JP2003120513A - Geothermal power generation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binary type geothermal power generation device using water instead of low boiling point medium. SOLUTION: This geothermal power generation device is provided with an evaporator 11 heating and vaporizing supplied water by steam and/or hot water from a heat source well 1 and returning the steam and/or hot water to a return well 2, a steam turbine 3 receiving steam generated by the evaporator 11, a generator 4 driven by the stream turbine 3, and a direct contact type condenser 5 or an air cooled condenser cooled by a fan receiving steam discharged from the steam turbine 3 and condensing the same. Condensed water from the condenser 5 is supplied to the evaporator 11 as the supplied water. The geothermal power generation device is preferably provided with an air extracting device 8 for extracting air from discharged water of the condenser 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-utilizing power generator that generates electricity using geothermal heat or industrial waste heat as a heat source.

[0002]

2. Description of the Related Art Various types of conventional geothermal power generation systems have been adopted, and briefly described with reference to FIGS. 3 to 7, FIG. 3 shows that only steam is ejected from a geothermal well. In this case, a system is shown in which geothermal steam is directly introduced into the steam turbine.

In FIG. 3, the steam ejected from the geothermal well 1 is guided into the steam turbine 3, where it performs work to rotate the rotary shaft 3a and drive the generator 4. The steam that has finished the work and has exited the steam turbine 3 is partially condensed in the direct contact condenser 5 to be condensed water, which is sent to the cooling tower 7 by the circulating water pump 6, and the rest is supplied to the air extraction device 8. It is released to the atmosphere via. Then, the drainage water from the cooling tower 7 is used as cooling water in the direct contact condenser 5 and the reduction well 2
It is supposed to be returned to.

FIGS. 4 to 7 show systems in which steam and hot water, or only hot water are jetted from a geothermal well, which includes a single flash system shown in FIG. 4 and a double flash system shown in FIG. There is a binary method of FIGS. 6 and 7.

The single flash system of FIG. 4 differs from the conventional example of FIG. 3 in that a separator 9 is provided in front of the steam turbine 3, and the steam separated by the separator 9 is introduced into the steam turbine 3. , Power is obtained in the same manner as in the method of FIG. In addition, in the double flash system of FIG. 5, a flasher 10 is further provided in addition to the separator 9, and the steam separated by the separator 9 is sent to the high pressure part of the steam turbine 3 and the separated hot water is guided to the flasher 10. To generate low-pressure steam and introduce the low-pressure steam into the low-pressure portion of the steam turbine 3. After that, power is obtained in the same manner as in the system of FIG.

The binary method shown in FIGS. 6 and 7 is for heating a low boiling point medium such as CFC or isopentane by means of geothermal heat to vaporize it. In FIG. 6, steam and / or heat from the geothermal well 1 is used. The low-boiling-point medium is vaporized by water in the evaporator 11, where it performs work to rotate the rotating shaft to drive the generator 4. The steam that has finished the work and has exited the steam turbine 3 is cooled in the surface cooling type condenser 14 by the cooling water fed from the cooling tower 7 by the cooling water pump 12 to become a liquid medium, and by the medium circulation pump 13. It is returned to the evaporator 11. On the other hand, in FIG. 7, an air-cooled condenser 16 is used instead of the surface-cooled condenser 14 and the cooling tower 7 of FIG. 6.

The binary type geothermal power generation system shown in FIGS. 6 and 7 has various advantages as compared with the geothermal power generation system shown in FIGS. (1) Geothermal steam and geothermal gas in hot water are returned to the reduction well 2 through the evaporator 11 as they are and are not released to the atmosphere.
Does not pollute the environment. (2) The geothermal power generation system of FIGS. 3 to 5 requires a large-capacity geothermal gas extraction device, but the binary system shown in FIGS. 6 and 7 is a device that discharges a small amount of air in the cooling water. It is sufficient to reduce the equipment cost of the gas extractor and the power of auxiliary equipment. (3) In the geothermal power generation system shown in FIGS. 3 to 5, since the steam line and the circulating water line include the corrosion component and the scale component, it is necessary to use a high-grade material having corrosion resistance.
Although there is a problem that the initial cost and maintenance cost increase, the binary method only requires consideration for the secondary steam generator (evaporator). (4) In the geothermal power generation system of FIGS. 3 to 5, geothermal steam and / or
Or, since a part of hot water is released to the atmosphere, silica may be concentrated in the reduction well, which may cause blockage.
In the binary method, the steam and / or hot water from the geothermal well absorbs only heat in the evaporator, so that reducing water does not concentrate, and thus reducing water does not concentrate easily.

[0008]

However, when a low boiling point medium is used as in the conventional binary method, this medium is harmful not only to the environment but also to the human body, and therefore, when it leaks out of the system. Is extremely dangerous, and when the medium is flammable and / or explosive, it needs to be carefully handled, and the low boiling point medium is generally expensive.

Accordingly, it is an object of the present invention to provide a binary heat-utilizing power generator which does not use such a low boiling point medium.

[0010]

In order to achieve the above object, according to the present invention as set forth in claim 1, a geothermal power generation apparatus heats feed water with steam and / or hot water from a heat source well to steam. From the steam turbine, an evaporator returning the steam and / or hot water to a reduction well, a steam turbine receiving steam generated by the evaporator, a generator driven by the steam turbine, A direct-contact condenser that receives discharged steam and condenses with cooling water is provided, and the condensate from the condenser is supplied to the evaporator as the supply water.

In order to achieve the above-mentioned object, according to the present invention as set forth in claim 2, the geothermal power generation device heats the feed water with steam and / or hot water from the heat source well to vaporize it. An evaporator that returns the steam and / or hot water to the reduction well, a steam turbine that receives the steam generated by the evaporator, a generator that is driven by the steam turbine, and a steam that is discharged from the steam turbine. And an air-cooled condenser that condenses water by fan cooling, and the condensed water from the condenser is supplied to the evaporator as the water supply.

Further, the geothermal power generator according to the first or second aspect is preferably equipped with an air extractor for extracting air from the water discharged from the condenser.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals indicate the same or corresponding parts. Further, as will be understood from the following description, the present invention is not limited to this embodiment, and various modifications can be made.

In FIG. 1 showing a binary type geothermal power generation apparatus according to an embodiment of the present invention, steam and / or hot water ejected from a geothermal well 1 is introduced to an evaporator 11, where cooling water described later is heated. After that, it is returned to the reduction well 2. The cooling water becomes steam in the evaporator 11 and is introduced into the steam turbine 3, where it performs work to rotate the rotary shaft 3a and to rotate the generator 4
To drive. The steam that finished the work and exited the steam turbine 3
In the direct contact condenser 5, a part is condensed into condensate, which is sent to the cooling tower 7 by the circulating water pump 6 and the rest is returned to the evaporator 11 as the above-mentioned cooling water. The gas phase portion of the direct contact condenser 5 is discharged to the atmosphere via a gas or air extraction device 8. The drainage water from the cooling tower 7 is used as sprinkling water for cooling in the direct contact condenser 5.

FIG. 2 is a schematic view showing another embodiment of the present invention, in which an air cooling type condenser is adopted.
In this embodiment, the steam and / or hot water ejected from the geothermal well 1 is guided to the evaporator 11, where the cooling water described below is heated and then returned to the reduction well 2. The heated cooling water becomes steam in the evaporator 11 and is introduced into the steam turbine 3, where it performs work to rotate the rotating shaft 3a and drive the generator 4. The steam that has finished the work and has exited the steam turbine 3 is condensed into condensate in the air-cooled condenser 16 equipped with the fan 16a, and is returned to the evaporator 11 as the cooling water by the circulating water pump 6. Has become. Then, the gas phase portion of the condensate is discharged to the atmosphere via the gas or air extraction device 8.

Although the embodiment in which the present invention is applied to a geothermal power generation device has been described, the present invention is not limited to this embodiment, and a power generation device utilizing heat generated by combustion of industrial waste, for example, as a heat source. Can also be applied to.

[0017]

As can be seen from the above description, the heat-utilizing power generator according to the present invention is of the binary type, and therefore has the advantage of the binary type, but uses water as the medium. Therefore, it does not have the drawbacks associated with the use of low boiling media. More specifically, in the geothermal power generation device according to the present invention described in claims 1 and 2, since it is a binary system, (1) geothermal steam and / or geothermal gas in hot water is directly reduced through an evaporator. Since it is returned to the well and not released to the atmosphere, it does not pollute the environment. (2)
It is sufficient if there is a device that discharges a small amount of air in the cooling water, and it is possible to reduce the gas extraction device equipment cost and auxiliary machine power. (3) In the conventional geothermal power generation system, the steam line and circulating water line Since corrosion and scale components are included, it is necessary to use high-grade corrosion-resistant materials, which increases the initial cost and maintenance costs.However, the binary method uses a secondary steam generator (evaporator). (4) In the conventional geothermal power generation method, part of the geothermal steam and / or hot water is released to the atmosphere, so silica can be concentrated in the reduction well and blockage can occur. In contrast, in the binary method, steam and / or hot water from the geothermal well absorbs only heat in the evaporator,
The reduced water does not concentrate, so that the reduced water does not concentrate easily.

Moreover, according to the present invention as set forth in claims 1 and 2, since water is used instead of the low boiling point medium,
(1) Not only is it easy to handle, but the medium cost can be practically ignored, and (2) Since water is the medium, no special leak prevention device is required, so the equipment cost is low, Further, (3) the circulating water flow rate is smaller than that of the low boiling point medium due to the difference in thermal characteristics, so that the circulating pump can be downsized and power consumption can be reduced.

[Brief description of drawings]

FIG. 1 is a schematic view showing a first embodiment of a geothermal power generation device according to the present invention that employs a direct contact condenser.

FIG. 2 is a schematic diagram showing a second embodiment of the geothermal power generator according to the present invention which employs an air-cooled condenser.

FIG. 3 is a schematic diagram of a conventional geothermal power generation system of a type in which geothermal steam is directly introduced into a steam turbine from a well.

FIG. 4 is a schematic diagram of a conventional single flash type geothermal power generation device when steam and hot water, or only hot water is jetted from a geothermal well.

FIG. 5 is a schematic diagram of a conventional double flash type geothermal power generation device when steam and hot water, or only hot water is jetted from a geothermal well.

FIG. 6 is a schematic diagram of a conventional binary geothermal power generation device using a conventional low-boiling-point medium that employs a surface-cooled condenser.

FIG. 7 is a schematic diagram of a conventional binary geothermal power generation device that uses a conventional low boiling point medium that employs an air-cooled condenser.

[Explanation of symbols] 1 geothermal well 2 reduction wells 3 steam turbine 4 generator 5 Direct touch condenser 6 circulating water pump 7 cooling tower 8 Air extractor 11 evaporator 16 Air-cooled condenser 16a fan

Claims (3)

[Claims] 1. An evaporator that heats feed water with steam and / or hot water from a heat source well to vaporize it, and returns the steam and / or hot water to a reduction well, and steam generated by the evaporator. A steam turbine that receives the steam, a generator that is driven by the steam turbine, and a direct-contact condenser that receives the exhaust steam from the steam turbine and condenses it with cooling water. A geothermal power generation device that supplies water to the evaporator as the water supply. 2. An evaporator that heats feed water with steam and / or hot water from a heat source well to vaporize it, and returns the steam and / or hot water to a reduction well, and steam generated by the evaporator. A steam turbine that receives the steam, a generator that is driven by the steam turbine, and an air-cooled condenser that receives the exhaust steam from the steam turbine and condenses the water by fan cooling. A geothermal power generator that supplies water to the evaporator as the water supply. 3. The geothermal power generation device according to claim 1, further comprising an air extraction device for extracting air from the discharge water of the condenser.