Buildings with floor heating or thermally activated building structures offer significant potential for shifting the thermal load and thus reduce peak demand for heating or cooling. This potential ...can be realised with the help of model predictive control (MPC) methods, provided that sufficiently descriptive mathematical models of the thermal characteristics of the individual thermal zones exist. Creating these by hand is infeasible for larger numbers of zones; instead, they must be identified automatically based on measurement data. In this paper an approach is presented that allows automatically identifying thermal models usable in MPC. The results show that the identified zone models are sufficiently accurate for the use in an MPC, with a mean average error below
$1.5{\rm \; K}$
1.5
K
for the prediction of the zone temperatures. The identified zone models are then used in a distributed optimisation scheme that coordinates the individual zones and buildings of a city quarter to best support an energy hub by flattening the overall load profile. In a preliminary simulation study carried out for buildings with floor heating, the operating costs for heating in a winter month were reduced by approximately 9%. Therefore, it can be concluded that the proposed approach has a clear economic benefit.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
In this paper the development and application of an urban building energy simulation model is presented to analyse an existing 5th generation district heating and cooling network (5GDHC) with regard ...to possible sector coupling potentials. It was evaluated, how the heat energy production through large industrial heat pumps and the total thermal capacities of the 5GDHC network can provide flexibilities for power to heat applications.
In a first step a multi model dynamic simulation was set up using the simulation environment IDA ICE. A previously developed urban energy simulation model formed the basis to implement the special requirements of the investigated 5GDHC network. This was followed by the calibration of the multi model simulation utilising the monitoring data of the existing 5GDHC network. In a second step the flexibilities of network sub areas were systematically investigated using step response tests. This was done with respect to key performance indicators like heat-up time or electrical energy consumption as a function of different boundary conditions like indoor comfort or outdoor air temperature. The third step comprised of a cumulative network analysis using different heating setpoint control strategies to optimise the operation of the network regarding heat production costs.
•Sector coupling potentials of a 5th generation district heating and cooling network.•Novel district energy system model especially designed for the considered network.•Automated calibration of the simulation model using monitoring data of the existing network.•Systematic investigation of the network flexibilities with regard to specific KPIs.•Cumulative network analysis using a peak shaving control strategy for utilising additional profits.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this project, different combinations of solar energy and heat pump systems for preparation of DHW （domestic hot water） and space heating of buildings are analyzed through dynamic system ...simulations in TRNSYS （Transient System Simulation Program）. In such systems, solar thermal energy can be used, on one hand, directly to charge the buffer storage and, on the other hand, as heat source for the evaporator oftbe HP （heat pump）. In this work systems, in which solar heat is only used directly （parallel operation of solar and HP）, systems using the collectors also as a heat source for the HP are analyzed and compared to conventional air HP systems. With a combined parallel solar thermal HP system, the system performance compared to a conventional HP system can be significantly increased. Unglazed selectively coated collectors as source for the HP have the advantage that the collector can be used as an air heat exchanger. If solar radiation is available and the collector is used as source for the HP, higher temperatures at the evaporator of the HP can be achieved than with a conventional air HP system.
District energy systems are a central element in transforming the energy system towards a low-carbon system. Simulation is regarded as key method for concept development and assessment as well as for ...operational optimization to address the growing complexity of these systems and to derive quantitative feedback e.g., as input for decision-support or operational processes. In this paper we present a comprehensive comparison of four widely used general-purpose modelling tools for district-scale energy systems, including a detailed discussion of modelling paradigms and co-simulation capabilities. This comparison is based on an extensive literature review, a comprehensive questionnaire that was conducted by tool and library developers, as well as a comparison of pipe model behavior of various libraries against measured data. The results including the experimental data are openly available and can support users in academia and industry with the selection of suitable modelling paradigms and associated tools and libraries.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
This paper presents results from the national Austrian project “Highly efficient combinations of solar thermal and heat pump systems (SolPumpEff)”. In this project different combinations of solar ...energy and heat pump systems are considered through dynamic system simulations in TRNSYS 1. In such systems solar thermal energy can be used on one hand directly to charge the buffer storage and on the other hand as heat source for the evaporator of the heat pump (HP). In this work systems, in which solar heat is only used directly (parallel operation of solar and HP) and systems using the collectors also as a heat source for the HP are analysed and compared to conventional air HP systems. With a combined parallel solar thermal HP system the system performance compared to a conventional HP system can be significantly increased. Unglazed selectively coated collectors as source for the HP have the advantage, that the collector can be used as an air heat exchanger. If solar radiation is available and the collector is used as source for the HP, higher temperatures at the evaporator of the HP can be achieved than with a conventional air HP system.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
•A plus energy network for a mixed-use district is designed, simulated and realized.•Optimized energy management with exchange of energy between buildings.•Energy production on site provides an ...optimized energy management.•Extensive simulation on building and district level enables early.•Holistic approach and monitoring of the pilot project as basis for further research.
“+ERS – Plus Energy Network Reininghaus Süd” is an integrative part of the Building of Tomorrow research flagship project “Energy City Graz-Reininghaus (ECR), which is an important part of the greater urban development framework of the City of Graz. The +ERS research project is carried out by AEE – Institute for Sustainable Technologies (AEE INTEC) (scientific project management), “Aktiv Klimahaus Süd GmbH” (real estate developer), Nussmüller Architekten ZT GmbH, and the Institute of Urbanism (Graz University of Technology). A combination of energy efficiency measures, energy production on site and energy exchange between the buildings will establish a plus energy housing estate. This paper highlights the main technical measures and strategies required to achieve plus energy standard for the housing district and discusses problems and hurdles of its actual realization.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Constructing dynamic building models of entire urban districts or cities is a time consuming effort. An automation process is required to shorten the considerable time needed for manual input and to ...parameterize simulation tools. This paper presents a generation tool for fully automated thermal city modelling that generates dynamic building models with detailed heating systems. The tool is an interface between a PostgreSQL database and the dynamic building energy simulation environment IDA ICE. Tests show that up to 300 automated generated buildings with a simple geometry and 70 buildings each with a heating system can be simulated per CPU.
The Austrian project “solSPONGEhigh” 1 examines the use of thermal activation of building components in order to increase the solar fraction of the heat demand of buildings. The aim of the project is ...to evaluate, under which conditions a high solar fraction of a single family house (low energy building) can be achieved with solar technologies (PV and solar thermal, in this paper the focus is on solar thermal). Different heat supply systems based on solar thermal energy (basic or complex supply systems) have been defined. The systems were modeled in the simulation environment TRNSYS 2, analyzed concerning their system behavior and further developed. The investigated systems range from classical monovalent heat supply systems, systems combined with solar thermal up to complex integrated hydraulic solutions. The heating of the building via concrete core activation was compared with a conventional underfloor heating system. A detailed analysis of the dynamic system and building simulation results shows that the system efficiency can be significantly increased, if solar heat is used to charge the storage capacity of the building structure directly. A further advantage when activating the building structure (primarily concrete) is the less rapidly changing room air temperature with strongly fluctuating environmental conditions.
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