The electrical output of generators operating at a continuous load point are strictly constrained by the thermal performance. Ensuring the operating temperature does not exceed material limits is crucial to delivering high efficiency, reliability and long service life.
Optimisation of the cooling performance of generators ensures that maximum output can be achieved without compromising these performance criteria.
ECS was approached by a customer to improve the cooling of a generator that was exhibiting higher than expected temperatures.
The baseline performance and thermal characteristics was established, using a combination of CFD and thermal resistance modelling. These simulation results were validated against real-life test data.
With reference to our experience of generator cooling, several areas for thermal management improvements were identified.
- Stator cooling vents for improved cooling
- Fan design, including volute and housing, to deliver optimal flow with minimal power consumption
- Internal air baffling to distribute air within the generator for best utilisation of air flow
Surface cooling effectiveness, calculated using CFD
Air velocity flow pattern passing through the stator cooling vents from the CFD simulation.
Effective design and placement of stator cooling vents are instrumental in improving cooling performance.
ECS undertook and review and redesign of the vents, shown right, to facilitate good airflow and cooling direct to heat generating components.
The best positioning of the vents was considered, determined using an optimisation study using a combination of tools that produced significant improvements with minimal simulation time and cost.
Consideration of impacts on the electromagnetic and mechanical design as well as manufacturing and assembly were considered when considering viable design options.
- Maximum Stator Winding temperature reduced by 12% at some operating load after optimisation of cooling
- Thermal performance was validated by test data
- Minimal impact on redesign & tooling ensuring improvements were quick & cheap to implement
- Product achieved targeted performance
ECS used their experience and knowledge of generator cooling to reduce operating temperature using streamlined simulation methods.
Efforts were focused on areas known to effectively improve cooling, allowing analysis to be completed quickly for high value results.
Consideration of electromagnetic, mechanical and manufacturing implications were considered to ensure changes had minimal cost and redesign impacts.