power generating device, to simplify the process and to significantly reduce the cost required to build a system, to provide a power generation system using the salt water-salinity energy between the brine-fresh water, which has improved economic efficiency. do.

It is also an object of the present invention to provide a power generation system using salinity-fresh water between salt water and fresh water that can be continuously operated without manual operation by using a pressure exchange device using two cylinders and an automatic valve.

In addition, by optimizing its configuration, such as arranging various valves between the osmotic pressure generating unit and the pressure exchange device due to the salinity difference, it is an object to provide a power generation system using the salinity difference energy between salt water and fresh water that can maximize energy efficiency. It is done.

In order to achieve the above object, a power generation system using the salinity difference energy between salt water and freshwater, according to the present invention, a power generation system using the salinity difference energy between salt water and fresh water, the fresh water supply unit for supplying the fresh water; A brine supply unit for supplying the brine; An osmosis unit having a low concentration region connected to the fresh water supply unit and a high concentration region connected to the salt water supply unit, at the boundary of the semipermeable membrane; And a pressure exchange unit having at least two cylinders having an outlet port, a piston located inside each of the at least two cylinders, and a piston rod connecting the pistons. The salt water in the high concentration region is introduced into any one of the cylinders of the pressure exchange unit, thereby reciprocating the piston rod to recover the pressure generated in the osmosis unit.

And a power generating unit connected to the piston rod to recover the reciprocating kinetic energy of the piston rod to generate power.

Further, in the pressure exchange unit, the inside of the cylinder is divided into a first region in which the piston rod is located, and a second region in which the piston rod is located, and is connected to the cylinder and the brine supply unit, wherein the brine Salt water inlet valve for supplying the first area; Or a non-return valve connected to the cylinder to prevent a reverse flow of the brine discharged from the first region; It further comprises at least one of.

The pressure exchange unit is characterized in that composed of a plurality, the brine supply unit, the starting pump for increasing the supply pressure of the brine; characterized in that it further comprises.

In the osmotic part, the fresh water in the low concentration region moves to the high concentration region due to the difference in concentration, so that the pressure in the high concentration region increases, and each of the cylinders of the osmosis unit and the pressure exchange unit is connected to a pipe. There is an automatic valve for each pipe connected to each of the cylinders, and in the pressure exchange unit, when the salt water in the second region is discharged due to the reciprocating motion of the piston rod, the automatic valve is operated. It characterized in that it is adjusted to introduce the brine of the high concentration region into the discharged empty second region.

Further, in the pressure exchange unit, due to the reciprocating motion of the piston rod, the salt water discharged by being discharged from the first region is introduced into the high concentration region of the osmosis portion, in the low concentration region of the osmosis portion, the fresh water Characterized in that it further comprises; a discharge valve for controlling the discharge of the.

According to the power generation system using the salinity difference energy between the salt water and the fresh water of the present invention, unlike the system for generating power by simply turning the turbine by osmotic pressure, two pistons are linked to the high pressure salt water flow due to the osmotic pressure. The pressure exchanger is used to recover the pressure and reuse it for system operation, as well as to generate power using the mechanical energy of the piston reciprocating motion of the pressure exchanger. There is an advantage that can significantly improve the energy recovery efficiency.

In addition, by integrating the pressure recovery device and the power generating device, there is an advantage that the economy can be improved by simplifying the process and significantly reducing the cost required to build the system.

In addition, by using a two-cylinder pressure exchange device and an automatic valve, it can be operated continuously without manual operation, and its configuration is optimized by arranging various valves between the osmotic pressure generation unit and the pressure exchange device due to salinity difference. By doing so, there is an advantage that can maximize the energy efficiency.

1 is a schematic diagram illustrating an embodiment of a power generation system using the salinity difference energy between salt water and fresh water according to the present invention.
Figure 2 is a simulation of the operation of the pressure exchange unit in the power generation system using the salinity difference energy between salt water and fresh water according to the present invention
Figure 3 is a simulation of the operation of the pressure exchange unit in the power generation system using the salinity difference energy between the salt water and fresh water according to the present invention

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings for a power generation system using the salinity difference energy between saline and fresh water according to the present invention. The present invention may be better understood by the following examples, which are for the purpose of illustrating the present invention and are not intended to limit the scope of protection defined by the appended claims.

One embodiment of the power generation system using the salinity difference energy between the salt water-fresh water of the present invention, as shown in Figure 1, the osmosis unit 10, the salt water supply unit 20, fresh water supply unit 30, pressure exchange unit ( 50) and the power generating unit 70 is characterized in that it comprises.

First, the osmosis unit 10 has a low concentration region 13 connected to the fresh water supply unit 30 and a high concentration region 12 connected to the salt water supply unit 20, bordering the semi-permeable membrane 11. This is a configuration for generating an osmotic pressure due to the salinity difference between fresh water and saline. As shown in FIG. 1, the chamber called the osmosis part 10 is divided into two regions due to the semipermeable membrane 11, and among these regions, The region connected to the fresh water supply unit 30, the fresh water supply region is connected to the low concentration region 13 and the brine supply unit 20, and the region to which the salt water is supplied is defined as the high concentration region 12.

In the osmosis part 10, the fresh water in the low concentration region 13 moves to the high concentration region 12 due to the difference in concentration, thereby increasing the pressure in the high concentration region 12.

In addition, it is preferable to further include a discharge valve 33 for controlling the fresh water discharged from the low concentration region 13 of the osmosis portion (10). It is located in the low concentration region 13 outlet of the osmosis section 10, by controlling the fresh water discharge amount of the low concentration region 13, thereby serves to optimally adjust the salinity concentrated in the low concentration region (13).

Next, the brine supply unit 20 is a configuration for supplying the brine, basically serves to supply the brine at normal pressure (normal pressure). Here, the brine may be any water containing salt, but it is more preferable to use sea water.

The brine supply unit 20 preferably further includes a starting pump 21 for increasing the supply pressure of the brine. This is for the initial operation of the power generation system using the salinity difference energy between the brine-fresh water of the present invention, in order to operate the system, inevitably, the starting pump 21 between the brine supply unit 20 and the osmosis unit 10 In order to increase the supply pressure of the brine.

After the operation using the start pump 21 in this way, through the pressure exchange unit 50, the pressure increased in the osmosis unit 10 is recovered and reused for the supply of the brine, the start pump 21 only at the time of pressure reduction It will only serve as a subsidiary of.

Therefore, unlike the prior art, the operation time of the start pump 21 is significantly reduced, there is an advantage that can reduce the energy consumption by that much.

In addition, the fresh water supply unit 30 is a configuration for supplying fresh water, basically serves to supply the brine at normal pressure (normal pressure). Here, fresh water means water without salt.

Next, the pressure exchange unit 50 includes at least two cylinders 51 and 52 having an outlet port, pistons 58 and 59 and pistons positioned inside the at least two cylinders 51 and 52, respectively. It means a configuration having a piston rod 57 connecting the 58, 59. This is one of the core configuration of the present invention, by recovering the pressure generated in the osmosis portion 10, serves to increase the energy efficiency.

As shown in FIG. 1, at least two cylinders 51 and 52 exist, and these cylinders 51 and 52 have ports through which fluids, such as fresh water and brine, can flow in or out. By operating two pairs of cylinders 51 and 52 in pairs, the pressure exchange unit 50 can be operated continuously.

In addition, the piston rod 57 is rod-shaped, is connected to both cylinders, characterized in that both ends are located in the two cylinders (51, 52), respectively. By the reciprocating motion of the piston rod 57, it is possible to generate power, and to enable repeated operation between the two cylinders.

In addition, the pistons 58 and 59 are located at both ends of the piston rod 57, and are configured in a disk shape or a cylindrical shape depending on the shape of the cylinder. It serves to divide the space inside each cylinder (51, 52) into two spaces.

In the pressure exchange unit 50, the interior of the cylinders 51 and 52 are bounded by the pistons 58 and 59, and the first regions 55 and 56 in which the piston rods 57 are located, and the others. It is divided into second regions 53 and 54. That is, the inside of the cylinders 51 and 52 is separated into two areas on the pistons 58 and 59 as a boundary.

The pressure exchange unit 50 is a piston in the osmosis unit 10, the brine in the high concentration region 12 of the high pressure flows into any one of the two cylinders (51, 52) of the pressure exchange unit 50, It causes the reciprocation of the rod 57, and serves to recover the pressure generated in the osmosis portion (10).

In addition, the pressure exchange unit 50 is connected to the cylinders 51 and 52 and the salt water supply unit 20 to supply salt water to the first zones 55 and 56, or a salt water inlet valve 40 or 41 or a cylinder ( 51, 52, and preferably further includes at least one of the non-return valve 42, 43 to prevent the back flow of the brine discharged from the first region (55, 56).

The salt water inflow valves 40 and 41 serve to supply insufficient salt water by discharging the salt water from the first regions 55 and 56 according to the reciprocating motion of the piston rod 57.

In addition, the non-return valves 42 and 43 may flow back into the osmosis unit 10 at a high pressure due to the brine discharged from the first regions 55 and 56 according to the reciprocating motion of the piston rod 57. Prevents the flow of water.

That is, in the pressure exchange unit 50, the brine pressurized and discharged from the first regions 55 and 56 due to the reciprocating motion of the piston rod 57 flows into the high concentration region of the osmosis unit 10. It is desirable to be. By reusing part of the pressure generated in the osmosis unit 10, it is possible to reduce the use of the pump to increase the brine supply pressure in the brine supply unit 20, there is an effect to maximize the energy efficiency.

The pressure exchange unit 50 is a set of two cylinders 51 and 52, a piston rod 57 and a piston 58 and 59, and the pressure exchange unit 50 is composed of a plurality. It is effective for treating large volumes of brine and for efficient energy recovery.

In addition, the cylinders 51 and 52 and the osmosis unit 10 of the pressure exchange unit 50 are connected by pipes, respectively, and there are automatic valves 62 and 63 for each pipe connected to the cylinders 51 and 52. It is desirable to.

Here, the automatic valves 62 and 63 are discharged from the pressure exchange unit 50 when the brine in the second regions 53 and 54 is discharged due to the reciprocating motion of the piston rod 57. It serves to control the brine in the high concentration region into the two regions (53, 54). Due to such automatic valves 62 and 63, the pressure exchange unit 50 is operated continuously by the interaction between the two cylinders.

In addition, the connecting valve 24 is composed of four ports, and serves to control the fluid supply in two directions.

Next, look at an example of the operation of the pressure exchange unit 50, as shown in FIG.

As the brine in the high concentration region 12 transmitted from the osmosis part 10 flows into the cylinder 51, and by the inflow of the brine, the second region 53 increases and the first region 55 decreases. The piston rod 57 is moved in the direction of the other cylinder (52). Due to the movement of the piston rod 57, the second region 54 of the other cylinder 52 is reduced, the first region 56 is increased, so that the automatic valve 63 is operated, the osmosis portion 10 The brine in the high concentration region 12 of the will enter the second region 54 of the other cylinder (52).

Therefore, as the second region 54 of the other cylinder 52 is expanded, the piston rod 57 is moved toward the cylinder 51 again. This automatic system causes reciprocation.

In addition, in this process, while the first region 55 of the cylinder 51 is reduced, the brine in the first region 55 is discharged toward the non-return valve 42, to supplement the brine inlet valve 40 ) Is operated so that the brine supplied from the brine supply unit 20 flows into the first region 55.

As described in the example of the operation of the pressure exchange unit 50, the power generation system using the salinity difference energy between the brine-fresh water of the present invention, through the organic coupling and operation between the components, maximize the energy efficiency, automatic There is an advantage to driving.

Finally, the pressure exchange unit 50, further comprising a power generating unit 70 is connected to the piston rod 57, to recover the reciprocating kinetic energy of the piston rod 57, to generate power desirable. The pressure is recovered by the reciprocating motion of the piston rod in the pressure exchange unit 50, and the pressure is recovered and reused in the salt water input to the osmosis part 10, as well as generating energy by using the mechanical energy of the reciprocating motion. Make the most of it.

That is, the power generating unit 70 may be installed any device that can generate power by using the reciprocating kinetic energy.

In the above, the configuration of the present invention was described in detail with reference to one embodiment. However, the scope of the present invention is not limited to the above embodiment, and may be embodied in various forms of embodiments within the appended claims. Without departing from the gist of the invention as claimed in the claims, it is intended that such modifications can be made by anyone of ordinary skill in the art to be within the scope of the claims.

10: osmosis 11: semipermeable membrane
12: high concentration area 13: low concentration area
20: salt water supply unit 21: starting pump
22, 23: piping 24: connecting valve
25: piping 30: fresh water supply
31: pipe 32: discharge valve
33, 34: pipe 40, 41: salt water inlet valve
42, 43: non-return valve 44, 45, 46: piping
50: pressure exchange part 51, 52: cylinder
53,54: second area 55,56: first area
57: piston rod 58, 59: piston
61, 64, 65, 66, 67: piping 62, 63: automatic valve
70: power generating unit

Claims (9)

In a power generation system using salinity difference energy between salt water and fresh water,
Fresh water supply unit for supplying the fresh water;
A brine supply unit for supplying the brine;
An osmosis unit having a low concentration region connected to the fresh water supply unit and a high concentration region connected to the salt water supply unit, at the boundary of the semipermeable membrane; And
And a pressure exchange unit having at least two cylinders having an outlet port, a piston located inside each of the at least two cylinders, and a piston rod connecting the pistons.
The brine in the high concentration region delivered to the pressure generated in the osmosis section flows into any one of the cylinder of the pressure exchange section, thereby reciprocating the piston rod to recover the pressure generated in the osmosis section- Power generation system using salinity difference energy between freshwater
The method of claim 1,
In the pressure exchange unit, the power generation unit is connected to the piston rod, recovering the reciprocating kinetic energy of the piston rod, generating a power; Generation system 3. The method according to claim 1 or 2,
In the pressure exchange unit, the inside of the cylinder is divided into a first region in which the piston rod is located and another second region on the piston boundary,
A salt water inlet valve connected to the cylinder and the salt water supply unit and supplying the salt water to the first region; or
A backflow check valve connected to the cylinder and preventing a backflow of the brine discharged from the first region; Power generation system using the salinity difference energy between brine and freshwater, characterized in that it further comprises at least one of
3. The method according to claim 1 or 2,
The power generation system using the salinity difference energy between salt water and fresh water, characterized in that the pressure exchange unit is composed of a plurality.
3. The method according to claim 1 or 2,
The brine supply unit, the start-up pump for increasing the supply pressure of the brine; Power generation system using the brine-fresh water salinity difference characterized in that it further comprises
3. The method according to claim 1 or 2,
In the osmosis part, the fresh water in the low concentration region is moved to the high concentration region due to the difference in concentration, so that the pressure in the high concentration region is increased, the power generation system using the salinity difference energy between salt water-fresh water
The method of claim 3, wherein
Each of the cylinders of the osmosis unit and the pressure exchange unit is connected to the pipe, there is an automatic valve for each pipe connected to each cylinder,
In the pressure exchange unit, when the brine in the second region is discharged due to the reciprocating motion of the piston rod, the automatic valve is controlled so that the brine in the high concentration region flows into the empty second region. Power generation system using salinity difference energy between salt water and fresh water, characterized in that
The method of claim 3, wherein
In the pressure exchange unit, due to the reciprocating motion of the piston rod, the brine pressurized and discharged in the first region is introduced into the high concentration region of the osmosis portion, characterized in that the power generation system using the salinity difference energy between salt water-fresh water.
3. The method according to claim 1 or 2,
In the low concentration region of the osmosis portion, the discharge valve for controlling the discharge of the fresh water; Power generation system using the salinity difference energy between saltwater and freshwater, characterized in that it further comprises.

Images