#TRNSYS MANUAL#
#TRNSYS CODE#
#TRNSYS PC#
#TRNSYS WINDOWS#

The remainder of this section describes the background for the ABSIM code and presents its special features in comparison with other simulation codes.

#TRNSYS MANUAL#

This user manual is organized into eight sections and two appendices. The code in its present form may be used not only to evaluate new cycles and working fluids, but also to investigate a system's behavior in off-design conditions, to analyze experimental data, and to perform preliminary design optimization. Eleven absorption fluids are presently available in the code's property database, and 12 units are available to compose practically every absorption cycle of interest. Some of these results will be described briefly in Sect. ABSIM has been used successfully to simulate a variety of single-, double- and triple-stage absorption chillers, heat pumps and heat transformers using the working fluids LiBr-HOH and more. Based on this information, the program calculates the temperature, flowrate, concentration, pressure, and the vapor fraction at each state point in the system and the heat duty at each unit, from which the coefficient of performance may be determined. After drawing the cycle in terms of the units recognizable by the code and showing their interconnections, the user must specify the size of each exchange unit in terms of its heat and mass transfer characteristics, the working fluid(s) at each state point and the given operating conditions, such as temperatures, flowrates, and the like, fixed at specific state points. The code requires relatively simple inputs, consisting of the minimum information needed to define an absorption system properly. The equations generated by the code are listed and solved simultaneously by a mathematical solver routine. Each unit subroutine, when activated, addresses a property database for the thermodynamic properties of the working fluids. These subroutines are activated by a main program that interprets the input for the cycle, calls the units, and links them to each other in an order corresponding to the user's specification to form the complete system. Recognizing this, ABSIM has been structured around unit subroutines, each of which contains the governing equations for the particular unit. Most absorption systems consist of a number of standard components or units (e.g., absorber, condenser) that may be combined in different forms to produce various cycles. Special moreВ В» utilities enable the user to plot the results and produce a pressure-temperature-concentration (P-T-X) diagram of the cycle. A graphical user interface enables the user to draw the cycle diagram on the computer screen, enter data interactively, run the program and view the results either in the form of a table or superimposed on the cycle diagram. ABSIM makes it possible to investigate various cycle configurations with different working fluids, to calculate their operating parameters, to predict their performance and to compare them with each other on a uniform basis. В«В lessДЄBSIM (an acronym for ABsorption SIMulation) is a user-oriented computer code designed for the simulation of absorption systems at steady state, in both flexible and modular form. The other package incorporates a general front-end, called IISIBat, that is a general simulation tool front-end.

#TRNSYS WINDOWS#

One package closely resembles the DOS version and includes TRNSHELL for Windows and PRESIM for Windows. Several organizations worked on this conversion that has resulted in two distinct Windows packages. Therefore, the next logical step in increased usability was to port the current TRNSYS package to the Windows operating system.

#TRNSYS PC#

Most TRNSYS users operate on PC computers with the Windows operating system. The increase in usability leads to a decrease in the time necessary to prepare moreВ В» the simulation. PRESIM, which allows the graphical creation of a simulation system, and TRNSED, which allows the easy sharing of simulations. These programs include TRNSHELL, which encapsulates TRNSYS functions. This package represents a significant step forward in usability due to several graphical utility programs for DOS. Each physical component in the system, such as a pump or solar collector, is represented by a different FORTRAN subroutine. TRNSYS, commercially available since 1975, is a computer program used primarily to simulate thermal energy systems.

Trnsys