Energy modelling and field testing of natural gas absorption heat pump system in cold climate - Canada
The feasibility of a Natural Gas Absorption Heat Pump (GAHP) was investigated through the use of a technology screening tool developed in Excel and TRNSYS simulations that used experimentally evaluated performance curves using 50% propylene glycol (PG)/water solution. The Excel tool was used for cost and greenhouse gas (GHG) reductions analysis and indicated that the GAHP was cost effective compared to an Air-Source Heat Pump (ASHP) in locations where the primary heating fuel was natural gas and had significantly lower GHG emissions compared to a 90% efficient natural gas furnace. During the heating season, it was found that the system only had more than 100% heating Gas Utilization Efficiency (GUE) at -1.5°C or above and would go as low at 66% GUE at nominal flow and return temperatures. Part load performance was analyzed using experimental data and implemented in a TRNSYS model. The TRNSYS model shows significant losses from part load performance and 50% PG/water derating for both heating and cooling season due to excessive cycling.