Facility Warm Up Time

Units:	h
Mode:	Input Only
Multi-band:	False
Default Value:	0
Validation Rule:	≥0
Key Property:	No
Description:	Number of hours required to warm up the Facility

Facility Warm Up Time is the number of hours required to warm up the Facility. The warm up period is triggered when there are any number of Units Started after a period where Units Operating is zero. During the warm-up period, only the Warm Up Process runs i.e. Production is zero and the Warm Up Process runs at the output level set by the Warm Up Operating Level.

Table 1: Warm Up Time Example

Child Object	Property	Value	Units
NH3.Plant	Min Up Time	48	h
NH3.Plant	Min Down Time	4	h
NH3.Plant	Warm Up Time	48	h
NH3.Plant	Warm Up Operating Level	2	MW

The number of hours spent warming up is reported in the Warm Up Hours output property.

When Warm Up Time is combined with Min Down Time the warm up behaviour changes as follows:

• The Min Down Time constraint is ignored
• The Min Down Time becomes a trigger point at which the warm up period can be interrupted if the unit has been off for no longer than the Min Down Time hours.

In the above example, the Facility must warm up for 48 hours unless it has been off for no more than four hours in which case it can warm up in four hours.