Use of thermal cooling technologies and optimal combination with other heat energy consumers to use during summer the available district heating based on renewable energy sources: example of the municipality of Mureck

Status

completed

Summary

Initial situation and motivation

The rural area around the Climate Alliance municipality Mureck in the south of Styria can be described as a multifunctional energy centre: various regional resources (wood chips, colza, used edible oil, liquid manure and corn) are used to produce energy. Different technologies are combined to produce electricity, heat and biodiesel from these renewable energy carriers. Because of the operation of a biogas driven combined heat and power plant in Mureck, heat is also produced in summer. But as a result of a low heating energy demand, the biggest part of the energy can currently not be used.

Contents and objectives

This project will present a concept for an optimal use of the excess of heating energy (for heating and cooling), so that the efficiency of the whole system can be enhanced.

Because of an existing cooling energy demand in many buildings, thermal energy could be used to run absorption chillers. But the use of exclusively chillers would not increase the efficiency of the whole system, because only absorption chillers can not ensure the low return temperature which is required in the district heating system. That is why the combination with other direct customers of heating energy will be analysed in this project to optimize the whole system.

The targets of the project are:

• optimization of operation of the district heating network in order to increase the use of waste heat defining an optimal combination of possible heating energy consumers.
• evaluation of the ecological and economical impacts of the investments (demand-side measures for the use of the heating energy from a biogas driven combined heat and power plant) towards the reduction of the power peaks.

Methodology

• Description of existing district heating network in a simulation environment
• Potential analysis for additional heating energy consumers (mainly for cooling uses)
• Acquisition of electricity consumption of room air conditioning units and analysis of indoor comfort parameters with monitoring of one object (office building of SEEG)
• Calculation of cooling loads and load profiles for potential heating energy consumers for cooling uses
• Analysis of the effect of absorption chillers on the operation of the district heating network with simulation of heating network and elaboration of concept for an optimal operation of the network (connections between components)
• Elaboration for requirement specifications for the potential absorption chillers
• Realisation of an economical feasibility study

Results

• survey and data collection for potential analysis
• thermal modelling of the district heating system
• calculation of cooling load profiles for the buildings from the potential analysis
• thermal simulation of the district heating network with integration of absorption chillers
• first recommendations on the integration of absorption chillers and technical optimisation measures
• monitoring analysis of installed room air conditioning units in an office building
• results of a cost-effectiveness calculation for the acquisition of district heating driven absorption chillers

Project management

DI Olivier Pol
arsenal research

Project collaborator

DI (FH) Gernot Haslinger, Dr Dong-Seon Kim
arsenal research

Project or cooperation partner

• Ing. Gerhard Repnik
  DI Sebastian Sautter
  enerep schöner tag
• DI (FH) Reinhard Ungerböck
  CONNESS
• Ing. Gernot Breitenhuber
  Herbert Leitgeb
  Nahwärme Mureck

DI Olivier Pol
Geschäftsfeld Nachhaltige Energiesysteme / Business Unit Sustainable Energy Systems
1210 Wien, Giefinggasse 2
Tel.: +43 (0) 50550-6592
Fax: +43 (0) 50550-6613
E-Mail: olivier.pol@arsenal.ac.at
Internet: www.arsenal.ac.at