Batch Cooling: Oper. Conds Tab

CoolOperConds.jpg
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

 

○ Final Temperature (oC)
The final temperature of vessel contents after the end of the operation.

20.0

Positive

○ Ignore Cooling Utility
Check this box to ignore the cooling utility type.

No

Yes/No

○ 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

● Power (kW)
The total power consumed for the operation (per cycle).

0.0

Positive

○ Coefficient of Performance
The ratio of cooling load (negative enthalpy change of material contents) to electricity consumption.

4.5

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.

<Chilled 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

● Duty (kcal/h)
The heat transfer rate of the cooling agent.

0.0

Positive

○ Heat Transfer Efficiency(%)
The heat transfer agent efficiency. If the value is lower than 100% then an increased heat transfer agent amount will be calculated by the program to satisfy the required duty.

90.0

[0,100)

○ 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.

5.0

Positive

◙ Cooling Time (min)
The actual duration of the operation.

15.0

Positive

◙ Cooling Rate (oC/min)
The cooling rate of the vessel contents.

1.0

Positive

◙ Overall UA (kcal/h-oC)
The product of overall heat transfer coefficient and heat transfer area.

10500

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 Batch Cooling: Modeling Calculations.

•If the Cooling Utility is ignored...

No energy balances are done.

•If the Cooling Utility is set to ‘Electricity’...

You must specify a power type used for the operation.

•If the Cooling Utility is set to ‘Cooling Agent’...

You must specify a cooling agent used for the operation.

•Duration options...

You can set the process time (cooling time), or have the process time calculated based on cooling rate, or match the duration of this operation to the duration of another operation by introducing a master-slave relationship between the two operations. There are two options for specifying the cooling rate: you can either specify a constant cooling rate or an exponential cooling rate (specify the overall UA). If you introduce a master-slave relationship, the program will match the setup time, the process time and the turnaround time of this operation (the ‘slave’) with the corresponding times of the reference operation (the ‘master’ operation). For more details on how to setup a master-slave relationship, see The Scheduling Tab.