A novel heat pump cycle to enable the flexible storage and deployment of harvested waste heat in cold climates

The increasing desire for renewable energy and decarbonization demands a transformation in the way we manage thermal and electrical energy in residential HVAC systems. New regulations and an increase in renewable energy participation in our power systems will increasingly incentivize fully electric solutions, flexible loads and load reductions for consumers. A novel heat pump concept is proposed that integrates a PCM-embedded heat exchanger in the injection line of a vapor injection heat pump system. Waste heat may be harvested from drain water or similar source, stored in the PCM and then deployed to heat a residential space using this concept. A system model was constructed for the proposed system as well for two baseline cases. The model demonstrates that when waste heat is directly deployed to the injection line when the heat pump is active, the COP can be increased to 5.0 from the baseline of 3.6. The waste heat utilization in this case is roughly 28%. Waste heat utilization can be much greater when waste heat is harvested and stored in the PCM while the heat pump is inactive. The performance of the heat pump was also simulated during a discharge state however the results are not representative of the true performance due to model stability issues which will be resolved in future work. More work is needed to understand the performance of the proposed heat pump but initial results demonstrate that it has potential to enable significant load reductions in residential settings.

Name thesis:degree_name

M.S.

Level thesis:degree_level

Thesis

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois Urbana-Champaign

Year dc:date

2025

Author dc:creator

• Wills, James

Contributors dc:contributor

• Miljkovic, Nenad

• Waste Heat Recovery
• TES Integrated Heat Pump

Statement dc:rights

• Copyright 2025 James Wills

Language dc:language

en

Handle dc:identifier

https://hdl.handle.net/2142/132584

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/132584