Steam conditioning stations

In the processes of power stations, the steam is usually produced as superheated steam to avoid unnecessary condensation in the transfer line and to maintain it in the steam form. However, the heat transfer capability of superheated steam is modest as compared to the heat transfer capability of saturated steam, for which reason it should be cooled to the temperature that corresponds to the pressure of saturated steam. This can be performed in a steam conditioning station.

Accuracy determines the cooling method selected

The superheated steam is usually cooled so that cooling water is fed into the steam in a controlled way. For this purpose, the cooling water is sprayed directly into the valve seat or immediately after the valve. The operation is relatively simple and reliable. In the best case, adding cooling water allows reaching +3°C temperature from saturated steam.

The steam conditioning station is often provided with a special extension positioned immediately after the valve. This enables the expansion of steam at dropping pressure. The extension prolongs valve service life and contributes to noise level control.

Depending on the required accuracy of the cooling and the amount of water, the cooling water is fed into the extension part using different techniques. It can be atomised among the steam as water vapour or the steam can be lead through a water film. If necessary, perforated plates/absorbers can be added to the extension parts to drop the flow rate in a controllable way and to reduce the noise level.

If the process requires fully saturated steam, this can be produced by a special desuperheater unit.
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