JP2008298309A - Steam separator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a steam separator capable of keeping high separating capacity of boiled water. <P>SOLUTION: In this steam separator 7 for a boiler with a vertically long cylindrical barrel 4 portion, having a steam taking-out pipe 1 connected with an upper portion of the steam separator 7 and a return water pipe 2 connected with a bottom portion of the steam separator 7, and circulating the gas-liquid two-phase flow composed of the steam and the boiled water inside of the steam separator 7, so that the steam and the boiler water are separated by action of centrifugal force, a collection space 5 having a diameter smaller than an inner diameter of the steam separator barrel 4 portion and larger than an inner diameter of the water return pipe 2 is defined at a lower portion in the steam separator, and the return water pipe 2 is connected with a lower portion of the collection space 5. Further the collection space 5 has the shape of which cross-section is reduced downward. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a steam / water separator for a boiler that separates steam and can water by centrifugal action.

  In general, in a steam boiler that generates steam by heating water, a steam / water separator for separating steam and can water is provided in order to prevent boiling can water from being taken out together with the steam and lowering the steam quality. The steam-water separator has a centrifugal-type steam-water separator that swirls a gas-liquid two-phase flow along the inner wall surface inside a vertical cylindrical body and separates steam and can water by the action of centrifugal force. Widely used. The centrifugal steam-water separator has a steam communication pipe connected in the tangential direction of the steam-water separator body, and when the gas-liquid two-phase flow flowing into the steam-water separator is swirled in the steam-water separator, The can water having a high specific gravity is separated by centrifugal force and falls while swirling along the inner wall of the cylinder, and the steam having a low specific gravity collects in the upper part of the cylinder, so that the steam and the can water can be separated. The steam separated by the steam separator is taken out through a steam outlet pipe connected to the top of the steam separator, and the can water separated by the steam separator is returned to the bottom of the steam separator. It returns to the bottom of the boiler body through the water pipe.

In the boiler, the amount of canned water flowing into the steam separator varies depending on the operating conditions. If the amount of canned water entering the steam separator becomes large and the canned water discharge from the steam separator to the return pipe cannot be made in time, the amount of canned water that accumulates in the lower part of the steam separator increases and the water level increases. Become. When the water level in the steam / water separator becomes high, the space capacity for separating the steam and the can water becomes small, so that the separation ability is lowered. If the separation capacity of can water is reduced, the problem is that the can water is taken out together with the steam and the quality (dryness) of the steam is lowered.
JP 2002-48303 A

  The problem to be solved by the present invention is to provide a steam separator capable of maintaining a high separation capacity of can water.

  The invention according to claim 1 is a steam / water separator having a vertically long cylindrical body, a steam take-out pipe connected to the top of the steam / water separator, and a return water pipe connected to the bottom of the steam / water separator. In a steam / water separator for a boiler, the steam / water two-phase flow consisting of steam and can water is swirled inside the steam / water separator and separated into steam and can water by the action of centrifugal force. In the lower part of the inside, a collecting space having a diameter smaller than the inner diameter of the steam-water separator body and larger than the inner diameter of the returning water pipe is provided, and the returning water pipe is connected to the lower part of the collecting space. And

  The invention according to claim 2 is characterized in that, in the steam-water separator, the collective space has a shape in which a cross-sectional area is reduced downward.

  When the cross-sectional area is gradually reduced from the steam separator to the return water pipe, the swirling flow from the can water gradually gathers in the direction of the central axis with the swirling diameter gradually reduced. The pressure loss that occurs when the can water is drained from the vessel to the return pipe is reduced. When the pressure loss at the bottom of the steam / water separator is reduced, the flow of canned water flowing from the bottom of the steam / water separator to the return water pipe becomes smooth, and the amount of canned water remaining in the steam / water separator is reduced. Can keep the water separation capacity high. The steam / water separator can be made compact by increasing the steam / water separation capability, and if it has the same volume, the dryness of the steam taken out from the steam / water separator can be increased.

  An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a schematic diagram of a boiler embodying the present invention, FIG. 2 is an explanatory diagram of a swirling water flow in a steam separator implementing the present invention, and FIG. 3 is a can water in a conventional steam separator. It is explanatory drawing of a swirl flow.

  The boiler generates steam by heating the can water in the steam generating section 6. Since the steam taken out from the steam generation unit 6 contains canned water that is lifted by boiling, a steam separator 7 is provided for separating the canned water from the steam. The steam separator 7 swirls steam containing can water inside and separates steam and can water using centrifugal force. The separated steam is taken out from the top of the steam separator and used as steam. The can water is taken out from the lower part of the steam separator and returned to the lower part of the steam generating unit 6.

  The steam / water separator 7 is a container having a vertical cylindrical barrel 4 whose upper and lower sides are covered with end panels, each having a steam extraction pipe 1 at the top, a return water pipe 2 at the bottom, and a steam communication pipe 3 at the side. Connecting. The steam extraction pipe 1 and the return water pipe 2 are connected so as to be concentric with the trunk 4. The steam communication pipe 3 is connected in the tangential direction of the body wall surface so that the steam flow swirls along the inner wall of the body when the steam is introduced into the body 4.

  A collecting space 5 having a diameter smaller than the inner diameter of the steam-water separator body and larger than the inner diameter of the return water pipe 2 is provided below the steam-water separator. The collective space 5 is also concentric with the trunk 4 and the return water pipe 2, and the return water pipe 2 is connected to the lower part of the collective space 5. The collective space 5 is intermediate between the inner diameter of the steam-water separator and the inner diameter of the return water pipe, and the cross-sectional area of the flow path is stepwise so that the cross-sectional area of the steam-water separator> the cross-sectional area of the gather space> the cross-sectional area of the return water pipe Keep it getting smaller. Further, it is more preferable that the collecting space 5 has an inclined shape so that the cross-sectional area of the flow path gradually decreases from the upper part connected to the steam separator to the lower part connected to the return water pipe. The inclination of the collective space 5 may be one in which the diameter is reduced with a shape having a straight section, or may be one in which the diameter is reduced with a shape having a curved section.

  The steam communication pipe 3 connects the steam generator 6 and the steam / water separator 7, and introduces steam generated by the steam generator 6 into the steam / water separator 7. When the steam is generated by heating the can water by the steam generating unit 6, the boiling of the can water is generated simultaneously with the generation of the steam. For this reason, the steam in the steam communication pipe 3 contains a large amount of can water. In particular, when the pressure in the boiler is low, the amount of water that enters the steam separator increases because boiling increases.

  When a gas-liquid two-phase flow composed of steam and can water is introduced into the shell 4 of the steam-water separator 7, the gas-liquid two-phase flow swirls along the inner wall surface. When the two-phase flow is swirled, the liquid canned water has a heavy weight per unit volume, so it keeps swirling along the inner wall surface of the trunk by the action of centrifugal force and falls downward by the action of gravity. It becomes the flow of. However, since the vapor, which is a gas, is light in weight per unit volume and hardly affected by centrifugal force or gravity, even if it initially flows along the inner wall surface of the trunk, the central portion of the steam separator 7 is gradually And go out through the steam extraction pipe 1 connected to the upper part of the steam separator 7.

  The can water that has a spiral flow in the trunk is moved downward under the influence of gravity and enters the assembly space 5. The can water swirling along the inner wall surface of the trunk 4 swirls along the inner wall surface of the collective space 5, and the collective space 5 is a space having a slightly smaller diameter than the inner diameter of the trunk 4. Therefore, the swirl flow of the can water gathers in the direction of the central axis of the steam separator 7.

  In the conventional steam / water separator in which the steam / water separator 7 having a large inner diameter and the return water pipe 2 having a small inner diameter are directly connected and the flow path area is drastically reduced, the can water is generated when entering the return water pipe 2. Pressure loss increased, and the discharge of canned water from the steam separator 7 to the return water pipe 2 was worsened. Therefore, a collective space 5 having an intermediate diameter between the body portion of the steam separator and the return water pipe is provided so as to enter the return water pipe 2 through the collective space 5. In this way, the cross-sectional area gradually decreases from the steam separator to the return water pipe, and the swirling flow due to the can water gradually decreases the swirling diameter and gathers in the direction of the central axis. Go. If the swirling flow of the can water is gathered stepwise in the direction of the central axis, the pressure loss at the return water pipe connecting portion is greatly reduced, and the can water easily escapes from the steam separator to the return water pipe. If the amount of canned water staying in the lower part of the steam separator is reduced, a large separation space volume in the steam separator can be ensured, so that the ability to separate canned water is improved. Thus, if the water level of the can water in the steam separator can be kept low, the steam separator can be made compact. If the steam separator has the same volume, the dryness of the steam As a result, an increase of about 0.5% was obtained.

Outline diagram of boiler implementing the present invention Explanatory drawing of can water swirl flow in the steam separator which is carrying out the present invention Explanatory drawing of canned water swirl flow in conventional steam separator

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steam extraction pipe 2 Return water pipe 3 Steam communication pipe 4 Body 5 Collecting space 6 Steam generation part 7 Steam-water separator

Claims (2)

A steam / water separator having a vertically long cylindrical body with a steam take-out pipe connected to the top of the steam / water separator and a return water pipe connected to the bottom of the steam / water separator. In a steam / water separator for boilers that swirls a gas / liquid two-phase flow consisting of steam and can water and separates it into steam and can water by the action of centrifugal force, a steam / water separator is installed at the bottom of the steam / water separator. An air / water separator, characterized in that a collecting space having a diameter smaller than the inner diameter of the body portion and larger than the inner diameter of the return water pipe is provided, and the return water pipe is connected to a lower portion of the collecting space.   The steam-water separator according to claim 1, wherein the collective space has a shape in which a cross-sectional area is reduced downward.

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