University of Illinois Urbana-Champaign

Improvements on performance of a heat pump water heater system

Shi, Ce

Content Files
SHI-THESIS-2018.pdf

Permalink

https://hdl.handle.net/2142/102850

Description

Title
Improvements on performance of a heat pump water heater system
Author(s)
Shi, Ce
Issue Date
2018-12-12
Director of Research (if dissertation) or Advisor (if thesis)
Hrnjak, Predrag
Department of Study
Mechanical Sci & Engineering
Discipline
Mechanical Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Date of Ingest
2019-02-07T20:44:27Z
Keyword(s)
  • Heat Pump Water Heater
  • COP
Abstract
Heat Pump Water Heater (HPWH) is classified as one renewable energy efficient technology, which could be explained by their environmentally friendly nature with low energy consumption. The Coefficient of Performance (COP) of the HPWH can be influenced by multiple factors: ambient temperature, relative humidity, hot water usage profile, the size and shape of heat exchangers (evaporator and condenser), type and shape of compressor, refrigerant, filling capacity of refrigerant, etc. Therefore, in this study, the performance of HPWH is critically examine to ascertain its optimal operation condition. Three main factors are considered here: use pattern of water in tank, drop-in refrigerant R1234yf and condenser configuration. This study examines two different models, HPWH-66 and HPWH-50. Simulation is employed and suggestions are made towards a better performance. The performance of HPWH system is found to strongly depend on the stratification of water in the storage tank, then 3D CFD simulation has been used to explore the entrance effects on the thermal tank. In the drop-in experiments, it is shown that R1234yf can be a desirable alternative for the baseline R134a without any special changes to the heat pump facility. By closing the valves at the inlet and outlet of one condenser circuit, a one-circuit condenser system could be achieved. For both refrigerant system, one-circuit condenser only brings the COP down within 5.5%. Finally, a linked EES-Fluent model has been developed to simulate the transient heating-up performance of the HPWH system with the validation by experimental data.
Graduation Semester
2018-12
Type of Resource
text
Permalink
http://hdl.handle.net/2142/102850
Copyright and License Information
Copyright 2018 Ce Shi

Owning Collections

Graduate Dissertations and Theses at Illinois PRIMARY
Graduate Theses and Dissertations at Illinois
Dissertations and Theses - Mechanical Science and Engineering