How can plant efficiency be increased when utilizing a closed feedwater heater?

Utilizing steam that is bled from a steam turbine enhances plant efficiency in a closed feedwater heater because this process utilizes low-pressure steam that has already done work in the turbine. When the steam is bled off at an intermediate point, it carries considerable thermal energy, which can be transferred to the feedwater, raising its temperature before it enters the boiler.

This preheating of the feedwater reduces the amount of energy required to convert water into steam within the boiler, thereby improving overall plant efficiency. The heat exchanger in the closed feedwater heater effectively captures waste heat, ensuring that more of the energy input into the system is converted into useful work, leading to an increase in thermal efficiency.

By leveraging the heat from steam that has already been utilized in energy generation, a closed feedwater heater minimizes fuel consumption and reduces greenhouse gas emissions, further enhancing the efficiency of the entire steam cycle.