JPH05184830A - Moisture separator - Google Patents

Abstract

PURPOSE:To obtain the efficient moisture separator which is easily assembled and not damaged by providing an element vane at the side end between the separation elements or between the element blocks and forming a vapor passage between the vanes. CONSTITUTION:Many corrugated element vanes 3a having a V-shaped bend are arranged in parallel between the side plates 3c provided on both ends and separation element 3 and bound together by a spacer shaft and spacer. The elements 3 are arranged in parallel, and the adjacent side plates 3c are welded to constitute a separation element block 21. The element vane 3a is arranged outside the side plate 3c of the block 21, the block is combined with the like block, and a vapor passage 41 is formed by the gap 42 having a width M. The damage of the moisture separator due to the difference in thermal expansion between the internal components is prevented in this way, and the wet vapor is not leaked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for separating liquid particles contained in a gas, for example, an apparatus for separating moisture in a steam turbine used in a nuclear power plant.

[0002]

2. Description of the Related Art Generally, in a nuclear power plant or the like, steam that has passed through a high-pressure turbine and has worked contains water droplets of 10% or more and is wet steam. Therefore, when the steam that has passed through the high-pressure turbine is directly supplied to the low-pressure turbine, the turbine blades are eroded by water droplets and the turbine efficiency is reduced. Therefore, usually, a moisture separator is provided between the high-pressure turbine and the low-pressure turbine, and the steam that has passed through the high-pressure turbine by this moisture separator is supplied to the low-pressure turbine as almost dry saturated steam to prevent erosion of turbine blades and Prevents turbine efficiency from decreasing.

4 to 6 are vertical sectional views of a conventional moisture separator, FIG. 4 is an overall vertical sectional view, FIG. 5 is a sectional view taken along the line AA in FIG. 4, and FIG. FIG. 6 is a sectional view taken along line BB in FIG. In the closed cylindrical main body 1, between the end plates 2 and 2 mounted near the front and rear ends thereof, two rows of separating elements 3 and 3 extending in the axial direction parallel to each other are arranged. The separation elements 3 and 3 in each row extend in the axial direction between the both end plates 2 and 2, respectively, and are composed of two support leg plates 4a and 4b on the inner and outer sides which are parallel to each other.
Supported by.

The tops of the separating elements 3 and 3 in each row are located at the left and right ends of the ceiling plate 5 extending between the end plates 2 and 2.
Each is supported. On the other hand, the inner support leg plates 4a, 4a of the both support legs 4, 4 extend in the axial direction between the both end plates 2, 2 and are separated from the bottom wall portion of the main body body 1 and the bottom wall portions thereof. Both end portions of the bottom plate 7 forming the drain duct 6 therebetween are fixed to each other.

On the bottom plate 7, the top ends are adjacent to each other and the bottom ends are widened, and the bottom edges of the vapor distributing perforated plates 8, 8 extending parallel to the separating elements 3, 3 are provided. The perforated plates 8 are attached to the ceiling plate 5 at their top edges. Further, the space surrounded by the left and right separating elements 3, 3, the ceiling plate 5 and the bottom plate 7 is divided into front and rear by two duct wall plates 9 and 9 arranged in the center of the space. The duct wall plates 9 and 9 are connected at their upper ends to the ceiling plate 5 and at their lower ends to the bottom plate 7, respectively, and form a flash steam duct 10 which is in communication with a drain duct 14 described later.

By the way, the bottom plate 7 includes the end plate 2, the bottom plate 7,
Wet steam inlet pipes 12 and 12 that are formed by the perforated plate 8 and the duct wall plate 9 and that open to the front and rear steam distribution chambers 11 and penetrate the main body 1 wall are connected to each other,
Further, the inner support leg plate 4a of the support leg 4 is provided with a plurality of notches 13. On the other hand, a drain tank 14 is vertically provided at the center of the bottom wall of the main body 1, and a drain outlet 15 is provided at the lowermost portion. A steam outlet 16 is provided on the top wall.

The wet steam 30 discharged from the high pressure turbine (not shown) flows into the steam distribution chambers 11, 11 through the wet steam inlet pipes 12, 12 provided in the lower part of the moisture separator main body 1. And the wet steam 30 flowing into the steam distribution chamber 11
Is a substantially uniform flow rate over the entire surface of the perforated plate 8 due to the perforated plate 8 for distribution having a large number of holes having different opening areas according to the distance from the wet steam inlet pipe 12 and the like, and the separation element Inflow to 3. The wet vapor 30 that has flowed into the separation element 3 has water droplet particles captured and separated by the separation element 3, becomes dry vapor 31 and flows out of the separation element 3, and the vapor outlet 16 disposed at the upper part of the main body 1 is discharged. After that, it is guided to a low-pressure turbine (not shown).

On the other hand, in the separating element 3, the wet steam 30
The water droplet particles separated from become drain and fall into the support leg 4 composed of the inner and outer support leg plates 4a and 4b by gravity,
Further, it flows out into the drain duct 6 from the notch 13 provided in the inner support leg plate 4a and falls into the drain tank 14 vertically provided at the lower portion of the main body case 1. Then, the drain dropped into the drain tank 14 is introduced from a drain outlet 15 arranged in the lower portion of the drain tank 14 to a low-pressure feed water heater (not shown) or the like.

On the other hand, during operation, the steam turbine trips,
When the drain in the drain tank 14 causes self-evaporation due to a sudden pressure drop in the system when an accident such as load interruption occurs, it is necessary to quickly discharge the generated steam. For that purpose, a dedicated passage is provided, the self-evaporated vapor rises in the drain tank 14, flows into the flash vapor duct 10 which is a passage dedicated to the discharge of the self-evaporated vapor, and is installed in the flash vapor duct 10. By passing through the separation elements 3 and 3, the dry saturated steam 31 is obtained, and the dry steam 31 flowing out from the other separation elements 3
And flows out from the steam outlet 16 to the low-pressure turbine.

By the way, the separating element 3 is shown in FIG.
8B and a perspective view of the main part of FIG. 8A, and FIG.
As shown in the sectional view taken along the line CC in FIG.
The plurality of element vanes 3a, 3a are attached to the spacer shaft 3
b, 3b and spacers 3d, 3d are supported at equal intervals, and these are sandwiched by two side plates 3c to form a sandwich structure. The element vane 3a is shown in FIG.
As shown in FIG. 5, the steam 30 has a corrugated plate shape having a V-shaped bent portion and contains a large amount of moisture. Inflow to 40.

As the steam flows through the curved steam flow path 40, the moisture in the steam adheres to the surface of the element vane 3a and is separated from the steam by the centrifugal force and inertia due to the bending of the flow. The separated moisture becomes water droplets, which flows by gravity along the element vanes 3a and flows downward to become drains. The separation element 3 formed in this way is provided with the end plate portion of the main body 1 between the support leg 4 including the inner and outer support leg plates 4a and 4b and the holding plate 17 provided on the lower surface of the end of the ceiling plate 5. It is inserted so as to be slid from the side, a large number of separation elements 3 are housed without a gap, a separation element block is configured, and is fixed by an end plate 2.

However, the following problems occur during operation of the separation element block housed in the above structure. That is, in general, the difference between the room temperature when the separation element 3 is stored and the temperature inside the moisture separator during operation is 100 ° C.
As described above, the difference in elongation occurs due to the difference in the coefficient of linear expansion of the constituent materials in each part in the device. In particular, the difference between the carbon steel main body 1 and the supporting legs 4 and the stainless steel separating element 3 is remarkable, and an extension difference of several millimeters is usually generated in the axial direction of the main body cylinder 1.

If the separating element 3 cannot move in the axial direction at this time, as shown in FIG.
The spacer shaft 3b has a compressive load J corresponding to the above expansion difference.
Will be received. This load J reaches several tons, and so-called thermal stress generated in the spacer shaft 3b exceeds the normal allowable stress. Further, if the separation element block does not uniformly absorb the difference in elongation, excessive stress is locally generated, and if it is significant, the spacer shaft 3b and other members will be damaged.

Therefore, conventionally, as shown in the front sectional view of the main part of FIG. 9, for example, adjacent side plates 3c of three separating elements 3 are provided.
The upper and lower ends are welded and fixed to each other as shown in the enlarged plan view of the main part taken along the line EE in FIG. 10 to form one separation element block 18, and the expansion difference due to the temperature rise is further reduced. A plurality of separation element blocks 18 are connected in series to form a separation element block group with an appropriate gap 19 taken into consideration.

Also, in one separation element 3 of each separation element block 18, stopper pieces 20a, 20b are provided so as to contact the inner surfaces of the two side plates 3c, respectively.
It is welded and fixed to the upper surface of the inner support leg plate 4a. Therefore, considering the difference in expansion due to thermal expansion during operation of the moisture separator, the separation element block 18 in FIG.
It uniformly extends in _one direction and D ₂ direction, and this amount of extension is absorbed by the gaps 19 set on both sides of the separation element block 18.

[0016]

There is a gap in operation due to an installation error in the installation of the separation element 3 in the moisture separation device and a variation in the linear expansion coefficient of the material of the separation device such as the main body 1 and the separation element 3. 19 does not become the design value of zero, and some gaps may remain. FIG. 11 is a plan view taken along the line FF in FIG. 9, and as shown in FIG. 11, originally, the moist steam 30 passes through the steam flow passage 40 of the width K formed between the element vanes 3a. , The moisture should be separated to become dry steam 31, but if there is a gap 19 of width L between the side plates 3c on both sides of the separation element block 18, the wet steam 30 remains as it is. It passes through 19 and leaks. This has a problem that the separation performance of the moisture separation device is deteriorated.

The object of the present invention is to dispose an element vane at the end of the separation element or separation element block on the side of the gap, so that the assembly is easy and the difference in expansion due to the difference in linear expansion coefficient is absorbed. Another object of the present invention is to provide a moisture separation device that prevents damage due to the difference in thermal expansion and also has a moisture separation function in the gap to improve the moisture separation performance.

[0018]

A separation element or a separation element block formed by integrally connecting a plurality of separation elements in which a plurality of vapor flow paths for separating moisture are formed by a large number of element vanes in a main body cylinder. In a moisture separator in which a plurality of moisture separators are arranged with a gap between each other, an element vane is arranged at the gap side end of the separation element or separation element block, and moisture is separated between the element vanes at the gap side end. Form a vapor flow path that separates.

Further, the width of the vapor flow path for separating the moisture formed between the separation elements or the separation element blocks is larger than the difference in thermal expansion of the materials constituting the moisture separation device, and the humidity inside the separation element is large. It is characterized in that the width is the same as or smaller than the width of the vapor flow path for separating the components.

[0020]

The gap between the separation elements or the separation element blocks is a steam flow path formed by the element vanes facing each other, and has a function of separating moisture similarly to the steam flow path inside the separation element. .. Further, by setting the width dimension M of the gap which is the vapor flow path to be smaller than the width dimension K of the vapor flow path of the separation element (M <K), the moisture separation performance in the vapor flow path due to this gap is improved. It is higher than the steam flow path inside. Therefore, the moist vapor that has flowed into this gap also becomes dry vapor after passing, and the moist vapor does not leak in the separation element block group, and the moisture separation performance of the moisture separation device is improved.

Further, the width dimension of the gap between the separation element blocks is different from the conventional width dimension close to zero.
Since it is a gap that is close to the width dimension of the vapor flow path inside the separation element, the installation allowable range when incorporating the separation element etc. into the main body cylinder is large, workability is improved, and a moisture separation device is configured. Damage due to the difference in thermal expansion due to the difference in the linear expansion coefficient of the material can be prevented with a margin.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to the drawings. It should be noted that the same components as those of the above-described conventional technique are denoted by the same reference numerals and detailed description thereof will be omitted. In the separation element block of the present invention, as shown in the plan view of the main part of FIG. 1, a large number of corrugated plate-shaped element vanes 3a having V-shaped bent portions between the side plates 3c provided at both ends, Separation elements 3 formed by arranging them in parallel and joining together with side plates 3c, 3c at both ends by spacer shafts 3b and spacers 3d, and three such separation elements 3 are arranged in parallel, and adjacent side plates 3c are welded together for separation. The element block 21 is configured.

Further, element vanes 3a are arranged outside the side plates 3c located at both ends of the separation element block 21, and the element vanes 3a are arranged at the ends of the adjacent separation element blocks 21. In combination with the element vane 3a thus formed, a vapor passage 41 which is a gap 42 having a width dimension M is formed. The size M of the gap 42 is larger than the difference in thermal expansion between the separation element blocks 21, but is the same as or smaller than the width K of the vapor passage 40 inside the separation element (M ≦ K). Specified in.

Next, the operation of the above configuration will be described. gap
Like the conventional gap 19, the reference numeral 42 can improve workability when the separation element block 21 is incorporated into the main body 1 of the moisture separator and can absorb the difference in thermal expansion during operation. Since 42 forms a steam flow path 41 for separating moisture similarly to the steam flow path 40 inside the separation element described above, the wet steam 30 flowing into this gap 42 also becomes a dry steam 31 after passing. The moist steam 30 does not leak from the group of separation element blocks, and therefore the moisture separation performance of the moisture separation device is improved.

When the width M of the gap 42 which is the steam flow path 41 is set to be smaller than the width K of the steam flow path 40 inside the separation element, the moisture separation performance in the steam flow path 41 is determined by the steam flow inside the separation element. Since it is improved from the path 40, the steam passing through the steam flow path 41 in the gap 42 becomes the steam 31 which is further dry than the steam passing through the steam flow path 40 inside the separation element, and the moisture separation performance is further improved.

The width K of the vapor passage 40 inside the separation element of the present embodiment is approximately expressed by a specific number.
16 mm, the thermal expansion difference of the separation element block 21 at this time is about 2 mm. Thus, for example, in one embodiment,
The width M of the gap 42 between the element vanes 3a at the gap side ends of the adjacent separation element blocks 21 may be set to 2 to 16 mm.

Further, in the prior art, the installation work of the separation element block 18 should be performed with great care so that the width L of the gap 19 between the side plates 3c of the adjacent separation element blocks 18 shown in FIG. 11 is 2 mm. However, according to the present invention, the allowable range of the width dimension M of the gap 42 is 2
It is extremely wide, up to 16 mm, and the separation element block 21 can be easily installed, reducing the number of man-hours and the work period.

In the present embodiment, the separation element block 21 has been described as a structure in which three separation elements 3 are combined, but the number of combinations is not limited to three, and the dimensions of the moisture separation device are Depending on the shape and workability, the number may be one or another number, and the same operation and effect as those of the above-described embodiment can be obtained.

FIG. 2 is a plan view of a main portion of a separation element block showing another embodiment of the present invention. Like the above-mentioned prior art, a perforated plate 8 for vapor distribution is provided before and after the separation element 3.
Is provided. Further, FIG. 3 (A) is GG in FIG.
FIG. 3B is a front view taken along the arrow, and FIG. 3B is a sectional view taken along the line HH of FIG. As is apparent from FIG. 3 (A), the perforated plate 8 is a plate provided with a large number of holes 8a and is attached to all the separation elements 3 so that the vapor is evenly distributed.

Although the side plates 3c at both ends of the separating element 3 provided for the purpose of reinforcement in FIG. 1 are not provided in the structure of the other embodiment, the porous plate 8 is separated by using bolts 50. It is attached to the mounting bracket 51 of No. 3. As a result, the perforated plate 8 has not only the function of uniformly distributing the vapor, but also the role of reinforcing the separation element 3. For this reason, in order to reinforce the separation element 3 in the related art and in the above-described embodiment, the element vanes 3a can be additionally installed at the portions where the side plates 3c, 3c provided at both ends thereof are removed.

Incidentally, as shown in FIG.
Is supported by the support legs 4 and the ceiling plate 5,
The perforated plate 8 is attached to the front and rear of the separation element 3, and a cutout portion 52 is provided in the lower portion of the perforated plate 8. A stopper piece 53 is inserted into the cutout portion 52 and welded to the support leg 4. The separation element 3 is fixed to the support leg 4 by being fixed. Further, in the above-described embodiment shown in FIG. 1,
Inner method of side plate 3c indicated by dimension N and element vane 3a
The outer portion of the above is an ineffective portion having no moisture separation function, but in the other embodiments, the ineffective portion is eliminated, and the separation element 3 can be downsized accordingly.

The width of one separation element 3 is usually about 500 m
The size N of the side plate 3c is the size of the ineffective part, which is about 50 mm per one separating element. Therefore,
According to the other embodiment, the separation element 3 can be downsized by about 10%, and the moisture separation device can be downsized in the same manner to reduce the manufacturing cost and the construction period. The element vanes 3a at the end of each separation element 3
In the same manner as in the above-described embodiment, the vapor passages 41 are formed facing each other with the gap 42 between the adjacent separation elements 3 interposed therebetween.

Here again, the gap 42 has a width dimension M which is larger than the difference in thermal expansion, but the vapor flow path inside the separation element 3
Set the width to the same as or smaller than the width K of 40 (M ≦ K). As described above, also in the other embodiment, since the difference in thermal expansion is absorbed in the gap 42, there is no risk of damage due to the difference in thermal expansion, and the gap 42 is the same as the vapor flow path 40 in the separation element 3 or the above vapor. Since the steam flow path 41 has a separation function, the moisture separation performance does not deteriorate due to the leakage of the wet steam 30 from the separation element group.

In each of the above-described embodiments, the element vane is described as an example of the separation element 3 employing the corrugated plate-shaped element vane 3a having a V-shaped bent portion. Needless to say, the same action and effect can be obtained also in the separation element having the element vane of the shape.

[0035]

As described above, according to the present invention, the inside of the moisture separator is constituted by using the gap provided for absorbing the difference in expansion due to the difference in the linear expansion coefficient of the material constituting the moisture separator as the vapor passage. Prevents damage due to the difference in thermal expansion of objects, improves the moisture separation performance by eliminating the leakage of moist steam, and facilitates downsizing of the separation element and the moisture separation device. Since the assembling work becomes easy, there is an effect that the production cost and the construction period can be compressed.

[Brief description of drawings]

FIG. 1 is a plan view of a main part of a separation element block showing an embodiment of the present invention.

FIG. 2 is a plan view of a main part of a separation element block showing another embodiment of the present invention.

3 is a separation element block showing another embodiment of the present invention, and FIG. 3 (A) is a front view taken along the line GG in FIG.
(B) is a sectional view taken along the line H-H in FIG. 3 (A).

FIG. 4 is a vertical sectional view of a conventional moisture separator.

5 is a cross-sectional view taken along the line AA in FIG.

FIG. 6 is a sectional view taken along the line BB in FIG.

FIG. 7 is a perspective view of a main part of a conventional separation element.

8A is a sectional view of a conventional separation element block, FIG. 8A is a front sectional view of a main part, and FIG. 8B is a sectional view taken along the line CC in FIG. 8A.

FIG. 9 is a front sectional view of a main part of a conventional separation element block.

10 is an enlarged plan view of an essential part taken along the line EE in FIG.

FIG. 11 is a plan view of a main part of a conventional separation element block (plan view taken along the line GG in FIG. 9).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Body trunk, 2 ... End plate, 3 ... Separation element, 3a ... Element vane, 3b ... Spacer shaft, 3c ... Side plate, 3d
... Spacers, 4 ... Support legs, 4a ... Inner support leg plates, 4b ...
Outside support leg plate, 5 ... Ceiling plate, 7 ... Bottom plate, 8 ... Perforated plate, 17
... Presser plate, 18, 21 ... Separating element block, 19, 41 ...
Gap, 30 ... Wet steam, 31 ... Dry steam, 40 ... Vapor flow path inside separation element, 41 ... Vapor flow path in gap, 50
... Bolts, 51 ... Mounting brackets, 52 ... Notches, 53 ... Stopper pieces, J ... Load, K ... Width dimension of vapor passage inside separation element, L ... Width dimension of gap, M ... Vapor passage of gap Width dimension, N ... Dimension of side plate part.

Claims (2)

[Claims] 1. A separation element formed by forming a large number of vapor flow paths for separating moisture by a large number of element vanes in a main body cylinder, or a separation element block in which a plurality of separation elements are integrally connected are separated from each other by a gap. In a plurality of moisture separators arranged via the element, the element vane is arranged at the gap side end of the separation element or the separation element block, and the vapor flow for separating moisture between the element vanes at the gap side end. A moisture separator characterized in that a channel is formed. 2. The width of the vapor flow path for separating moisture formed between the separation elements or the separation element blocks is larger than the difference in thermal expansion of the materials constituting the moisture separation device, and the humidity inside the separation element is large. The moisture separation device according to claim 1, wherein the width of the vapor flow path for separating the components is equal to or smaller than the width.