KR20110106711A - Method of using high temperature vapour and apparatus for using high temperature vapour - Google Patents

Abstract

Disclosed is a method and apparatus suitable for hot steam, characterized in that the hot steam directly contacts the coolant to exchange heat with the coolant in a confined space before the condenser through which the hot steam passed through the turbine passes as a next step. In this case, in order to increase the surface area of the cooling water in contact with the steam, the cooling water may be sprayed on the hot steam in the form of droplets such as aerosols, or may flow along the surfaces of a plurality of conduits or fibrous bodies installed in the hot steam path.
According to the present invention, the cooling water is brought into direct contact with the hot steam and the contact area is increased to increase the efficiency of heat transfer between the two media, to facilitate the use of heat transferred from the steam, and to quickly discharge steam from the turbine. It is effective.

Description

Method and apparatus for using high temperature vapor {method of using high temperature vapour and apparatus for using high temperature vapour}

The present invention relates to a method and apparatus for obtaining hot water or steam using hot steam used to turn a steam turbine of a power plant and enabling rapid discharge of steam.

In thermal power generation, water is heated by heat generated when burning or reacting fuel to obtain high temperature and high pressure steam. The turbine is rotated by this steam, and power generation is carried out with the rotational force obtained here.

The steam after power generation is still at a high temperature of about 150 ° C. In power plants, this hot steam is usually brought into water by contacting the cooling water piping in the condenser. This water is sent back to the combustion chamber to form high pressure steam.

Thermal power plants use large amounts of cooling water for hot steam cooling. The hot water that is discarded after high temperature steam cooling in a power plant causes environmental and social problems due to its enormous amount.

Therefore, a number of methods for minimizing waste heat, increasing energy efficiency, effectively mass-producing, and suppressing environmental pollution due to waste heat have been proposed.

The operation of the condenser of the power plant is an important factor in this problem. Condensor is a facility that serves to reduce steam pressure to water to lower steam pressure in the condenser to promote steam discharge. As the vacuum degree of the condenser increases, the efficiency of the turbine is improved, so that the heat exchange between the steam and the cooling medium is efficiently performed at the condenser or the front of the condenser and the pressure lowering is important.

The present invention can efficiently reduce the high-temperature steam impulse in the turbine in the thermal power plant in the pre-stage stage, heat exchange to increase the power generation efficiency and energy utilization efficiency, and produce hot water at around 100 ℃ in real life It is an object of the present invention to provide an apparatus and method for using high temperature steam which can alleviate the problem of hot water drainage.

The method of using the high temperature steam of the present invention for achieving the above object is characterized in that the high temperature steam in direct contact with the cooling water in a limited space until the high temperature steam passing through the turbine passes through as a next step to exchange heat with the cooling water. do.

To increase the surface area of the coolant in contact with the steam, the coolant may be sprayed on the hot steam in the form of droplets, such as aerosols, or flow along the surface of a number of conduits or fibers installed in the hot steam's path of travel.

The coolant may be heat exchanged by contacting hot steam in the condenser or in a separate heat exchange space before the condenser. At this time, the resultant product (hot water or steam) obtained as a result of heat exchange between the steam and the cooling water may be drawn out of the space through a pipe connected to the limited space.

The apparatus for using high temperature steam of the present invention includes a heat exchange chamber having an outlet for discharging high temperature steam therein, a coolant pipe for supplying coolant into the heat exchange chamber, and a coolant for contacting the steam while the coolant is exposed to the heat exchange chamber. An area enlargement means, a steam pipe for connecting the hot steam to the discharge port, and a discharge pipe for discharging the hot water or low temperature steam which is the result obtained by contacting the coolant with the high temperature steam from the heat exchange chamber to the outside.

The cooling water area expansion means is composed of a cooling water injection nozzle installed in the heat exchange chamber and a compression means such as a pump for applying pressure to the nozzle, or a plurality of conduits or fibers connected to the cooling water container or pipe so that the cooling water flows to the surface thereof. Can be a sieve.

In the present invention, sea water (salt water) may be used as the cooling water, in which case, a desalination filter for treating the salt in the vaporized contact result may be operated.

In the present invention, when hot water is obtained as a result of the contact between the steam and the cooling water, it is preferable that the discharge pipe is formed on the bottom or lower side of the heat exchange chamber in order to withdraw the hot water out.

According to the present invention, in the condenser or its predecessor, the cooling water is brought into direct contact with the hot steam used in the steam turbine, and the contact area between the steam and the cooling water for heat exchange can be increased to increase the amount of heat transferred between the two media. And the cooling efficiency of the hot steam can be increased.

In addition, since the cooling water and the high-temperature steam is in direct contact with each other, there is no pipe piping such as a heat exchanger, and the heat transfer resistance is reduced because the heat transfer is not an indirect heat transfer through the pipe wall, thereby increasing the cooling efficiency.

As a result, when the cooling efficiency is increased, the pressure of the hot steam from the turbine can be significantly lowered faster than before, and the turbine efficiency can be increased by lowering the back pressure of the turbine installation space connected to the heat exchange chamber.

In addition, the result obtained in the heat exchange chamber is suitable for use in district heating and the like because the temperature can be higher than the conventional conditions if the cooling efficiency is higher, the waste heat pollution due to the warm water is intensified by releasing the result to outside Can be reduced.

When seawater is used as cooling water, fresh water can be obtained as a result using the present invention.

1 is a conceptual configuration diagram schematically showing an embodiment to which the present invention is applied in a power plant such as a cogeneration plant.
FIG. 2 is a conceptual configuration diagram schematically showing a modified embodiment in FIG.
3 is a conceptual configuration diagram schematically showing an embodiment to which the present invention is applied in a seawater desalination combined cycle power plant.
4 is a longitudinal cross-sectional view of a heat exchange chamber and a condenser of another embodiment of the present invention.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a conceptual configuration diagram schematically showing an embodiment to which the present invention is applied in a power plant such as a cogeneration plant.

The overall configuration is similar to that of a conventional cogeneration plant, but there is a difference in the configuration of the condenser as a result of the present invention. That is, the condenser of the cogeneration plant forms a limited space in which the method of the present invention is implemented, and the condenser and the peripheral equipment constitute the apparatus of the present invention.

First, in a power plant, fuel is combusted in a combustion chamber 110 in which fuel and air are supplied to boil water supplied to a boiler 120 and generate steam to be supplied to a steam turbine 130. Water vapor generated in the boiler 120 proceeds along the steam pipe and is discharged to impinge on the wings of the steam turbine 130 through the nozzle. As the volume or pressure increases during the phase change of water into water vapor, the steam impinging on the blades through the nozzle is ejected at high pressure, which creates mechanical rotation of the turbine to enable power generation.

The steam turbine 130 is rotated and discharged through the condenser pipe 148 to be moved to the condenser 140 connected to the steam turbine space. The condenser 140 to which the present invention is applied constitutes a closed container having a high height, and the high temperature steam from the steam turbine spreads upward through the steam outlet 142 at the end of the condenser pipe 140 formed upward from the closed container. Discharged into the condenser. The upper portion of the closed vessel upwards of the steam outlet 142 is provided with a coolant nozzle 144 sprayed downward toward the steam outlet. The cooling water nozzle 144 is sprayed in the form of an aerosol or a droplet having a small particle diameter through high pressure injection while supplying cooling water from the external cooling water pipe 146 to the condenser 140. Therefore, the steam and the coolant in the condenser 140 are in contact with each other on the surface of the droplet to exchange heat. Therefore, in this embodiment, the condenser 140 becomes the heat exchange chamber of the present invention.

Here, the heat transfer between the medium and the liquid phase is proportional to the contact area, proportional to the temperature difference, and related to the heat transfer coefficient of the medium, provided that the amount supplied per given time is constant. The boiler steam supply temperature is usually constant, which is mainly proportional to the contact area.

Therefore, if the mass of the cooling water is the same, the number of water droplets and the smaller the particle size increase the area of contact with the cooling water and water vapor, so the heat exchange is more efficient. In addition, since it is not an indirect heat transfer through the pipe wall, such as a conventional condenser, the heat transfer resistance is reduced to allow for faster and more heat transfer.

However, if the particle size of the droplets is too small, the droplets are gathered together along the air stream of the vapor discharged from the steam outlet, so that the droplets and vapor do not mix well, and the spray pressure of the nozzle must be increased in order to reduce the particle diameter. Since there is a problem that the amount of cooling water is easily limited, the particle diameter and nozzle injection pressure are selected so that the droplets mix with the rising water vapor while naturally falling due to gravity.

At this time, the supply amount of cooling water, the supply amount of water vapor, and the temperature of the water vapor can be controlled in which range, and the result of the contact is adjusted in consideration of whether it is hot water or a medium temperature steam having a lower temperature than the water vapor supplied from a steam turbine. do.

The result of the contact of the steam and the coolant may come out together with some hot water and low temperature steam, so that the hot water can be collected at the bottom of the condenser, and the hot water outlet and the hot water discharge pipe 149 may be formed at the bottom or the bottom thereof. Cold steam outlets and cold steam discharge piping may be provided.

One important matter to be considered is the degree of vacuum of the condenser 140. The hot steam exiting the steam turbine 130 to be supplied to the condenser 140 condenses into water when it meets the cooling water and loses heat, so the volume is rapidly reduced and the air pressure is rapidly lowered in the condenser internal space. This air pressure affects the space of the steam turbine connected to the condenser, thus affecting turbine efficiency.

Condensate, the result of the contact between steam and coolant, has a large amount of heat, so the water that is supplied in the form of hot water for district heating and recovered after being used for district heating is used as cooling water or to produce steam in the boiler. Can be supplied for.

FIG. 2 is a variation of FIG. 1, in which low temperature steam from the condenser 140 is introduced into the secondary condenser 150 through the low temperature steam discharge pipe 158 and spreads upwardly through the steam outlet 152. Discharged. The upper portion of the closed vessel above the steam outlet 152 is provided with a coolant nozzle 154 sprayed downward toward the outlet. The cooling water nozzle 154 supplies the cooling water to the secondary condenser 150 from the external cooling water pipe 146. The lower portion of the secondary condenser 150 has a space for collecting the hot water is connected to the hot water discharge pipe 149 of the previous embodiment.

In this embodiment, the condenser 140 and the secondary condenser 150 may be regarded as the heat exchange chamber of the present invention, and the secondary condenser 150 is provided separately in the prior art condenser and the condenser 140 in the prior art. It can also be seen as a heat exchange chamber. Therefore, although the secondary condenser 150 has the same configuration as the condenser 140 here, it may have a form in which the coolant is in thermal exchange with the low temperature steam through the pipe surface as in the conventional condenser.

3 is a conceptual configuration diagram schematically showing an embodiment to which the present invention is applied in a seawater desalination combined cycle power plant.

Similarly to the case of FIGS. 1 and 2 in the embodiment of FIG. 3, the overall peripheral configuration is similar to that of a conventional power plant, but there is a difference in the peripheral configuration in the configuration after the steam turbine which is an embodiment of the present invention.

The fuel is combusted in the combustion chamber to boil the water supplied to the boiler and generate water vapor to be supplied to the steam turbine 330. The superheated steam is released to impinge on the wings of the steam turbine 330. The steam impinging on the wing is ejected at high pressure to turn the steam turbine 330, the steam discharged through the steam turbine is introduced into the seawater evaporator 340 corresponding to the heat exchange chamber of the present invention.

The seawater evaporator 340 to which the present invention is applied constitutes a closed container, and is discharged while the hot water vapor is widely spread upward through the steam outlet 342 at the end of the hot steam pipe 348 facing upward from the bottom of the closed container. On the side of the steam outlet 342 is provided a seawater nozzle 344 for spraying the coolant to cross the direction that the steam outlet 342 is directed.

The seawater nozzle 344 supplies seawater from the outside to the seawater evaporator 340 through the seawater pipe 346 to inject the seawater in the form of an aerosol or droplets having a small particle diameter through high pressure injection. Therefore, the hot steam and the seawater in the seawater evaporator 340 is in contact with each other on the surface of the droplet to exchange heat.

The smaller the particle diameter of the water droplets of the seawater sprayed from the seawater nozzle 344, the more the area where the water vapor contacts the heat exchange is more efficient. In addition, direct heat transfer is achieved without a pipe wall, which enables faster and more heat transfer.

Normally, when the pressure and temperature of steam passing through the turbine are 5 kgf / cm ² and 150 ° C., the amount of seawater and the amount of water vapor supplied is adjusted so that the result of the contact is lower than that of the steam supplied from the steam turbine 330. Adjust to steam close to ° C.

Part of the result of the steam and sea water contact is the steam is coming out together with the steam discharge pipe 351 formed on the sea water evaporator. The remainder of the product in contact with the steam and seawater may be discharged to the outside through the brine discharge pipe 349 at the bottom of the seawater evaporator 340 in the form of high concentration of brine.

Here, the air pressure of the seawater evaporator 340 is dependent on the degree of vacuum resulting from the volume reduction due to the condensation of the vapor in the condenser 353 in the next step.

In the upper space of the seawater evaporator 340, there are a plurality of salt filters or salt adsorption plates 352 configured to contact the cold steam generated by the contact with the seawater in the path of the vapor discharge pipe 351 and the low temperature steam. Allow small salt masses that are mixed together to collect.

The low temperature steam exiting the seawater evaporator 340 exchanges heat with the seawater through the seawater pipe 346 in the condenser 353, and the seawater is condensed into water while losing the latent heat.

The water may be supplied through the hot water pipe 355 in the form of hot water to be used in a house or a factory, or may be supplied as fresh water to a consumer while releasing heat to the surroundings.

Although not shown, the seawater evaporator 340 may further include a cleaning spray nozzle for supplying fresh water or low salt water to clean the wall or the salt absorbing plate and to remove the salt collected therein.

4 is a cross-sectional view showing a longitudinal section of another embodiment of the present invention.

In this embodiment, the basic configuration of the surrounding steam turbine, boiler, etc. is not significantly different from the above embodiments, but the difference in the form of the heat exchanger 400 and the condenser 500 in which heat exchange is performed.

In this embodiment, the heat exchanger 400 is integrated with the condenser 500 and corresponds to the heat exchange space or heat exchanger of the present invention. The inner space of the heat exchanger 400 is roughly separated from the space of the condenser 500 by the cylindrical side wall 422, but between the top of the side wall 422 and the bottom wall of the upper seawater storage space 516 of the condenser 500. It is open, so it is not completely separated spatially.

A plurality of conduits 524 are installed in the region of the heat exchanger 400 surrounded by the side wall 422. The conduit 524 extends from the bottom wall of the upper seawater storage space 516 toward the bottom of the heat exchanger 540, and a micro-gap 518 near the conduit 524 on the wall forming the bottom of the seawater storage space 516. This allows seawater to flow along the surface of conduit 524 through this gap 518. The conduits 524 are installed so that a plurality of conduits have a high density at minute intervals.

In addition, there is a steam nozzle 430 installed at the end of the steam pipe 448 connected from the power plant steam turbine in the heat exchanger area, and the high temperature and high pressure water vapor is diffused while rising in the heat exchanger 400 space. The high temperature and high pressure steam diffuses from the steam nozzle 430 into the heat exchanger due to the pressure difference and encounters a plurality of conduits 524 in the path, and exchanges heat with seawater flowing on the surface of the conduit. In this process, a part of the seawater gets heat to become steam, and the high temperature and high pressure steam from the steam turbine loses heat and the temperature and pressure decrease. These water vapors flow into the condenser 500 region beyond the sidewalls 422. Even though some of the seawater is steam, the salt in the seawater is simply included in the seawater in a state where the concentration of seawater is increased and flows into the space under the heat exchanger to form a hydrothermal layer. The hot water layer having a high salt concentration is discharged to the outside through the hot water discharge pipe 424.

The condenser is formed in a cylindrical shape in which the upper, lower and side surfaces 520 are mostly closed, and a heat exchanger is installed at the center to be connected to the heat exchanger. Seawater pipes 512 for transporting seawater are connected to the lower storage space 514 at a part of the side of the condenser 500, and the lower storage space 514 is connected to the upper seawater storage space 516 and the plurality of connecting pipes ( 510 is connected. The condensate discharge pipe 528 is installed on a portion of the lower side wall of the condenser 500.

When water vapor in a temperature and pressure drop state flows into the inner space of the condenser from the heat exchanger 400, the water vapor diffuses and moves from the center of the heat exchanger to the outer side and heat is transferred from the surface of the plurality of connection pipes 51. Loses and becomes condensate. Condensate flows down the surface of the connecting pipe 510 to form a condensate layer under the condenser, and the condensate layer is discharged to the outside of the condenser through the condensate discharge pipe 528. This condensate contains little salt and can be supplied to the outside as fresh water and to the steam boiler as make-up water.

Conduit 524 may be made of a solid rod, tube, etc. made of a heat-resistant material, but the whole of the conduit may be made of fibers to provide more seawater contact area for the high temperature and high pressure steam as seawater flows between the fibers, It may have the same effect by covering the fiber layer on the surface of the solid rod. When the whole is made of a fiber body, the fiber body may form a planar body like a cloth, not a linear body such as a string, and may allow water vapor to move through the cloth.

The low temperature steam exiting the heat exchanger 400 exchanges heat with seawater through the connecting pipe 510 in the condenser 500 as in the embodiment of FIG. 2, and condenses into water by depriving the vaporization heat while raising the temperature of the seawater. . In this process, the volume of water condenses as water condenses into water, and the pressure decreases rapidly, facilitating the movement of water vapor from the heat exchanger to the condenser, and the movement of water vapor from the steam turbine to the heat exchanger through the steam discharge pipe (448). It lowers the turbine back pressure and increases the efficiency of the turbine.

In order to control the pressure due to water vapor condensation, it is necessary to adjust the hourly supply of seawater, which is cooling water, and the size of the gap in the bottom of the upper seawater storage space that supplies the seawater to the conduits and the number of conduits, etc., during the manufacturing of the condenser and the heat exchanger. I can adjust it.

It is necessary to prevent the inflow of outside air or oxygen into the space inside the heat exchanger. In particular, when seawater is used as the cooling water as in this embodiment, the presence of air and salts promotes corrosion of the internal equipment. Since there may be air dissolved in the cooling water itself or air contained in water vapor supplied from the turbine side, the container wall, the seawater pipe wall, etc. is preferably formed of a material having corrosion resistance and heat resistance or surface treatment.

Although the present invention has been described in detail only with respect to the specific embodiments described, it will be apparent to those skilled in the art that various modifications and variations are possible within the technical spirit of the present invention, and such modifications and modifications belong to the appended claims. .

110: combustion chamber 120: boiler
130, 330: steam turbine 140, 150, 500: condenser
142, 152: steam outlets 144, 154: coolant nozzle
146: cooling water piping 148: condenser piping
149: hot water discharge pipe 150: secondary condenser
158: low temperature steam discharge pipe 200: condenser
340: seawater evaporator 342: steam outlet
344: seawater nozzle 346: seawater piping
348: high temperature steam piping 349: salt water discharge piping
351: steam discharge pipe 352: salt adsorption plate
353: heat exchanger 355: hot water piping
400: heat exchanger 422: side wall
424; Hot water drain line 430: Steam nozzle
448: steam tubing 510: connector
512: seawater piping 524: conduit
514, 516: seawater storage space 528: condensate discharge piping

Claims (7)

The method of using a high-temperature steam, characterized in that the hot steam is in direct contact with the cooling water in the limited space before the high temperature steam passing through the steam turbine in the thermal power plant to exchange heat with the cooling water. The method of claim 1,
Hot water steam using a method of spraying the cooling water in the form of an aerosol in the hot steam in order to increase the surface area of the cooling water, or flow along a plurality of conduit surfaces installed in the movement path of the hot steam. The method of claim 1,
High temperature steam using method characterized in that to supply the sea water to the cooling water. A heat exchange chamber into which hot steam flows in,
Cooling water pipe for supplying coolant into the heat exchange chamber,
Cooling water area expansion means for contacting the steam in the state that the cooling water is exposed in the heat exchange chamber,
A steam discharge pipe leading the high temperature steam into the heat exchange chamber;
And a discharge passage for discharging a result obtained by contacting the cooling water with the high temperature steam in the heat exchange chamber. The method of claim 4, wherein
The cooling water area expanding means includes a cooling water injection nozzle installed in the heat exchange chamber and compression means for applying pressure to the injection nozzle. The method of claim 4, wherein
The cooling water area expansion means is a high temperature steam using apparatus, characterized in that the plurality of conduits or fibers are connected to the cooling water container or pipe to the cooling water flow to the surface. The method according to any one of claims 4 to 6,
The hot steam is introduced into the heat exchange chamber via a steam turbine, and part of the resultant is connected to a separate condenser next to the heat exchanger through one of the discharge passages in the form of steam, and the other part of the resultant is in the form of hot water. High temperature steam using apparatus, characterized in that the discharge in the lower portion of the heat exchange chamber, the outside through the other of the discharge passage.

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