JPH0579776A - Condenser - Google Patents

Abstract

PURPOSE:To obtain a condenser in which a starting time can be shortened and a steam using amount can be reduced by separating a condenser hot well into a degassing chamber and a water storage chamber, raising a condensed water level in the degassing chamber to obtain a wide space for introducing steam and holding a level of a necessary water storage amount in the storage chamber. CONSTITUTION:Condensed water having high concentration of dissolved oxygen introduced from a condensing recirculation system 6 is sprinkled in the upper part of a ceiling plate 10 provided at the upper part of a water storage chamber 24, further passed through a cutout 21 provided at an isolation plate 20, and dropped in a degassing chamber 22. The condensed water dropped in the chamber 22 is heated and degassed by heated degassed steam to be supplied to a steam injection tube 15 so provided as to inject under the water surface, and dropped from the cutout 23 in the chamber 24. The condensed water dropped in the chamber 24 is fluidized toward a condensed water outlet 4 along a partition plate 11 so provided as to form a passage. Accordingly, a degassing time can be shortened, power of an auxiliary unit and steam using amount can be reduced, and a degassing effect can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam turbine condenser, and more particularly to a condenser equipped with degassing means for condensate and make-up water stored in a hot well of the condenser.

[0002]

2. Description of the Related Art In recent years, thermal power plants are often operated by a so-called DSS (Daily Starst) operation, which is started and stopped every day.

In order to reduce the power of the auxiliary equipment in the DSS operation plant, it is effective to break the vacuum of the condenser at night when it is stopped. In this case, water is stored in the hot well of the condenser when stopped. The condensate being absorbed absorbs gas such as oxygen,
There is a problem that the dissolved oxygen concentration in the condensate becomes high when restarting the next morning.

When condensed water having a high dissolved oxygen concentration is supplied to the boiler, problems such as corrosion occur in the boiler. Therefore, it is necessary to degas the condensed water stored in the condenser hot well at startup. By the way, in a combined power plant using a gas turbine and a steam turbine, system simplification,
For reasons such as reduction of equipment cost and improvement of thermal efficiency,
In some cases, a deaerator is not installed in the water supply system, and in that case, it is necessary to deaerate the condensate with a condenser instead of the deaerator. This condenser having a deaeration function is called a deaeration condenser, and this deaeration condenser is disclosed in JP-A-60-2489.
No. 94 “Condenser with degassing mechanism” is known.

[0005]

The deaeration condenser is degassed during the winter when the condensate temperature and the outside air temperature are low, which greatly depends on the environment in which the deaeration condenser is placed, especially the temperature. Time tends to be long. The method of shortening the degassing time by introducing steam into the condenser and heating the condensate is effective for shortening the degassing time. It is necessary to have a structure for efficiently degassing while preventing the direct mixing of the condensed water that has been stored with the condensed water with a high dissolved oxygen concentration stored in the condenser hot well. To improve this, installing a ceiling plate in the condenser hot well is adopted as an effective measure.
This will limit the condenser structure.

The size of the condenser in the plane direction tends to be large due to the adoption of a titanium condenser, etc., and as a result, the condenser hot well water level corresponding to the required storage amount becomes low,
There is a problem that the heating effect is reduced because the space for introducing the degassing steam into the condensate becomes narrow. As a countermeasure, in order to expand the steam introduction space and improve the degassing performance, if the condenser water level is set above the water level equivalent to the required water storage volume, the condensate water supply device will be set based on the relationship between the condensed water recirculation amount and the degassing time. The power cost of
Moreover, the amount of steam to be heated increases, which causes another problem that the amount of steam increases. As described above, in order to improve the deaeration performance of the large-sized deaeration condenser with the current condenser structure, the auxiliary machine power is consumed more than necessary.

In view of the above, it is an object of the present invention to provide a condenser which can shorten the start-up time of the condenser and can save auxiliary power, steam consumption and the like.

[0008]

[Means for Solving the Problems] The condenser hot well is separated into a deaeration chamber and a water storage chamber, and the deaeration chamber has a high condensate water level to secure a wide space for introducing steam, and the water storage chamber is necessary. Separate the functions in each compartment to maintain the water level equivalent to the stored water volume.

Further, a ceiling plate is provided to prevent direct mixing of the deaerated condensate with the condensate having a high dissolved oxygen concentration stored in the condenser hot well, and the deaeration chamber and the water storage chamber are separated from each other. By installing a weir on the plate, the condensate is dropped to a specific place in the deaeration chamber.

Further, when the condenser is stopped, the deaeration chamber and the water storage chamber are isolated from each other by a valve or the like, and the plant is stopped while the water storage chamber is kept in a vacuum state to prevent gas such as air from leaking into the water storage chamber. ..

[0011]

[Function] By separating the functions in each section,
A wide steam introduction space can be secured, and only the required amount of water can be stored.

By dropping the condensate to a specific place in the deaeration chamber, it is possible to prevent the deaerated condensate from directly mixing with the high-concentration condensate.

By separating the deaeration chamber and the water storage chamber, it is possible to prevent gas such as air from leaking into the water storage chamber.

[0014]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 2 shows the connection between the condenser and an external piping system connected to the condenser. The condenser 1 is composed of a tube nest 2, a deaeration chamber 22 divided by a separator 20, a water storage chamber 24, a ceiling plate 10, a partition plate 11 and the like. The condenser 1 has a condensate recirculation system 6 connected to the condensate system 5 for performing a deaeration operation at the time of its startup, and a switching valve 8 is opened and a switching valve 7 is closed. The high-concentration recirculated water is sprinkled from the condensate outlet 4 through the gland steam condenser 26 and the nozzle 9 to the upper portion of the ceiling plate 10 for sprinkling. This watering or
The condensed water that has become water in the condenser 1 is collected in the deaeration chamber 22.
The deaeration chamber 22 has a steam ejection pipe 15 having an ejection port below the water surface.
Is provided, and heated degassing steam is supplied from the steam supply system 16 through the valve 17 to perform degassing. The non-condensable gas such as oxygen separated and remaining in the condenser 1 is passed through the air extraction system 13 from the air extraction port 12 provided in the condenser tube nest 2 by the air extraction device 14 to the condenser. 1 Discharge to the outside. As described above, deaeration is performed and the dissolved oxygen concentration system 31 measures the supplied dissolved oxygen concentration, and when the water supply regulation value is reached, the switching valve 8 is closed and the switching valve 7 is opened to start water supply to the boiler.

FIG. 1 is a bird's-eye view showing the structure of the device of the present invention, FIG. 3 (b) is a sectional view taken along the line AA from the upper part of the condensate recirculation in FIG. 1, and FIG. 3 (a) is FIG. 3 (b). 4 is a sectional view taken along the line CC of FIG.
1A is a sectional view taken along the line BB of FIG. 1 taken from the bottom of the ceiling plate 10, and FIG. 4B is a sectional view taken along the line D-D of FIG. 4A.

Condensate having a high dissolved oxygen concentration introduced from the condensate recirculation system 6 is sprinkled at the upper part of the ceiling plate 10 provided at the upper part of the water storage chamber 24, and the notch provided at the separator plate 20. It passes through 21 and falls into the deaeration chamber 22. The condensed water that has fallen into the degassing chamber 22 is heated and degassed by the heated degassing steam that is supplied by the steam jetting pipe 15 that is provided so as to jet below the water surface, and then falls into the water storage chamber 24 through the notch 23.

The deaeration effect in the deaeration chamber 22 is due to the heating and bubbling action of steam introduced into the condensate liquid having a high dissolved oxygen concentration. It has been experimentally verified that it is necessary to introduce heated degassing steam under water. Therefore, the height of the notch 23 is set to a height at which this required water depth can be secured. Further, the longitudinal position of the notch 23 is provided on the opposite side of the notch 21 in order to promote convection of condensate inside the degassing chamber 22.

Condensate that has been deaerated in the deaeration chamber 22 and dropped from the notch 23 into the water storage chamber 24 flows toward the condensate outlet 4 along the partition plate 11 provided so as to form a passage. Normally, condensate storage is 5 times the condensate flow rate during plant operation.
It is considered to be sufficient if there is a capacity equivalent to one minute, and the water storage unit 24
The water level can be determined independently of the water level in the deaeration chamber 22 by the width and length dimensions that are uniquely determined from this capacity and the overall size of the condenser, and the water level gauge 25 controls the water level to an optimum value. .. Further, at the time of long-term stoppage, the control valve 30 is opened to discharge the condensate from the condensate bypass system 29 or collect it in the collecting device.

Next, another embodiment of the present invention will be described with reference to FIGS.
Will be explained. As shown in FIG. 5, the deaeration chamber 22 and the water storage chamber 24 are connected by a connecting pipe 27 to the condenser having the configuration shown in FIG. Condensate bypass system 29 that connects between the air chambers 22
And control valves 30, 32. As shown in more detail in the bird's-eye view of FIG. 6, in this embodiment, as compared with FIGS. 1 and 2, the notch 23 for dropping the condensed water from the deaeration chamber 22 to the water storage chamber 24 is eliminated, and the space between both chambers is eliminated. Communication pipe 27 and isolation valve 2
8 are provided. Further, by connecting the condensate bypass system 29 to the water supply system 5 and switching the control valves 30, 32 and the isolation valve 28, the deaeration chamber 22 and the water storage chamber 24 are completely isolated and connected.

As a result, in addition to the function of dropping condensed water from the deaeration chamber 22 to the water storage chamber 24, the isolation valve 28 is closed before the vacuum is broken when the plant is stopped to completely isolate the deaeration chamber 22 and the water storage chamber 24. However, leakage of gas such as air into the water storage chamber 24 is eliminated.
In this way, by maintaining the vacuum in the water storage chamber 24 even after the vacuum break, condensed water having a low dissolved oxygen concentration, which is the same as immediately before the plant is stopped, can be stored in the water storage chamber 24.
When the plant is started in this case, the control valve 32 on the side of the water storage chamber 24 is closed, condensate with a low dissolved oxygen concentration in the water storage chamber 24 is stored in the water storage chamber 24, and the control valve 30 on the side of the deaeration chamber 22 is opened. , The condensate in the deaeration chamber 22 can be recirculated through the condensate bypass system 29 to introduce deaeration while introducing heated deaeration steam, and the deaeration operation in this case requires deaeration. Since the amount of water is only the amount stored in the degassing chamber 22, degassing can be obtained in a short time. After that, the dissolved oxygen concentration meter 31 confirms that the dissolved oxygen concentration is equal to or lower than a predetermined supply water specified value, and the pressure inside the condenser measured by the pressure gauge 19 and the water storage chamber measured by the pressure gauge 19a 24
When the internal pressures become almost equal, the control valve 30 is closed and 3
2 is opened, the isolation valve 28 is opened, and the deaeration chamber 22 and the water storage chamber 24 are opened.
Will be connected and water will be supplied to the boiler.

In the above structure, the condensate in the deaeration chamber 22 may be recovered by a drain recovery device or the like, or the signals of the pressure gauges 19 and 19a may be sent to a control device (not shown). It goes without saying that the control valve, the switching valve, and the isolation valve may be automatically operated by.

[0023]

According to the present invention, by more effectively using the heated degassing steam, the degassing time can be shortened, the auxiliary machine power and the steam usage amount can be reduced, and the degassing chamber and the water storage chamber can be reduced. By completely isolating, the degassing effect can be improved. Further, the isolation structure can be easily manufactured only by connecting the isolation plate and the notch or the deaeration chamber and the water storage chamber with the connecting pipe and the isolation valve. Further, since the connecting pipe and the isolation valve do not require a large space, the valve can be installed at a position where workability is good, so that maintainability can be improved.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention.

FIG. 2 is a structural diagram of a condenser according to an embodiment of the present invention.

FIG. 3 is a sectional arrow view of FIG.

FIG. 4 is a cross-sectional arrow view of FIG.

FIG. 5 is an overall configuration diagram of another embodiment of the present invention.

FIG. 6 is a condenser structure diagram of another embodiment of the present invention.

[Explanation of symbols]

1 ... Condenser, 2 ... Tube nest, 3 ... Condensate water supply device, 4 ... Condensate outlet, 5 ... Condensate system, 6 ... Condensate recirculation system, 7, 8 ... Switching valve,
9 ... Nozzle, 10 ... Ceiling plate, 11 ... Partition plate, 12 ... Air extraction port, 14 ... Air extraction device, 15 ... Steam injection pipe, 1
7, 30, 32 ... Control valve, 18 ... Control device, 19, 19
a ... pressure gauge, 20 ... separator, 21, 23 ... notch, 22
... Deaeration chamber, 24 ... Water storage chamber, 25 ... Water level gauge, 26 ... Grand steam condenser, 27 ... Communication pipe, 28 ... Isolation valve, 29 ... Condensate bypass system, 31 ... Dissolved oxygen concentration meter.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoshio Sumitani 3-1-1 Hitachi-machi, Hitachi-shi, Ibaraki Hitachi Ltd. Hitachi factory (72) Inventor Yasuaki Mukai 3-chome, Hitachi-shi, Ibaraki No. 1 Stock company Hitachi Ltd. Hitachi factory

Claims (5)

[Claims] A condenser hot well is divided into a portion for degassing dissolved gas in the condensate and a portion for storing the condensate. 2. The condenser hot well is separated into a portion for degassing dissolved gas in the condensate and a portion for storing the condensate, and the water level of the degassing portion is made higher than that of the water storage portion. Characteristic condenser. 3. A first condenser hot well with a ceiling plate,
A second condenser hot well in which heated steam is introduced into the water, and a means for guiding the condensed water dropped on the ceiling plate of the first condenser hot well to the second condenser hot well, the second condenser hot well. Means for guiding the condensate of the well to the first condenser hot well,
Second condenser A condenser comprising means for sending condensate from the hot well to the outside. 4. The condenser according to claim 3, wherein the means for guiding the condensate of the second condenser hot well to the first condenser hot well is stopped when the first condenser hot well and the second condenser hot well are stopped. Water condenser A condenser characterized by being designed to isolate a hot well. 5. The condenser hot well is separated into a portion for degassing dissolved gas in the condensate and a portion for storing the condensate, and the condensate storage portion is isolated from other spaces when stopped. Characteristic condenser.