JPS5810168A - Method of utilizing heat possessed by hot water discharged from geothermal heat utilizing steam turbine - Google Patents

Abstract

PURPOSE:To make an efficient use of heat, by utilizing hot water, left after utilization steam contained in underground hot water for driving a steam turbine, in a plurality of pressure stages, exchanging a heat between the hot water and a low-boiling medium at each pressure stage, and using the vapor of said low-boiling medium thus produced also as a driving source. CONSTITUTION:Underground hot water drawn up from a well 1 is separated into steam and hot water in a separator 2. The steam is used to turn a turbine 4 and to thereby generate electric power by a generator 5, while hot water separated from steam is introduced into the first stage 10 of a multi-stage flasher after its pressure is reduced by a hot-water nozzle 24 and exchanges heat with a low- boiling medium (for instance, Freon) passed through heat exchanger tubes in the first flasher 10, thus producing vapor of the low-boiling medium. By repeating the above process also in the second and the third flashers 11, 12, all of the low- boiling medium is converted into vapor, which is used to turn a turbine 13 and to thereby generate electric power by a generator 14. Hot water discharged from the third flasher 12 is carried back to a return well 20 via the second last stage 18 and the last stage 17 by a pump 19.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of utilizing hot water heat in a geothermal steam turbine, and particularly relates to a method of utilizing hot water heat using a low boiling point medium such as Freon R, 114 or isobutane.

Generally speaking, the use of geothermal heat from the volcanic areas that exist in Japan is
Rather than using geothermal heat directly, underground water absorbs heat from the geothermal heat and uses the heat of evaporated steam. However, underground hot water contains a large proportion of steam and a sufficient amount of saturated steam can be obtained. It has a low steam content, and is rather similar to hot water. Therefore, a low boiling point medium,
In other words, heat is transferred to Freon R114 or isobutane, etc. to evaporate it, and the vapor of the low boiling point medium causes i
A power generation system was used to drive the bins.

This type of method uses steam in hot water gushing out from underground to
This is an indirect method in which heat is first transferred to another heat medium and turned into steam to be used in a turbine to generate electricity, and it was not necessarily appropriate from the standpoint of effective heat utilization.

An object of the present invention has been made in view of the above, and it is an object of the present invention to provide a method that can effectively utilize the heat of underground hot water to drive a steam turbine, and also use the heat of the hot water of the steam turbine as a power source. .

The present invention provides a steam turbine power generation facility using steam contained in underground hot water, in which the hot water from the steam turbine is divided into multiple pressure stages, and the steam generated by reducing the pressure of the hot water in each stage is used to drive the steam turbine. It is characterized by heat exchange between the hot water generated from the source, a low boiling point medium, and the low boiling point medium being evaporated to serve as a power source.

Embodiments of the present invention will be described below based on the drawings. 1st
Figure 1 is a system diagram of a power generation cycle using underground hot water to explain the implementation state of an embodiment of the present invention. Figure 2 is a detailed vertical sectional view of the paragraphs of the fluorocarbon boiling heat exchange section equipped with vertically arranged heating tubes of the multi-stage flasher shown in Figure 1, and Figure 3 is a detailed longitudinal sectional view of the fluorocarbon boiling heat exchange section equipped with horizontally arranged heating tubes. FIG. 4 is a detailed cross-sectional view of the paragraph, and FIG. 4 is a plan view thereof. In these figures, the same parts or parts that act in the same way are given the same reference numerals; 1 is a production well for underground hot water; 2 is a steam-water separator;
3 is the main steam pipe, 4 is the steam turbine, 5 is the generator, 6 is the direct contact condenser, 7 is the cooling tower, 8 is the circulating water port,
9 is a condensate pump, 10 is a multi-stage flasher first stage, 1
1 is the second stage of the multi-stage flasher, 12 is the third stage of the multi-stage flasher,
13 is a fluorocarbon steam turbine, 14 is a fluorocarbon turbine generator, 15 is a fluorocarbon steam condenser, 16 is a fluorocarbon condensate pump, 17 is a multi-stage crusher final stage, 18 is a multi-stage crusher before the final stage, 19 is a hot water return pump, 20 is a Reduction well, 21 is a flasher body, 22 is a flasher ice chamber, 23 is a flasher heating pipe, 24 is a hot water nozzle, 25 is a hot water inlet pipe, 26 is a hot water outlet pipe, 27 is a next stage hot water nozzle, 28 is a flasher housing, 29
is a hot water supply pipe, 30 is a hot water nozzle, 31 is a hot water fountain,
32 is a condensate enclosure, 33 is a baffle plate, 34 is a condensate downcomer pipe, 3
5 is a fluorocarbon liquid heating tube, 36 is its plate, and 37 is a water chamber.

As shown in Figure 1, underground hot water, which is a mixture of steam and water, is
The production well 1 passes through a conduit to a steam separator 2. Here, the steam is separated into steam and hot water, moisture is removed, the steam reaches the main steam pipe 3, enters the steam turbine 4, drives the generator 5, and generates electricity.

- On the other hand, the hot water from which the steam has been separated is depressurized by the hot water nozzle 24, and together with the expanded steam, the first stage 10 of the multi-stage flasher
is injected into the flasher cylinder 21. At this time, the inflow hot water is
The pressure inside the flasher cylinder 21 decreases, and the temperature of the flasher cylinder 21 drops, reaching the temperature of the saturated liquid at that pressure, and part of the hot water turns into steam. This flashed hot water flows down along the outer wall of the vertically arranged flasher heating tubes 23, heating and evaporating the fluorocarbon vapor and its saturated liquid flowing upward in the tubes.

The saturated hot water that has flown down the outer wall accumulates in the lower part of the flasher barrel 21, and is ejected from the next-stage hot water nozzle 27 due to the pressure difference within the barrel of the second stage multistage flasher 11, enters the barrel of the second stage flasher 11, and expands. The same operation as in the flasher first stage 10 is performed.

As described above, in the third stage 12 of the multi-stage flasher, all of the fluorocarbon in the tube becomes steam, reaches the fluorocarbon steam turbine 13, drives the turbine, rotates the fluorocarbon turbine generator 14, and generates electricity.

The fluorocarbon vapor that has done work enters the fluorocarbon vapor condenser 15 and is cooled to become a fluorocarbon liquid, which is then pressurized by the fluorocarbon condensate pump 16 and sent to the final stage 17 of the multi-stage flasher. In this way, it is heated in the multi-stage flasher and becomes steam again and is circulated.

The hot water that has passed through the third stage 12 of the multi-stage crusher flows into the front stage 18 of the multi-stage crusher through the hot water supply pipe 29. Next, the saturated hot water, which is expanded by the hot water nozzle 30 and partially turned into steam, uniformly gushes out from the dish-shaped wide weir of the hot water spring 31, whereupon the steam is separated from the hot water and reaches the fluorocarbon liquid heating pipe. By heating the fluorocarbon liquid in the pipe, it loses its latent heat of vaporization and condenses to liquefy. At this time, in order to effectively exchange heat, a condensate enclosure 32. The baffle plate 33 defines a steam passage. The condensed water passes through the condensate downcomer pipe 34 and is combined with the condensate accumulated at the bottom of the shuffler housing 28.

The multi-stage flasher final stage 1°°7 supplies hot water by the difference in cylinder pressure between the final stage 18 and the final stage 17, and other phenomena and operations are the same as the multi-stage flasher final stage 18.

The condensate accumulated at the bottom of the flasher casing 28 is returned to the ground through the return well 20 by the hot water return pump 19.

The fluorocarbon liquid heating tubes 35 of the final stage 17 of the multi-stage flasher and the pre-final stage 18 of the seven-stage flasher are arranged horizontally. This is because the liquid must not be mixed with steam to pass through the pipe, and because steam passes outside the pipe and becomes condensate, the structure is designed to make the steam flow path as short and uniform as possible. It is.

As explained above, according to the present invention, underground hot water can be effectively used by a multi-stage flash method to drive a steam turbine, and the hot water heat can be used to generate a low boiling point medium by heat exchange with a low boiling point medium. It can be evaporated and used as a power source, making it compact and providing excellent practical effects.

[Brief explanation of the drawing]

Fig. 1 is a system diagram of a power generation cycle using underground hot water to explain the implementation state of one embodiment of the present invention, and Fig. 2 is a diagram of the fluorocarbon boiling heat exchange section equipped with the vertically arranged heating tubes of the multi-stage flash shown in Fig. 1. FIG. 3 is a detailed cross-sectional view of the paragraph of a fluorocarbon boiling heat exchange section similarly equipped with horizontal tube array heating tubes, and FIG. 4 is a plan view thereof. 1... Production well, 4... Steam turbine, 10-12.
...Multi-stage flasher 1st to 3rd stage, 13...Freon steam turbine 3rd figure °° η figure

Claims (1)

[Claims] 1. In a steam turbine power generation facility using steam contained in underground hot water, the hot water from the steam turbine is divided into multiple pressure stages, and the steam generated by reducing the pressure of the hot water in each stage is used as a driving source for the steam turbine. 1. A method for utilizing hot water heat in a geothermal steam turbine, which comprises exchanging heat between the generated hot water and a low boiling point medium while using the geothermal steam turbine, and evaporating the low boiling point medium to provide a power source.