Développement d’une pompe à chaleur à adsorption d’ammoniac-carbone.

The overall objective of the research is to develop a domestic air source gas-fired heat pump to replace standard condensing boilers cost-effectively. The working pair is ammonia and active carbon. A succession of sorption generators have been prototyped, culminating in the 'kebab' design in which monolithic carbon is compressed between aluminum fins on a steel tube containing pressurized water that either heats or cools the adsorbent in a two-bed cycle with heat and mass recovery. A 10 kW system was built and tested. Initial results were poor with Coefficient of Performance (COP) a little above 1. This was due to mass transfer resistance in adsorption being too high, due to an excessive binder fraction. A new formulation has been tested in a single 'kebab' and the results are consistent with an internal COP of 1.40 when delivering 10 kW at 50°C and evaporating at 0°C or 1.34 when delivering 20 kW.