Why does air entry into the main condenser...

Question 1 / 270705eccef9cbacbc34ba4d45767

Question 1 of 270705eccef9cbacbc34ba4d45767

Why does air entry into the main condenser reduce the efficiency of the steam cycle?

Question 1 of 27070

Why does air entry into the main condenser reduce the efficiency of the steam cycle?

🔍 Key Concepts

• Main condenser function in a steam cycle (creating vacuum, condensing exhaust steam, recovering condensate) • Effect of non‑condensable gases (air) on condenser vacuum and heat transfer • Relationship between condenser pressure and turbine exhaust steam enthalpy

💭 Think About

• Think about what happens to the condenser pressure and vacuum when air leaks in. How does that change the turbine’s exhaust conditions? • Which option describes a thermodynamic change that would make the turbine do less work per pound of steam? • Consider which choices are simple statements of flow/mixing, and which relate directly to energy (enthalpy) at the turbine exhaust.

✅ Before You Answer

• Identify how air (a non‑condensable gas) affects heat transfer and pressure in the condenser • Recall what happens to steam enthalpy when condenser pressure rises (saturation temperature and enthalpy at exhaust change) • Eliminate any choices that do NOT clearly tie back to a change in turbine work output or overall cycle efficiency

Question 1 of 27070

Why does air entry into the main condenser reduce the efficiency of the steam cycle?

Steam flow rate through the main turbine increases

Condensate sub cooling in the main condenser increases

Low pressure turbine exhaust steam enthalpy value increases

The air mixes with the steam and enters the condensate

Question 1 / 270705eccef9cbacbc34ba4d45767

Question 1 of 270705eccef9cbacbc34ba4d45767

Why does air entry into the main condenser reduce the efficiency of the steam cycle?

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Question 1 of 27070

Why does air entry into the main condenser reduce the efficiency of the steam cycle?