Selected research projects: 

Development and validation of a parameter matrix for the analysis of TIR images in terms of the condition assessment of district heating pipes - AIF / BMWi project 15 802 N

Temperature field in the surrounding soil of the district heating pipe

Based on the data of airborne thermal imaging, state changes of district heating lines should in the future be recorded through measurements which are made in definded time intervals. Consequently you can carry out condition assessments. The production of the TIR image data will be influenced by a variety of parameters, so that after a  certain time  variations in measurements are not always due to a change to the state of the district heating-network. Via a calculation model that considers and also represents the factors in the best possible approximation to reality, sophisticated statements of evaluation and changes of state of the district heating network should, in the future, be represented.  more information

Utilisation of district heating pipe systems in air conditioning and process cooling supply systems AiF - 13849 N

Experimental set up for the cooling test at the FFI

Growing demand of air conditioned buildings and of application of process cooling is noticeable in the fields of trade and industry. Producing companies and management companies for buildings are seeing their main activities in a new dynamic "Cooling Service" for power suppliers and related companies. For the most efficient usage of machinery and plants the trend points towards energy centres which produce the medium air pressure, cooling, energy and heat. In order to be able to make good use of the advantages of such a energy centre in respect of carefully handling energy resources, a distribution net of the media to the various consumption points is necessary.

Numeral designation for evaluation of the construction and operating of heat accumulators

Visualization of  inlet procedures  on model of an acryl glass  accumulator 

Together with the "Institut für Energietechnik" of the Technical University Dresden we carried out tests - theoretical and experimental - in respect to the thermic behaviour of heat accumulators for drinking water and heating. The main aspect of the tests was the evaluation of the energetic and exergetic efficiency of heat accumulators and evaluation with numeral designation without dimension. Of special interest were the influences of the inner process of loss of heat, as well as the vertical heat conduction and the timely changes of the temperature area of the numeral designation systems. The input and output behaviour had to be described and a calculation method for quantification of the inner losses and the total losses of a heat accumulator was developed. In addition a norm for defining the numeral designations and the recommendations for the accumulator construction was prepared. Improvement for the evaluation and testing methods, a better comparison of heat accumulation, primary energy saving, and better installations for using thermic energy and increased economic efficiency can be expected in the future. 

Remaining service life of 30 years old insulated bonded pipes

Flow- and return pipe of a 30 years old insulated bonded pipe

A 30 year old insulated bonded pipe has been examined by the FFI in order to ascertain the estimated remaining service life. Results have shown that the quality of the 30 year old bonded plastic jacket pipe was clearly better than initially expected and  PUR-foam fulfils requirements of today's norms. The conclusion after analysis was, that estimated remaining service life is up to 38 years. That means an amount to total service life of 68 years.

Comparison of ageing between R11 and CO₂ PUR-foams 

Comparison between R11 and
CO₂ foams

In the context of FCKW - issue and prohibition of R11, PUR-supplements with different non-polluting foaming agents were investigated. CO₂- and Pentan-foams are ecologically beneficial foam-systems. In order to ascertain similarities and differences with R11-foams which were used until recently, several ageing tests have been carried out. As a result can be said that CO₂-system shows higher values only concerning thermal conductivity.

Risks of frost to earth laid water pipelines 

Construction during
the measurement

Risks of frost to earth laid water pipelines were tested by FFI in cooperation with SWM-Versorgungs GmbH. In the test, the coverage level was reduced from 1,6 meters to 0,85 meters. In spite of surface temperature of minus 17°C, the soil around the pipes was not frozen.