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Flashcards in Powerpoint notes pg. 1+2 Deck (51)
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1

Compressors are essentially ______ pumps

vapour

2

What can damage the compressor?

too much liquid

3

Vapour comes in as _____ temp, _____ pressure and leaves as _____ temp, _____ pressure

low, low,

high, high

4

How does a compressor raise temperature and pressure?

by decreasing volume and compressing

5

In a reciprocating compressor, the refrigerant vapour enters the cylinder when the pressure in the cylinder is _____ that of the suction line

below

6

In a reciprocating compressor, refrigerant vapour is discharged from the cylinder when pressure in the cylinder is ______ than the discharge line

greater

7

what term describes the space 1lb of gas occupies at a certain temperature and pressure?

specific volume

8

Increase in pressure means ________ in specific volume

decrease

9

______ _____rate is based on the density number in lbs in a cubic foot of gas

mass flow

10

________ _____ _____ is determined by the compressor type and design

volumetric flow rate

11

A compressor that delivers a constant volume of gas under a constant speed is called

positive displacement

12

How is capacity measured?

but/hr

13

capacity increases as mass flow rate increases resulting from a decrease in _______ _______

specific volume

14

capacity increases as specific volume decreases resulting from an increase in ____\_____

sst/pressure

15

Capacity increases as volumetric flow rate increases resulting from an increase in ____ _________

comp. displacement

16

Capacity increases as compression ratios decreases resulting from a decrease in _______ _______

specific volume

17

What are the main parts of a reciprocating compressor?

crankshaft
crank throw
eccentric
piston
connecting rods
cylinder

18

Mass flow rate =

Volumetric flow rate/specific volume

19

name two types of reciprocating compressor crankshafts

crank throw and eccentric

20

What is the purpose of the shaft seal?

keeps refrigerant in and air out

21

What type of compressor is the centrifugal?

non-positive displacement compressor

22

Reciprocating compressors have pistons that when moving down pull air __ through the intake and when moving up push high pressure air ___ the exhaust valve

in, out

23

Three types of valves in a reciprocating compressor

Reed valve, ring valve, discuss valve

24

Methods of cooling for reciprocating compressors?

Air cooled, water cooled, refrigerant vapour cooled

25

How do Hermetic reciprocating compressors look?

round and covered

26

how do reciprocating semi-hermetic compressors look?

bolts everywhere

27

Hermetic cooling method of cooling?

primary method of vapour

28

Semi-hermetic primary method of cooling?

vapour/air/water

29

Open drives primary methods of cooling?

air/water/oil

30

Oil pressure in a refrigeration compressor is the difference between ______ pressure and ___ _____ pressure

crankcase pressure and oil pump pressure