Contrac – Electric Actuators

Introduction

The water injection valve on a steam boiler controls the amount of cooling water injected into the superheated steam in the superheater and reheater.

The amount of water injected is decisive for the temperature of the steam inside and at the output of the superheater.

Too much water injection can lead to excessive cooling of the steam, which negatively affects efficiency.

On the other hand, insufficient water injection leads to excessive steam temperature and pressure.

The risk of damage to the superheater, turbine and downstream components increases as a result.

For optimal operation of the superheater at the lowest possible steam temperature and the highest possible hot steam temperature, the

continuous and precise mass flow control of the injected cooling water is first required.

Depending on the operating conditions, this requirement means that very small amounts of water need to be supplied, thus requiring highly accurate positioning in disproportionate areas of the valve.

The operating environment is extremely harsh.

In addition, the ambient temperature in the superheater area can be very high.