A1 Journal article (refereed), original research

Numerical analysis of working fluids for large scale centrifugal compressor driven cascade heat pumps upgrading waste heat


Open Access publication

Publication Details
Authors: Uusitalo Antti, Turunen-Saaresti Teemu, Honkatukia Juha, Tiainen Jonna, Jaatinen-Värri Ahti
Publisher: Elsevier
Publication year: 2020
Language: English
Related Journal or Series Information: Applied Energy
Volume number: 269
ISSN: 0306-2619
JUFO-Level of this publication: 3
Open Access: Open Access publication
Location of the parallel saved publication: http://urn.fi/URN:NBN:fi-fe2020062345371

Abstract

Heat pump technology has the capability to upgrade unusable
low-temperature waste heat and make the upgraded heat usable for
different types of industrial and domestic heating applications. Heat
upgrading could allow to reach significant energy savings and reduced
emissions when compared to other heat production methods. In this paper,
upgrading waste heat into a higher temperature with large-scale
centrifugal compressor driven cascade heat pumps was studied
numerically. A combined method for heat pump thermodynamic analysis and
compressor design analysis was developed and implemented in order to
investigate the effect of different working fluid combinations and the
effect of the cascade heat exchanger temperature level on the heat pump
performance. Seven potential fluid candidates were included and
condenser temperature of 90 °C, evaporator temperature of 20 °C, and
evaporator heat rate of 1 MW were used in the analysis. It was
concluded, that the implemented method can provide an efficient tool for
evaluating suitable working fluids and design operating conditions for
centrifugal compressor driven high temperature cascade heat pumps. The
highest coefficient of performance of 3.08 was simulated by using R601
as the fluid in the low-temperature cycle and R245fa in the
high-temperature cycle. These fluids also resulted in feasible
compressor geometries and rotational speeds, as well as allowed to reach
high compressor efficiencies of well above 80% based on the enthalpy
loss models. Coefficient of performances of over 3.0 were simulated also
with the fluid combinations R601/R600, R245fa/R245fa and R600/R245fa.


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Last updated on 2020-31-08 at 13:34