Recent Advances in Absorption Chillers for Low-Grade Waste Heat Recovery
Yunho Hwang
Research Professor, Co-Director of CEEE
University of Maryland
ABSTRACT
A staggering 72% of the energy we produce is lost as waste heat, a consequence of utilizing heat engines in power plants. This inefficiency demands increased fuel consumption to meet energy demands, leading to amplified greenhouse gas emissions and accelerating global warming. However, absorption chiller (ABC) technology offers to harness this waste heat for decarbonization. ABCs boast the following advantages: (1) Low-grade heat recovery: they can utilize heat as low as 70°C, making them ideal for capturing previously wasted energy. (2) Environmental friendliness: their working fluids have zero global warming potential, minimizing their environmental footprint. Recent advancements in ABC technology are particularly exciting: (1) Cascade ABC: this design enables the utilization of even lower-grade heat sources. (2) Integrated ABC-vapor compression chiller: This system optimizes cooling efficiency for data centers. (3) Multi-generation with LNG regasification: this approach combines ABC technology with natural gas regasification processes for enhanced efficiency. The advanced ABC approaches can simultaneously provide cooling, heating, and power to various facilities, like industries, universities, and hospitals, while significantly reducing their environmental impact. Large-scale implementation of ABCs promises even greater benefits for the economy, environment, and energy.