Search for dissertations about: "electronic expansion valve"

Found 3 swedish dissertations containing the words electronic expansion valve.

2. 1. On Techno-economic Assessment of a Multi-terminal VSC-HVDC in AC Transmission Systems

   Author : Feng Wang; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Transmission Grid.; Loss minimization; AC DC system; Transmission expansion planning; Multi-terminal VSC-HVDC; Cost minimization; Cost-benefit analysis; Electric power system; Optimal power flow;

   Abstract : The Voltage Source Converter based Multi-Terminal high voltage Direct Current transmission system (VSC-MTDC) is currently considered as an attractive technical option for increased transmission capacity and improved controllability and flexibility of an electric power grid, thanks to its unique performance characteristics, and the possibility of using the extruded XLPE cables. In the planning process of embedding a VSC-MTDC system into an ac transmission grid, one must assess the potential values in terms of improved energy efficiency, i. READ MORE

4. 2. Integrated Control of Heat Pumps

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

   Abstract : 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. READ MORE

5. 3. Measurements and Modelling of Convective Vaporization for Refrigerants in a Horizontal Tube

   Author : Peter Melin; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; n-butane; HFC134a; pressure drop; propane; HFC143a; horizontal flow boiling; in-tube vaporization; HFC125; HFC32; experimental study; HCFC142b; HCFC22; non-azeotropic mixtures; CFC12; modelling; mixture effects;

   Abstract : An evaporator facility has been constructed to measure local values of heat transfer and pressure drop. The evaporator resembles a normal working evaporator tube in a direct-expansion evaporator applicable to large heat pump/refrigeration cycles, typically over 500 kW. The evaporator is brine-heated and uses an expansion valve to control the inlet. READ MORE