About 60 Percent of the energy consumption of Jordan's industrial sector is accounted for by process heat. This is still largely generated through the combustion of fossil fuels. In the future, linear concentrating solar collectors could cover a considerable part of the industrial heat demand. As part of the JOSSI project, researchers from DLR, together with the company Industrial Solar and researchers from the HZDR Helmholz-Zentrum Dresden-Rossendorf, are investigating the water-steam flow in the solar collectors. Here, the flow simulation models are compared with the measured data from a grid sensor. With the help of the knowledge gained, improved monitoring and control methods can be developed. The acquired knowledge will be disseminated further by the Jordanian partners, thus advancing the level of awareness of the technology in Jordan.
The DLR Institute of Solar Research is mainly responsible for building up a better understanding of water/steam flow in solar absorbers and for the topic of knowledge transfer and capacity building in the scientific field. DLR is also involved in plant monitoring and in the development of measures aimed at supporting the acceptance and implementation of SHIP (Solar Heat for Industrial Processes) projects in the Jordanian market.
In Jordan, the project is supported by eight partner organisations from research, industry and administration:
Better understanding of the flow pattern in solar absorbers
The mechanical load on the absorber pipes is significantly influenced by the existing flow pattern. For safe operation, critical flow situations such as steam hammer and local drying out must be avoided. As the temperature rises and the steam content increases, the flow pattern along the absorber pipes changes. While at the beginning there is typically still a plug flow, it changes into a ring or wave flow as the length of the run increases. If the liquid and vapour phases are unevenly distributed in the pipes, this leads to significant temperature differences on the pipe walls, which can ultimately cause the pipes to deform.
Due to small temperature differences, the annular flow is the flow form to be preferred within the absorber tubes. For the prediction of the flow pattern occurring in an absorber tube, we use a model that is based on the flow map of Taitel and Dukler (Figure 3). We then compare the calculated flow state with the measured data from a grid sensor developed by the HZDR. By measuring local transient electrical properties over a pipe cross-section, it is possible to infer the distribution of the liquid and vapour phases and thus the flow form that has formed. For this purpose, the sensor is installed in the existing process steam plant of Japan Tobacco International Manufacturing Jordan (JTI) in Amman.
Recording and evaluation of the plant’s performance data
In addition, the performance data of the process steam plant is recorded and evaluated over a long period of time with regard to its availability and efficiency. The data obtained can then be used to calculate the yields of future plants and identify technical improvement measures. From this, measures can be derived that increase plant availability in the long term.
Development of a plant monitoring concept
Together with Industrial Solar, DLR is developing automated fault detection and remote diagnosis procedures. These are demonstrated using operating data from the plant. For this purpose, Industrial Solar installs a web-based monitoring system at the test facility. The automated operation of a process steam plant requires less staff and effort on site, which reduces operating costs.
Knowledge transfer to commercial plants and Universities
For the Jordanian industry partners, the project results are of great benefit because they can use them to improve the operation of commercial plants. The participating Jordanian Universities benefit from the acquired knowledge in the university training of professionals.
With the gained understanding of the flow pattern and the long-term data collected in the JOSSI project, the equipment of commercial process steam plants can be further improved. In Jordan, interest in concentrating solar systems as a technology is being promoted, so further developments in Jordanian industry and economy can be expected.
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