Compressors
Increase pressure and temperature of refrigerant.
What is the primary function of a compressor in a refrigeration system?
What role does the evaporator play in the refrigeration cycle?
What is, absorbs heat from the internal controlled space?
What is the main purpose of the condenser in a refrigeration system?
What is rejects heat to outside the controlled space.
What is the function of a metering device in refrigeration?
To restricts pressure and flow of refrigerant causing it to flash-off to lower temperature to absorb heat.
What is a refrigerant, and why is it essential in refrigeration systems?
It is a liquid with a low boiling point that can absorb heat and reject heat through heat transfer and pressure changes.
Name the most common type of compressor used in refrigeration 5 tons or less.
What is Hermetically sealed reciprocating?
Describe the process that occurs to the refrigerant in the evaporator.
Changes phase from high pressure liquid to low pressure low temperature vapor.
What happens to the refrigerant as it moves through the condenser?
Changes phase from high pressure high temperature vapor to high pressure high temperature liquid.
Name two types of metering devices commonly used in refrigeration systems.
Thermostatic Expansion Valve and Capillary Tube
Name a common refrigerant used in modern systems and one of its properties.
R410-A Is high energy efficient.
How does a compressor affect the pressure of the refrigerant?
What is raise pressure through compression.
What is the difference between a direct expansion evaporator and a flooded evaporator?
What is evaporator contains liquid through heat transfer process while DX requires refrigerant to boil off to vapor.
Explain the role of ambient temperature in the efficiency of a condenser.
Higher Ambient temperature causes slower heat transfer.
How does a thermal expansion valve (TXV) regulate refrigerant flow?
A thermal bulb is attached at the suction line leaving the evaporator maintaining the proper super-heat for proper evaporator temperature.
How do safety regulations impact the choice of refrigerants in commercial refrigeration?
What is high Global Warning Potential
The design a scroll compressor has that a reciprocating compressor does not which allows a minimal amount of liquid on the suction side.
What is Float?
How does the temperature of the refrigerant change as it passes through the evaporator?
Changes from low temperature to cool temperature as it absorbs heat.
What are the differences between air-cooled and water-cooled condensers?
Air cooled uses the fan to reject heat to the air while water cooled uses water from a separate loop to dissipate heat into the flowing water.
What is the significance of super-heat in relation to a metering device?
maintains proper cool temperature and ensures no liquid returns to compressor.
Discuss the environmental impacts of traditional refrigerants like CFCs and HCFCs.
They have high ozone depletion properties.
What are the potential consequences of compressor failure in a refrigeration system?
What is refrigerant contamination?
Discuss the impact of low airflow on the performance of an evaporator.
What is coil freezes up.
How can a dirty condenser coil affect the overall system performance?
Raises the head pressure and current draw of the compressor and slows heat transfer through air or water.
Discuss the effects of improper sizing of a metering device.
Over-sized allows too much flow causing compressor damage and undersized reducing heat transfer and efficiency
What is the significance of the refrigerant's boiling point in its function within the system?
It must be low enough to absorb heat from the environment while transferring heat through phase changes.