JP2003207284A - Condenser and condensing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To eliminate deterioration of performance by restraining a stagnation part 8 of uncondensed gas to maintain inside of a shell in a desired vacuum condition. <P>SOLUTION: In this condenser, a pipe group 4 of a heat transfer pipe 3 for circulating cooling seawater is provided in a shell, and vapor is circulated in the pipe group 4 to cool the vapor into condensate water. A fluid extract pipe 11 having the same diameter as that of the heat transfer pipe 3 and extracting uncondensed gas to the outside is arranged at the position of the heat transfer pipe in an arbitrary position of the pipe group 4. By easy improvement, the uncondensed gas is absorbed in the fluid extract pipe 11 and discharged to the outside, and the stagnation part 8 of the uncondensed gas is restrained, so as to maintain the inside of the shell in a desired vacuum condition for eliminating the deterioration of a performance. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a condensing device in which steam is made to flow through a tube group of heat transfer tubes through which a cooling medium flows to form condensed water.

[0002]

2. Description of the Related Art In steam turbine equipment, steam that has finished its work is introduced from a turbine to a condenser, which is a condenser, and condensed in the condenser to be condensed water. Condensed water condensed by the condensing device is supplied to the boiler side and converted into steam, which is used as a drive source for the steam turbine.

The condensing device is provided with a tube group of heat transfer tubes in which cooling water (eg, seawater) circulates, and steam is allowed to flow into the tube group to cool the steam to be condensed water. Because the inside of the body of the condenser is maintained at a high degree of vacuum, the steam introduced from the turbine exhaust chamber contains air and some chemical components that suppress corrosion on the boiler side, in addition to water vapor. . Since air and chemical component gases are non-condensing gases,
The condenser is equipped with air extraction means for discharging the non-condensed gas to the outside.

In the condensing device, the size and arrangement of the device,
It is designed so that the part where the air extraction means is installed by the flow of steam becomes the condensation completion part, and the non-condensed gas is discharged from the condensation completed part to eliminate the stagnation of the non-condensed gas and to perform the predetermined transfer by the heat transfer tube. It is designed to ensure thermal performance.

[0005]

In the conventional condensing device (condensing device), air extraction means is provided at the condensation completion portion to eliminate the stagnation of the non-condensable gas. However, if there is a large distribution of steam flow due to the operating conditions of the turbine, or if there is deterioration over the years, such as when the turbine is replaced or the heat transfer tubes are plugged more, there will be a deviation from the condensation completion position as designed and There was a possibility that the non-condensable gas could not be discharged. When stagnation of the non-condensed gas occurs, it is conceivable that the heat transfer performance at the stagnation site deteriorates and the degree of vacuum decreases, and the heat transfer tube is exposed to the chemical gas and corroded.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a condensing device capable of avoiding stagnation of non-condensable gas.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a condensation method capable of appropriately suppressing the stagnation of non-condensed gas.

[0008]

In order to achieve the above-mentioned object, the structure of a condenser of the present invention is provided with a tube group of heat transfer tubes through which a cooling medium flows in a cylinder, and steam is introduced into the cylinder. In a condenser for cooling steam to condensed water, a fluid extraction pipe having the same diameter as the heat transfer pipe and extracting the in-body fluid to the outside is arranged at the position of the heat transfer pipe at an arbitrary position of the tube group. .

Further, the fluid extraction tube is characterized in that it is arranged at a portion of the tube group where the non-condensable fluid has settled. Further, the fluid extraction pipes are arranged at a plurality of positions of the pipe group, and the fluid extraction pipes are provided with selection means for selecting the plurality of fluid extraction pipes and extracting the fluid to the outside. Also, the fluid inside the body is reduced by extracting the fluid from the fluid extraction pipe selected by the selection means (the degree of vacuum is increased).
It is characterized in that it is provided with a judging means for judging that the uncondensed fluid has stagnated when it is judged that the amount has decreased.

In order to achieve the above object, the structure of the condenser of the present invention is provided with a group of heat transfer tubes through which a cooling medium flows, and the steam is made to flow into the cylinder to cool the steam and condense water. In the condensing device described above, a fluid extraction tube having the same diameter as the heat transfer tube is arranged in place of the heat transfer tube of the tube group in the portion where the non-condensed fluid has settled.

In the condenser according to any one of claims 1 to 5, the cooling water flows through the heat transfer tubes, and the steam flowing through the tube group is condensed and liquefied by the exhaust of the steam turbine. It is a condensing device.

The condensing method of the present invention for achieving the above object is provided with a tube group of heat transfer tubes through which a cooling medium flows in the body,
A method of condensing in a condenser that cools the steam by passing it through the tube group to form condensed water, and selectively extracts the fluid at multiple points in the tube group, and It is characterized in that the extraction site selected at the time of the determination is determined to be the site where the non-condensed fluid has settled.

[0013]

1 is a perspective view showing a schematic configuration of a condenser as a condenser according to an embodiment of the present invention, FIG. 2 is a vertical cross section of the condenser, and FIG. 4 shows a side cross section of the condenser, FIG. 4 shows a vertical cross section of the tube group, FIG. 5 shows a perspective view of the fluid extraction pipe, and FIG. 6 shows a side cross section for explaining the installation condition of the fluid extraction pipe.

As shown in FIGS. 1 to 3, tube plates 2 are provided at both ends of a body 1 into which exhaust steam of a steam turbine is introduced, and a large number of heat transfer tubes 3 are connected to the tube plate 2. The plurality of heat transfer tubes 3 form a tube group 4. The outer side of the tube sheet 2 (shown in FIG. 2 is four tube groups 4) is a water chamber 5, and the inlet chamber of one of the water chambers 5 is supplied with seawater as cooling water. After flowing through the heat transfer tube 3, it is sent to the other water chamber 5 and discharged.

In the tube group 4, for example, at the central portion, the heat transfer tube 3
An air extraction pipe 7 having a larger diameter than the above and having a hole 6 formed at an appropriate portion is provided, and the air extraction pipe 6 is guided to the outside and connected to an air hole extraction device (not shown) via a valve 9.
The air extraction tubes 6 and the multiple heat transfer tubes 3 of the tube group 4 are supported inside the case 1 by a plurality of partition plates (not shown), and both ends thereof are connected to the tube plate 2.

By circulating the steam through the tube group 4 composed of the heat transfer tubes 3 through which seawater flows, condensation proceeds from the outer peripheral side of the tube group 4 to the inner peripheral side, and the steam is cooled to be condensed water. Condensed water is pumped up by a not-shown condensate pump and used for supplying water to the boiler. Since the inside of the body 1 of the condenser is maintained at a high degree of vacuum, the steam introduced from the turbine contains air and some chemical components that suppress corrosion on the boiler side, in addition to steam. . Since the air and the chemical component gas become non-condensable gas, the non-condensable gas accumulates in the vicinity of the air extraction pipe 6 which is the condensation completion portion of the tube group 4, and the non-condensed gas becomes the holes 6
Is sucked into the air extraction pipe 7 and discharged to the outside.

As a result, the non-condensable gas is discharged at the condensation-completed portion, the stagnation of the non-condensable gas is eliminated, and the predetermined heat transfer performance by the heat transfer tube 3 can be secured. For this reason, stagnation of the non-condensable gas is generated, the heat transfer performance of the heat transfer tube 3 in the stagnation portion is decreased, the vacuum degree is decreased, the condenser performance is decreased, and the heat transfer tube 3 is exposed to the chemical gas. Corrosion is prevented.

By the way, when the steam flow has a large distribution due to the operating condition of the turbine, or when the turbine is replaced or the heat transfer tube 3 is increased in plugging, the condensation is not completed as designed. However, there is a possibility that the non-condensable gas cannot be discharged from the air extraction pipe 7. That is, as shown in FIG. 4, the condensation-completed portion is located at a position different from the air extraction pipe 7, and the non-condensable gas is not properly discharged, and the stagnation portion 8 of the non-condensable gas is generated.
May occur. When the stagnation part 8 occurs, the stagnation part 8
Since the heat transfer performance of the portion of the heat transfer tube 3 is lowered and the degree of vacuum is lowered, the stagnation portion 8 can be analogized by detecting the in-body pressure. Further, since the temperature also rises, the stagnation portion 8 can be analogized by detecting the temperature.

Therefore, in this embodiment, instead of the heat transfer tube 3 at the position corresponding to the stagnation portion 8, a fluid extraction tube 11 having the same diameter as the heat transfer tube 3 for extracting the noncondensable gas as a fluid to the outside.
Is equipped with. The fluid extraction pipe 11 is provided with a large number of holes 12 for sucking the non-condensable gas, and when the stagnation part 8 also exists in the axial direction of the tube group 4, the part where the stagnation part 8 of the fluid extraction pipe 11 is generated. A hole 12 is formed corresponding to

As shown in FIG. 6, when the fluid extraction pipe 11 is installed, the water chamber 5 is removed from the body 1, and the heat transfer pipes 3 at a position supposed to be the stagnation portion 8 are first attached to the tube plate. 2 and then pulled out from the condenser, and the fluid extraction pipe 11 is inserted into that portion and connected and fixed to the tube plate 2. The fluid extraction pipe 11 is connected to the air extraction pipe 7 outside the water chamber 5. For this reason, the improvement work for providing the fluid extraction pipe 11 can be minimized, and the fluid extraction pipe 11 can be easily provided in the operating condenser.

Since the stagnation portion 8 is provided with the fluid extraction pipe 11, the non-condensable gas is formed in the hole 12 at a position different from the air extraction pipe 7.
The non-condensed gas in the stagnation portion 8 can be discharged to the outside by being sucked into the fluid extraction pipe 11 from the above. Therefore, even if the condensation completion portion is located at a position different from that of the air extraction pipe 7, the non-condensed gas is discharged to the outside, the heat transfer performance of the heat transfer pipe 3 is maintained, and the condenser is brought to a desired vacuum state. It can be maintained, and it is possible to eliminate performance degradation.

In FIG. 4, the stagnation part 8 has been described as an example at one location below the air extraction pipe 7. However, the stagnation part 8 is optional depending on the operating condition of the turbine and the deterioration over time. No matter where it occurs in the tube group 4 or in which tube group 4, the non-condensed gas is provided outside by arranging the fluid extraction tube 11 at that position. Can be discharged to. Further, the fluid extraction pipes 11 can be provided at a plurality of locations for one pipe group 4. Also,
Although the fluid extraction pipe 11 is provided in place of the heat transfer pipe 3 of the stagnation portion 8, the fluid extraction pipe 11 may be provided at an arbitrary position in advance.

A condensing device as a condensing device according to another embodiment and a condensing method (condensing method) using this condensing device will be described with reference to FIG. FIG. 7 shows a perspective view showing a schematic configuration of a condenser as a condenser according to another embodiment of the present invention. The same members as those of the condensing device shown in FIGS. 1 to 6 are designated by the same reference numerals, and a duplicate description is omitted.

In the condensing device shown in FIG. 7, a plurality of fluid extraction pipes 15 having the same diameter as the heat transfer pipes 3 of the tube group 4 for extracting noncondensable gas as a fluid to the outside are used instead of the heat transfer pipes 3. It is equipped with a position. The fluid extraction pipe 15 is provided with a large number of holes 16 for sucking the non-condensable gas. Each of the fluid extraction pipes 15 is guided to the outside of the condensing device and connected to the air extraction pipe 7, and an opening / closing valve 17 as a selection means is provided at an outside position of the fluid extraction pipe 15. On-off valve 17
Is selectively opened / closed by a command from the control means 18 as the determination means, and the detection information of the pressure detection means 19 for detecting the pressure inside the body 1 of the condenser is input to the control means 18.

An example of the condensing method in the above-mentioned condensing device will be described.

When all the on-off valves 17 are closed, the steam is circulated through the tube group 4 composed of the heat transfer tubes 3 through which seawater flows, whereby condensation proceeds from the outer peripheral side of the tube group 4 to the inner peripheral side, and steam is generated. It is cooled and made into condensate. Condensed water is pumped up by a not-shown condensate pump and used for supplying water to the boiler.

When the non-condensable gas is not discharged and the non-condensable gas is not discharged because the condensation-completed part is located at a position different from the air extraction pipe 7, the heat transfer performance of the part of the heat transfer pipe 3 in the stagnation part is improved. Since the pressure decreases and the degree of vacuum decreases, the pressure detecting means 19 detects that the pressure has increased. Pressure detecting means 19
When it is detected that the pressure inside the body 1 has increased, it is determined that a stagnation portion has occurred inside the body 1.

In this state, when the on-off valves 17 are individually opened sequentially, the non-condensed gas is sucked from the fluid extraction pipes 15 only when the stagnation portion is generated around the fluid extraction pipes 15 of the opened on-off valves 17. Then, the heat transfer performance of the portion of the heat transfer tube 3 starts to recover, and the pressure detecting means 19 detects that the pressure inside the case 1 has dropped. Fluid extraction pipe 1 of open on-off valve 17
When there is no stagnation around 5, the heat transfer performance of the heat transfer tube 3 remains unchanged and no pressure drop is detected.

For this reason, when the on-off valve 17 is selectively opened and the pressure detecting means 19 detects that the pressure inside the case 1 has dropped, the surroundings of the fluid extraction pipe 15 of the on-off valve 17 selected are detected. It can be determined that this is the site where the stagnation occurs. Therefore, by lowering the internal pressure of the fluid extraction pipe 15, the stagnation portion can be accurately identified and the non-condensed gas can be discharged to the outside, and the heat transfer performance of the heat transfer pipe 3 can be maintained and the condensing device. Can be maintained in a desired vacuum state, performance deterioration can be eliminated even if a stagnation portion occurs at an arbitrary position, and it is possible to significantly reduce restrictions on turbine equipment and the like.

The present invention can be applied to a condenser such as an absorption refrigerating machine in addition to the above-mentioned condenser.

[0031]

The condenser of the present invention is provided with a tube group of heat transfer tubes through which a cooling medium flows, and cools the steam by flowing steam into the cylinder to form condensed water. Since a fluid extraction pipe having the same diameter as the heat transfer pipe and extracting the fluid inside the body to the outside is arranged at the position of the heat transfer pipe at any position of the tube group,
With a simple modification, the non-condensable fluid can be sucked into the fluid extraction pipe and discharged to the outside. As a result, it is possible to suppress the stagnation of the non-condensable gas and maintain the inside of the cylinder in a desired vacuum state, and it is possible to eliminate the deterioration of performance.

Further, since the fluid extraction pipe is arranged at the portion of the tube group where the non-condensable fluid has settled, the non-condensable fluid can be reliably discharged.

Further, the fluid extraction pipes are arranged at a plurality of positions in the pipe group, and the selection means for extracting the fluid to the outside by selecting the plurality of fluid extraction pipes is provided, so that the non-condensed fluid can be reliably discharged. it can.

Further, when the fluid is extracted from the fluid extraction pipe selected by the selection means and it is determined that the pressure in the cylinder has dropped, it is determined that the uncondensed fluid is a stagnation site. Therefore, the uncondensed fluid can be discharged by accurately detecting the stagnation portion.

Further, in a condenser equipped with a tube group of heat transfer tubes through which a cooling medium flows, the steam is circulated in the barrel to cool the steam into condensed water, and the tube group in the portion where the non-condensable fluid has settled. Since the fluid extraction pipe having the same diameter as that of the heat transfer pipe is arranged instead of the heat transfer pipe of No. 1, the non-condensable fluid in the stagnation portion can be sucked into the fluid extraction pipe and discharged to the outside. As a result, stagnation of the non-condensable gas can be eliminated and the inside of the cylinder can be maintained in a desired vacuum state, so that it is possible to eliminate deterioration of performance.

Further, in the condenser according to any one of claims 1 to 5, cooling water flows through the heat transfer tubes, and the steam flowing through the tube group is condensed and liquefied by the exhaust of the steam turbine. Since it is a condenser, the inside of the body of the condenser can be maintained in a desired vacuum state, and deterioration of performance can be eliminated.

The condensing method of the present invention is a condensing method in a condenser in which a tube group of heat transfer tubes through which a cooling medium flows is provided in a cylinder, and steam is allowed to flow into the cylinder to cool the steam into condensed water. Therefore, when fluid is selectively extracted at multiple points in the tube group and it is determined that the pressure inside the cylinder has dropped, it is determined that the selected extraction site is the site where the non-condensed fluid has settled. Since the stagnation portion is accurately detected, the non-condensed fluid can be surely discharged. As a result, stagnation of the non-condensable gas can be eliminated and the inside of the cylinder can be maintained in a desired vacuum state, so that it is possible to eliminate deterioration of performance.

[Brief description of drawings]

FIG. 1 is a perspective view showing a schematic configuration of a condensing device as a condensing device according to an embodiment of the present invention.

FIG. 2 is a vertical cross-sectional view of a condenser.

FIG. 3 is a side sectional view of the condenser.

FIG. 4 is a vertical cross-sectional view of a tube group.

FIG. 5 is a perspective view of a fluid extraction tube.

FIG. 6 is a side sectional view for explaining the installation situation of the fluid extraction pipe.

FIG. 7 is a perspective view showing a schematic configuration of a condensing device as a condensing device according to another embodiment of the present invention.

[Explanation of symbols]

1 torso 2 tube sheet 3 heat transfer tubes 4 tube group 5 water chamber 6 holes 7 Air extraction tube 8 stagnation part 9 valves 11,15 Fluid extraction tube 12, 16 holes 17 on-off valve 18 Control means 19 Pressure detection means

Continued front page    (72) Inventor Koichi Inoue             2-1-1 Niihama, Arai-cho, Takasago City, Hyogo Prefecture             Takasago Works, Mitsubishi Heavy Industries, Ltd.

Claims (7)

[Claims] 1. A condenser comprising a tube group of heat transfer tubes, through which a cooling medium flows, provided inside a case, and the steam is allowed to flow into the case to cool the steam to form condensed water. A condensing device characterized in that a fluid extraction pipe having the same diameter as the heat transfer pipe and having the same diameter as that of the heat transfer pipe is arranged to extract the fluid in the body to the outside. 2. The condensing device according to claim 1, wherein the fluid extraction pipe is arranged at a portion of the tube group where the non-condensed fluid has settled. 3. The condensing device according to claim 1, wherein the fluid extraction pipes are arranged at a plurality of locations of the pipe group, and the fluid extraction pipes are provided with a selection unit that selects the plurality of fluid extraction pipes and extracts the fluid to the outside. . 4. The method according to claim 3, wherein the fluid is extracted from the fluid extraction pipe selected by the selection means, and when it is determined that the pressure in the body has dropped, it is determined that the uncondensed fluid is a stagnation site. A condensing device comprising a determination means. 5. A condenser comprising a tube group of heat transfer tubes through which a cooling medium flows, wherein steam is allowed to flow into the body to cool the steam into condensed water, and the tube group is at a portion where the non-condensable fluid has settled. A condensing device characterized in that a fluid extraction tube having the same diameter as the heat transfer tube is arranged in place of the heat transfer tube. 6. The condenser according to any one of claims 1 to 5, wherein the cooling water flows through the heat transfer tubes, and the steam flowing through the tube group is condensed and liquefied by the exhaust of the steam turbine. A condensing device characterized by being a condensing device. 7. A condensing method in a condenser in which a tube group of heat transfer tubes, through which a cooling medium flows, is provided in a barrel, and steam is allowed to flow into the barrel to cool the vapor into condensed water.
It is characterized in that the fluid is selectively extracted at a plurality of locations in the tube group, and when it is determined that the pressure inside the body has dropped, it is determined that the selected extraction site is a site where the non-condensed fluid has settled. How to condense.