Which intermediate refrigerants were used for the first time in the cascade system?
A. CO2 and CO
B. CO and SO2
C. NH3 and CO2
D. CO2 and SO2
Answer:D
Which intermediate refrigerants were used for the first time in the cascade system?
A. CO2 and CO B. CO and SO2 C. NH3 and CO2 D. CO2 and SO2