Gas-Fired Absorption Heat Pump Water Heater Development at ORNL Kyle Gluesenkamp Omar Abdelaziz Ed Vineyard Building Equipment Research Oak Ridge National Laboratory Sept. 4, 2013 ACEEE Hot Water Forum Atlanta, GA
Overview Background Water heater primary energy consumption Market for gas heat pump water heaters Prototype development Working fluids Glycols Ionic liquids Simulation tools for absorption machines (ABSIM) 2 / 15 GHPWH Development at ORNL
Project at ORNL Project goals: Increase energy factor (EF) of gas storage water heating from ~0.65 to >1.0, with zero GWP and zero ODP Target retrofit market Identify and meet appropriate cost targets Impact: Reduce 1.29 Quads/yr used in water heaters by >0.45 Quads with full adoption 3 / 15 GHPWH Development at ORNL
Project at ORNL Partners and Collaborators: CRADA partner is GE. Other collaborators are: Yankee Scientific, Inc. breadboard prototype Ionic Research Technologies, LLC ionic liquids Purdue University update of ABSIM University of Florida membrane systems Sentech/SRA International, Inc. market assessment Technology Transfer: Target is a commercialized residential unit with EF>1.0 at <$300 price premium over standard gas technology 4 / 15 GHPWH Development at ORNL
Primary Energy Ratio of Water Heaters Non-condensing gas burner WH Fuel Gas WH Hot water PER = EF PER 0. 65 Losses Non-condensing gas HPWH Fuel Ambient heat Gas HPWH Hot water Losses PER = EF PER 1. 0 + HPWHs can leapfrog condensing gas WHs Cost and novelty are current barriers R&D needed 5 / 15 GHPWH Development at ORNL
Primary Energy Ratio of Water Heaters Fuel Power plant Losses Electricity Elec WH Hot water PER = η grid EF Losses PER 0.33 0.9 PER 0. 30 Fuel Power plant Losses Electricity Ambient heat Electric HPWH Hot water Losses PER = η grid EF PER 0.33 2.5 PER 0. 83 Fuel Ambient heat Gas HPWH Hot water Losses PER potential of gas HPWH greater than electric HPWH Cost and novelty are current barriers R&D needed PER = EF PER 1. 0 + 6 / 15 GHPWH Development at ORNL
HVAC Burden: Gas vs. Electric HPWH Electricity 0.4 unit 0.6 unit Evaporator: heat from conditioned space 0.1 unit Losses to conditioned space Mechanically driven heat pump COP elec 3 0.9 unit EF 2.5 Hot water Q evap Q HW = 1 1 EF Nat. gas 0.8 unit 0.2 unit Evaporator: heat from conditioned space Thermally driven heat pump COP th 1.5 (ignores flue losses for gas) 0.1 unit Losses to conditioned space 0.9 unit Hot water EF 1.2 (example only) Space cooling effect is ~3-5x lower for gas HPWHs compared to electric HPWHs (also less CFM required) Enhanced suitability for conditioned spaces in cold climates 7 / 15 GHPWH Development at ORNL
Market for Gas-fired HPWHs Water heater install location Retrofit payback period favorable with ~$300 price premium (compared with standard efficiency gas storage) 8 / 15 GHPWH Development at ORNL
Temperature Prototype Development Absorption heat pump Heat from combustion Heat from ambient Hot water Heat to water from fuel and ambient 9 / 15 GHPWH Development at ORNL
Working Fluids Crystallization Crystallization of salt solution at high temperature lift Characterization of water/libr with 1,3 Propylene glycol anticrystallization additive in progress at ORNL 10 / 15 GHPWH Development at ORNL
Working Fluids Ionic Liquids Ionic liquid: an organic salt, liquid at room temperature. Represent unique opportunity to advance absorption technology Safe, environmentally benign Less corrosive than typical fluids No crystallization risk 10 10 possible combinations of cations and anions 10 3 described in literature 10 2 commercially available Need to explore options through modeling Common cations Common anions 11 / 15 GHPWH Development at ORNL
Working Fluids Ionic Liquids Ionic liquid development is in progress. Physics-based modeling is coupled to process model and guided synthesis. Precise lab characterization Process modeling / life cycle analysis Computational property predictions Guided synthesis 12 / 15 GHPWH Development at ORNL
ABSIM Application designed specifically for modeling absorption heat pump cycle performance Publically available, free tool Updating for modern computing environment Enhanced with advanced plotting functions and GUI Currently in beta phase Old version available upon request 13 / 15 GHPWH Development at ORNL
References Patent Applications: Abdelaziz, O., Vineyard, E., Zaltash, A. (2010). US Patent application 12/829,940, filed July 2, 2010. Absorption heat pump system and method of using the same. UT-Battelle ID 201002389. Publications: Abdelaziz, O., Maginn, E., Morrison, D. (2013). Ionic fluid design for absorption heat pump applications. Seminar 58 of 2013 Winter ASHRAE Conference, Dallas, TX, USA. Sikes, K., Blackburn, J., Abdelaziz, O. (2012). Market assessment for high-performance gas absorption water heaters. November 2012. Wang, K., Abdelaziz, O., Kisari, P., Vineyard, E. (2011). State-of-the-art review on crystallization control technologies for water/libr absorption heat pumps. International Journal of Refrigeration, vol. 34, pp. 1325-1337. Wang, Kai, Omar Abdelaziz, and Edward A. Vineyard. "The impact of water flow configuration on crystallisation in LiBr/H 2 O absorption water heater." International Journal of Energy Technology and Policy 7.4 (2011): 393-404. Brownell, D., Stevenson, A., Guyer, E. (2011). Absorption heat pump water heater prototype, design report B. Submitted by Yankee Scientific, Inc., under subcontract number 4000101964, May 24, 2011. Kisari, P., Wang, K., Abdelaziz, O., Vineyard, E. (2010). Crystallization temperature of aqueous LiBr solutions at low evaporation temperature. Road to Climate Friendly Chillers, Cairo, Egypt. Wang, K., Kisari, P., Abdelaziz, O., Vineyard, E. (2010). Testing of crystallization temperature of a new working fluid for absorption heat pump systems. Road to Climate Friendly Chillers, Cairo, Egypt. 14 / 15 GHPWH Development at ORNL
Acknowledgments DOE Building Technologies Program, Emerging Technologies 15 / 15 GHPWH Development at ORNL