Refrigeration test (Assessments and solutions)2025 1st Edition

The rate at which a refrigeration system will remove heat from the refrigerated medium is defined as: Coefficient of Performance Net cooling coefficient Refrigeration capacity Compression Ratio Differential efficiency - answer-Refrigeration capacity Which of the following correctly describes the heat transfer that takes place in a simple ice-box? There is a net loss of heat from the system, as the air cools. Air gives up sensible heat; ice does not gain any heat. Air gives up sensible heat; ice gains sensible heat. Air gives up sensible heat; ice gains latent heat of fusion. Air gives up latent heat; ice gains latent heat of condensation. - answer-Air gives up sensible heat; ice gains latent heat of fusion. (4-113-1.04) The saturation temperature of a refrigerant is the same as its: Boiling point Freezing point Flash point Fire point Auto ignition temperature - answer-Boiling point If the first column of a refrigeration table lists the saturation temperature of a refrigerant, which column will most likely list the saturation pressure? Column 1 Column 2 Column 3 Column 4 Column 5 - answer-Column 2 (4-113-1.08) Refrigerants will evaporate when the: Pressure is increased. Temperature is increased to saturation temperature. They are diluted. Temperature is reduced below saturation temperature. Heat is removed from them. - answer-Temperature is increased to saturation temperature. The net refrigerating effect of a refrigerant is the amount of heat: Discharged by the condenser. Absorbed by the refrigerant in the evaporator. Absorbed by the refrigerant in the condenser. Discharged by the refrigerant in the evaporator. Absorbed by the evaporator. - answer-Absorbed by the refrigerant in the evaporator. (4-113-1.02) Heat that causes an increase in temperature, is called _____ heat: Conductive Radiant Sensible Latent Convective - answer-Sensible Which of the following is an example of a loss of latent heat? Steam condenses Water evaporates Ice melts Refrigerant evaporates Air is cooled - answer-Steam condenses In a refrigeration system, the liquid refrigerant is changed to a gas in the: Condenser Charging drum Receiver Compressor Evaporator - answer-Evaporator (4-113-2.01) The function of the condenser in a refrigeration system is to: Lower the temperature of the liquid refrigerant. Change high pressure refrigerant vapour to liquid. Pressurize low pressure refrigerant vapour. Vent off vaporized refrigerant. Lower the liquid refrigerant pressure. - answer-Change high pressure refrigerant vapour to liquid. In a closed vessel, the boiling point of a liquid can be raised by: Raising the liquid level in the vessel. Lowering the pressure in the vessel. Raising the pressure in the vessel. Lowering the liquid level in the vessel. Raising the temperature in the vessel. - answer-Raising the pressure in the vessel. The net refrigerating effect of a refrigerant is the amount of heat: Discharged by the condenser. Absorbed by the refrigerant in the evaporator. Absorbed by the refrigerant in the condenser. Discharged by the refrigerant in the evaporator. Absorbed by the evaporator. - answer-Absorbed by the refrigerant in the evaporator With regard to the condenser in a refrigeration system, which of the following statements is true? In the condenser, heat transfers from the cooling medium to the refrigerant. The condensing temperature of the refrigerant vapour is 15°-20°C higher than the temperature of the cooling medium. The condensing temperature of the refrigerant will be lower if the pressure of the refrigerant is increased. The condenser transfers latent heat from the cooling medium and adds it as sensible heat to the refrigerant. The refrigerant absorbs latent heat of condensation from the cooling medium. - answer-The condensing temperature of the refrigerant vapour is 15°-20°C higher than the temperature of the cooling medium. hich of the following is not a physical property of refrigerants: Toxicity Odour Leakage tendency Corrosiveness Miscibility - answer-Corrosiveness