Operability of a Residential Gas-Fired Clothes Dryer Using Hydrogen-Blended Natural Gas

Abstract

Hydrogen blending in natural gas (NG) is being implemented as a transitional strategy for residential decarbonization. Although hydrogen-blended natural gas (HBNG) has been investigated across a range of residential appliances, operability impacts on gas-fired clothes dryers (GFCD) remain insufficiently characterized. A standard size 7.4 ft3 (0.21 m3) DLGX5501V GFCD was used across three dry load weights (2, 4, and 6 kg) to assess drying performance for four fuel blends (NG, 20, 40, and 50 vol% H2-NG). Cycle duration, efficiency, costs, emissions, and safety metrics were evaluated under the US Department of Energy (DOE) and Canadian Standards Association (CSA) listed testing guidelines. Drying time monotonically increased with hydrogen content in NG, with the largest penalty relative to NG occurring at 2 kg and 50% HBNG (Δt = 4.89 minutes; 23.3% increase). All test trials remained below the 80-minute ENERGY STAR® cycle time limit. An empirically regressed sigmoidal correlation was developed and compared with an adapted numerical GFCD model. Both predictive models reproduced measured drying times accurately for the set of test conditions (empirical: R2 = 0.973, RMSE = 1.46 minutes; numerical: R2 = 0.987, RMSE = 1.50 minutes) and were validated using a 3 kg intermediate load weight, yielding drying time errors of 2.2% and 5.4% for the empirical and numerical approaches, respectively. Cycle efficiency increased from 42.8% to 44.1% with 20% HBNG operation, with slight declines below NG efficiency for increased blending up to 40 and 50% HBNG. Steady-state emissions decreased progressively with hydrogen blending up to 50% HBNG, with CO2 reductions from 0.371 to 0.236 vol%, CO from 4.14 to 3.00 ppm, and NOx from 2.46 to 1.97 ppm for 50% HBNG. Operational temperatures remained below upper safety limits and no instances of flashback occurred in this study. The optimum fuel in terms of efficiency and cost in this work was 20% HBNG, with heightened efficiency and minimal drying time extensions relative to NG operation. Overall effects of HBNG use on a GFCD supported maintained operability up to 50% hydrogen blending and informed the recommended upper blending limit of 50% HBNG for this appliance. Future research should investigate the long-term effects of HBNG use on GFCDs, different textile materials, and the scalability of this work with industrial drying technologies for HBNG operation.