Energy efficiency of railway coaches: innovative heat recovery solution for HVAC systems

The transportation sector's energy consumption is rising, with a doubling of energy use in the EU-13 countries between 1990 and 2018, and this trend is expected to continue in the next decade. Within this sector, railways consume a significant amount of energy, with a global annual consumption of 280 TWhel. Within this context, HVAC systems on trains account for up to 30% of the onboard energy use, highlighting a need for improved efficiency. In this framework, this research introduces a patented waste heat recovery solution to enhance HVAC system energy efficiency on trains. It uses heat from the cooling systems of electronic components (up to 70°C) for space heating by adding a heating coil to the HVAC layout, allowing for partial or total space heating from recovered heat. A dynamic simulation tool developed in MATLAB was used to assess the system's energy, economic, and environmental performance in a modern inter-regional train, adopted as case study. The results showed significant energy savings and reduced CO2 emissions, proving the system's effectiveness.