Technology Insights – Vehicle Thermal Management Systems (VTMS 15)
20th June 2022
Our colleague Chris Parker was given the exciting opportunity to attend and present at the 15th Vehicle Thermal Management Systems (VTMS 15) conference organised by the Institute of Mechanical Engineers (IMechE) and hosted by The British Motor Museum. The historical vehicles made the perfect backdrop for an evolving topic. As you walk through the museum you can clearly see the evolution of vehicle design as the physics of aerodynamics become more understood, and the manufacturing process became more streamlined and automated. The thermal management systems have undergone a similar progression and will continue to do so as the challenges of battery electric vehicles (BEVs) and hydrogen fuel cells prompt a re-think on the suitability of the established solutions.
The principle thermal management requirements of an internal combustion engine (ICE) is primarily focused on removing waste heat and preventing temperature exceedance. While the top thermal output of BEVs are less than an ICE, the thermal requirements are arguably more complex due to a lower temperature limit and the prospect of rapid battery degradation when operated outside the temperature window.
This prompts a discussion, what thermal management system is most suitable for cooling and heating (yes heating) a battery pack? An established pumped water-glycol loop and electric resistance? A reversible heat pump? I see the need for a study to answer this question. The choice of working fluid and the mode of delivery will have a profound affect on the vehicle image. The removal of the ICE will (potentially) leave the working fluids of the thermal systems as the most polluting component of the vehicle whether that’s acting as a global warming potential or a persistent organic pollutant, or both. Therefore, choosing the right working fluid and system combinations will impact the future image of the vehicle.
While the question of vehicle thermal management is on the table we should also discuss the options of integrating the vehicle HVAC system with the BEV or fuel cell system. While more complex than separate systems and therefore more expensive initially, the operational energy saving cannot be denied. By keeping energy within the systems rather than being thrown away, the engineers would be fulfilling their duty of reducing wasted energy. By reducing the wasted energy, the overall energy consumption can be reduced. For an electric vehicle specifically, reduced energy consumption is of vital importance to reduce the impact of range anxiety, a deciding factor for customers to purchase a BEV. Of course, the overall cost of integrated systems must be weighed up against the operational savings to justify the investment to the customers.
WAVE’s extensive experience with thermal management systems places us in the fortunate position to support the development of thermal management systems in next generation vehicles. One day, the next generation of vehicles will be added to the museum, and the design decisions of today will be on display for generations to come.