3b2 power engineer exam practice

3b2 power engineer exam practice



The0disadvantages0of0a0gas0turbine0are:0
1.0High0cost0of0manufacture0
2.0High0levels0of0noise0pollution0are0produced0
3.0Low0thermal0efficiency0
4.0Requires0many0auxiliaries0to0be0efficient

A.01,02,03
B.01,03,04
C.02,03,04
D.01,02,04
E.01,02,03,040-0ans✔E

The0most0common0process0method0of0refrigeration0is:
Select0one:
A.0Absorption
B.0Lithium0bromide
C.0Water0vapor
D.0Vapor0compression0or0mechanical
E.0Ammonia0compression0system0-0ans✔D

To0facilitate0the0removal0of0moisture0and0oil0from0the0compressed0air,0a/
an0_____0is0installed.
Select0one:
A.0Intercooler
B.0Oil0separator
C.0Unloader
D.0Expansion0tank
E.0Aftercooler0-0ans✔E

In0a0two-
stage0refrigeration0system,0the01st0stage0compressor0is0also0known0as0a0_____0comp
ressor.
Select0one:
A.0Booster
B.0Standby
C.0Low0volume
D.0Extraction

,E.0Refrigerant0-0ans✔A

In0the0rotary0vane0compressor:
Select0one:
A.0Vanes0close0to0the0central0hub0by0centrifugal0force
B.0There0is0a0rotor0in0the0exact0center0of0the0casing
C.0Refrigerant0is0trapped0between0the0roller0and0the0decreasing0volume0of0the0eccentr
ic0casing
D.0The0rotor0oscillates
E.0The0vanes0move0in0the0rotor0-0ans✔E

In0a0gas0turbine,0there0are0fewer0turbine0stages0than0compressor0stages0because:
Select0one:
A.0Energy0can0be0extracted0more0efficiently0in0the0turbine
B.0Turbine0blades0are0bigger0so0require0fewer
C.0Higher0exhaust0temperatures0can0be0tolerated
D.0The0hot0gases0occupy0more0volume
E.0Hot0exhaust0gases0are0required0for0the0HRSG's0-0ans✔A

Pressure0limiting0devices0of0refrigeration0systems0shall0be0connected:
Select0one:
A.0Between0the0compressor0and0the0stop0valve0on0the0suction0side
B.0To0a0blowdown0tank
C.0Between0the0inlet0of0the0condenser0and0the0outlet0of0the0receiver
D.0Between0the0compressor0and0the0stop0valve0on0the0discharge0side
E.0To0the0receiver0outlet0-0ans✔D

The0warm-up0time0required0of0a0turbine0is0dependant0on:
Select0one:
A.0How0quickly0the0turbine0is0required
B.0The0manufacturer's0instructions
C.0The0size0of0the0turbine
D.0The0type0of0turbine
E.0Whether0the0steam0is0dry0or0wet0-0ans✔C

_____0compressors0require0intake0and0discharge0valves.
Select0one:
A.0Rotary
B.0Centrifugal
C.0Sliding0vane
D.0Rotary0lobe
E.0Reciprocating0-0ans✔E

Besides0reducing0NOx,0water0injection0systems
Select0one:

, a.0stabilize0the0combustion0process,0thereby0increasing0the0life0of0hot0section0compon
ents
b.0help0keep0the0compressor0blading0clean
c.0reduce0the0gas0turbine's0thermal0efficiency
d.0decrease0the0power0output0-0ans✔C

The0pressure0at0the0outlet0from0the0moving0blades0is0the0same0as0the0pressure0at0the
0inlet0to0the0moving0blades0in0a/an0__________0turbine.
Select0one:
A.0Topping
B.0Reaction
C.0Back0pressure
D.0Impulse
E.0Extraction0-0ans✔D

A0condenser0shell0may0be0fitted0with0an0expansion0joint0if0the:
Select0one:
A.0Expected0temperature0differentials0will0be0greater0than020°C
B.0Condenser0tubes0are0U-shaped
C.0Condenser0is0of0welded0construction
D.0Condenser0tubes0are0expanded0into0the0tube0sheets
E.0Tube0sheets0are0made0of0Admiralty0brass0-0ans✔D

Adjustable0inlet0diffuser0vanes0on0centrifugal0air0compressors0are0implemented0to:
Select0one:
A.0Change0the0operating0characteristics0of0the0compressor
B.0Change0the0direction0of0the0air0flow0to0remove0moisture
C.0Remove0foreign0particles0from0the0air
D.0Only0reduce0the0amount0of0air0entering0the0compressor
E.0Prevent0back0or0reverse0flow0of0air0-0ans✔A

Positive0displacement0compressor0types0include:0
1.0Sliding0vane0
2.0Axial0flow0
3.0Internal0gear0
4.0Volute0casing0
5.0Rotary0screw0
6.0Multi0lobe
Select0one:
A.01,03,04,06
B.02,04,05,06
C.01,03,05,06
D.01,02,04,05
E.02,03,04,060-0ans✔C

Reciprocating0Compressor0valves0are0usually0automatic0and0open0and0close0by: