Abstract
A promising solution to improve the first hour rating (FHR) of a heat pump water heater (HPWH) involves employing a secondary tank which contains phase change material (PCM) capsules. To better understand the influence of PCM thermal storage on the HPWH operational performance, a dynamic model was developed to simulate and analyze the behavior of a newly developed HPWH technology that incorporates PCM storage into a standard HPWH to optimize key parameters such as the uniform energy factor and FHR. Mathematical models of several key components of the proposed HPWH-PCM integrated thermal energy storage (TES) system, e.g., water heater tank, PCM TES tank, evaporator, compressor, and expansion valve, have been elaborated. Also, a model-based control co-simulation platform was developed to integrate a embed PCM storage HPWH dynamic model with a control model for better supporting control design, analysis, verification, and validation. The model accuracy has been validated through comparing simulation results with lab test results, with a mean average percentage error of <5.5% for most of the selected performance variables. In addition, using the developed co-simulation platform, the demand response control strategy was studied to evaluate the load flexibility of the combined HPWH-PCM storage system by shifting system power usage to outside of the 3.5 h peak load period.
| Original language | English |
|---|---|
| Article number | 106917 |
| Journal | International Communications in Heat and Mass Transfer |
| Volume | 146 |
| DOIs | |
| State | Published - Jul 2023 |
Funding
Funding for this research was provided by the US Department of Energy Office of Energy Efficiency and Renewable Energy. The authors would like to thank Mr. Antonio Bouza, Program Manager of the Building Technology Office, for their support of this work. Funding for this research was provided by the US Department of Energy Office of Energy Efficiency and Renewable Energy . The authors would like to thank Mr. Antonio Bouza, Program Manager of the Building Technology Office , for their support of this work. This manuscript has been authored in part 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 ).
Keywords
- Heat pump water heater
- Model-based co-simulation
- Phase change materials
- Thermal energy storage