This combination of wet and dry cooling tower ensures on the one hand, the efficiency and constant temperature level of warm and cold water of a wet cooling tower and on the other hand prevents, to a very large degree, the formation of visible plume by the mixture of the warmed-up air of the dry part with the saturated plume forming air from the wet part.
The mixed discharge air of the PAFAND cooling tower, which is warmed-up over the dew point in this way, leaves the outlet air almost invisible (no visible plume for the vast majority of the operational period).
Due to the necessary integration of the Hybrid unit into the components of the power plant at a stage when the planning was nearly complete, the local conditions meant that there is restricted room for the cooling tower and severe noise protection requirements. Both of these restrictions posed a big challenge to the procedural design, which has been solved by accompanying air flow trials in the wind tunnel and fluid-dynamic software simulations.
The allocation of two power plant blocks to one cooling tower unit is new in the Moorburg PAFAND cooling tower and is therefore designed with two independent hydraulic segments.
On the air side, an outage circuit breaker was chosen for each block-associated cooling tower segment in order to stay plume-free as long as possible when only one block is in operation.
As the power plant is normally operated with continuous cooling, the change-over to the circuit operation with the Hybrid unit can be made without special provisions if required. Thus the availability of the power plant is continuous all year round.
The axial flow fans, which are installed to reduce the height of the cooling tower, are arranged on two levels. The level between the fan platforms of the wet and the dry parts is used for the placement of the auxiliary power units, the booster pump, the tube cleaning (heat exchanger) and air evacuation equipment. This design provides compliance with the restricted space conditions at the Moorburg location.
This commission demonstrates that Hamon technology for cooling systems of all types meets the highest requirements and provides state-of-the-art solutions.