OPTIMAL STRATEGY OF LARGE CITIES DISTRICT HEATING SYSTEMS
T e c h n iic a ll U n iiv e r s iit y o f G d a n s k — F r a u n h o f e r I n s t iit u t U M S I C H T
Techn ca Un vers ty of Gdansk — Fraunhofer Inst tut UMSICHT
Development of an energy management system (EMS) suitable for modern DH systems was a goal of common Polish —German research project. Design and implementation of different required mathematical and software tools
have been carried out to achieve the purpose. Appropriate adaptatio n to practical DH conditions was reached with help of industrial partners – Gdansk DH Enterprise (GPEC) and Energy Supply Company of Oberhausen (EVO).
AUTOMATIC AGGREGATION OF MODELING AND SIMULATION OF PUMPING POWER MINIMIZATION OPTIMAL ARRANGEMENT OF HEAT
DISTRICT HEATING NETWORKS DISTRICT HEATING SYSTEMS IN DISTRICT HEATING SYSTEMS SUPPLY ALTERNATIVES
by Achim Loewen by Andrzej Augusiak by Michael Wigbels by Andrzej Reński
Solving very complex systems of equations in DH simulation A very crucial in optimal operation of large DH systems is their Target of the pumping power minimization in DH systems is A research method has been formulated to support effective-
programs often requires long computing times or can in some proper design and exact pressure and temperature distribution to determine operational mode of all pumps and valves that ness evaluation in modernization and development process
cases be even impossible. Thus a methodology has been deve- over the whole net. minimizes the total energy costs for pumping. In order to within large DH systems. A mathematical model and prepared
loped to simplify the structure of models for complex district achieve the absolute minimum of the costs, a DH network has software consisting of several modules that describe main ele-
To improve the quality and ease of thermo–hydraulic analysis,
heating networks (‘aggregation’) without causing any to be regarded as a total system. That is why the objective ments of district heating system has been prepared and tested.
an integrated computer system DBNet for modeling and
essential alteration in their mathematically modeled behavior. function is formulated by the sum of the pumping power
simulation of complex DH structures has been created, with two It is based on a Mixed-Integer-Programming (MIP) optimization
Calculations for different networks have shown very good main functions implemented in: requirements Pi of all pumps in the network: Pi = MIN! algorithm with an objective function defined as a sum of
results. Where the input values are the same (total load, Computer tools for modeling of different DH network For the safe supply of all consumers the following boundary annual total costs of heat supply service in a considered
supply temperature and mass flow), up to a high degree of elements that utilize object-relational database conditions are regarded: period of time: (KS + KD) = MIN!
aggregation the pressures, temperatures, and supply times at connectivity and GUI interface communication in multi- Operational limits of the pumps and armatures, The mathematical model takes into account costs of:
the remaining nodes match those of the original network. Also user and open-platform environment, Design pressure of the network components,
Heat generation characteristics (supply side) — KS,
parameters of the whole network, such as heat storage and New and very efficient computational procedures for Minimum static pressure head of the pumps, Heat consumption factors (demand side), including
pumping energy are subject to only minor divergence. running steady-state simulations of DH systems based Boiling point of the heating water, market economy transformation driven ones — K D.
The aggregated networks can be calculated almost without on general-graph theory and sparse matrix algebra. Minimum pressure difference at the substations and
With case study of a typical large city area in Poland supplied
limitation for steady state and up to a degree of aggregation of The software tool has been implemented within a DH network Difference between middle pressure and static pressure.
by a district heating system, essential problems concerning
75% also for non-steady state thermo–hydraulic simulations. of a large Polish company, where it has fully proven its Mixed-Integer-Programming (MIP) has been used for the development of its heat supply alternatives has been analyzed.
Thus a considerable reduction in computation time (compared functional features and has been regarded as a very helpful solution of the optimization problem in case of German and It has proven that optimal arrangement of heat supply costs
to the non-simplified network) of 85% on average up to 98% means of computer aided operational analyses in DH Polish DH systems. By the application of the optimization tool, can largely increase the competitiveness of DH systems
in some cases can be achieved. systems under modernization and re-development. cost savings up to 20% are possible. and contribute to a sustainable development.
350 M od ern ize In stall n ew
BeforeOptimization u n it n o I u n it n o III
1 3 5 7 9 11 13 15 17 19
Aggregation of Gdansk DH net M od ern ize
u n it n o II T im e h o riz o n
Pump A Pump B Pump C Pump D total
Tech nica l U niv ers ity o f Gd ans k, De p t. In te rna ti o nal C oo p era ti on o n R e searc h Frau nh of er I nsti tu t fü r Um we lt- ,
Pow er P lan ts & En er g y Ec on o mics in En vir on m en tal Pr o tec tio n, Pr oces s Sich erh ei ts-, En er gi etech nik UMS I CH T
Narutowicza 11 /12, 8 0-952 Gdans k Safety a nd E n er gy T ec hn ol ogy Osterf el de r S tr . 3 , 4 6 047 Ob er hau se n