ACSIM

ACSIM is a simulation tool for single-stage air conditioning systems. It models systems comprising a compressor, finned-tube evaporator and condenser, thermostatic and electronic expansion valves, and interconnecting tubing. The program incorporates heat exchanger models from EVAP-COND, NIST’s stand-alone simulation tool for air-to-refrigerant heat exchangers ( https://www.nist.gov/services-resources/software/evap-cond-version-50). Since ACSIM is fully compatible with EVAP-COND, users can evaluate how optimized heat exchanger designs affect overall system performance.

Refrigerant Properties & REFPROP Integration

ACSIM uses refrigerant thermophysical properties based on the NIST Standard Reference Data 23; NIST Reference Fluid Thermodynamic and Transport Properties Database (REFPROP): Version 10.0 (https://www.nist.gov/srd/refprop), where refrigerant coefficients must be specified in individual files for each single-component fluid. To facilitate fast simulations, ACSIM uses look-up tables with refrigerant properties.

The ACSIM installation package includes pre-generated look-up tables for the following refrigerants: ammonia, isobutane, propane, R22, R32, R134a, R152a, R161, R404A, R407C, R410A, R444A, R446A, R447A, R450A, R452B, R454B, R460A, R507A, R513A, R515B, and R1234yf. The ACSIM installation package does not include REFPROP-compatible fluid files. (Only the R32 and R125 files are installed to allow you to run the tutorial example given in the Instruction Pages and Help Menu and to explore ACSIM features). The fluid files must be obtained by the user and loaded to C:>…>Documents>NIST>ACSIM>fluids, the designated ACSIM ‘fluids’ folder, for each refrigerant of interest. Additional refrigerant look-up tables can be generated using TableGen2, a utility available for free download on this website.

Installation Instructions

1. ACSIM Setup
   • Download the file ACSIM_1.0_Setup.zip.
   • Extract all files to a folder of your choice
   • Double-click setup.exe and follow the prompts. 
     The wizard will install the package, add a desktop icon, and create a shortcut for the Instruction Pages from the Start button.
      

2. Loading Fluids Files

   After ACSIM has been installed, you must manually copy the required REFPROP fluid files into the designated ACSIM ‘fluids’ folder (C:>…>Documents>NIST>ACSIM>fluids). You can obtain these files from any one of the following NIST Standard Reference Data (SRD) programs:

   • SRD 23, REFPROP, Ver. 10.0 https://www.nist.gov/srd/refprop,
     Location: C:>Program Files (x86)>REFPROP>fluids
   • SRD 49, CYCLE_D, Ver. 6.0 https://www.nist.gov/srd/nist-standard-reference-database-49,
     Location: C:>Program Files (x86)>NIST>CYCLE_D 6.0>fluids
   • SRD 73, REFLEAK, Ver. 6.0 https://www.nist.gov/srd/nist-standard-reference-database-73,
     Location: C:>Program Files (x86)>NIST>REFLEAK 6.0>fluids.

   Refer to the page on Installation of Refrigerant Files included in the Instruction Pages.

3. TableGen2 Setup
   • Download the file TableGen2.zip and extract it to a user-accessible folder.
   • Review and follow the instructions provided in TableGen2_Info.pdf.

User Tips & Support

• Tutorials: Refer to the Instruction Pages and Help Menu for comprehensive guides on input preparation, program execution, and results analysis.
• Display Issues: If the refrigerant circuitry schematic appears distorted, manually adjust your PC display resolution to 1360x768 or 1600x900 via the Start button > Settings > Display > Display resolution.