JP3366817B2 - Condenser - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a condenser, and more particularly to a condenser in which a tube nest portion and a hot well portion for storing condensed water are separated by a partition wall (ceiling plate). It is a thing.

[0002]

2. Description of the Related Art In a thermal power plant, it is general that the condenser vacuum is broken while the plant is stopped. In this case, the condensate stored in the condenser hot well absorbs oxygen, and the dissolved oxygen concentration of the condensate at the time of restart becomes high.If this condensate is supplied to the boiler, corrosion such as corrosion to the boiler will occur. May occur. Therefore, when the plant is started, the condensate with high dissolved oxygen concentration, which is stored in the hot well of the condenser, is always recirculated by the condensate recirculation system connected to the condenser outlet and at the same time degassed. It is necessary to perform degassing operation with the heating steam for use.

By the way, in a combined power generation plant or the like using a gas turbine and a steam turbine, a deaerator may not be installed in the water supply system for the reason of system simplification, reduction of equipment cost, and improvement of thermal efficiency. In some cases, a deaeration condenser having a deaeration function is used.

The steam turbine condenser of this type that has been generally adopted in the past has a deaeration means for condensing the water stored in the condenser hot well. A partition wall that prevents direct mixing with condensate with a high dissolved oxygen concentration stored in the hot well, that is, a ceiling plate is installed, and the condensate introduced on the ceiling plate passes through the ceiling plate and the condenser. Sent to hotwell.

The condensate sent to the hot well flows along a partition plate provided so as to form a flow path inside the hot well, and is sent to the condenser outlet. Is normal. In addition, as a thing related to this type of condenser, for example, Japanese Unexamined Patent Publication No. Hei 5-79776 can be cited.

[0006]

The condenser thus formed, that is, the structure in which the tube nest portion and the condenser hot well portion are divided by a ceiling plate or the like, and the flow passage in the condenser hot well are provided. In a condenser equipped with a partition plate that forms a condenser, the water level of the condenser hotwell condensate is optimally determined by the condensate flow rate during plant operation and the overall condenser size. Controlled by.

In a normal operating state, the pressure in the tube nest for condensing steam and the pressure in the portion for storing the condensate in the condenser hot well are equal, but in the operating state of the plant, for example, steam When backwashing the condenser to prevent fouling of the cooling tube nest that condenses the turbine exhaust steam, the amount of cooling water passing through the cooling tube nest temporarily becomes zero, and the degree of vacuum of the condenser is reduced. Will decrease and the pressure in the tube nest will rise.

As described above, when the pressure at the tube nest portion temporarily rises, the water storage portion of the condenser hot well has a structure separated from the tube nest portion as described above. In the water reservoir of the condenser hot well, a pressure difference is generated between the reservoir and the tube nest due to the delay of pressure transfer from the pressure in the tube nest. There is a problem that a water surface wave occurs in the condenser hot well due to this pressure difference, and the water level of the condenser hot well fluctuates, and an effective means for reducing this water level fluctuation has been desired.

The present invention has been made in view of the above, and an object thereof is to condensate hot even in an operating state of a plant such as a condenser backwashing operation in which the pressure in the tube nest temporarily rises. It is an object of the present invention to provide a condenser of this kind that can reduce fluctuations in the water level in the well and that does not hinder the operation of the plant.

[0010]

SUMMARY OF THE INVENTION
The tube nest that condenses the inflowing steam and the condensation inside this tube nest
A degassing chamber for degassing the condensed water collected, and a water passage between the degassing chamber
Reservoir separated from the deaeration chamber by a separator having a
And disposed between the deaeration chamber and the tube nest,
Condensed water that has separated from the chamber and the tube nest, and has fallen from the tube nest
In a condenser having a partition wall that allows air to flow into the deaeration chamber
Between the water storage chamber and the tube nest.
Suppressing the generation of surface waves in the water storage chamber due to pressure rise below
Equipped with a non-water-permeable and breathable communication means
That is.

Further, in this case, a plurality of the communication means are provided in the portion facing the water surface of the hot well at substantially equal intervals. Further, the opening area of the communication means is formed to be 0.2% or more and 75% or less of the area of the water surface of the hot well.

That is, in the condenser thus formed, a water impervious section is provided on the partition wall for partitioning the water storage section of the condensing hot well and the tube nest section for condensing the steam flowing from the turbine. Therefore, while preventing direct mixing of degassed condensate and condensate with high dissolved oxygen concentration, the pressure transfer between the tube nest and the reservoir of the condenser hot well is improved. , It is possible to prevent the fluctuation of the water level of the condenser hot well caused by the differential pressure, and therefore, even in the operating state of the plant such as the condenser backwash operation in which the pressure in the tube nest temporarily rises, It is possible to reduce the fluctuation of the water level in the condensate hot well part.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail based on the embodiments shown in the drawings. FIG. 1 shows the condenser and an external piping system connected to the condenser. In the figure, 1 is a condenser, 2 is its tube nest, and 19 is a water storage chamber. Condenser 1
Is composed of a tube nest 2, a deaeration chamber 17 divided by a separator 15, a water storage chamber 19, a ceiling plate 10, a partition plate 11 and the like. 2 is a three-dimensional view showing the structure of this condenser, FIG. 3 is a sectional view taken along line AA of FIG. 2, and FIG. 5 is taken along line BB of FIG.
FIG. 4 is a sectional view showing a detailed view of a portion A in FIG.

The condenser 1 of the present invention has a structure in which the condensate flowing on the ceiling plate 10 and the condensate dropped from the tube nest 2 do not flow into the water storage chamber 19 as shown in FIG. A ventilation device 22 is provided so that the nest portion 2 and the water storage portion 19 are ventilated.

As shown in detail in FIG. 4, the ventilation device 22 has a weir 22a so that the condensed water does not flow into the water storage chamber 19 when the condensed water flows on the ceiling plate 10. There is. The height b of the weir 22a is determined by the amount of condensed water above the ceiling plate 10 and the cross-sectional area of the flow path flowing into the degassing chamber 19.

A cover 22b is provided on the upper part of the bank 22a so that the condensed water falling from the tube nest 2 does not flow into the water storage chamber 19. Bank 22a and cover 22
The connecting portion of b is provided with an opening of the vent hole 22c to ensure the air permeability between the tube nest portion 2 and the water storage chamber 19. The required area of the ventilation port 22c is obtained from the maximum pressure difference between the tube nest 2 and the water storage chamber 19, the tube nest volume, the allowable width of pressure fluctuation, and the allowable pressure fluctuation time.

The condenser of the present invention is formed in this way. Next, a method of operating the condenser thus formed will be described. When the plant is started up, first, the cooling water supply device 23 allows the cooling water to flow into the pipe of the tube nest 2. Next, the vacuum of the condenser 1 is raised by the air extraction device 24. At this time, the condensate stored in the water storage chamber 19 has a dissolved oxygen concentration in a saturated state due to contact with the atmosphere,
It is about 0000 ppb. On the other hand, the dissolved oxygen concentration of the condensate sent by the condenser water supply device 3 is equal to or lower than the reference value of 7 ppb during the normal operation, and it is necessary to be equal to or lower than the reference value (10 ppb) at the time of startup. .

In the condenser 1, a condensate recirculation system 6 for performing deaeration operation at startup is connected to the condensate system 5, the switching valve 8 is opened, the switching valve 7 is closed, and the condensate water feeding device 3 is used. The recirculated water having a high dissolved oxygen concentration is sprayed from the condensate outlet 4 through the gland steam condenser 21 and the nozzle 9 to the upper portion of the ceiling plate 10. The sprinkled water or the condensed water that has become water in the condenser 1 is collected in the deaeration chamber 17.

The deaeration chamber 17 is provided with a steam ejection pipe 12 having an ejection port below the water surface, and heated deaeration steam is supplied from a steam supply system 13 via a valve 14 for deaeration. The deaeration is performed as described above, and when the concentration of the dissolved oxygen in the water supply reaches the water supply regulation value, the switching valve 8 is closed and the switching valve 7 is opened to start supplying water to the boiler.

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 19, and further the water flow provided at the separator plate 15 is carried out. It passes through the portion 16 and falls into the deaeration chamber 17. The condensed water that has fallen into the degassing chamber 17 is heated and degassed by the heated degassing steam supplied by the steam spouting pipe 12 provided so as to spout below the water surface, and is sent to the water storage chamber 19 from the water passing portion 18. Condensate outlet 4 along a partition plate 11 provided so as to form a passage
Flow toward.

The ceiling plate 10 of the water storage portion 19 is provided with the ventilation device 22 and connects the tube nest portion 2 and the water storage chamber 19 to each other to ensure air permeability. Therefore, the water storage room 19
Condensate that is sprinkled on the ceiling plate 10 of the
Flow into the ceiling plate 10 without flowing into the deaeration chamber 1
Sent to 7.

If there is a temporary pressure increase in the tube nest 2 due to backwashing of the condenser during such operation, the ventilation is ensured by the ventilation device 22. Since the pressure transfer between the section 2 and the water storage chamber 19 is good, the tube nest 2
The pressure difference between the water storage chamber 19 and the water storage chamber 19 can be reduced, and therefore, the fluctuation of the water level in the water storage chamber 19 of the hot well due to this pressure difference can be prevented.

Next, another embodiment of the present invention will be described. The embodiment shown in FIG. 6 is the same as the embodiment shown in FIG. 1 except that the ventilation device that connects the tube nest 2 and the water storage chamber 19 is different. FIG. 7 shows a ventilation device 26 according to the embodiment of FIG.
The structural drawing of is shown. The tube nest portion 2 and the water storage chamber 19 are connected by a communication pipe as shown in FIG. The dimension of b at this time is the same as the dimension of b shown in the embodiment of FIG. 4, the flow passage cross-sectional area of the communicating pipe is also the same as the cross-sectional area of the vent of FIG. 4, and b <c is there.

Even in the ventilation device 26 having such a structure,
While ensuring the air permeability of the tube nest 2 and the water storage chamber 19, the tube nest 2
It is possible to prevent the condensate from flowing into the water storage chamber 19 and prevent the level fluctuation due to the pressure change.

The embodiment shown in FIG. 8 is still another embodiment.
The ceiling plate 10 for partitioning the tube nest portion 2 and the water storage portion 19 shown in the embodiment of FIG. 1 has a structure having air permeability. 10
Reference numerals a, 10b, 10c, and 10d denote ceiling plates, which are independently configured and their respective relationships are as shown in FIG.

In the case of this embodiment, the condensate introduced on the ceiling plate 10 falls into each of the ceiling plates 10a to 10d, and
Condensed water that has fallen into a
b, 10c, 10d, and then the deaeration chamber 17
Sent to. Each ceiling plate 10a to 10d is provided with a weir at a higher height to prevent condensed water on the ceiling plate from directly flowing into the water storage chamber 19 of the hot well.

Between the ceiling plates 10a to 10d, there is a ventilation portion between the tube nest portion 2 of the condenser 1 and the water storage chamber 19. The dimension of b at this time is the same as that of the embodiment of FIG.
The required ventilation area is secured by the intervals of b, 10c, and 10d. Also in this embodiment, the air permeability between the tube nest portion 2 and the water storage chamber 19 is ensured while the tube nest portion 2 is moved to the water storage chamber 1.
It is possible to prevent the condensate from flowing into 9 and to reduce the degassing performance.
It is possible to prevent fluctuations in the water level in the hot well water storage chamber 19 due to pressure fluctuations in the tube nest 2 and the water storage chamber 19.

Further, in the embodiment of FIG. 9, the ceiling board 10
When the condensate falls from a to 10b, if there is a possibility that the ventilation area cannot be secured due to the condensate flow, a partition plate that partially prevents the condensate flow for securing the ventilation area as shown in FIG. It is also possible to install a part corresponding to the required ventilation area.

In the above-mentioned embodiments, the condenser having the deaeration function has been described. However, in the operating state of the condenser by the backwash operation, the pressure in the tube nest temporarily rises and the hot well The phenomenon in which the water level in the water storage chamber fluctuates is not limited to the degassing condenser, but it always occurs in the condenser that separates the tube nest for condensing steam from the hot well water storage chamber by the ceiling plate. Is. Therefore, the present invention is effective in a condenser configured by a tube nest, a hot well portion with a ceiling plate, and the like.

FIG. 11 shows the relationship between the ratio of the total area of the ventilation openings provided on the ceiling plate 10 divided by the water surface area of the hot well water storage chamber and the water level fluctuation amplitude during backwash operation. From the figure,
It can be seen that in the region where the aperture ratio is 0.2% or more, the value of the amplitude is 1/2 or less of that when there is no aperture. From this, the required ventilation area should be 0.2% or more of the water surface area of the hot well, and the upper limit is 75% due to the strength of the ceiling plate.
The following is good. In addition, it is desirable that the openings on the ceiling plate should be installed evenly along the hot well channel.

In the above description, it has been explained that the communication means for communicating both chambers is provided on the ceiling plate that separates both chambers, but it is not always necessary to provide this ceiling plate, and for example, a condenser. The two chambers may be communicated with each other through the outer frame of the above and the side wall of the hot well portion.

As described above, in the condenser thus formed, the ventilation part is provided in the ceiling plate which separates the water storage part of the condensing hot well and the tube nest part for condensing the steam flowing from the turbine. By providing it, the pressure transfer between the tube nest part and the water storage part of the condenser hot well is improved, and the fluctuation of the water level of the condenser hot well due to the differential pressure can be prevented.

[0033]

As described above, according to the present invention, the air permeability between the tube nest portion and the water storage chamber of the condenser hot well becomes good, and the temporary pressure of the tube nest portion due to the operating state of the plant is improved. It is possible to obtain a condenser of this kind capable of preventing the occurrence of a pressure difference between the condenser and the hot well water storage chamber due to the rise, and preventing the fluctuation of the water level due to this.

[Brief description of drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of a condenser of the present invention.

FIG. 2 is a partially cutaway perspective view showing an embodiment of the condenser of the present invention.

FIG. 3 is a plan view showing one embodiment of the condenser of the present invention (FIG.
A-A line).

FIG. 4 is a detailed view of a portion A of FIG.

5 is a cross-sectional view taken along the line BB of FIG.

FIG. 6 is a vertical sectional side view showing another embodiment of the condenser of the present invention.

FIG. 7 is a partial detailed view of FIG.

FIG. 8 is a vertical side view showing another embodiment of the condenser of the present invention.

9 is a partial detailed view of FIG. 8. FIG.

FIG. 10 is a partial detailed view of another embodiment of the present invention.

FIG. 11 is a characteristic diagram showing the relationship between the aperture ratio and the magnitude of the water level fluctuation amplitude.

[Explanation of symbols]

1 ... Condenser, 2 ... Tube nest, 3 ... Condensate water sending device, 4 ... Condensate outlet, 5 ... Condensate system, 6 ... Condensate recirculation system, 7, 8 ... Switching valve,
9 ... Nozzle, 10, 10a, 10b, 10c, 10d ...
Ceiling plates 11, 27 ... Partition plates, 12 ... Steam injection pipes, 13
… Condensate degassing system, 14… Control valve, 15… Separator, 16,1
8 ... Water inlet, 17 ... Deaeration chamber, 19 ... Water storage chamber, 20 ... Water level gauge, 21 ... Grand steam condenser, 22, 26 ... Ventilation device, 22a ... Weir, 22b ... Cover, 22c ... Vent port, 2
3 ... Cooling water supply device, 24 ... Air extraction device, 25 ... Air extraction system.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Shigeo Oda Inventor Shigeo Oda 3-1-1, Saiwaicho, Hitachi, Ibaraki Hitachi Ltd. Hitachi factory (56) References JP-A-60-200086 (JP, A) Kaihei 5-79776 (JP, A) Japanese Patent Publication No. 63-12238 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) F28B 9/10 F28B 9/08

Claims (3)

(57) [Claims] 1. A pipe nest for condensing steam flowing from a turbine, a degassing chamber for degassing condensed water condensed in the pipe nest, and a separator for separating the degassing chamber from the water passage. Is arranged between the deaeration chamber and the tube nest portion, which is in communication with the deaeration chamber via a portion, and partitions the water storage chamber and the tube nest portion and falls from the tube nest portion. In a condenser having a partition wall for allowing the condensed water to flow into the deaeration chamber, a water-impermeable and air-permeable communication means is provided between the water storage chamber and the tube nest portion, A condenser that suppresses the generation of a water surface wave in the water storage chamber due to an increase in pressure in the section. 2. A tube nest portion for condensing steam flowing in from a turbine, a deaeration chamber for deaerating condensed water condensed in the tube nest portion, and a separator plate for separating the deaerator from the water passage portion. A water storage chamber that is in communication with the deaeration chamber via a, is arranged between the deaeration chamber and the tube nest portion, partitions the water storage chamber and the tube nest portion, and dropped from the tube nest portion In a condenser having a ceiling plate that allows condensed water to flow into the degassing chamber, the ceiling plate that separates the water storage chamber and the tube nest has no water permeability, and
A condenser, comprising a communicating means having air permeability, and suppressing generation of a water surface wave in the water storage chamber due to a pressure increase in the tube nest portion. 3. The opening area of the communication means provided in the partition wall or the ceiling plate is formed to be 0.2% or more and 75% or less of the area of the hot well water surface of the water storage chamber. The condenser according to 1 or 2.