3

Question 1

Pumps

Answer 1

Used to increase pressure of liquid streams

Question 2

Model assumptions of pumps

Answer 2

Liquid is incompressible (constant density , liquid and volume is independent of pressure)

Question 3

Pumps specification

Answer 3

75% adiabatic efficiency (no heat transfer to/from liquid)

Question 4

Compressor

Answer 4

Used to increase pressure of an inlet gas stream

Question 5

Model specification of compressor

Answer 5

75% adiabatic efficiency (no heat transfer to/from gas)

efficiency is ideal/ actual

Question 6

Expander (turbines)

Answer 6

Used to decrease pressure of high pressure inlet gas stream to produce an outlet stream with low pressure and high velocity

Question 7

Model specification for expander

Answer 7

75% isotopic efficiency (no heat transfer to/from gas)

Question 8

Turbine

Answer 8

Gas expands in turbine and does work on surroundings so energy leaves system. Tout< Tin due to first law of thermodynamics

Question 9

Valve

Answer 9

No work is done and process is isenthalpic (constant enthalpy) when gas expands through a valve, its temperature drops due to Joule Thomson effect. When gas expands, intermolecular forces cause cooling

Question 10

Through valve

Answer 10

Gas - temperature decrease
Liquid- slightly increases

Question 11

Recycle operation

Answer 11

Used when downstream material streams mix with upstream material streams. Allows us to more easily converge flow sheets with one or more recycle streams

Question 12

Spreadsheet operation

Answer 12

Allows us to calculate non Hysys flow parameters

Question 13

Multiple compression stages ..

Answer 13

Needed in a natural gas processing plant to avoid downstream equipment damage due to temperature increase from compressing the gas