Objectif The aim of the project was to design, establish and operate (demonstrate) a one-pipe, pulsating district heating transmission line based on the application of smooth water i.e. use of tenside as a friction reducing additive in the water.The pipeline connects the combined heat and power station "Herningvaerket" with Koelkaer some 8 km south of Herning, where Herning Municipal Works has established a new district heating network.The superior aim was to show how the transmission cost can be reduced by applying this technology. Using only one pipe reduces the capital costs and the heat loss from the pipe compared to a conventional double pipeline. Adding the friction reducing agent pumping costs and/or the heat loss if the water velocity is increased. The result hereof improves the competitiveness of district heating.From a technical point of view the project has been a success. The pulsating operation has worked according to expectations and has not caused any inconveniences to consumers or operators of the system. However, a problem in relation to the long-term operation has not been solved as the two tanks of the plan are still operated in an open manner with access of atmospheric air/O2 to the system water. After the termination of the demonstration period, internal inspection of the tanks will take place, and a final decision of sealing the tanks will be taken.From an economical point of view, the advantages have shown to be smaller as expected. The overall economy of the plant operating with friction reducing additives is about the same directly connected to the regional heat transmission network, the economy would be sufficiently improved to name it a true success.From a technical point of view, there are good possibilities for replication provided a satisfactory solution is found forthe sealing of the tanks. The economy of any new plant will depend on local conditions.A conventional DH system has a flow and a return pipe, in which water circulates continuously. In this project only one pipe was installed, and the tenside-enriched water flows back and forth between tanks installed at either end. The operation can be described in three phases:1. HOT PULSE. Cold water in tank 1 is pumped via a heat exchanger, heated to 80 deg. C to station 2, where it is stored in tank 2.2. STAND-STILL. While the pulse line stands still, the heat content of tank 2 is distributed via a heat exchanger in the conventional DH system of Koelkaer. Thereby the water of tank 2 is being cooled to approx. 45 deg. C.3. COLD PULSE. The water in tank 2 is pumped back to station 1 and stored in tank 1. Then the hot pulse follows.Both investments (only one pipe) and operational costs (heat loss) are lower than for conventional systems. Due to the use of the friction reducing additive, also the pumping costs are reduced. The project was realized in 5 phases: 1. Optimization and Design, 2. Construction and Erection, 3. Testing, 4. Operation, 5. Reporting. Programme(s) ENG-THERMIE 1 - Programme (EEC) for the promotion of energy technology in Europe (THERMIE), 1990-1994 Thème(s) 2.2 - ENERGY INDUSTRY Appel à propositions Data not available Régime de financement DEM - Demonstration contracts Coordinateur HERNING MUNICIPAL WORKS Contribution de l’UE Aucune donnée Adresse ENGHAVEVEJ 10 DK-7400 HERNING Danemark Voir sur la carte Coût total Aucune donnée
