Engineering Case Study: STG-4 Condenser Issue

Questions and Answers

What event triggered the turbine trip logic in the STG-4 unit?

An increase in turbine speed

A high level in the condenser (correct)

Failure of the steam supply

A power supply interruption to the PRDS

What was the immediate effect of the condensate pump tripping at the STG-4 unit?

The temperature in the turbine increased

The condenser level started to climb (correct)

The PRDS opened automatically

The steam pressure decreased

What was the initial operational response of the PRDS upon turbine trip logic activation?

To open and direct steam to the condenser (correct)

To redirect steam to the cooling towers

To close and prevent steam flow

To maintain constant pressure for the turbine

What corrective action was taken after the critical incident involving the STG-4 unit?

Manually close the PRDS to mitigate steam flow Signup and view all the answers

Why was it necessary to update the control logic after the incident?

To prevent PRDS from opening during high condenser levels Signup and view all the answers

Which of the following was a direct consequence of the high condenser level in the STG-4 unit?

The condenser overflowed completely Signup and view all the answers

Study Notes

STG-4 Condenser Issue Overview

The STG-4 unit is one of four steam turbines at FPCL's power plant.
A power supply issue affected the condensate pumps, vital for regulating water levels in the condenser.
The failure of the condensate pump led to a rise in the condenser level due to inadequate water removal.

Consequences of the Pump Trip

An elevated condenser level triggered the turbine trip logic.
According to operational standards, a turbine trip necessitates the opening of the PRDS (Pressure Reducing and Desuperheating Station) to redirect excess steam.
In this case, the PRDS opening contributed to the condenser level reaching 100%, compounding the already critical situation.

Resolution Actions

The PRDS was manually closed to halt further increase in the condenser level.
A review of the control logic revealed flaws necessitating immediate updates.
The updated control logic now prevents the PRDS from opening during a turbine trip when the condenser level is already high, mitigating future risks.

Description

This quiz explores a critical engineering case study involving the STG-4 steam turbine at FPCL's power plant. It examines the failure of the condensate pump and the implications for the plant's control systems. Test your understanding of the operational challenges and technical solutions presented in this scenario.