Compression: Oper. Conds Tab

Variable Definitions, Ranges and Default Values

The following table shows a brief description of the variables appearing in this tab. The table also displays their default values and their generally acceptable range:

Variable	Default Value	Range

○ Pressure Set by User? Check this box to set the pressure change.	Yes	Yes/No
○ Pressure Change (bar) The pressure change in the compressor.	5.0	Positive
○ Power Type Indicates the power type that is used by the operation. Click on the list box to bring up a list of available power types in order to select one.	<Std Power>	Any Power Type
○ Efficiency (%) The efficiency of the compressor.	70.0	(0,100)
● Total Power (kW) The total power consumed for the operation (per cycle).	0.0	Positive
● Power Per Unit (kW) The power consumed for the operation per equipment unit.	0.0	Positive
○ Power Losses Dissipated to Heat (%) The percentage of power losses (power losses = power input - power output = operating power*(1-efficiency)) that are converted into heat, thereby raising the temperature of the material contained in the equipment.	0.0	[0,100)
○ Max Exit Temp. (^oC)	40.0	Positive
● Duty (kcal/h) The heat transfer rate of the cooling agent.	0.0	Positive
○ Cooling Agent Name Indicates the cooling agent used for the operation. Click on the list box to bring up a list of available cooling agents in order to select one.	<Cooling Water>	Any Cooling Agent
● Inlet Temp. (^oC) The inlet temperature of the cooling agent.	5.0	Positive
● Outlet Temp. (^oC) The outlet temperature of the cooling agent.	10.0	Positive
● Rate (kg/h) The mass flow rate of the cooling agent.	0.0	Positive
● Volumetric Throughput Per Unit (m³/h) The volumetric flowrate of the feed stream per equipment unit.	0.0	Positive
○ Setup Time (min) The amount of time (per cycle) spent before each operation is carried in preparation for the actual execution of the operation. It may involve actions like cleaning, vacuuming, setting up of equipment, etc. which the user opted not to model explicitly.	0.0	Positive
◙ Process Time (min) The actual duration of the operation (per cycle).	240.0	Positive
○ Ignore Labor? Check this box to ignore labor for this operation. This option is used only if the process time is set by a master-slave relationship.	Yes	Yes/No

Symbol Key: ○ User-specified value (always input); ● Calculated value (always output); ◙ Sometimes input, sometimes output

Specification Choices / Comments

The following list describes the available specification choices in this tab; for more details on how these are implemented, see Compression: Modeling Calculations.

•Pressure Change...

In Rating Mode, the pressure change can be specified or calculated. In Design Mode, it is always specified.

•Volumetric Throughput per Unit...

The volumetric throughput per unit is based on the feed volumetric flow rate.

•Duration Options...

In Rating Mode, you can set the process time (and the setup time), allow the process time to be calculated (based on the throughput and rating power of the units), or allow the duration to match exactly the duration of another operation either in the same procedure or in another procedure. In Design mode, you must either specify the process time (and the setup time) or allow the duration to match exactly the duration of another operation (either in the same procedure or in another procedure) in order for the program to calculate the required power (per step and per unit).

If you choose to match the duration of this operation with the duration of another operation, you introduce a master-slave relationship between the two operations. The program will match the setup-time, the process time and the turnaround time of this compressing operation (the ‘slave’) with the corresponding times of the reference operation (the ‘master’ operation). For more on master-slave relationship, see The Scheduling Tab.