JP6656515B2 - Power generation method using osmotic heat cycle - Google Patents

Description

The present invention relates to a Rankine cycle heat cycle for converting thermal energy into mechanical work, sustained, thereby stably generating power by utilizing the density difference of the solute in the semipermeable membrane and the working medium " Power generation method using osmotic heat cycle "(hereinafter referred to as" osmotic heat cycle ").

As prior art, there are JP-A-57-73810 and JP-A-57-73811 (the inventor is the same as one of the present inventors). The literature that uses a semi-permeable membrane for the main system of a Rankine cycle type heat cycle in which the working medium changes its phase to the gas phase and the liquid phase and the gas phase working medium expands with an expander to generate power is overseas. And no other cases. On the other hand, research on power recovery by hydro turbines using the difference in salinity between the surface layer and the bottom layer of the sea, river, and salt lake has been actively conducted since the late 1980s, and many publications such as the operation results of test plants have been made. .

Published Patent Application Sho 57-73810 Published Patent Publication No. 57-73811 U.S. Pat. No. 3,906,250 US Patent 4,193,267 Table 2010-509540 Patent No. 5160552 Patent No. 5295952 JP 2009-47012 A JP-A-2015-161280

Akihiko Tanioka, Osmotic Power Generation, Journal of the Japan Society of Sea Water (1), 4-7 Haruo Uehara, Ocean Thermal Energy Conversion, Applied Physics, 63, 8

The present invention is geothermal, ocean surface water, absorbs heat from the high heat source such as general waste heat, air, comprising relates thermocycling you mechanical work by discarding heat to a low heat source such as deep sea water The working medium that flows continuously changes into a liquid phase, a gas phase, and a liquid phase cyclically, and the working medium in the liquid phase process changes the solute concentration, thereby causing the working medium to penetrate the semipermeable membrane. The present invention relates to an osmotic heat cycle in which the flux is maintained and the working medium in the gas phase process can perform continuous mechanical work.

For geothermal power generation, a production well with a depth of 350 m or more is excavated to a high heat source called a hot water reservoir, and the jetted hot water is flashed by a steam-water separator to separate it into steam and hot water. In general, hot water is excavated in a location away from production wells, and hot water is returned deep underground or returned to rivers using return wells. Of course, there is also an example in which only steam is spouted and the steam turbine is turned by this. Various efforts have been made up to the use and treatment of hot water and steam extracted from the ground, but it cannot be denied that extracting hot water or steam will change the state of the ground, and the hot water reservoir It is not easy to completely explain the impact on the water level, earthquakes, and landslides. If hot water is cooled and then flowed into a river, it must be explained that the components contained in the hot water do not affect the natural environment and ecosystems in the long term. It has also been reported that the cost of drilling two wells accounts for 24% of the total cost.

Ocean temperature difference power generation performs Rankine cycle power generation using a temperature difference of about 20 ° C. between surface water and deep water, and is a relatively stable energy source if realized. However, the collection of seawater, especially the pumping of deep water (cold heat source), requires enormous power. It is clear that it can be as high as 30 to 50%. In addition, pumping a large amount of seawater, not only deep water and surface water, and flowing it to another location may itself have a significant impact on the environment.

According to a first aspect of the present invention, there is provided a semi-permeable membrane, a condensing working medium on one side of the semi-permeable membrane, and a solvent on the other side of the semi-permeable membrane, which is made of the same substance as the condensing working medium. And a concentrated liquid comprising a solute and a step in which the condensed working medium is drawn into the concentrated liquid on the other side of the semipermeable membrane by osmotic pressure, and an operation in which the concentrated liquid receives heat and is thermally vaporized. A step of separating the concentrated liquid into a medium and a highly concentrated liquid, a step of returning the concentrated liquid to a surface near the other surface of the semipermeable membrane, and a step of generating power by the vaporized working medium flowing into an expander. And an osmotic heat cycle characterized in that the working medium that has exited the expander radiates heat to become a condensing working medium and merges with the condensing working medium on one side of the semipermeable membrane. is there. Here, the high-concentration liquid is refluxed to the other side of the semipermeable membrane, that is, in the vicinity of the surface on the concentrated liquid side, because the condensed working medium containing no solute leaches into the concentrated liquid side, and the surface on the concentrated liquid side This is to prevent the osmotic pressure from decreasing due to the dilution of the solute concentration in the vicinity. Here, it is preferable that the solute is substantially non-volatile within a use temperature range.

A second invention of the present invention is an osmotic pressure heat cycle, wherein each of the above-described steps is performed in a closed closed path. Partial release outside the system poses the risk of unexpected chemical contamination into the system. With the passage of time, concentration polarization occurs on the surface on the one side of the semipermeable membrane, and both the osmotic pressure and the osmotic flux decrease. If all processes are performed in a closed route, management is easy, and if a problem occurs, its cause can be easily identified. In particular, when the osmotic heat cycle according to the present invention is used as a power plant, stable power generation and transmission are very important. However, the first invention of the present invention functions as an osmotic heat cycle according to the present invention even if not all steps are performed in a closed path. For example from the turbine of the intermediate stage by extracting steam, and the like for use in food processing. However, for this purpose, it is necessary to always introduce the water of the steam from the outside.

A third invention of the present invention is the osmotic heat cycle, wherein the closed path extends to the high heat source. This means that an osmotic heat cycle is realized by moving only heat without moving a heated "thing". Taking geothermal power generation as an example, conventional methods of extracting hot water and steam from underground hot water reservoirs lead to the release of various substances that are unfavorable to ecosystems along with heat, as well as existing hot springs and ground. A wide variety of problems will arise, including the impact on the environment. Here, if only the heat can be moved, such a concern is almost eliminated, and it is considered that the stagnant use of geothermal energy starts to progress at a stretch.

According to a fourth aspect of the present invention, there is provided an osmotic pressure cycle, wherein the closed path extends to a low heat source. This means the same as in the third invention. This means that only the heat is moved without moving the heated "thing". The heat in this case is cold, in other words, minus heat. Taking the ocean temperature difference power generation as an example, a conventional method is to extract low-temperature deep water from the sea at a depth of several hundred meters. The method is to pump up the tuna pups and the abalone eggs together with the cold heat. Creatures do not survive when caught in a high-pressure pump. Sea currents can also be disturbed. This would not happen if only cold heat was transferred.

According to a fifth aspect of the present invention, a concentrated liquid circulating system is provided on the other side of the semipermeable membrane, which generates a flow along the surface of the semipermeable membrane and promotes a step of being drawn by osmotic pressure. An osmotic heat cycle characterized in that: The reason for generating and promoting the flow along the surface is to prevent the concentration of the solute molecules and ions from being reduced on the concentrated liquid side surface due to the seepage of the condensing working medium on the concentrated liquid side of the semipermeable membrane. It is. In other words, concentration polarization is not caused. In order to prevent concentration polarization on the concentrated liquid side, it is important that the supply of the solute is not interrupted, the leached solvent is not retained, and the flow is not biased on the surface of the semipermeable membrane. The fifth invention aims at preventing the leached solvent from staying therein. In addition to the reflux of the highly concentrated liquid to the vicinity of the concentrated liquid side surface of the semipermeable membrane according to the first invention, the second internal liquid A circulation line is provided to support the first invention to provide a more preferable osmotic heat cycle.

The osmotic heat cycle according to the present invention,
1) When used for geothermal power generation, only high-temperature heat can be carried to the ground by heat transport pipes.
(1) It does not affect the water level of the underground hydrothermal reservoir. Therefore, there is no effect on existing hot springs and no effect on the ground.
(2) Chemical substances that have leaked to the ground along with hot water and steam will not be emitted, and will have little effect on the natural environment.
2) If used for ocean thermal energy conversion,
(1) The pump power for pumping deep water and surface water and for driving the working medium in the main system can be replaced with heat for maintaining the concentration of the concentrated solution. All of these pumps are not required, and the net output is the value obtained by multiplying the turbine shaft output by the generator efficiency.
(2) Since there is no pumping of deep water and surface water, there is no fear of adversely affecting the ecology of valuable marine life.

FIG. 1 is a schematic configuration diagram of a first example of an osmotic heat cycle according to an embodiment of the present invention applied to geothermal power generation. FIG. 2 is a partially enlarged view around the semipermeable membrane of FIG. FIG. 3 is a schematic diagram showing a temperature-entropy diagram (TS diagram) showing a state change of a working medium when the osmotic heat cycle of the embodiment of the present invention is applied to geothermal power generation. FIG. 4 is a schematic diagram showing a second embodiment of the osmotic heat cycle according to the embodiment of the present invention, which is applied to ocean thermal energy conversion. FIG. 5 is a partially enlarged view around the semipermeable membrane of FIG. FIG. 6 is a partially enlarged view around the second internal circulation line in FIG. FIG. 7 shows a third embodiment of the osmotic pressure heat cycle according to the embodiment of the present invention, in which heat transport pipes are horizontally arranged. FIG. 8 is a plan view showing an osmotic heat cycle according to an embodiment of the present invention, in which the heat transport pipe is not a double pipe but a bent pipe in the third embodiment .

First Embodiment A first embodiment of the present invention will be described with reference to FIGS. Note that the figure is a schematic diagram for explaining the method of the present invention, and is not a detailed design drawing.
Reference numeral 50 denotes a working medium continuously flowing in the closed path, which changes its state into a gas phase (vaporized working medium 50S) and a liquid phase (50L) in accordance with the section in the closed path of the osmotic pressure heat cycle. The vaporized working medium 50S in the state performs mechanical work to the outside via the turbine 3 which is an expander ( state change from (1) to (2) in FIG. 3), and releases heat to the atmosphere in the condenser 232, The condensed liquid becomes condensed liquid, that is, the condensed working medium 50Lp ( the state change from (2) to (3) in FIG. 3).

When the working medium is in the liquid phase, the concentration of the working medium changes to 50 Lp (condensed working medium), 50 Lm (concentrated liquid, solution containing solute), and 50 Lc (highly concentrated liquid). In this embodiment, the solvent is water and the solute is sodium chloride. The concentration of the condensed working medium 50Lp is 0%, the concentration of the concentrated liquid 50Lm is 8.3%, and the concentration of the highly concentrated liquid 50Lc is 21%. The highly concentrated liquid 50Lc is completely mixed with the condensed working medium 50Lp, which is a permeate flow, on the other side of the semipermeable membrane, that is, on the concentrated liquid side surface, to form a concentrated liquid 50Lm. Therefore, the concentration of the solution sucked downstream of the semipermeable membrane 1 and flowing through the second internal circulation line also becomes 50 Lm. The concentrated liquid 50Lm passes through the heat transport pipe 2, moves to the deepest part while increasing the head pressure, and ingests heat in the heat receiving zone (heater of the osmotic heat cycle according to the present invention) immersed in the geothermal reservoir. Some boiling begins. After moving to the ground while lowering the head pressure, gas-liquid separation was performed by the gas-liquid separator, and the steam flowed into the turbine 3, which was an expander, and the highly concentrated liquid, whose concentration increased from 8.3% to 21%, was vaporized. The liquid is returned to the other side of the semipermeable membrane chamber, that is, near the surface on the concentrated liquid side, via the liquid separation tank.
Here, the reason why the concentration is set to 21% is that the sodium chloride solution starts to precipitate when the solute concentration becomes 28%, so that the concentration is suppressed to 21% with a margin. The 8.3% sodium chloride solution has a solute concentration of 8.3 / (1-0.6) = 20.75 % when vapor having a dryness of 0.6 is subjected to gas-liquid separation. is there.
The degree of dryness is determined by the amount of heat input from the high heat source, and is determined by the depth of the heat receiving zone 231 in FIG. At the time of plant planning, the heat source is investigated in advance, the temperature and convection in the hot water reservoir are grasped, and data necessary for heat transfer calculation is collected, and then the depth of the 231 is determined. In this case, it is preferable that the heat transport pipe be moved up and down to adjust the depth of the heat receiving zone with a jack or the like. More preferably, the gap between the heat transport pipe and the ground is filled with a heat-resistant sealing material.

The role of the working medium in the liquid phase changes according to the location and concentration as follows.
1) Drive of working medium (location: semipermeable membrane 1, semipermeable membrane chamber 233)
The combination of the semi-permeable membrane, the 0% condensed working medium and the 8.3% concentrated liquid creates an osmotic pressure and creates a flux where the condensing working medium is drawn to the concentrated side. Here, driving means pressurizing and flowing the working medium.
2) Maintaining the density difference, which is the source of the driving force (see FIGS. 1 and 2)
(1) Replenish the highly concentrated liquid to the concentrated liquid side surface of the semipermeable membrane: 50 Lm of the working fluid, which is a concentrated liquid, receives heat in a heater (also referred to as a heat receiving zone) 231, and vapor 50 S in the gas-liquid separator 5. Then, the concentrated liquid, that is, the concentrated liquid 50Lc is separated, and the concentrated liquid 50Lc is returned to the concentrated liquid side surface of the semipermeable membrane 1 through the return pipe 6. The leaching (permeation flow) of 50 Lp of the condensed working medium from the semipermeable membrane is mixed with the concentrated liquid surface to prevent dilution of the concentrated liquid surface, that is, concentration polarization.
(2) The permeate flow of the solvent having a concentration of 0% is caused to flow off from the concentrated liquid side surface of the semipermeable membrane by increasing the circulating flow rate by the second circulation line: the concentrated liquid side of the semipermeable membrane is pumped by the pump 7a of the circulation line 7. The flow rate and flow rate of the concentrated solution along the surface are increased, and the solvent that tends to stagnate on the semipermeable membrane surface is flowed away by the concentrated solution and mixed.
Hereinafter, with reference to FIGS. 1, 2 and 3, the description will be given step by step along the flow of the working medium 50 starting from the semipermeable membrane 1.

1 is a semipermeable membrane, 233 is a semipermeable membrane chamber, 233a is an inlet pool, and 233b is an outlet pool. In the inlet reservoir 233a and the outlet reservoir 233b, once the velocity of the solution is reduced, the flow is rectified, and the flow along the concentrated liquid side surface of the semipermeable membrane is made uniform. The condensed working medium 50Lp having a concentration of 0% on one side of the semipermeable membrane passes through the semipermeable membrane and flows into the other side, that is, the concentrated liquid side at a flow rate Gt (in FIG. 3, the semipermeable membrane is (3 ) , Which is essentially one point).

  The internal circulation return pipe 6 and the second internal circulation line 7 are attached to the semipermeable membrane chamber 233 as described above, and in the present embodiment, the second internal circulation line 7 is connected to the enlarged diameter portion 6 b of the internal circulation return pipe 6. Is provided. The purpose of matching the direction of the internal circulation return flow with the direction of the blowout flow from the nozzle 7c is intended for the ejector effect. The flow rate of the internal circulation return flow is Gc. On the other hand, the second internal circulation flow is sucked at the flow rate Gf from the outlet pool of the semipermeable membrane chamber by the nozzle 7b. Although the nozzle 7b is used for the purpose of a schematic description, it is preferable that a scoop be provided inside the inner tube 22 so that the concentrated liquid is sucked while minimizing the pressure loss of the main flow flowing out of the semipermeable membrane chamber. 7a is preferable because the power is small. Since the concentration on the concentrated liquid side is maintained on the surface on the concentrated liquid side of the semipermeable membrane as described above, the concentration of the concentrated liquid sucked from the outlet reservoir 233b is 50 Lm. With this configuration, concentration polarization on the concentrated liquid side surface of the semipermeable membrane is prevented, the osmotic pressure is stabilized, and the flux of the osmotic flow does not change, so that the circulating flow rate of the working fluid 50 (the working medium flow rate in the turbine) ) Gt is also stably maintained. As described above, pressure change, mixing, concentration change, and temperature change are performed in the semipermeable membrane chamber, and it cannot be said that it is very isentropic change unlike the boiler feed pump of the Rankine cycle. Practically only one point. Changes in concentration and flow rate are as shown in FIG.

The concentrated liquid 50Lm descends through the inner passage 22a of the inner tube 22 of the heat transport tube 2 and is jetted from the tapered nozzle 221 to the double tube passage 23a at the lower end. A heat insulating lining is provided on the outside of the inner tube 22 as necessary. The reason why the nozzle 221 is tapered is to prevent the generated bubbles from flowing into the inner tube 22 in order to prevent boiling in the inner space 231a at the lower end of the outer tube under a high load. As a countermeasure against air bubbles flowing into the inner tube 22, it is also preferable to take measures such as bending the tip of the inner tube or providing a baffle plate. The state change of the working medium up to this point after passing through the semipermeable membrane is represented by (3) → (4) in FIG. 3 in consideration of an increase in the head pressure and some heat reception in the inner tube 22a of the heat transport pipe. Is done.

A range of 50 m above the inner space 231a at the lower end of the outer tube of the double tube passage 23a of the heat transport tube is a heater and is a heat receiving zone. The immersion depth 231 of the heat transport pipe 2 in the hot water storage layer HW is set to 50 m in this embodiment. In this embodiment, the immersion depth is set to 50 m as an example for convenience of description, but this depth is actually determined by heat transfer calculation between the outside (heat source HW) and the heat transport pipe 23 and is fixed at 50 m. is not. Further, in the present embodiment, the depth of the lower end inner space 231a is 364 m from the semipermeable membrane 1, but the present invention is not limited to this.

The heated concentrated liquid 50Lm has already partially entered the evaporation zone when passing through the heat receiving zone. If the state change in the heat receiving zone is described with reference to FIG. 3, it is considered that (4) → Q → (5) at the time of cold start, and close to (4) → P → (6) in the steady state. This is because during the steady operation, a multiphase flow develops in the double pipe passage 23a, and the influence of the head pressure is almost eliminated. However, since the pressure loss increases due to the increase in the amount of steam, the point P approaches the point Q, and it is considered that the change of P → (6) may not be parallel to the S axis as shown in FIG.

The working medium 50 exits from the heat receiving zone 231, and the head pressure decreases in the process of ascending, and a multiphase flow composed of a liquid phase and a gaseous phase develops. That is, the concentration of the concentrated liquid gradually increases, and the amount of separated steam also increases. When reaching the connection pipe 25 from the upper end of the outer pipe of the heat transport pipe, the inside of the pipe is dominated by steam in volume. State change of the working medium 50 in the process follows a path between the isenthalpic change and adiabatic change is expressed by (5) → (6). It is considered that an adiabatic change is approached when the rate at which the liquid phase changes to the gas phase increases.

The working medium 50 becomes a multi-phase flow, enters the gas-liquid separation tank 5a, and is separated into a gas phase 50S and a liquid phase 50Lc. 50S flows into the turbine 3 after the droplets entrained in the cyclone 5b are separated. The droplets separated here flow down from the cyclone return pipe 5c to the lower part of the steam separator with a head difference. The state change inside the gas-liquid separator will be described with reference to FIG. 3 as (6) → (1) . This is a process in which wet steam having a dryness of 0.6 is removed from water to become saturated steam.

The highly concentrated liquid (concentration 21% in this embodiment) entering the gas-liquid separation tank is returned to the concentrated liquid side surface of the semipermeable membrane 1 through the internal circulation return pipe 6 as described above. Here, the present embodiment is described on the premise that a cross-linked wholly aromatic polyamide-based composite membrane which has many achievements as a reverse osmosis membrane and has excellent chemical resistance is used as a semipermeable membrane. Since this material has a maximum continuous use temperature of 45 ° C., fins are provided on the outer surface of the internal circulation return pipe 6 to radiate a highly concentrated solution of 200 ° C. to the atmosphere of 45 ° C. to 50 ° C. The osmotic pressure heat cycle according to the present invention is not limited to the use of this cooling means. The turbine is arranged in a double row, and the steam at the turbine outlet of the previous stage is subjected to gas-liquid separation using a cyclone or the like, followed by heat exchange with the concentrated solution. Then, a method of forming superheated steam and leading it to the next stage is also preferably applicable. The osmotic heat cycle of the present invention is not limited to the material, membrane structure, mounting method, etc. of the semipermeable membrane.

The steam flowing into the turbine performs expansion work to generate power, and drives the generator 4. Whether the generator is a compressor or a pump, the present invention does not limit the use of power at all. The state change of the 50S in the turbine will be described with reference to FIG. 3, and isentropy change is represented by (1) → (2) . Since entropy actually increases, the turbine shaft output is obtained by multiplying the enthalpy difference between (1) and (2) by a turbine efficiency of 0.8. The turbine efficiency is not limited to 0.8 as it depends on the turbine design.

The osmotic heat cycle according to the present invention does not limit the expander to a turbine, and does not limit the system and structure inside the expander.

The vaporized working medium 50S exiting the turbine flows into the condenser and becomes the condensed working medium 50Lp, and the cycle goes around.

With the semipermeable membrane 1 as a boundary, 50 Lp of a condensed working medium having a concentration of 0% is present on one side, and 50 Lm of a concentrated liquid is present on the other side of the semipermeable membrane 1 stably. If the heat is taken from the hot water reservoir and the working medium is steadily cooled in the condenser, this cycle will be stable and the osmotic heat cycle according to the invention will continue to generate power.

In the case of this embodiment, water is used as the working medium, and sodium chloride is used as the solute.There are various combinations depending on the application object, and the osmotic heat cycle according to the present invention is not limited to the combination of this embodiment. Absent.

Here, the osmotic heat cycle according to the present invention does not necessarily require the second circulation line. It is sufficiently possible to function only by the reflux of the highly concentrated liquid shown in the first invention.

If it is necessary to increase the recirculation amount from the case return pipe 6, because the amount of heat released from the return pipe 6 is Ru increases, it is preferable to increase the reheat of the turbine turbine using this heat as double row. Specifically, the turbine outlet steam of the previous stage is first passed through a cyclone to become saturated steam, heat exchange between the saturated steam and the highly concentrated liquid is performed, and the saturated steam is superheated to the next stage. Increase. The droplets removed by the cyclone are preferably returned to the gas-liquid separation tank 5a by head difference.

FIG. 4 shows a second embodiment of the osmotic heat cycle according to the embodiment of the present invention, which is applied to ocean thermal energy conversion. The flow of the working fluid 50, the phase change, the concentration change, the internal circulation for preventing concentration polarization and the second internal circulation, and the operation thereof are basically the same as those of the first embodiment. However, unlike the geothermal power generation, in the ocean temperature difference power generation, the location of the high heat source and the location of the low heat source are different from each other, so the configuration has been changed accordingly.

Similarly to the first embodiment, reference numeral 50 denotes a working medium that continuously circulates in the closed path, and a gas phase (vaporized working medium 50S) and a liquid phase ( 50L), the vaporized working medium 50S in a gaseous state performs mechanical work to the outside through a turbine 3 as an expander, and releases heat to the deep water 1100 in a condenser 232 to condense. The liquid, that is, the condensed working medium 50Lp. See FIG. 4, FIG. 5 and FIG.

When the working medium is in the liquid phase, the concentration of the working medium changes to 50 Lp (condensed working medium), 50 Lm (concentrated liquid, solution containing solute), and 50 Lc (highly concentrated liquid).

The differences between the configurations of the first embodiment and the second embodiment are as follows.
In the second embodiment,
1) The solvent is anhydrous ammonia, the solute is ammonium chloride, and the concentration of ammonium chloride in ammonia solution is 12.8%. Here, the present invention is not limited to this concentration when the solvent is ammonia. This solution corresponds to the concentrated liquid 50Lm of the first embodiment, and is hereinafter referred to as the concentrated liquid 50Lm as in the first embodiment. In ocean thermal energy conversion, the temperature of the high heat source is at most 34 ° C, and on average 28 ° C to 30 ° C. Ammonia having a property close to that of water is selected as the solvent as a low boiling point medium. Since the molecular weight of ammonia is 17 with respect to the molecular weight of water, it is preferable to use a seawater desalination RO membrane because the permeability coefficient becomes larger than that of water. The ammonium salt is used as the solute because it has a high solubility in ammonia and the ammonium salt in the ammonia solution shifts the pH of the ammonia solution to the acidic side. Incidentally, the pH of anhydrous ammonia is 11, which is marketable at this value, and is in a state of finally meeting the use limit of the crosslinked wholly aromatic polyamide-based composite membrane whose performance has been verified. For the same reason, ammonium acetate and ammonium nitrate can be preferably used as a solute for ammonia.
2) High heat source, i.e. a temperature of 30 ° C. of surface water, and with a margin of heat exchange in the heater setting the turbine inlet conditions to the temperature 22 ° C. in saturated steam (pressure 9.3 kg / cm ²⁾ . In the case of a combination of ammonium chloride and liquid ammonia, the solubility of ammonium chloride is very high, and it is considered that it does not precipitate in this temperature range.
3) Since the temperature of the working medium 50 is low, the internal circulation return pipe 6 is not cooled.
4) The temperature of the low-temperature source, that is, the depth water is 6 ° C., and the turbine outlet condition is 8.66 ° C. (saturated steam at a pressure of 6 kg / cm ² ).
5) Since the low heat source is in the deep sea, the heat transport pipe 2 is extended to the deep sea, and the condenser (condensing zone) 232 is arranged to be exposed to the deep sea water 1100 which is the low heat source. See FIG.
6) The heat transport pipe has a triple pipe structure, and a partition pipe 26 is provided between the outer pipe 23 and the inner pipe 22 for refluxing the highly concentrated liquid.
7) The semipermeable membrane 1 is attached to the lowermost part of the partition pipe 26 as shown in FIGS.
The outline will be described below along the flow of the working medium 50 with the semipermeable membrane 1 as a starting point.

In FIG. 5, 50 Lp of the condensed working medium (solvent having a concentration of 0%, liquid ammonia) on the one side of the semipermeable membrane penetrates the semipermeable membrane 1 and the other side, that is, the concentrated liquid side (concentration of 12. (8% ammonia solution of ammonium chloride), it is mixed with the highly concentrated solution 50Lc to form a concentrated solution 50Lm. Refluxed concentrates 50Lc and 50Lm (these do not exist separately, but in a mixed concentrated solution, the concentration is a value between 50Lc and 50Lm, specifically determined by the mixing ratio of both). In the mixing mode, as shown in FIG. 5, the direction of the permeate flow from the semipermeable membrane and the flow direction of the concentrated liquid are orthogonal, and the permeate flow is sucked into the flow of the highly concentrated liquid. It is a way of mixing like this. The highly concentrated liquid is configured to be sufficiently rectified in the semi-permeable membrane chamber inlet reservoir and enter the semi-permeable membrane.

As shown in FIG. 6, the enlarged diameter portion 6b of the internal circulation return pipe 6 in the present embodiment as in the first embodiment, blowout nozzle 7 c of the second internal circulation line 7 is attached. The purpose of matching the direction of the internal circulation return flow with the direction of the blowout flow from the nozzle 7c is intended for the ejector effect. The flow rate of the internal circulation return flow is Gc. On the other hand, the second internal circulation flow is sucked at a flow rate Gf by the nozzle 7b disposed in the inner pipe 22. The concentration of the solution from the nozzle 7b entering the second internal circulation line, so the solution is that after mixing the 50Lc and 50 lp, is 50 lm. The flow rate of the solution rising through the inner pipe passage 22a is the sum of the turbine passage flow rate Gt, the internal circulation flow rate Gc, and the second circulation flow rate Gf before the nozzle 7b . See FIG. 5 and FIG.
Although the nozzle 7b is used for the purpose of a schematic description, it is preferable to provide a scoop inside the inner pipe 22 so as to suck the concentrated liquid while minimizing the pressure loss in the inner pipe passage 22a. Can be reduced.

In FIG. 6, even when the pump 7a is stopped, that is, when the second internal circulation is not functioning, the function of returning the highly concentrated liquid to the concentrated liquid side of the semipermeable membrane shown in the first invention works. ing. In FIG. 4, this circulation path is as follows : gas-liquid separation tank → return pipe 6 → partition pipe passage 26a → concentrated liquid side of semipermeable membrane → inner pipe passage 22a → gas-liquid separation tank entrance. It is a communicating route. However, the path from the gas-liquid separation tank to the return pipe 6 to the partition pipe passage 26a is filled with the highly concentrated liquid, and the inner pipe passage 22a is filled with the concentrated liquid. For example as the same at a temperature of both 20 ° C., a comparison of specific weight ammonia solution of 20% ammonia solution and 10% ammonium chloride ammonium chloride, the latter 664kg / m ³ to the former 710 kg / m ^3. Therefore, the highly concentrated liquid having a large specific weight is constantly pushing up the concentrated liquid in the inner pipe passage 22a having a small specific weight. In other words, the highly concentrated liquid is always flowing back to the concentrated liquid side of the semipermeable membrane.

Here, let's start the pump 7a. It can be seen that the pump 7a does not have a head pressure load, and only has to bear the flow resistance of the path corresponding to the circulating flow rate increase, that is, the flow rate Gf sucked from the inner pipe passage 22a. See FIG. 6, FIG. 5, and FIG. That is, in the second circulation shown in the fifth aspect of the invention, the pump power is merely idling in the circulation path, and the consumed power is only the fluid resistance power. This power is negligible compared to the pumping of deep water and surface water to which the head pressure acts and the power of a liquid supply pump for driving a turbine.

Upon reaching the heater 231, the concentrated liquid 50 Lm starts boiling and becomes saturated by heating, and flows into the gas-liquid separation tank 5 a via the connecting pipe 25. At the concentration of the concentrated liquid, the boiling point rises by 3.4 ° C., so that the vapor enters the superheated region in calculation. However, since the velocity in the connecting pipe 25 is large, the concentrated liquid accompanies much, and the vapor-liquid state in the mixed phase state It is considered to enter the separation tank.

Gas-liquid separation is performed in the gas-liquid separation tank 5a into the gas phase 50S and the liquid phase 50Lc. The steam is strong, and the height of the gas-liquid separation tank is preferably five times or more the liquid level, more preferably the louver. Etc. are provided inside. Next, the vaporized working medium 50S is separated from the accompanying droplets in the cyclone 5b and flows into the turbine 3. The droplets separated here flow down from the cyclone return pipe 5c to the lower part of the steam separator with a head difference.

The high-concentration liquid having a concentration of 20% separated in the gas-liquid separation tank reaches the semipermeable membrane chamber 233a via the internal circulation return pipe 6, the partition pipe passage 26a of the heat transport pipe, and the concentration of the semipermeable membrane 1. The liquid is evenly distributed to the liquid-side inlet, and is returned to the concentrated liquid-side surface of the semipermeable membrane 1.

On the other hand, the vaporized working medium 50S that has flowed into the turbine performs expansion work to generate power, and drives the generator 4. The present invention does not limit the use of power at all, whether it is a compressor or a pump, not a generator.

In the osmotic heat cycle of the present invention, the expander is not limited to the turbine, and the system and structure inside the expander are not limited.

The vaporized working medium 50S exiting the turbine flows into the condenser and becomes the condensed working medium 50Lp, and the cycle goes around.

With the semipermeable membrane 1 as a boundary, 50 Lp of a condensed working medium having a concentration of 0% is present on one side and 50 Lm of a concentrated liquid is stably present on the other side of the semipermeable membrane 1, and the working medium is stably passed through a heater. If heat is taken from the surface water and the working medium is stably cooled in the condenser, this cycle will continue stably and the osmotic heat cycle according to the invention will continue to generate power.

What is important here is that it does not use for pumping deep water and surface water, and the main system pump working medium for driving. The pump power for the second internal circulation line of this embodiment is at a substantially negligible level because the head pressure is not applied as described above. Therefore, a value obtained by multiplying the turbine shaft output by the generator efficiency is the net output. The pump power for pumping deep water and surface water, and for driving the working medium in the main system has been replaced by heat input from a high heat source for maintaining the concentration of the concentrated solution. Also, since there is no pumping of deep water and surface water, there is no fear of adversely affecting the ecology of valuable marine life.

FIG. 7 shows a third embodiment of the osmotic heat cycle according to the embodiment of the present invention, in which the heat transport pipe 2 is horizontally arranged. The osmotic heat cycle of the present invention can be preferably used even when the heat transport pipe is provided in this manner. Although the conventional heat transport pipe has a double pipe or triple pipe structure, a bent pipe structure as shown in FIG. 8 can also be preferably applied. This configuration is applicable to solar thermal power generation, private cars, trucks, and the like. In the case of a private car, truck, or the like, the heat source may be an exhaust pipe or a lithium ion battery. In the case of using solar heat, a solar panel can be provided in the gap between the bent pipes.

1: semi-permeable membrane 2: heat transport tube 22: heat transport tube inner tube 22a: heat transport tube inner tube passage 221: heat transport tube inner tube taper nozzle 23: heat transport tube outer tube 23a: heat transport tube passage 231: heater (heat receiving) (Also called a zone)
231a: Heat transport pipe lower end inner space 232: Condenser 232a: Radiation fin 233: Semipermeable membrane chamber 233a: Semipermeable membrane chamber inlet pool 233b: Semipermeable membrane chamber outlet pool 25: Connecting pipe 26: Partition pipe 26a: Partition Pipe passage 3: expander 4: generator 5: gas-liquid separator 5a: gas-liquid separation tank 5b: cyclone 5c: cyclone return pipe 50: working medium 50L: working medium in liquid phase, 50Lc, 50Lm, 50Lp below There is no 50L description in the generic drawing because it is complicated.
50Lc: Highly concentrated liquid (solution in which a high concentration of solute is dissolved in the condensing working medium)
50Lm: concentrated liquid (solution in which the solute is dissolved in the condensing working medium)
50Lp: Condensed working medium (condensate, 0% concentration solution, solvent)
50S: Evaporated working medium 6: Internal circulation return pipe 6a: Air cooling fin 7: Second internal circulation line 7a: Pump 8: Fresh water line 8a: Stop valve 9: Steam relief valve 10: Dryness meter 1000: Surface water 1100: Deep water FF: Barge GL: Ground Gc: Internal circulation return weight flow rate Gf: Second internal circulation line weight flow rate Gt: Weight flow rate of working medium (50S) HW: Hot water reservoir Hb: Semipermeable membrane and gas-liquid separation Distance to tank liquid level Hp: Distance between semi-permeable membrane and condenser liquid level Hsw: Distance from gas-liquid separation tank liquid level to lower end of heat transport pipe Pp: Pressure on the condensate side of semi-permeable membrane Psw: Half Pressure SB on the concentrated liquid side of the permeable membrane: sea bottom SL: sea surface

Claims (4)

A semi-permeable membrane,
A solvent on one side of the semipermeable membrane (hereinafter referred to as a condensing working medium);
On the other side of the semipermeable membrane, a solvent composed of the same substance as the condensed working medium and a solution composed of a solute (hereinafter referred to as a concentrated liquid) are arranged.
A step in which the condensed working medium is drawn into the concentrated liquid on the other side of the semipermeable membrane by osmotic pressure to generate an osmotic flow;
A step of receiving the concentrated liquid from a high-temperature heat source (hereinafter, referred to as a high heat source) and separating the concentrated liquid into a thermally vaporized working medium and a concentrated concentrated liquid (hereinafter, referred to as a highly concentrated liquid);
A step of refluxing the highly concentrated liquid to the inlet pool on the other side of the semipermeable membrane (hereinafter referred to as a highly concentrated liquid reflux step);
The concentrated liquid flowing into the inlet reservoir flows along the surface on the other side of the semipermeable membrane toward the outlet reservoir on the other side, and in the process, the concentrated liquid permeates on the surface. Mixing with a stream to maintain the surface at a predetermined concentration;
A step in which the vaporized working medium flows into an expander to generate power,
The working medium exiting the expander becomes a condensed working medium to the heat radiation to a low temperature heat source (hereinafter referred to as low-temperature heat source), it viewed including the the steps of merging the condensation working medium on one side of the semipermeable membrane,
A power generation method using an osmotic pressure heat cycle, wherein cooling means for the highly concentrated liquid is provided in a path of the highly concentrated liquid reflux step . The power generation method according to claim 1 , wherein the expander is a double-row turbine, and the high-concentration liquid cooling means is used for reheating the turbine. 2. The power generation method according to claim 1, wherein a path in which the respective steps are communicated includes a high heat source, a low heat source, or both. 2. The power generation method according to claim 1, further comprising an external path for sucking a part of the concentrated liquid from the outlet pool or a portion downstream thereof and returning the concentrated liquid to the inlet pool.