SU872907A2 - Deaeration feeding unit - Google Patents

Description

one

The invention relates to a power system, in particular to deaeration plants, can be applied in power plants to protect turbine shields from overflowing the steam-water mixture and improving the reliability of the feed pumps during load shedding.

According to the main author. St. The 10 aeration and feed installation is known, containing a de-aerator with a tank and a de-aeration column, a feed pump, feed water cooler and pipelines connecting the pump to the tank and 5 cooler, and the latter to the de-aerator, and pipelines connecting the cooler with the de-aerator connected to the buy-in and column at the levels of maximum permissible levels of liquid

ti 11.

The disadvantages of this installation are the danger of the steam mixture entering the turbine when the load is discharged due to the supply of steam from the 25 unregulated take-offs to the de-aerator and the low reliability of the feed pump.

The purpose of the invention is to prevent the steam-water mixture from drifting into the turbine and 30

increase the operational reliability of the feed pump during load shedding.

To achieve this goal, the deaerator tank is provided with an inclined perforated sheet with a vertical threshold in the middle part, with the lower end of the sheet located below the connection point of the pipeline connecting it to the cooler.

The drawing shows schematically a deaerating plant.

The installation contains a deaerator with tank 1 and deaeration column 2, feed pump 3 and feed water cooler 4. Pipeline 5 connects pump 3 to tank 1, and pipe 6 to coolant 4. Pipelines 7 and 8 connect cooler 4 to column 2 and tank 1, respectively. In the steam tank volume 1, by; the connection point to the last pipeline 8 connecting cooler 4 to tank 1 and above the maximum permissible level of liquid in tank 1 is installed a blocking section of tank 1 perforated inclined sheet 9 with vertical threshold 10 and with the ratio of the area of the living section of holes to the entire area of sheet 9 not more than ten%. The perforated sheet 9 is installed at an angle to the horizontal plane of the tank 1 by a slope in the direction of connecting to the last pipeline 8.

The installation works as follows.

When the deaerator is supplied with steam from an unregulated turbine take-off, when the load is relieved (rapidly reduced), the pressure in the extraction decreases sharply / which leads to a proportional pressure drop in the deaerator volume. The pressure drop in the deaerator causes boiling up of water accumulated in the tank 1, accompanied by intensive swelling of the layer liquid, and filling the steam volume of the tank 1 and the deaeration column 2 with the steam-and-vapor mixture, which is sucked into the selection of the turbine, leading to disruption of its operation and operation of the feed pump, This phenomenon is achieved in this installation by placing in the steam volume of tank 1 an inclined perforated sheet 9 with vertical threshold 10 placed under the connection point to tank 1 of pipeline 8 and above the maximum allowable level in tank 1. In normal operation, the turbine is drained from column 2 first, the water enters the tank 1 at the part of the lit 9 separated by the threshold 10, located on the side opposite to the connection point k of the tank 1 of the pipeline 8, from where it is jetted into the tank 1. The height of the threshold is chosen such that in the normal mode, the overflow of water therethrough at part of the sheet 9, placed side connecting truboprovrda 8 is eliminated, and the through-perforations of the sheet 9 pairs under it enters the column 2, thus permitting venting of steam required volume of the tank 1.

The inclination of the sheet 9 ensures a stable supply of water to the pipeline 8. When the turbine load, formed during the boiling up of the water accumulated in the tank 1, is relieved, the steam generator to the mixture leads to an increase in pressure under the sheet 9 relative to the pressure above it. As a result, the water dip through the perforation sheet 9, located on the opposite side

where the pipeline 8 is connected to block 1, it stops and the water overflows through threshold 10 onto a part of the sheet 9 located on the connection side of the pipeline 8, which causes the sections of sheet 9 used in the normal mode to pass through the sheet 9 column 2. From this point on, the steam duct on the mixture that forms when boiling: water in tank 1 can flow into column 2 and to steam supply manifold 11 only through a layer of water on sheet 9, the temperature of which continuously decreases over time. However, when the steam mixture passes through the perforation and the water layer on the sheet 9, there is an intense separation of moisture from the mixture and partial condensation of the steam, thereby providing the required heat for de-aeration of the water. Part of uncondensed steam and released during deaeration of gases, which are almost completely freed from suspended particles of moisture, comes from the vapor volume of tank 1 to column 2.

The separation of moisture in the water layer on sheet 9 eliminates the possibility of turbine malfunctioning if steam enters it from the deaerator. In addition, the installation allows for reliable water discharge in this mode from sheet 9 to pipeline 8, which significantly increases the reliability of the feed pump 3.

Claims (1)

1. USSR Author's Certificate, No. 624066, cl. F 22 O 11/02, 1977.