CIRO Chapter 7 questions & answers
latest update
Subcooling liquid ammonia feeding low temperature evaporators serves to
A. Reduce air unit capacity
B. Increase the amount of oil accumulation
C. Reduce the amount of flash gas handled by the booster compressor
D. Reduce condenser load - correct answer ✔✔
Operating a compressor at high compression ratios
A. Results in higher operating costs
B. Reduces oil migration
C. Reduces heat of compression
D. Improves overall system efficiency - correct answer ✔✔
Oil return from an R-22 system low temperature vessel is
A. Easy because oil vaporizes
B. Drained from the bottom of the unit
C. Recovered by special features in the low side vessels
D. Recovered by gravity flow - correct answer ✔✔
A cascade system should be used
A. To reduce initial equipment costs
B. To improve evaporator capacity
C. To obtain greater efficiency than an intercooler
D. To obtain -100deg F or lower temperature - correct answer ✔✔
, What is the big advantage of two stage compression in systems operating at low temperature
A. Only a two stage system can achieve the overall high compression rations necessary for low
temperature
B. The two stage system uses less equipment
C. The two stage system has lower initial cost
D. The two stage system is more efficient (lower kWh per ton) when operating at low temperatures -
correct answer ✔✔
High speed ammonia V/W compressors are limited to what practical compression ration
A. 4:1
B. 8:1
C. 75:1
D. 14:1 - correct answer ✔✔
Higher compression ratios
A. Consume more power
B. Increase refrigeration effect
C. Stabilize the operation of the system
D. Improve oil flow in the compressor - correct answer ✔✔
In a single stage compressor, what happens to theoretical compressor discharge temperature as
evaporator temperature is lowered
A. Compressed discharge temperature and evaporator temperature are not related
B. As evaporator temperature is lowered, compressor discharge temperature decreases
C. As evaporator temperature is lowered, compressor discharge temperature increases
D. Theoretical compressor discharge temperature becomes unstable as evaporator temperature is
lowered - correct answer ✔✔
As compressor discharge temperature increases
A. Compressor oil's lubricating quality is reduced
latest update
Subcooling liquid ammonia feeding low temperature evaporators serves to
A. Reduce air unit capacity
B. Increase the amount of oil accumulation
C. Reduce the amount of flash gas handled by the booster compressor
D. Reduce condenser load - correct answer ✔✔
Operating a compressor at high compression ratios
A. Results in higher operating costs
B. Reduces oil migration
C. Reduces heat of compression
D. Improves overall system efficiency - correct answer ✔✔
Oil return from an R-22 system low temperature vessel is
A. Easy because oil vaporizes
B. Drained from the bottom of the unit
C. Recovered by special features in the low side vessels
D. Recovered by gravity flow - correct answer ✔✔
A cascade system should be used
A. To reduce initial equipment costs
B. To improve evaporator capacity
C. To obtain greater efficiency than an intercooler
D. To obtain -100deg F or lower temperature - correct answer ✔✔
, What is the big advantage of two stage compression in systems operating at low temperature
A. Only a two stage system can achieve the overall high compression rations necessary for low
temperature
B. The two stage system uses less equipment
C. The two stage system has lower initial cost
D. The two stage system is more efficient (lower kWh per ton) when operating at low temperatures -
correct answer ✔✔
High speed ammonia V/W compressors are limited to what practical compression ration
A. 4:1
B. 8:1
C. 75:1
D. 14:1 - correct answer ✔✔
Higher compression ratios
A. Consume more power
B. Increase refrigeration effect
C. Stabilize the operation of the system
D. Improve oil flow in the compressor - correct answer ✔✔
In a single stage compressor, what happens to theoretical compressor discharge temperature as
evaporator temperature is lowered
A. Compressed discharge temperature and evaporator temperature are not related
B. As evaporator temperature is lowered, compressor discharge temperature decreases
C. As evaporator temperature is lowered, compressor discharge temperature increases
D. Theoretical compressor discharge temperature becomes unstable as evaporator temperature is
lowered - correct answer ✔✔
As compressor discharge temperature increases
A. Compressor oil's lubricating quality is reduced
