Abstract
While the use of energy efficient absorption heat pumps has been typically limited to the high capacity commercial and industrial applications, the use of a semi-open absorption heat pump for water heating has been demonstrated to be an energy efficient alternative for residential scale applications. A semi-open absorption system uses ambient water vapor as the refrigerant in the absorber where its heat of phase change is transferred to the process water, cooling the solution in the absorber. The solution is pumped to the desorber, where by adding heat, the water vapor is released from the solution and condensed in the condenser. The heat of phase change of water vapor is transferred to process water again in the condenser. This cycle when implemented with a membrane-based absorber in a plate and frame form of heat exchanger using ionic liquids can overcome the challenges related to the system architecture of conventional absorption heat pumps like the lower efficiency at small scale, crystallization/corrosion issues with the desiccants and the high cost of hermetically sealed components. The cycle COP for such a system was previously demonstrated by Chugh et al. for high humidity conditions. In this experimental study, design improvements were made that expand the system's applicability to more practical and standardized test conditions. With these improvements, the performance of the system was evaluated. The results presented in this study demonstrate the improved system's viability as a heat pump water heater conforming to standard water heater test conditions. Performance was measured at a cycle thermal COP of 1.2 with a hot water delivery water temperature of 56 °C and ambient air at 19 °C and 49% RH.
| Original language | English |
|---|---|
| Pages (from-to) | 919-927 |
| Number of pages | 9 |
| Journal | Applied Energy |
| Volume | 239 |
| DOIs | |
| State | Published - Apr 1 2019 |
Funding
This work was sponsored by the U. S. Department of Energy, Office of Energy Efficiency and Renewable Energy (EERE), under Award Number DE-EE0006718 with the University of Florida and DE-AC05-00OR22725 with UT-Battelle, LLC. The authors would also like to acknowledge Mr. Antonio Bouza, Technology Manager, Mr. Jim Payne, Technical Project Officer and Mr. Michael Geocaris, Project Engineer – HVAC&R, Water Heating, and Appliance, U.S. Department of Energy Building Technologies Office. This manuscript has been authored by the University of Florida under Award Number DE-EE0006718 and UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). This work was sponsored by the U. S. Department of Energy , Office of Energy Efficiency and Renewable Energy (EERE) , under Award Number DE-EE0006718 with the University of Florida and DE-AC05-00OR22725 with UT-Battelle , LLC. The authors would also like to acknowledge Mr. Antonio Bouza, Technology Manager, Mr. Jim Payne, Technical Project Officer and Mr. Michael Geocaris, Project Engineer – HVAC&R, Water Heating, and Appliance, U.S. Department of Energy Building Technologies Office.
| Funders | Funder number |
|---|---|
| U. S. Department of Energy | |
| U.S. Department of Energy | |
| Office of Energy Efficiency and Renewable Energy | DE-EE0006718 |
| University of Florida | DE-AC05-00OR22725 |
Keywords
- Absorption
- Dehumidification
- Ionic liquid
- Water heating
