Absorption Heat Transformers

Driven by the pressing need to reduce the environmental footprint of human activities and increase energy independence, a new topic has been developed. Type II Absorption Heat Pumps, also known as Absorption Heat Transformers, have the ability to utilize waste heat (low-exergy heat streams), but the vast majority of studies conducted on the topic have been numerical. A semi-industrial prototype of a Single Stage Absorption Heat Transformer (SSAHT) has been designed and built at the premises of INEGI to study the experimental heat transfer performance of such a device under different conditions. So far, the following topics have been covered:

• Numerical simulations of the thermodynamic performance of a 6.9 kW SSAHT;
• Sizing and design of the individual heat exchangers that compose the SSAHT;
• Construction of the prototype;
• Experimental characterization of the fluid flow and heat transfer within each heat exchanger;
• First steps towards the start-up of the SSAHT prototype.

This prototype allows future studies including:

• Design optimizations based on the acquired knowledge;
• Start-up and experiences using the working pair H₂O/LiBr;
• Experiences using novel working pairs, including ternary mixtures and ionic liquids.