الفهرس 
AbstractOnly 14 pages are availabe for public view
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Abstract
Refrigeration and air conditioning cycles consume a large amount of electrical energy and the shortage in traditional sources of energy is the main reasons for governments to use renewable energy. The most power consuming part in the Vapor Compression Cycle (VCC) is the vapor compressor. Therefore, the objective of this research is to increase the cooling rate of the VCC using the same compressor, and that is done by heating the refrigerant coming out from the compressor. The proposed cycle is similar to the VCC except that the compression processes is done in two stages, the first stage via a gas compressor and in the second stage by heating the refrigerant under constant specific volume. The heating process can be done using solar energy. An experimental setup has been developed to study the influence of heating the refrigerant after the compressor on the cooling rate of the VCC. The heating process is performed after the compressor, and it is done under constant volume in order to increase the pressure of the refrigerant. This study examined the influence of heating different refrigerants, i.e R143a, R22, and R600a on the cooling rate of the VCC. Four experiments have been performed; the first experiment is a normal VCC, i.e. without heating, while in the second, third, and fourth experiments were carried out to raise the temperature of the
refrigerant to 50°C, 100°C, and 150°C. It has been found that heating raises the refrigerant pressure in VCC and thereby improves
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the refrigerant’s mass flow rate resulting in an improvement in the cooling power for the same compressor power. Heating the refrigerant after the mechanical compressor increases the temperature of the condenser as well as the temperature of the evaporator when using refrigerant R134a, which prevents the refrigeration cycle to be used in freezing applications, however using refrigerant R22 or refrigerant R600a promotes the heated VCC to be used in freezing applications. Refrigerant R600a has the lowest operating pressure compared to R134a and R22, which promotes R600a to be used than R134a and R22 from a leakage point of view.