JPH0362879B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to artesian geothermal wells that spout steam;
The present invention mainly relates to a downhole pump for hot water production wells used in geothermal utilization plants including hot water wells that gush out hot water.

Normally, when using an artesian geothermal well (hereinafter referred to as a steam production well) that spouts steam and hot water containing a large amount of steam, this self-spouted steam is supplied to a geothermal steam power generation plant to drive a steam turbine and generate a generator. rotates to generate electricity. In such power plants, the capacity of steam production wells declines at a rate of several percent per year, so new wells are constantly dug to ensure power generation output. Wells that no longer generate steam or newly dug wells that produce a small amount of steam and a large amount of hot water (hereinafter referred to as hot water production wells) cannot be used for steam power generation. Geothermal binary power generation, which pumps up hot water and uses the heat, is used to utilize such wells. As mentioned above, geothermal binary power generation requires a downhole pump to pump hot water, and downhole pumps of the line shaft type, the well motor drive type, and the well steam turbine drive type are used. Among these, the line shaft type has a limit on the installation depth, and the in-well motor drive type has a limit on the operating temperature due to electrical insulation.

The in-well steam turbine drive method has no restrictions on depth or temperature, and is suitable for high-temperature use in deep wells, making it effective, but the energy recovery rate for the plant as a whole is poor.

An object of the present invention is to improve the energy recovery rate of a geothermal utilization plant having a steam production well and a hot water production well when an in-well steam turbine is used to drive a downhole pump.

The present invention provides a drive device for an in-well steam turbine-driven downhole pump for extracting underground hot water.
The downhole pump is installed in a hot water production well containing a large amount of hot water, and piping and equipment are provided to guide steam from another steam production well containing a large amount of steam to a steam turbine for driving the downhole pump. This is a drive device for an in-well steam turbine-driven downhole pump, which is characterized by the following.

Examples of the present invention will be described below. 1st
The figure is a flow sheet of an embodiment of the present invention. 1 is a steam production well that is mainly made of steam and contains steam and hot water; 2 is a reinjection well that returns the hot water from which thermal energy has been recovered in the geothermal steam power generation plant 3 supplied with steam from the steam production well 1 to underground; , 4 is a hot water production well that mainly gushes out hot water and may contain steam, and 5 is a geothermal binary power generation plant 6 that is supplied with hot water from the hot water production well 4, where thermal energy is recovered and the temperature becomes low. This is a reinjection well that returns hot water underground.

The geothermal steam power plant 3 is as follows.

The steam inlet 7a communicates with the steam outlet 1a of the sealed steam production well 1 via the artesian steam introduction pipe 10, and the separated hot water outlet 7b communicates with the separated water return pipe 10a.
A steam separator 7 that communicates with the reinjection well 2 via a steam outlet 7c, and a steam turbine 8 that has a steam inlet 8a that communicates with a steam outlet 7c of the steam separator.
A generator 9 connected to the output shaft of the steam turbine 8
The exhaust intake port 11a is connected to the exhaust port 8b of the steam turbine, one cooling water inlet connected to the water sprinkler 11c inside is connected to the discharge port of the cooling water pump 12, and a condensing water pipe is provided with a hot water outlet 11d. Vessel 11
, a hot water pump 13 whose suction port communicates with the hot water outlet 11d of the condenser 11, and a water sprinkler 14a therein.
A cooling tower 14 having an inlet communicating with the discharge port of the hot water pump 13, a blower 14b for cooling the liquid sprayed by the water sprinkler 14a, and an outlet 14c of the cooled water communicating with the suction port of the cooling water pump 12.
and a cooling water pump 12.

The downhole pump 2 of the hot water production well 4 is connected from the steam outlet 7c of the steam separator of the geothermal steam power generation plant.
A steam introduction pipe 15 is installed to guide steam to a steam turbine 25 for driving the hot water production well. An exhaust steam return pipe 16 for returning the steam sent to the hot water production well 4 at 15 to the geothermal steam power generation plant 3 is installed.

The geothermal binary power generation plant 6 is as follows.

A hot water pipe 1 that sends hot water from a hot water outlet 4a provided in a lid 4b that seals a hot water production well 4 to a reinjection well 5.
Heat exchanger 18 with heat exchange element 18a in 7
and a heat medium steam turbine 19 whose steam inlet 19a communicates with the heat medium outlet 18b of the heat exchanger 18.
a generator 21 connected to the output shaft of the steam turbine 19; a condenser 22 whose exhaust inlet communicates with the exhaust port 19b of the heat medium steam turbine 19; and a condenser 22 whose suction port communicates with the outlet of the condenser 22. It consists of a heat medium pump 23 whose discharge port communicates with the heat medium inlet 18c of the heat exchanger. Heat exchanger 18, steam turbine 1
9. A heat medium is sealed in a closed pipe line connecting the condenser 22 and the pump 23.

The steam production well 1 is a well from which steam self-gushes, and is sealed above ground with a lid 1b. The reinjection well 2 is a well that does not emit steam and is drilled underground to a stratum that connects underground to the stratum that generates steam in the steam production well 1 at a position that does not affect the steam artesian injection of the steam production well 1.The well is sealed above ground with a lid 2a. be.

The hot water production well 4 is a well that gushes out high-temperature hot water, and is sealed above ground with a lid 4b.

A downhole pump 24 is housed in the hot water production well 4 . The downhole pump 24 has an output shaft of an upper steam turbine 25 connected to a pump shaft of a lower hot water pump 26, and the casings of the steam turbine 25 and the hot water pump 26 are fastened together to form an elongated cylindrical shape as a whole. . In the hot water pump 26 , the geothermal water in the hot water production well 4 is sucked in through a suction strainer 27 at the lower part, and is increased in speed and pressure by an internal impeller, and then sent from the upper part of the hot water pump 26 to the hot water pump 26 and the steam turbine 25 . Geothermal water is discharged from a geothermal water discharge port 28 that opens at the outer periphery of the geothermal water, and the space between the outer periphery of the casing of the hot water pump 26 and the wall of the hot water production well 4 is sealed by a sealer 29.

Below the packer 29 of the hot water production well 4 is the gushing part of geothermal water, and above the packer 29 are the walls of the hot water production well 4, the steam turbine 25, and the outer cylinder 31.
A geothermal water discharge passage 30 is formed between the two and communicates with the hot water piping 17 described above.

The downhole pump 24 has an upper end fixed to the lid 4b of the hot water production well, and a lower end suspended by an outer cylinder 31 fixed to the upper end of the steam turbine 25.

An inner cylinder 32 is inserted and held in the outer cylinder 31 with a gap in between so as to form a driving steam inlet passage 33. One end of the inner cylinder 32 is connected to the exhaust steam return pipe 16, and the other end is connected to the steam return pipe 16. It is connected to communicate with the steam outlet of the turbine 25, and the inside of the inner cylinder 32 is a driving steam exhaust passage 34. The driving steam inlet passage 33 connects the above-ground steam introduction pipe 15 and the steam turbine 2.
It communicates with the steam inlet of 5.

The reinjection well 5 is a well drilled at a location that does not affect the production of geothermal water in the hot water production well 4 to a stratum underground that is connected to the stratum that produces geothermal water in the hot water production well 4, and is located above ground with a lid 5a. It's sealed.

The operation of the above embodiment of the present invention will be explained as follows.

The steam produced in the steam production well 1 enters the steam water separator 7 from the steam inlet 7a through the artesian steam introduction pipe 10, the hot water in the artesian steam is separated, and the separated hot water is separated from the separated hot water outlet 7b. The water is returned to the reinjection well 2 through the water return pipe 10a, and the remaining steam is returned to the steam outlet 7.
c, enters the steam turbine 8 through the steam inlet 8a, drives the steam turbine 8, and also enters the steam introduction pipe 1.
5. Drive the steam turbine 25 through the drive steam inlet passage 33; The steam turbine 8 drives a generator 9 to convert the heat and pressure of the steam into electrical energy, and this electric power becomes the output of the geothermal steam power generation plant 3. The steam turbine 25 rotates a hot water pump 26, which sucks geothermal water through a suction strainer 27, sends out the hot water from a geothermal water outlet 28, and supplies it to the geothermal binary power generation plant 6.

Exhaust gas discharged from the exhaust port 8b of the steam turbine 8 enters the condenser 11 from the exhaust intake port 11a. The exhaust gas of the steam turbine 25 passes through the drive steam exhaust passage 34, passes through the exhaust steam return pipe 16, and enters the condenser 11 from the exhaust intake port 11a. In the condenser 11, the exhaust gas of the steam turbines 8 and 25 is sent to the water sprinkler 11.
The cooling water sprayed from c is directly mixed and cooled to liquefy and become high-temperature water, which is then sucked into the hot water pump 13 through piping from the hot water outlet 11d at the bottom of the tank.
3, the high temperature water is sent to the cooling tower 14, and in the cooling tower 14, the high temperature water sent in is sprayed by a water sprinkler 14a, and outside air is sent to the sprayed high temperature water by a blower 14b to cool it. Steam generated when high-temperature water is cooled is released into the atmosphere from between the blower 14b and the upper opening circumferential wall of the cooling tower 14, and the cooled cooling water is passed from the cooling water outlet 14c to the cooling water pump 1 through piping.
2 and is sent from the discharge port of the cooling water pump 12 to the water sprinkler 11c of the condenser 11 through piping.

From the geothermal water discharge passage 30 to the hot water outlet 4a,
The geothermal water passing through the hot water pipe 17 heats and evaporates the heat medium passing outside the heat exchange element 18a of the heat exchanger, and the geothermal water itself lowers its temperature and returns to the reinjection well 5, where it is returned underground.

In the heat exchanger 18, the heat medium heated through the heat exchange element 18a described above reaches the steam inlet 19a of the steam turbine 19 from the heat medium outlet 18b, and the steam turbine 19 converts the heat and pressure energy of the heat medium into rotational force. , drives the generator 21. generator 21
The output is the output of the geothermal binary power generation plant 6. The heat medium whose energy has been recovered by the steam turbine 19 is transferred from the exhaust port 19b to the condenser 22.
and is condensed in the condenser 22. The heat medium condensed in the condenser 22 is sent to the heat medium inlet 18c of the heat exchanger 18 by the heat medium pump 23, and is then transferred to the heat medium inlet 18c of the heat exchanger 18.
Cycles through 8.

The present invention provides piping and equipment for guiding a part of the steam from a steam production well supplied to a geothermal steam power generation plant to a steam turbine for driving a downhole pump driven by an in-well steam turbine installed in a hot water production well. Since the steam turbine is driven by the self-propelled steam generated by the steam production well, it is extremely efficient and more efficient than an electric motor driven from within the well or from the ground, which is driven by the privately generated electricity of the geothermal binary power generation plant. Reduced efficiency due to heat exchange, such as when steam generated by heating a heat medium from hot water using a heat exchanger in a private geothermal binary power generation plant is used to drive the steam turbine of a hall pump. Since there is no energy at all, the energy recovery rate of a geothermal power plant that combines a geothermal steam power plant and a geothermal binary power plant is high.

In order to supply and discharge steam to the steam turbine for driving such a downhole pump, a steam introduction pipe 15 that communicates the steam outlet of the steam separator of the geothermal steam power generation plant and the drive steam inlet passage of the turbine and the exhaust of the water sprinkler are used. It is only necessary to install an exhaust steam return pipe 16 that communicates the intake with the driving steam exhaust passage of the steam turbine for driving the downhole pump, and the equipment cost is low.

In the above explanation, a geothermal binary power generation plant generally receives geothermal water from the hot water production well 4 and heats the heat medium through heat exchange, and the output is geothermal binary for electrical load, refrigeration load, and heating load. It only needs to be a plant.

[Brief explanation of drawings]

FIG. 1 is a flow sheet of an embodiment of the present invention. 1...Steam production well, 1a...Steam outlet, 1b...
...Lid, 2...Reduction well, 2a...Lid, 3...Geothermal steam power generation plant, 4...Hot water production well, 4a...Hot water outlet, 4b...Lid, 5...Reduction well, 5a... …
Lid, 6... Geothermal binary power generation plant, 7... Steam water separator, 7a... Steam inlet, 7b... Separated hot water outlet, 7c... Steam outlet, 8... Steam turbine,
8a... Steam inlet, 8b... Exhaust port, 9... Generator, 10... Self-propelled steam introduction pipe, 10a... Separated water return pipe, 11... Condenser, 11a... Exhaust intake port, 11c... Water sprinkler, 11d...Hot water outlet, 1
2...Cooling water pump, 13...Hot water pump, 14
...Cooling tower, 14a...Water sprinkler, 14b...Blower, 14c...Outlet, 15...Steam introduction pipe, 16
...Exhaust steam return pipe, 17...Hot water piping, 18...
...Heat exchanger, 18a...Heat exchange element, 18b...
Heat medium outlet, 18c... Heat medium inlet, 19... Steam turbine, 19a... Steam inlet, 19b... Exhaust port, 21... Generator, 22... Condenser, 23...
... Heat medium pump, 24 ... Downhole pump, 25 ... Steam turbine, 26 ... Hot water pump, 27 ... Suction strainer, 28 ... Discharge port,
29...Patzker, 30...Geothermal water discharge passage, 3
1... Outer cylinder, 32... Inner cylinder, 33... Drive steam inlet passage, 34... Drive steam exhaust passage.

Claims (1)

[Claims] 1. In a drive device for an in-well steam turbine-driven downhole pump that extracts underground hot water, the downhole pump is installed in a hot water production well containing a large amount of hot water, and another steam production well containing a large amount of steam is produced. 1. A driving device for an in-well steam turbine-driven downhole pump, comprising piping and equipment for guiding steam from a well to a steam turbine for driving the downhole pump.