Abstract
Water heating is a major energy consumption in the US residential sector. According to the annual energy outlook of the EIA (EIA 2021), the total US national primary energy efficiency of water heating is only 60%. Heat pump water heaters can significantly increase the thermal efficiency of water heating. Electric powered heat pump water heaters are already commercially available in the US. On the other hand, no fuel-fired heat pump water heaters are available, but two are in development, both employ absorption cycle. Thermally driven ejector heat pumps have been discounted for their low efficiency and narrow operating range. In this paper we present performance analysis of a novel ejector heat pump for water heating that overcomes the shortcomings of conventional ejector heat pumps. The heat pump uses binary fluid mixture and active back pressure control. The use of the binary mixture results in high thermal efficiency and the active back pressure control widens the operating range of the heat pump. Two configurations of the heat pump are presented and analyzed. The maximum achievable COP of each was 1.95 and 1.7 at output heating capacities of 5.7 and 6.7 kW, respectively.
| Original language | English |
|---|---|
| Title of host publication | 2022 ASHRAE Winter Conference |
| Publisher | ASHRAE |
| Pages | 146-153 |
| Number of pages | 8 |
| ISBN (Electronic) | 9781955516068 |
| State | Published - 2022 |
| Event | 2022 ASHRAE Virtual Winter Conference - Virtual, Online Duration: Jan 29 2022 → Feb 2 2022 |
Publication series
| Name | ASHRAE Transactions |
|---|---|
| Volume | 128 |
| ISSN (Print) | 0001-2505 |
Conference
| Conference | 2022 ASHRAE Virtual Winter Conference |
|---|---|
| City | Virtual, Online |
| Period | 01/29/22 → 02/2/22 |
Funding
Notice: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE 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 material is based upon work supported by the US Department of Energy, Office of Science, Building Technologies Office. This research used resources of the Building Technologies Research and Integration Center of the Oak Ridge National Laboratory, which is a DOE Office of Science User Facility.