Heat load plan Weser 1974

The thermal load plan has been set up to estimate the present and future changes of the temperature ratios in the Weser due to the introduction of warm water. A principal difference was made between the Upper and Middle Weser and the Lower Weser. From the considerations presented and the calculated temperature longitudinal sections, the following results can be concluded: the determining influence on the water temperature of the Weser in the Upper and Middle Weser is the power plant chain Wuergassen, Grohnde (from 1980), Veltheim, Heyden, Robert Frank and Hastedt, and in the Lower Weser the power plants Niedervieland (from 1980), Hafen, Kloeckner, Mittelsbueren, Farge and Esenshamm. At present (loading conditions 1972), the permissible water temperatures cannot be maintained at low river discharge in the Weser in Summer, Autumn and Winter as the necessary cooling towers are partly missing. The loading conditions for 1980/85, assuming that cooling towers with drainage cooling are used for all large power plants on the Upper and Middle Weser, show that the maximum temperature of 280C for the Summer loading condition will not be exceeded. The drainage cooling of all large power plants on the Upper and Middle Weser, assumed for the calculation, is not sufficient for the Autumn and Winter loading conditions 1980/85 in order to keep the water temperatures within the heating span of Δt = 3 degrees. To maintain the heating spans and limiting temperatures, it is necessary to use open-cycle cooling or closed cooling cycles. The thermal load must be adapted through them to the needs of the waters. The losses due to evaporation on the Upper and Middle Weser, referred to Q0 - 66.5 m3/s at the level of Intschede, are for 1972 about 2%, for 1980 about 5% and for 1985 almost 7%. The evaporation losses for the Lower Weser are insignificant. In setting up the thermal load plan Weser, a general heating span of Δt = 3 degrees and a maximum temperature in the waters of 280C or Δt = 2 degrees and 260C as maximum temperature in the brackish water region of the Lower Weser is taken as basis. (orig./LH)