Session: 06-06 Heat Pumps-II

Paper Number: 153828

Increasing Heat Pump Efficiency Through Expansion Turbine Integration: A Comparative Study of Refrigerants and Process Cycles 

The growing demand for energy efficient thermal systems highlights the importance of optimizing heat pump performance. This study investigates the replacement of conventional expansion valves with expansion turbines in heat pump processes, allowing partial recovery of compressor work. Process simulation software was used to investigate different refrigerants, process parameters and cycle configurations to evaluate potential improvements in system performance. The focus was on propane (R290), a refrigerant of increasing importance due to its environmental benefits and favorable thermodynamic properties. The results show significant improvements in the coefficient of performance (COP) of heat pumps, particularly at lower operating temperatures where systems typically lose efficiency due to the large temperature rise. By integrating an expansion turbine, COP improvements were observed across the operating range, with the most significant improvements at colder heat source temperatures. In addition, this approach extended the efficient operating range of the heat pump system, allowing it to operate more effectively under challenging conditions. These findings contribute to the development of more sustainable and efficient energy systems, especially for large heating applications such as industrial and district heating, as well as high temperature heat pumps. The findings can have significant implications for the future design and operation of heat pumps, contributing to global efforts to achieve sustainable energy use and reduce carbon footprints.

Presenting Author: Leopold Müller Institute of Thermal Turbomachinery and Machinery Laboratory

Presenting Author Biography: I have been an academic researcher at the Institute for Thermal Turbomachinery and Machine Laboratory (ITSM) at the University of Stuttgart since December 2022, where I conduct research in the field of turbomachinery for novel processes. Previously, I studied Energy Engineering (Master) at the University of Stuttgart with specializations in combustion and power plant engineering as well as thermal turbomachinery. During my studies, I was able to gain practical experience through two internships at Accelleron (former ABB Schweiz AG) in the field of turbocharging in research and development as well as instrumentation and testing. I also completed my bachelor's degree in aerospace engineering at the University of Stuttgart.

Authors:

Leopold Müller Institute of Thermal Turbomachinery and Machinery Laboratory
Fabian F. Müller Institute of Thermal Turbomachinery and Machinery Laboratory, University of Stuttgart
Damian M. Vogt Institute of Thermal Turbomachinery and Machinery Laboratory