JPH07180916A - Steam generator - Google Patents

Abstract

PURPOSE:To provide a steam generator which has a high efficiency, a small size and a steam separating function. CONSTITUTION:A steam generator comprises a first glass tube 12 with a bottom, and a second glass tube with a bottom having a selective absorption film 13a having characteristics in which absorption in a solar radiation spectrum region is large and radiation rate in the heat radiation spectrum region is small and formed on a surface, and having a smaller diameter than that of the tube 12. The generator also comprises a heat collecting glass tube 11 in which both are superposed at an interval and opening ends of the tubes are hermetically integrally connected, a steam generating tube 14 with a bottom inserted from the opening end of the tube 11 into its interior, a feed water tube 16 for supplying water from the vicinity of the opening end of the tube 14 into the tube 14, and a heating medium 17 filled between the tube 14 and the tube 13 of the tube 11. Further, the generator comprises a gas reservoir 18 provided between the generating tube and the tube 13 of the tube 11 to absorb volumetric expansion of the medium 17, and a sealing member 19 provided in the opening of the tube 11 to seal the medium 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam generator used in a power generator using solar heat.

[0002]

2. Description of the Related Art Next, the structure of a steam generator used in a conventional solar thermal power generator will be described with reference to FIG.

In the figure, reference numeral 1 is a water supply tank for storing water, and 2 is a pump for sending water stored in the water supply tank 1 to a steam generator 3. The steam generator 3 has a plurality of U-shaped copper pipes (inner diameter 5 mm) on the reflector plate 4 that reflects sunlight.
5 are arranged, one end of each copper pipe 5 is connected to the water supply header 6 connected to the outlet of the pump 3, and the other end is connected to the steam header 7.

The steam header 7 is connected to a steam separator 8,
The steam discharged from the steam separator 8 reaches the generator. Next, the operation of the above configuration will be described. Water sent from the water supply tank 1 by the pump 2 is supplied to each copper pipe 5 via the water supply header 6 of the steam generator 3.

The water in the copper pipe 5 is heated by sunlight, and steam is generated inside. Then, the steam and the hot water move to the steam separator 8 via the steam header 7, where the steam and the hot water are separated, and the steam is supplied to the generator.

[0006]

However, the steam generator 3 having the above structure has the following problems. Only by disposing the copper pipe 5 on the reflector 4, the efficiency of taking in the solar heat is poor and the inner diameter of the copper pipe 5 can only be about 5 mm. Therefore, many copper pipes 5 are required,
The device becomes larger.

When water becomes steam, the volume expands about 1000 times, but since the inner diameter of the copper pipe 5 is about 5 mm, it is difficult for steam to pass through and the steam and hot water cannot be separated. The present invention has been made in view of the above problems, and an object of the present invention is to provide a steam generator that has high efficiency, can be downsized, and has a steam-water separation function.

[0008]

According to the present invention for solving the above-mentioned problems, a first glass tube having a bottom is selected which has a large absorption in the solar radiation spectral region and a small emissivity in the thermal radiation spectral region on the surface. A heat collecting glass tube in which an absorption film is formed and which is composed of a second glass tube having a bottom and a diameter smaller than that of the first glass tube, both of which are polymerized at intervals and the open ends of these glass tubes are hermetically joined integrally. And the second of the heat collecting glass tube
With a diameter smaller than that of a glass tube, a bottomed steam generating tube inserted inside from the opening end of the heat collecting glass tube, and a water supply tube for supplying water into the steam generating tube from the vicinity of the opening end of the steam generating tube, A heat medium filled between the steam generating tube and the second glass tube of the heat collecting glass tube, and provided between the steam generating tube and the second glass tube of the heat collecting glass tube, It comprises a gas pool that absorbs the volume expansion of the medium and a sealing member that is provided at the opening of the heat collecting glass tube and seals the heat medium.

[0009]

In the steam generator of the present invention, sunlight is collected by the heat collecting glass tube and heats the steam generating tube through the heat medium. The water supplied into the steam generation pipe via the water supply pipe is heated, steam is generated, and only steam exits from the steam header pipe.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a configuration diagram of essential parts of a steam generator according to an embodiment of the present invention.

In the figure, 11 is a heat collecting glass tube.
The heat collecting glass tube 11 has a bottomed first glass tube 12 and a selective absorption film 13 having a large absorption in the solar radiation spectrum region and a small emissivity in the thermal radiation spectrum region on the surface.
a is formed and is composed of a bottomed second glass tube 13 having a diameter smaller than that of the first glass tube 12, and both are polymerized with a space therebetween,
It is formed by airtightly connecting the open ends of the glass tubes 12 and 13 together and reducing the space between the glass tubes 12 and 13 to a high vacuum.

From the open end of the heat collecting glass tube 11, a copper steam generating tube 14 having a diameter smaller than that of the second glass tube 13 of the heat collecting glass tube 11 and having a bottom is inserted.
(In this embodiment, the steam generating tube 14 has an inner diameter of about 25 mm). The open end of the steam generation pipe 14 is connected to the steam header pipe 15. A water supply pipe 16 for supplying water into the steam generation pipe 14 is provided near the open end of the steam generation pipe 14.

Second of the steam generating tube 14 and the heat collecting glass tube 11
Castor oil 17 is filled between the glass tube 13 and the glass tube 13 as a heat medium. Further, a gas reservoir 18 that absorbs the volume expansion of castor oil is provided at the bottom of the steam generation pipe 14. The castor oil 17 filled in the heat collecting glass tube 11 is provided at the open end of the heat collecting glass tube 11.
It is sealed by a ring 19.

Next, an example of a solar thermal power generator using the steam generator 20 having the above structure will be described with reference to FIG. In the figure, 21 is a water supply tank for storing water. Reference numeral 22 is a water supply pump for feeding water in the water supply tank 21, and a check valve 23 and a mixer 24 are provided on the discharge side of the water supply pump 22. A preheating device 25 is provided on the discharge side of the mixer 24. In this preheating device 25, a water supply header pipe 27 and a preheating water header pipe 28 are provided side by side on a reflecting plate 26, and inside a heat collecting glass pipe 29 filled with a heat medium as in the steam generator of this embodiment. A U-shaped copper pipe 30 having one end connected to the water supply header pipe 27 and the other end connected to the preheated water header pipe 28, respectively, and a plurality of units sealed by a sealing member (not shown) are provided. It has a structure provided.

The preheated water header pipe 28 is connected to a high temperature tank 31, and a line from the high temperature tank 31 to the mixer 24 via a circulation pump 32 and a line to a steam generator via a hot water pump 33. It is provided.

The discharge side of the hot water pump 33 reaches the steam generator 35 via the check valve 34. This steam generator 35
1 has a structure in which a hot water header pipe 37 and a steam header pipe 15 to which the water supply pipe 16 in FIG. 1 is connected are juxtaposed on the reflecting plate 36, and a plurality of steam generators 20 of this embodiment are provided. There is.

The steam generated by the steam generator 35 is sent to the superheater 38. In this superheater 38, a steam header tube 40 and a superheated steam header tube 41 are arranged side by side on a reflection plate 39, and one end is inside the heat collecting glass tube 42 filled with a heat medium. 40, the other end of which is connected to the superheated steam header pipe 41
A character-shaped copper pipe 46 is inserted and a plurality of units sealed with a sealing member (not shown) are provided.

The superheated steam header pipe 41 is connected to the steam generator 45, and the steam used in the steam generator 45 is returned to the water supply tank 21. Next, the operation of the solar thermal power generator having the above configuration will be described. The water stored in the water supply tank 21 is supplied to the check valve 2 by the water supply pump 22.
3, liquid is sent to the copper pipe 30 of the preheating device 25 via the mixer 24 and the water supply header pipe 27 of the preheating device 25.

Here, the water is heated to 80 ° C. to 95 ° C. by solar heat and becomes hot water, which is stored in the high temperature tank 31 through the preheated water header pipe 28. A part of the hot water stored in the high temperature tank 31 is returned to the mixer 24 by the circulation pump 32 and mixed with the water from the water supply tank 21. The hot water remaining in the high temperature tank 31 is supplied to the check valve 34, the hot water header pipe 37 of the steam generator 35, and the water supply pipe 1 by the hot water pump 33.
The liquid is sent to the steam generating pipe 14 of the steam generating device 35 via 6. In the present embodiment, the hot water pump 33 is turned on / off at the liquid level of the hot water in the steam generating pipe 14 of the steam generator 35.

In the steam generator 20, the heat collecting glass tube 1
The solar rays incident on the first glass tube 1 are efficiently absorbed in the second glass tube 13 through the selective absorption film 13a after passing through the first glass tube 12. The absorbed heat is transferred to the steam generation pipe 14 via castor oil. At this time, the castor oil is also heated and expands in volume, but this volume expansion is absorbed by the gas reservoir 18. Then, the selective absorption film 13a suppresses convection, radiation, and conduction of heat to the outside, and the liquid inside is heated before boiling. In this embodiment, the preheater 25 and the superheater 38 also use the heat collecting glass tubes 29 and 42 similarly to the steam generator 35, but the operation is the same.

In this way, the hot water in the steam generating tube 14 is heated and steam of about 130 ° C. is generated. Then, the generated steam moves upward and is separated, and only the steam reaches the copper pipe 46 of the superheat device 38 through the steam header pipe 15 of the steam generator 35 and the steam header pipe 40 of the superheat device 38.

Here, the steam is further heated to 150 ° C. due to solar heat.
After being heated to some extent, it reaches the steam generator 45 and power is generated. The steam used in the steam generator 45 is the water tank 2.
Returned to 1 and used again as water.

According to the steam generator having the above structure, the first glass tube 12 having a bottom has a selective absorption film 13a having a large absorption in the solar radiation spectrum region and a small emissivity in the thermal radiation spectrum region on the surface. Formed, the first glass tube 12
By using the heat collecting glass tube 11 which is composed of the second glass tube 13 having a smaller diameter and having a bottom, and which are polymerized at intervals and the open ends of these glass tubes 12 and 13 are hermetically joined together, The efficiency of taking in is improved and the device can be downsized.

Since the inner diameter of the steam generation pipe 14 is larger than that of the conventional copper pipe, steam and hot water can be separated, and a steam separation device is unnecessary.

[0025]

As described above, according to the present invention, the heat collecting glass tube and the second glass tube of the heat collecting glass tube have a smaller diameter,
A bottomed steam generating tube inserted inside the opening end of the heat collecting glass tube, a water supply pipe for supplying water into the steam generating tube from near the opening end of the steam generating tube, a steam generating tube and the heat collecting A heating medium filled between the glass tube and the second glass tube;
A gas reservoir provided between the vapor generating tube and the second glass tube of the heat collecting glass tube to absorb the volume expansion of the heat medium, and a seal provided at the opening of the heat collecting glass tube to seal the heat medium. By being configured with the stop member, it is possible to realize a steam generator having a high efficiency, a compact device, and a steam-water separating function.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a main part of a steam generator according to an embodiment of the present invention.

FIG. 2 is a diagram illustrating an example of a solar thermal power generator using the steam generator shown in FIG.

FIG. 3 is a diagram illustrating a configuration of a steam generator used in a solar thermal power generation system.

[Explanation of symbols]

 11 Heat Collecting Glass Tube 12 First Glass Tube 13 Second Glass Tube 13a Selective Absorption Film 16 Water Supply Pipe 17 Castor Oil (Heat Medium) 18 Gas Reservoir 19 O Ring (Sealing Member)

Claims (1)

[Claims] 1. A selective absorption film (13a) having a bottomed first glass tube (12), which has a large absorption in the solar radiation spectral region and a small emissivity in the thermal radiation spectral region on the surface.
And a bottomed second glass tube (13) having a diameter smaller than that of the first glass tube (12), both of which are polymerized with a space therebetween, and the open ends of these glass tubes are hermetically bonded together. Heat glass tube (11) and a bottomed steam generator having a diameter smaller than that of the second glass tube (13) of the heat collecting glass tube (11) and inserted inside the open end of the heat collecting glass tube (11) A pipe (14), a water supply pipe (16) for supplying water into the steam generating pipe (14) from the vicinity of an open end of the steam generating pipe (14), the steam generating pipe (14) and the heat collecting glass The heat medium (1) filled between the tube (11) and the second glass tube (13).
7) and a gas pool () which is provided between the vapor generating tube (14) and the second glass tube (13) of the heat collecting glass tube (11) and absorbs the volume expansion of the heat medium (17). 18) and a sealing member (19) provided in the opening of the heat collecting glass tube (11) and sealing the heat medium (17).