JPH0726789B2 - Condensing device and method for open-cycle ocean thermal energy conversion - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condensing device, and more particularly to an open cycle system in so-called ocean temperature difference power generation, in which surface water and deep water of the ocean are used as a high temperature source and a low temperature source respectively to generate electricity. The present invention relates to a condenser suitable for use.

[0002]

2. Description of the Related Art Open-cycle ocean thermal energy conversion has the advantage that, together with the generated power, valuable by-products can be obtained as fresh water that can be used as drinking water or industrial water. Therefore, it is expected that even small and medium-scale systems can be put to practical use as remote island electricity and freshwater supply systems. However, in order to obtain fresh water, it is necessary to install a partition type condenser and to condense water there to obtain fresh water.

Therefore, the conventional system, as conceptually shown in FIG. 5, is a system including an efficient direct contact condenser and a multi-stage condenser of a partition type condenser.

[0004]

However, in such a conventional system, installation of a shell-and-tube type or plate type condenser made of a material having seawater resistance such as titanium. A lot of equipment and space such as piping for supplying cold seawater and a flow control system are required. In the partition type, in order to perform heat exchange, it is generally necessary to pass cold seawater through a narrow tube or a heat transfer surface gap at a flow rate of 1 to 2 m / s. It is generated at the bend and the pump power must be increased.

Further, in the open cycle, the pressure inside the vessel is as low as 0.03-0.01 atm, so it is necessary to have a vacuum hermetic structure. Therefore, it is necessary to carefully keep the airtightness of the equipment joint part, the pipe and the plate with the seawater side, and the manufacturing process becomes complicated. If there is a leak, it will take a lot of effort to find it.

As described above, although the open cycle has an advantage that fresh water can be obtained as a by-product, the conventional one requires extra equipment, labor, power, etc., so that fresh water is required. Is not a true by-product, and has become a major issue in the practical application of the system.

The object of the present invention is, in particular, in a direct contact condenser in which seawater and steam originally come into direct contact with each other, without separately installing a bulkhead condenser in the condensing section of the open-cycle ocean temperature difference power generation. By having a function that enables desalination in the inside, it is possible to simplify the condenser device, simplify the equipment, simplify the piping, save the material, save the labor, and reduce the pump power. To provide a condensation method.

[0008]

In order to achieve the above object, the invention according to claim 1 is directed to the first chamber in which the steam leaving the turbine is introduced and the fresh water receiving portion is formed on the lower side. , The first
A cylindrical member connected to the upper side of the first chamber and opening to a second chamber above the first chamber, and provided above the upper opening of the cylindrical member in the second chamber at a predetermined distance. A plate member and a supply means for supplying cold seawater to the upper surface of the plate member.

According to a second aspect of the present invention, the tubular member has a taper and an inclined surface, and the size and shape of the plate member are set so that the cold seawater uniformly drops on the inclined surface. Is characterized by.

According to a third aspect of the present invention, the supply member has a cylindrical member whose one end faces above the plate member and whose other end communicates with a third chamber provided above the second chamber. It is characterized by including.

The invention according to claim 4 is characterized in that a porous component for direct contact condensation is arranged around the cylindrical member.

According to a fifth aspect of the present invention, in the open-cycle ocean thermal energy conversion system, before the steam leaving the turbine reaches the direct contact condensation zone, the cold seawater used in the direct contact condensation zone causes the steam to flow. It is characterized in that fresh water is obtained in the form of taking away heat from a part of and condensing it.

According to a sixth aspect of the present invention, heat is removed from a part of the steam by the heat transfer surface cooled by the cold seawater, and the remaining steam exchanges heat by collision jet heat transfer to the steam side. After the fresh water is obtained, it is condensed with the cold seawater by direct contact heat transfer.

[0014]

According to the present invention, the steam exiting the turbine is guided to the first chamber in which the fresh water receiving portion is formed on the lower side, and the steam is continuously provided on the upper side of the first chamber and above the first chamber. The cylinder member that opens to the second chamber of the cylinder moves up while being accelerated. Then, the steam that has become a jet flow collides with the lower surface of the plate member, which is provided a certain distance apart from the upper opening of the cylindrical member and is provided above the cylindrical member, and whose upper surface is cooled by the supplied cold seawater. It condenses and falls. The dropped condensed water, that is, fresh water, is received by the fresh water receiving portion of the first chamber. On the other hand, the remaining uncondensed vapor proceeds from between the plate member and the opening of the tubular member to the second chamber, where direct contact condensation is performed by the cold seawater that is supplied to the upper surface of the plate member and is falling.

[0015]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a half sectional perspective view showing an outline of an open cycle ocean thermal energy conversion system to which the present invention is applied.

The basic constituent elements are an evaporator 10, a turbine / power generator 20, and a condenser 30.

The evaporation section 10 is provided with a warm seawater chamber 12 into which warm seawater is introduced by a pump or the like, and an evaporation chamber 14 above it. A large number of jet pipes 18 are formed on the partition wall 16 between the warm seawater chamber 12 and the evaporation chamber 14 so as to project toward the evaporation chamber 14 side, and the warm seawater is jetted into the evaporation chamber 14.

In the turbine / power generation section 20, a turbine 24 is provided in a duct 22 communicating with the evaporation chamber 14, and a hollow columnar body 25 is provided in the center of the outlet side of the turbine 24.
An annular expansion chamber 26 is formed. The generator 28 driven by the turbine 24 is provided outside in the hollow portion of the columnar body 25.

The condenser section 30 is connected to the expansion chamber 2 from the turbine 24.
First as the first chamber into which the steam discharged through 6 is introduced
Annular chamber 32, second annular chamber 34 as a second chamber formed above the first annular chamber 32, and third annular chamber as a third chamber formed above the second annular chamber 34. Equipped with 36. The lower side of the first annular chamber 32 is the expansion chamber 2 described above.
It is lower than the inlet 29 from 6 and serves as a fresh water receiving portion 32A capable of storing condensed fresh water. Therefore, the fresh water extraction pipe 32C equipped with the valve 32B is connected to the bottom of the first annular chamber 32, that is, the bottom surface of the fresh water receiver 32A, and fresh water can be taken out as necessary.

In the partition wall 33 between the first annular chamber 32 and the second annular chamber 34, a large number of truncated cone-shaped tubular members 35 are provided so as to project into the second annular chamber 34. The tubular member 35 in this embodiment is tapered and has an upper opening 35A at the tip and an inclined surface 35B at the side.

The partition wall 33 including the tubular member 35 is preferably made of a material having seawater resistance and good thermal conductivity. The tubular member 35 may have a shape other than the truncated cone shape of this example or the cylindrical shape exemplified later. The shape may be a truncated pyramid, a parabolic trapezoid, a hemispherical trapezoid, or a prismatic shape. The surface may be a smooth surface, an inner grooved surface, an outer grooved surface, or a double-sided grooved surface.

Since it is used under pressure equalization conditions in terms of pressure resistance, a thin material may be used as long as it has a strength capable of withstanding a falling water flow as described later.

Further, a separating plate 37, which is a plate member having a diameter larger than the diameter of the opening 35A, is spaced above the upper opening 35A of the cylindrical member 35 by a predetermined distance.
Is provided. In the present embodiment, as shown in FIG. 2, the separation plate 37 is horizontally supported by the tubular member 35 with the stay 37A. The separation plate 37 has a function of controlling the heat transfer of the impinging jet and the direction of gas-liquid,
If these are satisfied, the shape is a flat disc,
It may have a radial groove, a edging plate, or an umbrella shape or an inverted umbrella shape.

Further, a nozzle 39 for supplying cold seawater is provided above the separation plate 37 in a partition wall 38 between the second annular chamber 34 and the third annular chamber 36. A water supply pipe 36A is connected to the third annular chamber 36, and cold seawater is supplied by a pump. In the above-mentioned second annular chamber 34, the drain pipe 34A is connected to the first annular chamber 32, slightly above the partition wall 33.

In the present embodiment having the above-mentioned structure, warm seawater (about 27 ° C.) which is the surface water of the ocean is supplied to the warm seawater chamber 12 by the pump, and the warm seawater (about 27 ° C.) is supplied to the warm seawater chamber 12.
About 5% becomes steam. The vapor pressure is about 0.03 atm, and the turbine 24 is rotated to generate electricity while the vapor pressure in the expansion chamber 26 is expanded to about 0.015 atm.
The steam discharged from the turbine 24 enters the first annular chamber 32 through the inlet 29 and is guided to the tubular member 35 (the flow of steam is indicated by arrow A). In the tubular member 35, the steam is accelerated,
It spouts from the opening 35A and collides with the separation plate 37. On the upper surface of the separation plate 37, cold seawater, which is the deep sea water supplied to the third annular chamber 36 by a pump, is dropped and ejected through the nozzle 39, and this cold seawater is further discharged from the separation plate 37. It falls as a falling film from the outer edge and falls and collides with the inclined surface 35B of the tubular member 35 (the flow of cold seawater is indicated by arrow B). As a result, a part of the steam accelerated in the above-mentioned tubular member 35 has a slope 35B.
Is condensed on the heat transfer surface inside and is dropped and stored in the fresh water receiving portion 32A below the first annular chamber 32. On the other hand, the tubular member 3
As described above, the vapor that has not condensed in 5 collides with the lower surface of the separation plate 37 and a portion thereof is condensed by the collision jet heat transfer and drops into the fresh water receiving portion 32A and is stored, but most of it is Towards the second annular chamber 34 side. Then, the vapor falls and collides with the inclined surface 35B of the tubular member 35 while directly contacting with the above falling falling film. Here, sufficient agitation and mixing are performed, the cold seawater makes direct contact with the steam, and at the same time, heat is taken from the inclined surface 35B by forced convection heat transfer, and becomes the cold heat source for the fresh water production described above. After the drop cold seawater has sufficiently exchanged heat, it passes through the bottom of the second annular chamber 34 and then to the drain pipe 34A.
It is drained to the outside via.

The desalination ratio can be determined almost arbitrarily at the time of system design, but in open cycle ocean thermal energy conversion, about 0.5% of the seawater flow rate becomes steam, and if all of it is desalinated, the desalination flow rate will change. It becomes enormous, and the need for total desalination is not large except for a special scale, so it is possible to obtain the necessary and sufficient amount of desalination even with such a position as a pure by-product. The control range can be about 10 to 80% of the total amount of steam.

Next, another embodiment of the present invention will be described with reference to FIG.

In this embodiment, heat transfer in direct contact can be effectively performed as compared with the previous embodiment, and a seawater resistance such as a polymer material is provided around a cylindrical tubular member 35 '. The porous structure 40 composed of a material having Further, the separation plate 37 'has an inverted umbrella shape, and is supported at its center by a stem 41 standing on the bottom surface of the first annular chamber 32. The outer edge of the separation plate 37 'is set to a size located above the porous structure 40. Since other configurations are the same as those of the previous embodiment, the same parts are designated by the same reference numerals to avoid redundant description.

In the present embodiment, fresh water is generated only on the lower surface of the separation plate 37 ', and the generated fresh water partially falls, but most of it is an inverted umbrella-shaped separation plate 3'.
It is transmitted through the lower surface of 7'and the stem 41 and stored in the fresh water receiving portion 32A below the first annular chamber 32.

Since the area ratio of the inlet and outlet of the tubular member 35 'is 1, and only the residual kinetic energy of steam can be used,
No extra pressure loss.

The uncondensed vapor is directly contacted with the falling film falling from the outer edge of the separation plate 37 'or is effectively directly contacted with heat in the porous structure 40 to be condensed.

[0033]

According to the present invention, the steam leaving the turbine is guided, and the first chamber in which the fresh water receiving portion is formed on the lower side and the first chamber connected to the upper side of the first chamber are connected to each other. A cylindrical member opening to a second chamber above the chamber, a plate member provided above the upper opening of the cylindrical member at a predetermined distance in the second chamber, and an upper surface of the plate member. Since a supply means for supplying cold seawater is provided, one condenser serves as a condenser for the steam necessary for power generation, and at the same time, a part of the steam is effectively condensed to obtain fresh water. Can
There is no need to separate steam or separate cold water pipes for fresh water production, which simplifies the condenser. Therefore, it is possible to obtain various effects such as improvement of performance, improvement of net output, saving of equipment cost, and labor saving of maintenance.

[Brief description of drawings]

FIG. 1 is a half cross-sectional perspective view showing an outline of an open-cycle ocean thermal energy conversion system to which the present invention is applied.

FIG. 2 is a partially enlarged sectional view showing an embodiment of the present invention.

FIG. 3 is a half sectional perspective view showing an embodiment of the present invention.

FIG. 4 is a half sectional perspective view showing another embodiment of the present invention.

FIG. 5 is a conceptual sectional view showing a conventional example.

[Explanation of symbols]

 10 Evaporator 20 Turbine / Power Generator 30 Condenser 32 First Annular Chamber 32A Fresh Water Receptor 34 Second Annular Chamber 35, 35 'Cylinder Member 36 Third Annular Chamber 37, 37' Separation Plate 39 Nozzle 40 Porous Structure 41 Stem

Claims (6)

[Claims] 1. A first chamber, into which steam exiting the turbine is introduced, and a fresh water receiving portion is formed on a lower side, and a first chamber above the first chamber, which is connected to the upper side of the first chamber. A tubular member opening to the second chamber, a plate member provided above the upper opening of the tubular member at a predetermined distance in the second chamber, and a supply of cold seawater to the upper surface of the plate member A condensing device for open-cycle ocean thermal energy conversion, comprising: 2. The tubular member has a taper and an inclined surface, and the size and shape of the plate member are set so that the cold seawater uniformly drops on the inclined surface. The condensing device for open cycle ocean thermal energy conversion described in. 3. The supply means includes a tubular member whose one end faces above the plate member and whose other end communicates with a third chamber provided above the second chamber. The condensing device for open-cycle ocean thermal energy conversion according to claim 1 or 2. 4. The condensing device for open-cycle ocean thermal energy conversion according to claim 1, wherein a porous structure for performing direct contact condensation is arranged around the cylindrical member. 5. In the open cycle ocean thermal energy conversion system, before the steam leaving the turbine reaches the direct contact condensation zone, the cold seawater used in the direct contact condensation zone removes heat from a part of the steam. A condensing method for open cycle ocean thermal energy conversion characterized by obtaining fresh water in a condensed and separated form. 6. The heat transfer surface cooled by the cold seawater removes heat from a part of the steam, and the remaining steam exchanges heat by collision jet heat transfer to obtain fresh water on the steam side, and then, The condensing method for open-cycle ocean thermal energy conversion according to claim 5, wherein the condensing is performed by direct contact heat transfer with cold seawater.