HXAIR - Specs Options

Use this window to enter details of the Specs Options Window where you enter data related to the Type of Specifications.

The Options available are:

TUBESIDE TEMPERATURE (ISPXSD = 0)
SHELL SIDE TEMPERATURE (ISPXSD = 1)
TUBESIDE LIQUIDFRACTION (ISPXSD = 2)
HOCI (HOT OUTLET AND COLD INLET) (ISPXSD = 4)
HIHO (HOT INLET AND HOT OUTLET) (ISPXSD = 5)
HICO (HOT INLET AND COLD OUTLET) (ISPXSD = 6)
CICO (COLD INLET AND COLD OUTLET) (ISPXSD = 7)
OVERALL DUTY (ISPXSD = 3)
None (For rating mode only) (ISPXSD = 8)

The User has to select all the different types of Specifications and enter their values.

Usage

TEMPERATURE

Specifies the outlet temperature of the stream specified by the TUBE or AIR keyword.

TUBE or AIR

Specifies the side of the exchanger being used by the TEMPERATURE specification. TUBE can also be used with the LFRAC keyword.

LFRACTION

Specifies the liquid weight fraction of the stream. Enter a value from 0.0 (all vapor) to 1.0 (all liquid).

DUTY

Specifies the total heat transferred in the exchanger. You cannot use DUTY with any other specification keywords. Units are: MMBtu/hr (English), MMkcal/hr (metric), and MMkJ/hr (SI).

There is no default.

HOCI= or COCI= or HIHO= or HICO=

Specifies the exchanger approach temperature. Use only one of these four and enter a numerical value. Each keyword specifies a subtraction operation where the first set of two characters defines a value, and the second set of two characters defines a value that is subtracted from it. In the operation, H refers to HOT side, C refers to COLD side, I refers to Inlet, and O refers to Outlet. Therefore, HOCI specifies hot outlet temperature minus cold inlet temperature. You cannot use DUTY with any other specification keywords. Valid units are F (English), C, (metric and SI). There are no defaults.

None Specification

For None Specification mode the program calculates the Duty and Air Side/Tube Side outlet temperatures.

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