JPH0154515B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention mainly relates to a downhole pump for a hot water production well used in a geothermal utilization plant including a hot water production well that gushes out hot water.

When pumping hot water from a geothermal well that contains a large amount of hot water that does not emit steam, the line shaft type,
A downhole pump driven by an in-well motor or an in-well turbine is used.

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 is poor.

An object of the present invention is to improve the energy recovery rate when using an in-well steam turbine for a downhole pump.

The present invention provides a drive device for an in-well steam turbine-driven downhole pump that extracts underground hot water from a hot water production well, and includes means for generating steam using a part of the hot water pumped up by the downhole pump. The steam drives an in-well steam turbine.

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 hot water production well that mainly gushes hot water and may contain steam, and 2 is a geothermal binary power generation plant 3 that is supplied with hot water from hot water production well 1, where thermal energy is recovered and the temperature becomes low. This is a reinjection well that returns hot water underground. 4 is a steam generator, and 5 is a condensing device.

The hot water production well 1 is a well that gushes out high-temperature hot water, and is sealed above ground with a lid 1b.

A downhole pump 6 is housed in the hot water production well 1 . The downhole pump 6 has an output shaft of an upper steam turbine 7 connected to a pump shaft of a lower hot water pump 8, and the casings of the steam turbine 7 and the hot water pump 8 are connected to form an elongated cylindrical shape as a whole. . In the hot water pump 8, the geothermal water in the hot water production well 1, which is sucked in through the suction strainer 9 at the bottom, is sped up and pressurized by an internal impeller.
Geothermal water is discharged from the upper part of the casing of the hot water pump 8 and the geothermal water production well 1, which is connected to the connection part between the hot water pump 8 and the steam turbine 7 and opens at the outer periphery of the geothermal water outlet 11. Patsucar 12 between walls
It is sealed by.

The area below the hot water production well 1's well 12 is a gushing part of geothermal water, and the space between the wall of the hot water production well 1 above the hot water production well 12, the steam turbine 7, and the outer cylinder 13 is a geothermal water discharge passage 14. ing.

The downhole pump 6 has an upper end fixed to the lid 1b of the hot water production well, and a lower end suspended by an outer cylinder 13 fixed to the upper end of the steam turbine 7.

An inner cylinder 16 is inserted and held in the outer cylinder 13 with a gap therebetween so as to form a driving steam inlet passage 15, and one end of the inner cylinder 16 is connected to an exhaust pipe 17.
The other end is connected to communicate with the steam outlet of the steam turbine 7, and the inside of the inner cylinder 16 is a driving steam exhaust passage 18. The drive steam inlet passage 15 communicates the air supply pipe 19 on the ground with the steam inlet of the steam turbine 7 .

Reduction well 2 is a well that is drilled underground to a stratum that connects underground to the geothermal water-producing stratum of hot water production well 1 at a location that does not affect the production of geothermal water of hot water production well 1. It's sealed.

Geothermal binary power generation plant 3 is as follows.

A hot water supply pipe 21a, a hot water main pipe 21b, and a hot water primary pipe 21c, which send hot water from a hot water outlet 1a provided in a lid 1b that seals the hot water production well 1 to the reinjection well 2, branch off and meet at a confluence point. Hot water piping 21 connected by
a heat exchanger 22 having a heat exchange element 22a therein;
A heat medium steam turbine 23 whose steam inlet 23a is connected to the heat medium outlet 22b of the heat exchanger 22 via piping, a generator 24 connected to the output shaft of the steam turbine 23, and whose exhaust inlet is connected to the heat medium Condenser 2 communicating with exhaust port 23b of medium steam turbine 23
5, and a heat medium pump 26 whose suction port communicates with the outlet of the condenser 25 and whose discharge port communicates with the heat medium inlet 22c of the heat exchanger. A heat medium is enclosed in a closed pipe line consisting of a heat exchanger 22, a steam turbine 23, a condenser 25, and a pump 26.

The steam generator includes a water supply pump 28 whose suction port is connected to a branch pipe 27 branched from a hot water supply pipe 21a at a branch A, and a water supply pump 28 whose hot water inlet 29a is
The hot water outlet 29b is connected to the hot water pipe 21 at the confluence point RO by the outlet pipe 31, and the steam outlet 29c is connected to the drive steam inlet passage 1.
and a steam generator 29 connected to an air supply pipe 19 communicating with the steam generator 5.

A heating device may be attached to the steam generator 29 in order to start the steam turbine 7 and to dry the steam supplied to the steam turbine 7.

The condensing device 5 is as follows.

The exhaust intake port 41a is connected to the exhaust pipe 17, the cooling water inlet leading to the water sprinkler 41c inside is connected to the discharge port of the cooling water pump 42, and the condenser 41 equipped with the hot water outlet 41d and the suction port are connected to each other. Condenser 4
Hot water pump 43 communicating with hot water outlet 41d of No. 1
The inlet leading to the water sprinkler 44a inside thereof communicates with the discharge port of the hot water pump 43, and is provided with a blower 44b for cooling the liquid sprayed by the water sprinkler 44a. It consists of a cooling tower 44 communicating with the suction port and a cooling water pump 42.

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

To start the downhole pump 6, steam within the system or other steam generation means outside the system is supplied to the steam turbine 7 by a heating device attached to the steam generator 29 through the air supply pipe 19 and the drive steam inlet passage 15. .

Geothermal water pumped up by a hot water pump 8 due to the rotation of the steam turbine 7 is sucked through a suction strainer 9, speeded up and pressurized, and sent to the ground from a geothermal water outlet 11 through a geothermal water discharge passage 14.

From the geothermal water discharge passage 14 to the hot water outlet 1a,
The geothermal water passing through the hot water piping 21 consisting of the hot water supply pipe 21a, the hot water main pipe 21b, and the hot water primary pipe 21c heats the heat medium passing outside the heat exchange element 22a of the heat exchanger, evaporates, and self-generates. The water cools down and returns to reinjection well 2, where it is returned underground.

In the heat exchanger 22, the heat medium heated through the heat exchange element 22a described above reaches the steam inlet 23a of the steam turbine 23 from the heat medium outlet 22b, and the steam turbine 23 converts the heat and pressure energy of the heat medium into rotational force. , drives the generator 24. generator 24
The output is the output of the geothermal binary power generation plant 3. The heat medium whose energy has been recovered by the steam turbine 23 is transferred from the exhaust port 23b to the condenser 25.
and is condensed in the condenser 25. The heat medium condensed in the condenser 25 is sent to the inlet 22c of the heat exchanger 22 by the heat medium pump 26, and circulates through the heat exchanger 22.

Due to the rotation of the steam turbine 7, the same geothermal water as described above flows during startup and in a steady state, and the geothermal water branches as follows and flows after startup and in a steady state.

A part of the hot water flowing through the hot water supply pipe 21a passes through the branch pipe 27 from branch A to the water supply pump 28, is pressurized by the water supply pump 28, enters the steam generator 29 from the hot water inlet 29a, and is depressurized. The steam generated during the pressure reduction is sent out from the steam outlet 29c, while the liquid remaining as hot water after the pressure reduction flows through the outlet pipe 31 and joins the hot water pipe 21 at the confluence point RO. Steam is supplied from the steam outlet 29c to the steam turbine 7 through the air supply pipe 19 and the drive steam inlet passage 15.

Thus, in a steady state, the geothermal water pumped up by the hot water pump 8 energized by the steam turbine 7 converts the geothermal water pumped up from the hot water production well 1 into steam through the steam generator 29, and the steam turbine 7 is operated. Ru.
Note that if a heating device is attached to the steam generator 29 and the high enthalpy steam is supplied to the steam turbine 7, the steam turbine 7 can be made smaller and the efficiency of the steam turbine 7 can be improved.

The exhaust of the steam turbine 7 is carried out through the driving steam exhaust passage 18
through the exhaust pipe 17 to the exhaust intake port 41a.
It enters the condenser 41 from there. In the condenser 41, the exhaust gas of the steam turbine 7 is liquefied by directly mixing and cooling the cooling water sprayed from the water sprinkler 41c, and is liquefied into high-temperature water, which is sucked into the hot water pump 43 via piping from the hot water outlet 41d at the bottom of the tank. The high-temperature water is then sent to the cooling tower 44 by the hot water pump 43, where the high-temperature water is sprayed by a sprinkler 44a, and outside air is sent to the sprayed high-temperature water by a blower 44b to cool it. Steam generated when high-temperature water is cooled is released into the atmosphere from between the blower 44b and the upper opening peripheral wall of the cooling tower 44, and the cooled cooling water is passed through the cooling water outlet 44c.
The cooling water is sucked into the cooling water pump 42 through piping,
The water enters the water sprinkler 41c of the condenser 41 through piping from the discharge port of the cooling water pump 42 and is distributed and circulated.

The present invention includes means for generating steam by installing a pump integrated with a steam turbine in a geothermal production well containing a large amount of hot water and using a portion of the hot water taken out. Since piping is provided to supply the generated steam to the steam turbine in the well, it can be used in deep hot water production wells, compared to installing an electric motor and steam turbine above ground and driving the pump in the well with a line shaft. When a downhole pump is driven by an electric motor using the output of a geothermal binary power generation plant, the total efficiency of the heat medium steam turbine η _t is equal to the total efficiency of the downhole pump steam turbine, and the efficiency of the heat exchanger η _h is calculated as follows: If the total efficiency of the machine is η _d and the efficiency of the electric motor that drives the downhole pump is η _n , then the efficiency is η _h・η _d・η _n , but in the present invention, the efficiency of the water supply pump 28 η _p is related instead. It is very efficient.

[Brief explanation of drawings]

FIG. 1 is a flow sheet of an embodiment of the present invention. 1...Hot water production well, 1a...Hot water outlet, 1b...
...Lid, 2...Reduction well, 2a...Lid, 3...Binary power generation plant, 4...Steam generator, 5...
Condensing device, 6... Downhole pump, 7... Steam turbine, 8... Hot water pump, 9... Suction strainer, 11... Discharge port, 12... Packer, 1
3... Outer cylinder, 14... Geothermal water discharge passage, 15...
Drive steam inlet passage, 16... Inner cylinder, 17... Exhaust pipe, 18... Drive steam exhaust passage, 19... Air supply pipe, 21... Hot water piping, 21a... Hot water supply pipe,
21b...Hot water main pipe, 21c...Hot water primary pipe,
22...Heat exchanger, 22a...Heat exchange element, 22
b... Heat medium outlet, 22 c... Heat medium inlet, 23
... heat medium steam turbine, 23a ... steam inlet,
23b... Exhaust port, 24... Generator, 25... Condenser, 26... Heat medium pump, 27... Branch pipe, 28... Water supply pump, 29... Steam generator,
29a...Hot water inlet, 29b...Hot water outlet, 29
c... Steam outlet, 31... Outlet piping, 41... Condenser, 41a... Exhaust intake, 41c... Water sprinkler, 41d... Hot water outlet, 42... Cooling water pump, 43... Hot water pump, 44...cooling tower, 44
a...water sprinkler, 44b...blower, 44c...exit, a...branch, b...merging point.

Claims (1)

[Claims] 1. In a drive device for an in-well steam turbine-driven downhole pump that takes out underground hot water, the pump is installed in a hot water production well containing a large amount of hot water, and a part of the hot water taken out is used to generate steam. 1. A driving device for an in-well steam turbine-driven downhole pump, comprising means for generating steam, and piping for supplying steam generated by the steam generating means to an in-well steam turbine.