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## Analysis of dynamic states of operation of a transcritical carbon dioxide heat pump

### Dominik Przemysław Dziekan

#### Abstract

This work aims to investigate how transcritical heat pumps react to dynamic changes in the return temperature of the upper source. The solutions presented in the literature force this type of devices to maintain stable operating parameters despite high pressure fluctuations in the gas cooler resulting from sudden stoppage of hot utility water intake. The theoretical part begins with a discussion of the technology and economic issues of heat pumps. The work contains information about the history and development of these devices, the basic thermodynamic informations of their operation and how their situation on the Polish market looks like. In the next part of the work we delve into the construction of the most common type of heat pump, which also includes the tested device. The next stage concerns working mediums, their classification, thermodynamic properties, safety of use and environmental impact. The work presents, in comparison to other discussed refrigerants, the properties of carbon dioxide, which is an ecological alternative to the most commonly used substances. Before the experimental part, the use of carbon dioxide in subcritical and transcritical heat pump systems is a particularly important chapter of the study. The work also shows Gustav Lorentzen's contribution to technology development. The experimental part of the work begins with a description of the tested device and the test stand. Then, the methodology of performing the experiment is presented. In the presentation and analysis of the results of the experiment it is shown how the temperature of carbon dioxide in the heat pump, the temperature of the sources and the pressure in the installation change in relation to the return temperature of the upper source. In addition, performance parameters such as the power consumed by the compressor, the power of the sources and their COP are calculated and displayed. The maximum COP Lorentz achieved and the reversibility of the sources are also calculated. These values are compared with the return temperature of the upper source and the pressure after the compressor, which, according to Gustav Lorentzen's patents, is crucial to optimize the operation of the device. In order to better illustrate the changes that carbon dioxide undergoes in the pump cycle, in the work, there are graphs of the state of the medium in the pressure-entalpia diagram. The work ends with a summary of information contained in the theoretical part and conclusions from the experimental part
Diploma type
Engineer's / Bachelor of Science
Diploma type
Engineer's thesis
Author
Dominik Przemysław Dziekan (FPAE) Dominik Przemysław Dziekan,, Faculty of Power and Aeronautical Engineering (FPAE)
Title in Polish
Analiza dynamicznych stanów pracy nadkrytycznej pompy ciepła z obiegiem na dwutlenku węgla
Supervisor
Tomasz Wiśniewski (FPAE/IHE) Tomasz Wiśniewski,, The Institute of Heat Engineering (FPAE/IHE)Faculty of Power and Aeronautical Engineering (FPAE)
Certifying unit
Faculty of Power and Aeronautical Engineering (FPAE)
Affiliation unit
The Institute of Heat Engineering (FPAE/IHE)
Study subject / specialization
, Energetyka (Power Engineering)
Language
(pl) Polish
Status
Finished
Defense Date
24-09-2019
Issue date (year)
2019
Pages
143
Internal identifier
MEL; PD-5235
Reviewers
Tomasz Wiśniewski (FPAE/IHE) Tomasz Wiśniewski,, The Institute of Heat Engineering (FPAE/IHE)Faculty of Power and Aeronautical Engineering (FPAE) Karol Pietrak (FPAE/IHE) Karol Pietrak,, The Institute of Heat Engineering (FPAE/IHE)Faculty of Power and Aeronautical Engineering (FPAE)
Keywords in Polish
pompa ciepła, nadkrytyczna, transkrytyczna, dwutlenek węgla, Gustav Lorentzen, temperatura powrotu górnego źródła, ciśnienie za sprężarką
Keywords in English
heat pump, transcritical, carbon dioxide, Gustav Lorentzen, temperature of the return of the upper source, pressure after the compressor
Abstract in Polish
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Identyfikator pracy APD: 35611

Uniform Resource Identifier
urn:pw-repo:WUT9b36bb09ebad413bb6021d395287138f