Paper Conference

Proceedings of BauSim Conference 2020: 8th Conference of IBPSA-Germany and Austria

     

MODELLING AND SIMULATION OF INNOVATIVE DECENTRAL DOMESTIC HOT WATER SYSTEMS WITH HEAT PUMPS FOR MULTI-FAMILY BUILDINGS

F. Ochs, S. Breuss, E. Venturi, M. Magni, G. Dermentzis, S. Fisco

DOI: https://doi.org/10.3217/978-3-85125-786-1-15
Abstract: Designing cost-optimal and efficient DHW systems for multi-family buildings (MFB) that allow providing a high level of comfort as well as following the hygienic requirements is not trivial. Building and HVAC simulation can help to improve the system design, to find appropriate dimensioning of the components, to improve control strategies and set points, to assist in commissioning the system and finally to detect and fix faults. In order to meet these requirements different decentral heating systems for MFBs were proposed and tested recently. For decentral, i.e. flat wise DHW preparation systems, it is challenging to model the different scales (flat, building, HVAC system) at different design stages (pre-design, design, commissioning, operation, fault detection) appropriately. DHW comfort (i.e. delay times) can be modelled only on the level of the flat, while the energy performance (distribution and storage losses, efficiency of HVAC system) can only be investigated on building or even district level. For the entire building, if all flats would be simulated together, different profiles need to be generated in order to account for different times of use (simultaneity of DHW use). Accordingly, stochastic or “smoothed” tapping profiles are required. For large buildings with more than 10 flats such an approach would lead to a very heavy simulation model with extensive simulation times. Contrariwise, a “lumped” model with one heat exchanger would be easy to use but could not predict the dynamics and the return flow temperature correctly. The paper discusses several modeling approaches and presents results of a case study with decentral DHW heat exchanger in combination with flow type post heater.
Pages: 135 - 142
Paper:
bausim2020_15