JPH04334507A - Degassing device - Google Patents

Abstract

PURPOSE:To achieve sufficient degassing by improving the sprinkling state of the water from a perforated bottom plate even in such a case that the amount of water is little by providing two degassing towers and performing degassing by two degassing towers when the amount of the water supplied to the degassing towers is much and performing degassing by one degassing tower when the amount of said water is little. CONSTITUTION:Two degassing towers 20, 21 are provided and, when the amount of the water supplied to the degassing towers is much, degassing is performed by two degassing towers and, when the amount of said water is little, the degassing is performed by one degassing tower. That is, in a degassing device 1 equipped with the degassing towers 20, 21 heating the water falling from the perforated bottom plate 5 of a water storage case 8a by steam to degass the same, even when the load of a plant becomes low and the amount of the water supplied to the degassing towers becomes little, the sprinkling state of the water from the perforated bottom plate is improved to make it possible to sufficiently perform degassing.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to water degassing, and more particularly to a sprinkler tray type deaerator for degassing water to be fed to a boiler.

0002

[Prior Art] Water sent to boilers installed in thermal power plants, nuclear power plants, chemical plants, and private power generation equipment is sent to a deaerator to remove oxygen dissolved therein, that is, to degas it. Water is sent. Figure 3 shows this type of deaerator.
The watering tray type shown in is known.

[0003] In FIG. 3, a deaerator 1 is composed of a deaerator 2 and a water storage tank 3. In the degassing tower 2, a water storage case 8 is disposed above the casing 4 and has a porous bottom plate 5 and stores water supplied through a water supply pipe 6 penetrating the casing 4.

[0004] A deaeration tray 9 is provided below the water storage case 8 within the casing 4 . Further, below the degassing tray 9 inside the casing 4, water that falls from the water storage case 8 through the degassing tray 9 is stored, and this water is boiled by steam supplied through the steam supply pipe 10 penetrating the casing 4. A boiling tank 11 is provided.

The water storage tank 3 stores water degassed in the deaeration tower 2 and is provided below the deaeration tower 2. The deaeration tower 2 and water storage tank 3 are comprised of a steam pipe 12 through which steam in the water storage tank 3 flows into the deaeration tower 2, and a water supply pipe 13 through which deaerated water from the deaeration tower 2 is sent to the water storage tank 3. are connected by. Note that 14 is a steam inlet that supplies steam to the water storage tank 3, and 15 is a water supply outlet that supplies deaerated water stored in the water storage tank 3 to the outside.

[0006] With this configuration, water supplied from the outside to the degassing tower 2 via the water supply pipe 6 is stored in the water storage case 8. The stored water falls as a water column from the porous bottom plate 5 and is sprayed into the casing 4 by the degassing tray 8. The sprinkled water is then stored in the boiling tank 11.

On the other hand, steam is supplied from the outside through a steam supply pipe 10 to a boiling tank 11, and this steam boils water stored in the boiling tank 11 to generate steam. This steam flows upward, falls from the porous bottom plate 5, heats the water sprinkled by the deaeration tray 9, vaporizes the oxygen dissolved in the water, and deaerates the water.

Further, the steam flowing into the water storage tank 3 from the steam inlet 14 heats the water stored in the water storage tank 3. Note that the steam generated at this time passes through the steam pipe 12 to the degassing tower 2.
The water flows into the casing 4 and flows upward, is cooled by the sprayed water, falls as water, and is degassed.

[0009] The degassed gas is discharged to the outside from a vent port (not shown) in the upper part of the casing 4 along with accompanying steam.

The water degassed in this manner is transferred to the boiling tank 11.
is stored in the boiling tank 11 and boils as described above.
The deaerated water overflowing from the tank falls through the water supply pipe 13 into the water storage tank 3, where it is stored, and is sent to the outside through the water supply outlet 15.

[0011]

[Problems to be Solved by the Invention] In the deaerator 2 of the deaerator 1 described above, the formation of a water column falling from the porous bottom plate 5 of the water storage case 8 is caused by the formation of a water column that flows out from the hole determined by the water level H on the porous bottom plate 5. It is controlled by the flow velocity. Therefore, if the amount of water supplied to the degassing tower 2 decreases due to a decrease in the plant load,
The water level on the porous bottom plate 5 decreases, and as a result, the outflow rate from the holes slows down and a water column is no longer formed, making it impossible to obtain a good watering condition, resulting in incomplete contact with the steam rising from below. , resulting in poor heat transfer from steam to water. Therefore, there is a drawback that the water is not sufficiently heated and the performance of the deaerator is reduced.

An object of the present invention is to provide a deaerator whose deaerator performance does not deteriorate even if the amount of water supplied to the deaerator decreases due to a reduction in plant load.

[0013]

[Means for Solving the Problems] In order to solve the above problems, the present invention includes a case having a porous bottom plate for storing water supplied from the outside in an upper part of the casing, and the water is stored in the case, A degassing unit that includes a degassing tower that heats and degasses the water falling from the porous bottom plate with steam supplied into the casing from the outside, and a water storage tank that stores the water degassed in the degassing tower. A first deaeration tower is used when the amount of water supplied is small, and a second deaeration tower is used in addition to the first deaeration tower when the amount of water supplied is large. A deaeration tower shall be constituted by two deaeration towers.

[0014]

[Operation] When the load on the plant is large and the amount of water supplied to the deaeration tower is large, the water is divided and supplied to each of the two deaeration towers, and the water level stored in the water storage case of each deaeration tower is Make sure to maintain good watering conditions. In such a configuration, when the load on the plant is small and the amount of water supplied to the deaeration tower is small, water is supplied to only one deaeration tower and the water is stored in the water storage case of this deaeration tower. As mentioned above, keep the water level at a good level for watering.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described below based on the drawings. FIG. 1 is a block diagram of a deaerator according to an embodiment of the present invention. Note that in FIG. 1 to FIG. 2, which will be described later, the same parts as in the conventional example shown in FIG. In FIG. 1, the difference from the conventional example is the first degassing tower 20.
, a second deaeration tower 21 is connected to the water storage tank 3 through a steam pipe 12 and a water supply pipe 13, and a branch water supply pipe 24 supplies water to each water storage case 8a of the deaeration towers 20 and 21; 25 is branched from the water supply pipe 6, and further a branch water supply pipe 24 is provided.
, 25 are provided with valves 26 and 27, respectively.

The rated capacities of the degassing towers 20 and 21 are each half of the rated water amount for the load of the plant. Therefore, when the plant is under the rated load and the amount of water supplied is the rated amount, the water level H formed in each water storage case 8a of the degassing towers 20 and 21 is 1/2 the rated water amount, which is the water level that maintains a good watering condition. In addition, 9a is a deaeration tray, and 11a is a boiling tank.

With this configuration, when the load of the plant is from the rated load to 1/2 load, the valves 26 and 27 are opened to reduce the amount of water flowing through the water supply pipe 6 to the two deaerators 20 and 21. /2 of the water is supplied to deaerators 20 and 21 via branch water supply pipes 24 and 25, respectively.

In this state, in each deaeration tower 20, 21, the water level H of the water stored in each water storage case 8a maintains a good sprinkling state, and the water supplied to the deaeration towers 20, 21 is sufficient. It is degassed.

When the load of the plant is less than 1/2 load, one of the valves 26 and 27, for example, as shown in FIG. 2, the valve 27 is closed and the valve 26 is opened. In this state, the amount of water passing through the water supply pipe 6 flows only into the degassing tower 20 via the branch steam supply pipe 24.

In this case, the amount of water when the load of the plant is 1/2 is stored in the water storage case 8a, and the water level H
will be the same as the water level at the rated water level mentioned above. Therefore, even if the amount of water is less than 1/2 load, the water supplied to the degassing tower 20 is sufficiently degassed.

[0021]

Effects of the Invention As is clear from the above explanation, according to the present invention, two deaeration towers are provided, and when the amount of water supplied to the deaeration tower is large, two deaeration towers are provided, and when the amount of water supplied to the deaeration tower is small, two deaeration towers are provided. Sometimes, by using one deaeration tower for deaeration, even when the amount of water supplied to the deaeration tower is small, the water level stored in the water storage case is the same as when the amount of water is large.
Even when the amount of water is small, water is sprinkled from the perforated bottom plate of the water storage case in a good manner, and therefore sufficient deaeration is achieved.

[Brief explanation of drawings]

FIG. 1 is a diagram showing a degassing system equipped with a deaerator according to an embodiment of the present invention.

[Fig. 2] A diagram showing the state when the amount of water supplied to the deaeration tower in the deaeration system of Fig. 1 is less than 1/2 of the rated water amount.

[Figure 3
】Conventional deaerator configuration diagram

[Explanation of symbols]

1 Deaerator 2 Deaeration tower 3 Water storage tank 4 Casing 5 Porous bottom plate 8 Water storage case 8a Water storage case 20 First degassing tower 21 Second degassing tower

Claims (2)

[Claims] [Claim 1] A case having a porous bottom plate for storing water supplied from the outside above the casing, the water stored in the case and falling from the porous bottom plate being absorbed by steam supplied into the casing from the outside. A deaerator consists of a deaeration tower that heats and deaerates the water, and a water storage tank that stores the water degassed in the deaeration tower.The deaeration tower is used when the amount of water to be supplied is small. A deaerator comprising a first deaerator and a second deaerator which is used in addition to the first deaerator when a large amount of water is supplied. 2. A deaerator according to claim 1, wherein the rated capacities of the first and second deaerators are each half of the rated water amount of the load of the plant.