Expressed in SI units, one standard ton of refrigeration equals___________________?
Show answer Hide answer
Answer: A. 210 kJ/min
Explanation
One standard ton of refrigeration is precisely defined in SI units as two hundred ten kilojoules per minute. This numerical value corresponds to the latent heat required to melt one ton of ice daily. Multiplying the latent heat of ice by mass and dividing by minutes gives this standard rate. Refrigeration capacity historically relates to the cooling effect produced by melting ice over time. One US short ton equals two thousand pounds, which translates to approximately twelve thousand BTU per hour. Converting imperial heat units to SI units yields the standard metric refrigeration capacity rate.
HVAC engineers use standard tonnage ratings to specify commercial air conditioning and chiller equipment. Standardized units ensure clear communication among manufacturers, contractors, and building facility designers. Accurate capacity conversions prevent under-sizing of large commercial cooling and refrigeration systems. Values like 21 kJ per minute are off by a factor of ten and underestimate refrigeration capacity. Values such as 420 kJ per minute represent double the correct standard tonnage heat absorption rate. Other options fail to match internationally recognized standard SI conversion factors for refrigeration.
- Subject
- Engineering
- Category
- Mechanical Engineering
- Topic
- —
- Difficulty
- medium
Related questions
Q1. In a vapor compression cycle, the thermodynamic condition of the refrigerant entering the compressor suction is________________?
Show answer Hide answer
Answer: E. before entering the compressor
In a vapor compression cycle, the refrigerant enters the compressor suction right after leaving the evaporator. Entering vapor must be slightly superheated to ensure no liquid droplets enter the compressor cylinders. Thi...
Q2. Air refrigeration cycles are predominantly employed in applications such as ____________________?
Show answer Hide answer
Answer: D. gas liquefaction
Air refrigeration cycles like the Bell-Coleman cycle are predominantly employed in extreme low-temperature applications like gas liquefaction. Although less efficient for moderate cooling, air systems excel in cryogenic...
Q3. One primary engineering purpose of sub-cooling liquid refrigerant before expansion is to________________?
Show answer Hide answer
Answer: D. ensure that only liquid and not the vapour enters the expansion (throttling) valve
Sub-cooling the liquid refrigerant before the expansion valve ensures that only pure liquid enters, preventing flash gas formation. Sub-cooling lowers the liquid temperature below its saturation point, increasing the net...
Q4. The Clapeyron equation is applicable for thermodynamic calculations involving___________________?
Show answer Hide answer
Answer: A. saturation point of vapor
The Clapeyron equation relates pressure and temperature along a phase boundary for saturated vapor. It mathematically connects latent heat, volume changes, and saturation slope in thermodynamics. This fundamental relatio...
Q5. To attain a high coefficient of performance, the compressor operating pressure ratio should be_______________?
Show answer Hide answer
Answer: B. low
To attain a high coefficient of performance, the compressor operating pressure ratio across the system should be kept low. A low pressure ratio minimizes the specific work input required by the compressor to achieve the...
Q6. In a vapor compression cycle, the refrigerant state upon leaving the condenser is________________?
Show answer Hide answer
Answer: A. after passing through the condenser
In a vapor compression cycle, the refrigerant state upon leaving the condenser is high-pressure liquid. High-pressure superheated vapor enters the condenser, rejects heat to the environment, and condenses into saturated...