SIMULATION STUDY FOR THE SOLAR RETROFITTING OF A DISTRICT HEATING SYSTEM

摘要

To boost the dissemination of renewable heat production in Germany’s urban housing estates, new concepts for the integration of solar-thermal plants into existing district heating networks have to be developed. The underlying research project of this paper is aiming at a decentralised integration of the collector arrays. It comprises a review of existing large solar-thermal systems, a simulation study and the retrofitting of a district heating network. In this paper, a simulation based comparison of the energetic and economic performance of several standard system designs including state-of-the-art solar district heating and decentralised plants is conducted. The results serve as a benchmark for the assessment of the novel concept. The model of the district heating network was built in MATLAB/Simulink by use of the CARNOT block set. None of the simulated concepts leads to a reduction of the already low fossil heat generation costs. Nevertheless, by a decentralised integration of solar-thermal plants of the aimed size, solar fractions of up to 5.7 % can be reached. The investigated systems for a centralised integration reach 3.8 % solar fraction.