Development of a High Performance Compact Refrigeration Cooling Prototype

  • Mahmoud Alzoubi

Student thesis: Master's Thesis

Abstract

Reliability and performance of high power-density devices can be enhanced through deployment of efficient cooling systems. Compact refrigeration cooling systems offer distinct benefits for use in portable and small-scale applications compared to other technologies. They can work at high ambient conditions and provide uniform device cooling. In order to reduce the redundancy of conventional refrigeration systems, this thesis aims at developing a compact recuperator-based Vapor Compression Cycle (VCC) prototype. The VCC system composes of a 300W linear compressor and fluid-to-fluid recuperator that utilize the temperature difference between condenser and evaporator. Comprehensive guidelines to design and build a test-bed setup are presented with all related aspects such as material selection, test-bed construction, leakage test procedure, insulation, and refrigerant charges. Several parametric studies are performed to investigate the influence of changing the compressor capacity, heat source temperature and expansion valve opening position on the VCC performance. Component models for linear compressor, fin-tube heat exchanger, brazed plate heat exchanger, and metering valve are developed and validated with the experimental data. These component models are further integrated to predict the pressure and temperature changes in the VCC test-bed. In the compressor model, increasing piston velocity and piston stroke distance lifts the exit pressure and temperature. Heat exchanger characteristics indicate that the pressure drop is negligible due to low refrigerant flow rate. There are several advantages to use the recuperator-based VCC configuration. The refrigerant exiting the condenser heats the refrigerant flow at the evaporator exit to maintain the superheated flow at the compressor inlet. With this design, the condenser size could be reduced, which leads to a more compact system. Meanwhile, the evaporator is able to extract more heat from the heat source by maintaining two-phase refrigerant flow between the inlet and exit. As a result, the cooling test-bed was able to achieve a high coefficient of performance (COP) of 4.5. This study contributes to the development of energy-efficient compact VCC systems for various cooling applications.
Date of AwardJul 2014
Original languageAmerican English
SupervisorTJ Zhang (Supervisor)

Keywords

  • Vapor Compression Cycle
  • Recuperator
  • Linear Compressor
  • Prototype.

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