List the four major components of the compression refrigeration cycle in order.
- Why do both the compression cycle and absorption cycle have a high-pressure side and a low-pressure side?
- What components are responsible for maintaining the high and low pressures in a compression refrigeration system?
The Correct Answer and Explanation is:
1. Four Major Components of the Compression Refrigeration Cycle (in order):
- Compressor
- Condenser
- Expansion Valve (or throttling device)
- Evaporator
2. Why Do Both the Compression Cycle and Absorption Cycle Have a High-Pressure Side and a Low-Pressure Side?
Both cycles rely on pressure differences to move refrigerant and achieve cooling. The low-pressure side allows the refrigerant to absorb heat from the environment (cooling effect), while the high-pressure side enables the refrigerant to release heat to the surroundings. The pressure differential is essential for the phase changes (evaporation and condensation) that drive the refrigeration process, regardless of whether it’s mechanical (compression) or chemical (absorption).
3. Components Responsible for Maintaining High and Low Pressures in a Compression Refrigeration System and Explanation
Correct Answer:
- Compressor maintains the high-pressure side
- Expansion valve maintains the low-pressure side
300-Word Explanation:
In a compression refrigeration system, maintaining distinct high-pressure and low-pressure zones is essential for its operation. This pressure separation is achieved primarily through two key components: the compressor and the expansion valve.
The compressor is the heart of the system. It draws in low-pressure, low-temperature refrigerant vapor from the evaporator and compresses it into a high-pressure, high-temperature vapor. By doing so, the compressor raises the refrigerant’s pressure and temperature, sending it to the condenser, where it can release heat to the environment and condense into a high-pressure liquid. This establishes and maintains the high-pressure side of the system—from the compressor through the condenser up to the expansion valve.
After condensation, the high-pressure liquid refrigerant passes through the expansion valve (also known as a throttling device or metering device). This valve restricts the flow of refrigerant, causing a sudden drop in pressure. As the refrigerant exits the valve, it enters the evaporator as a low-pressure, low-temperature mixture. In the evaporator, it absorbs heat from the surrounding environment and evaporates, creating the cooling effect. This region, from the expansion valve through the evaporator back to the compressor, constitutes the low-pressure side.
Thus, the compressor and expansion valve work in tandem to maintain the necessary pressure differential. This difference in pressure enables the refrigerant to undergo phase changes—evaporation at low pressure and condensation at high pressure—ensuring continuous refrigeration. Without this separation, the refrigeration cycle would not function effectively.
