Approach to Avoid Thermal Short Circuit and Energy Loss Caused by the Unfavorable Arrangement of Air Inlets and Outlets on a Train

摘要

Aerodyn.iinie losses and effects are often not considered properly at railways or locomotives. Four aerodynamic aspects shall be controlled to ensure functionality, availability, durability and energy efficiency: 1. Thermal short circuits have to be avoided. They occur if hot exhaust air is sucked in by air inlets. 2. Pressure differences between the air inlet and outlet due to the airstream may influence the volume flow of ventilators. 3. Hot air should not reach passengers in the railway or the station platform. 4. The exhaust air of the combustion engine may not be sucked to the inside of the railway. In chapter two there is a possible way to validate railways regarding aerodynamics and HVACs. The interaction between the airstream and the air inlets and outlets of HVACs are analyzed for a generic train. By using CFD DB Systemtechnik compares thermal short circuits and pressure differences for three HVAC designs. The influence on the energy consumption caused by these phenomenons is calculated by simplified equations.