单项选择题
Which of the conditions listed represents the greatest effect of excess frost accumulation on the evaporator coils?（）
A.Keeps the refrigerated space cooler
B.Reduces the efficiency of the plant
C.Takes the load off the compressor
D.Has no affect on the system
点击查看答案
相关考题
-
单项选择题
When the vessels steering wheel on the navigation bridge is turned, the difference existing between the position of the wheel and that of the rudder is known as （）.
A.proportional band
B.the error signal
C.the reset signal
D.feedback -
单项选择题
Which of the listed statements is correct concerning refrigeration systems?（）
A.Dehydrators must be used continuously in a refrigeration system
B.A 25 ton refrigeration system has the same cooling effect as melting 25 tons of ice in 24 hours
C.A thermostatic expansion valve is used to control refrigerated space temperature
D.The liquid receiver functions to collect and remove non- condensable gases -
单项选择题
By which of the following means is force efficiently provided to vary the pitch of the blades on a modem controllable pitch propeller?（）
A.Hydraulic
B.Mechanical
C.Pneumatic
D.Electrical
