These reports may be ordered, free of charge, from the Simulation Research Group at
Lawrence Berkeley National Laboratory.
Kathy Ellington
MS: 90-3147
Lawrence Berkeley National Laboratory
Berkeley, CA 94720
USA
Fax: 510-486-4089
Email:
info@gundog.lbl.gov
LBL-29610 -- DYNAMIC SIMULATION OF A LIQUID DESICCANT COOLING SYSTEM USING THE ENERGY
KERNEL SYSTEM
Abstract:
The Energy Kernel System (EKS) is a simulation environment for building
energy analysis under development at Lawrence Berkeley National
Laboratory, ELS is a very flexible, highly modular environment that
allows users to create customized models of thermal systems by linking
together calculation objects -- either defined by the user or obtained
from a library -- that describe the individual components of the
system. A principal departure from other simulation environments is
that system models are constructed from submodel objects that are
defined without prescribed input or output interfaces, yielding
greater modeling flexibility. Also, graph theoretic techniques are
employed to determine the solution sequence, including reduction of the
iterative problem size at each time step. o demonstrate the use of EKS
for modeling complex physical systems, we present herein a dynamic EKS
simulation of a hybrid liquid desiccant cooling system. We show how EKS
calculation objects are generated automatically using MACSYMA, given
the basic algebraic and differential equations for the system, how EKS
objects are linked into macro objects that describe system components,
and how macro objects are linked together to form a mathematical
network representing the entire system. Finally, we show graphically
the numerical results of running a time-dependent simulation of the
system.
LBL-19735 -- OVERVIEW OF THE DOE-2 BUILDING ENERGY ANALYSIS PROGRAM (V. 2.1D)
Abstract:
The DOE-2 building energy analysis program was designed to assist
engineers and architects in the performance of design studies of
whole-building energy use under actual weather conditions. Program
development was guided by several objectives: That the description of
the building entered by the user be readily understood by non-computer
scientists;
That the calculations be based upon well-established algorithms; That
the program permit the simulation of commonly available heating,
ventilating, and air-conditioning equipment; That the costs of running
the program be minimal; and That the predicted energy use of a building
be acceptably close to measured values.
These objectives have been met. We present here an overview of the
DOE-2.1D version of the program with an annotated example of
input/output in the appendix.
LBL-28273
RADIANT TRANSFER DUE TO LIGHTING:
AN EXAMPLE OF SYMBOLIC MODEL GENERATION
FOR THE SIMULATION PROBLEM ANALYSIS AND RESEARCH KERNEL (SPARK)
Abstract:
The Simulation Problem Analysis and Research Kernel (SPARK) is a
simulation environment under development at Lawrence Berkeley National
laboratory. A principal departure from other simulation environments is
that system models are constructed from submodel objects that are
defined without prescribed input ot output interfaces, yielding greater
modeling flexibility. Also, graph theoretic techniques are employed to
determine the solution sequence, including reduction of the iterative
problem size. In this paper we show one role of symbolic manipulation
in SPARK processing, namely automatic generation of submodels using the
MACSYMA package. This is demonstrated in the context of steady state
radiant and convective heat transfer in a room with a fluorescent
lighting system, and then in the corresponding dynamic context.
Submodel definition and generation and described, followed by the
solution of several interesting problems defined with the submodels.
LBL-29419 -- ADVANCES IN SPARK
Abstract:
The Simulation Problem Analysis and Research Kernel (SPARK),
formerly SPANK, was originally described in a paper presented at
the 2nd International Conference on System Simulation in
Buildings in 1986. Since that time, it has undergone several
enhancements and has been integrated into a larger software
system for building energy analysis. Among the enhancements is
the capability to simulate dynamic problems. Also, symbolic
manipulation techniques are now used to generate objects and
macro objects from equations expressed as text. Currently
underway is the development of a graphical user interface. Newer
developments include a re-evaluation of the semantics of dynamic
problem definition, which will ultimately result in much greater
generality in user specification of numerical methods. This
paper reports on these developments and indicates directions for
future SPARK development.