TRNFIT: A TRNSYS-IMSL

PARAMETER ESTIMATION ROUTINE

PROGRAM DESCRIPTION

TRNFIT is a parameter estimation routine to allow cataloged components to be used in TRNSYS thermal system simulations. Using mechanistic models based on fundamental correlations, a TRNSYS component to be used with TRNFIT requires the definition of characteritic parameters. These characteristic parameters are combinations of geometric terms, fin efficiencies, and other quantities that would be difficult to determine from the limited information given in manufacturers catalogs. The values of these characteristic parameters are calculated by comparing the calculated outputs of the TRNSYS Type with catalog data points contained within an Input Data File. An IMSL optimization routine performs the actual parameter estimation.

This general method has been successfully applied to sensible heat exchangers, chilled water cooling coils, and direct expansion cooling coils while removing some of the assumptions and detailed specifications of the existing TRNSYS components. For example, the Type 5 Heat Exchanger uses either a constant effectiveness or a constant UA but the new Type 80 Heat Exchanger calculates heat transfer coefficients using fluid properties and the characteristic parameters.

INSTALLING AND RUNNING THE PROGRAM

You may download the self-extracting, self-installing executable file TRNFIT.EXE to your hard disk. This demonstration application requires that your computer be running the Windows 95 or Windows NT 4.0 operating system as it is a 32-bit application.

After installation, there will be five subdirectories within the installation directory.

The DOCS subdirectory contains a TRNFIT manual and documentation for the Type 80 Heat Exchanger, the Type 85 Direct Expansion Cooling Coil, the Type 94 and 95 Chilled Water Cooling Coils, and the Type 99 Fitter. All of these documents are in MS Word format.

The TYPES subdirectory contains the TRNSYS components for Types 80, 85, 94, 95, and 99, associated subroutines (DRYCOIL and WETCOIL), and new utilities (NEWFLUID and REFTRANS).

The DATA subdirectory contains the following sample Input Data Files:

80dpi.dat: Used for determining characteristic parameters for the pressure drop of the inner (e.g. tube) fluid of a Type 80 Heat Exchanger

80dpo.dat: Used for determining characteristic parameters for the pressure drop of the outer (e.g. shell) fluid of a Type 80 Heat Exchanger

80qdata.dat: Used for determining characteristic parameters for the heat transfer rate of a Type 80 Heat Exchanger

95ddpo.dat: Used for determining characteristic parameters for the air pressure drop of a dry Type 95 Cooling Coil

95dpi.dat: Used for determining characteristic parameters for the liquid pressure drop of a Type 95 Cooling Coil

95qdata.dat: Used for determining characteristic parameter for the total heat transfer rate of a Type 95 Cooling Coil

95wdpo.dat: Used for determining characteristic parameters for the air pressure drop of a wet Type 94 Cooling Coil

The IGV subdirectory contains the following sample IGV files for calculating guess values and lower and upper bounds of the characteristic parameters:

80dpiigv.for: Inner fluid pressure drop IGV routine for a Type 80 Heat Exchanger

80dpoigv.for: Outer fluid pressure drop IGV routine for a Type 80 Heat Exchanger

80qigv.for: Heat transfer rate IGV routine for a Type 80 Heat Exchanger

95dpiigv.for: Liquid pressure drop IGV routine for a Type 95 Cooling Coil

95dpoigv.for: Air pressure drop IGV routine for a dry Type 95 Cooling Coil

95qigv.for: Heat transfer rate IGV routine for a Type 95 Cooling Coil

95wpoigv.for: Air pressure drop IGV routine for a wet Type 95 Cooling Coil

 

The OTHER subdirectory contains other files such as the TRNFIT.TRD file, the 99MODES.DAT file, the D2ARRAYS module, etc.

Consult the TRNFIT manual for more information about installing TRNFIT and running it with a PowerStation 4.0 project.

CONTACT INFORMATION

To this point, only Roger Rabehl has used TRNFIT. Feedback is requested from those who download and investigate these materials. Please contact trnsys@sel.me.wisc.edu.