Computational Fluid Dynamics for National Grid Wormington Ventilation System

Earlier analysis focussed on inlet geometry of different ventilation architectures. The results from these studies were then used to determine the inlet conditions for analysis of the GT enclosure flow. The GT enclosure was analysed for areas of stagnant airflow as this would have potential for a hazardous build-up of gas in the event of a gas leak. The thermal contributions from turbomachinery were then combined with the turbulent flow analysis to examine the coupling effect on the flow. 

Problem  

The existing ventilation system is a negative pressure system but was found to be insufficient to maintain target temperatures within the Gas Turbine enclosure, leading to overheating. 

Solution  

CFD was conducted using COMSOL Multiphysics 5.6a with the CFD module and LiveLink for Inventor module. The flow was analysed using a turbulent RANS k-ε model.  

Different inlet configurations where studied as well as enclosure flow distribution and thermals. Cullum used results to redesign the ventilation system to be a vertical/symmetrical design with positive pressure system. Flow distribution within enclosure also used to prove Fire& Gas system sensor locations and specification will meet functional requirements. 

Unique Challenges  

Overheating of Gas Turbine enclosure 

Key Customer Outcomes 

Cost effective solution that will allow customer to run Gas Turbine without overheating