skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Simplifications for hydronic system models in modelica

Journal Article · · Journal of Building Performance Simulation
ORCiD logo [1];  [2]; ORCiD logo [1]
  1. Univ. of Leuven (Belgium); EnergyVille, Genk (Belgium)
  2. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
+ Show Author Affiliations

Building systems and their heating, ventilation and air conditioning flow networks, are becoming increasingly complex. Some building energy simulation tools simulate these flow networks using pressure drop equations. These flow network models typically generate coupled algebraic nonlinear systems of equations, which become increasingly more difficult to solve as their sizes increase. This leads to longer computation times and can cause the solver to fail. These problems also arise when using the equation-based modelling language Modelica and Annex 60-based libraries. This may limit the applicability of the library to relatively small problems unless problems are restructured. This paper discusses two algebraic loop types and presents an approach that decouples algebraic loops into smaller parts, or removes them completely. The approach is applied to a case study model where an algebraic loop of 86 iteration variables is decoupled into smaller parts with a maximum of five iteration variables.

Research Organization:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Organization:
USDOE Office of Energy Efficiency and Renewable Energy (EERE), Energy Efficiency Office. Building Technologies Office
Grant/Contract Number:
AC02-05CH11231
OSTI ID:
1437004
Journal Information:
Journal of Building Performance Simulation, Vol. none, Issue none; ISSN 1940-1493
Publisher:
Taylor & FrancisCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 6 works
Citation information provided by
Web of Science

References (4)

Modelica BuildingSystems − eine Modellbibliothek zur Simulation komplexer energietechnischer Gebäudesysteme journal February 2013
Modelica Buildings library journal March 2013
Depth-First Search and Linear Graph Algorithms journal June 1972
Depth-first search and linear graph algorithms conference October 1971

Cited By (3)

Model implementation and verification of the envelope, HVAC and controller of an office building in Modelica journal December 2018
Model implementation and verification of the envelope, HVAC and controller of an office building in Modelica text January 2018
Model implementation and verification of the envelope, HVAC and controller of an office building in Modelica text January 2018

Figures / Tables (7)

Table 1(p. 6)table Table 1
Figure 1(p. 9)figure Figure 1
Figure 2(p. 13)figure Figure 2
Figure 3(p. 14)figure Figure 3
Figure 4(p. 15)figure Figure 4
Figure 5(p. 18)figure Figure 5
Figure 6(p. 21)figure Figure 6

Similar Records

Related Subjects

42 ENGINEERING