Household refrigerators operating on the vapor compression cycle incorporate which specific expansion mechanism____________________?
Show answer Hide answer
Answer: D. capillary tube
Explanation
Household refrigerators use a long and narrow capillary tube as their primary expansion device. The frictional resistance inside the capillary tube drops refrigerant pressure from condenser levels. This simple mechanical design eliminates the need for complex valves in small refrigeration systems. Capillary tubes are fixed restriction devices widely used in domestic refrigerators and small freezers. They act as constant-flow expansion devices matching the steady operating conditions of household units. The length and inner diameter of the tube are precisely calculated for specific refrigerant charges.
Appliance manufacturers prefer capillary tubes because they are inexpensive and have no moving parts. The lack of mechanical valves makes domestic refrigerators highly reliable and maintenance-free for consumers. Service technicians must match exact tube dimensions when repairing residential refrigeration capillary lines. Electrically operated throttling valves are too costly and complex for standard domestic refrigerators. Manually operated valves require constant human adjustment and are unsuitable for household appliances. Thermostatic expansion valves are typically reserved for larger commercial and industrial refrigeration systems.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. How does the mass flow ratio of NH3 compare to Freon-12 under identical refrigeration load and temperature conditions___________________?
Show answer Hide answer
Answer: B. 1 : 9
Ammonia has a much higher latent heat of vaporization compared to Freon-12 under identical conditions. Higher latent heat means less mass flow rate of ammonia is needed for the same cooling load. This distinct thermodyna...
Q2. The grid of tubing mounted on the exterior back panel of a household refrigerator functions as_________________?
Show answer Hide answer
Answer: A. condenser tubes
The grid of tubing mounted on the exterior back panel of a household refrigerator functions as the condenser tubes. This exposed serpentine tubing rejects heat absorbed from the interior food compartment out into the sur...
Q3. Short horizontal segment lines plotted on a pressure-enthalpy diagram indicate__________________?
Show answer Hide answer
Answer: A. constant pressure lines
Short horizontal segment lines plotted on a pressure-enthalpy diagram indicate constant pressure processes during phase change. Along these horizontal lines, both pressure and temperature remain constant while the refrig...
Q4. One refrigeration ton equals the cooling effect produced by melting 1000 kg of ice_________________?
Show answer Hide answer
Answer: C. in 24 hours
One refrigeration ton equals the cooling effect produced by melting 1000 kg of ice in 24 hours. This traditional unit originated from the ice-making industry before mechanical refrigeration became widespread. It standard...
Q5. Moisture contamination within a Freon-based refrigeration system leads to________________?
Show answer Hide answer
Answer: C. freezing automatic regulating valve
Moisture contamination within a Freon-based refrigeration system freezes upon passing through the narrow expansion device. This ice crystal formation blocks the automatic regulating valve, completely starving the evapora...
Q6. Lowering the suction operating pressure in a refrigeration cycle results in_________________?
Show answer Hide answer
Answer: E. all of the above
Lowering the suction pressure decreases the evaporating temperature, increases power required per ton, reduces vapor density, and lowers compressor capacity. Every drop in suction pressure forces the compressor to operat...