Flashcards in Powerpoint notes pg. 1+2 Deck (51)
Compressors are essentially ______ pumps
What can damage the compressor?
too much liquid
Vapour comes in as _____ temp, _____ pressure and leaves as _____ temp, _____ pressure
How does a compressor raise temperature and pressure?
by decreasing volume and compressing
In a reciprocating compressor, the refrigerant vapour enters the cylinder when the pressure in the cylinder is _____ that of the suction line
In a reciprocating compressor, refrigerant vapour is discharged from the cylinder when pressure in the cylinder is ______ than the discharge line
what term describes the space 1lb of gas occupies at a certain temperature and pressure?
Increase in pressure means ________ in specific volume
______ _____rate is based on the density number in lbs in a cubic foot of gas
________ _____ _____ is determined by the compressor type and design
volumetric flow rate
A compressor that delivers a constant volume of gas under a constant speed is called
How is capacity measured?
capacity increases as mass flow rate increases resulting from a decrease in _______ _______
capacity increases as specific volume decreases resulting from an increase in ____\_____
Capacity increases as volumetric flow rate increases resulting from an increase in ____ _________
Capacity increases as compression ratios decreases resulting from a decrease in _______ _______
What are the main parts of a reciprocating compressor?
Mass flow rate =
Volumetric flow rate/specific volume
name two types of reciprocating compressor crankshafts
crank throw and eccentric
What is the purpose of the shaft seal?
keeps refrigerant in and air out
What type of compressor is the centrifugal?
non-positive displacement compressor
Reciprocating compressors have pistons that when moving down pull air __ through the intake and when moving up push high pressure air ___ the exhaust valve
Three types of valves in a reciprocating compressor
Reed valve, ring valve, discuss valve
Methods of cooling for reciprocating compressors?
Air cooled, water cooled, refrigerant vapour cooled
How do Hermetic reciprocating compressors look?
round and covered
how do reciprocating semi-hermetic compressors look?
Hermetic cooling method of cooling?
primary method of vapour
Semi-hermetic primary method of cooling?
Open drives primary methods of cooling?