Sökning: "variable speed compressor"

Visar resultat 1 - 5 av 7 avhandlingar innehållade orden variable speed compressor.

1. 1. Capacity Control of Residential Heat Pump Heating Systems

   Författare :Fredrik Karlsson; RISE; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; energy efficiency; variable-speed; air-source; performance; hydronic heating system; ground-source; heat pump; defrost; optimisation; circulator; capacity control;

   Sammanfattning : Heat pumps used for space and sanitary hot water heating of residential buildings are increasingly popular in northern Europe. As they compete with other heating equipment and in order to limit the environmental impact of their use, it is very important that heat pumps are energy efficient. LÄS MER

3. 2. Integrated Control of Heat Pumps

   Författare :Fredrik Karlsson; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; variable speed compressor; superheat; electronic expansion valve; optimisation; performance indication; control; heat pump; energy efficiency;

   Sammanfattning : The purpose of the work presented in this thesis is to investigate the potential and prerequisites for improved energy efficiency of heat pump systems using efficient components and proper methods for optimisation of operation. The background is that several investigations have reported on possibilities for increased energy efficiency of heat pumps if variable-speed capacity control is used instead of conventional on/off control. LÄS MER

4. 3. Modelling and Numerical Analysis of the Centrifugal Compressor and its Operation in the Pressurised SOFC GT Process

   Författare :Andre Hildebrandt; Kraftverksteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; applied thermodynamics; Thermal engineering; radial compressor; Gas Turbine; Termisk teknik; Solid Oxide Fuel Cell; termodynamik;

   Sammanfattning : Small-scale power plants based on the SOFC-GT (Solid Oxide Fuel Cell-Gas Turbine) system are foreseen for future application such as APU units in flight transportation systems or stationary power production. Although these new systems offer high load flexibility and potentially high efficiency, there are several constraints referring to thermal/mechanical stress of the fuel cell as well as to a potential risk of aerodynamic instability of the GT compressor due to the different physical behavior of the SOFC and the GT. LÄS MER

5. 4. Capacity-controlled Ground Source Heat Pump Systems for Swedish single-family dwellings

   Författare :Hatef Madani; Per Lundqvist; Joachim Claesson; Jose Miguel Corberan Salvador; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Heat Pump; Capacity control; ground; ground source; geothermal;

   Sammanfattning : The overall objective of this thesis is to develop a structured method to approach the challenge of better understanding the techniques and potential for capacity control in Ground Source Heat Pump (GSHP) systems used in Swedish single-family dwellings. This thesis aims at development of a generic model of the system that can be used for comparative, descriptive, and predictive analysis of capacity controlled GSHP systems in single-family dwellings. LÄS MER

7. 5. Economic analysis of air-water heat pump technologies with a screening method

   Författare :Gunda Mader; Björn E. Palm; José Miguel Corberan; KTH; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Early on in the process of product development a decision has to be made which technologies to focus on. Under a purely techno-economic viewpoint for a heat pump only these technologies should be considered which maximize heat pump performance for a given cost. LÄS MER