The hybrid dry cooler is a combination of aircooled dry coolers and closed evaporative cooling towers, thus combining the advantages of conventional dry and wet cooling in a single product. Among these advantages are a low cooling water temperature, little space requirement, no contamination of the primary circuit, less noise emission than a cooling tower (up to 10 dB less), hygienic operation with little maintenance work, perfect access for inspection and maintenance as well as plume-free operation throughout the year. And the construction can of course be modified to suit the particular premises.
Designing hybrid dry coolers
Design software optimises the dry cooler for each individual application – taking into account the annual temperature variation at the site and the plant’s expected load profile.
The result: Plume-free hybrid dry coolers with minimal noise emission and low water and energy consumption. Thanks to its lower operating costs, the payback period is quite short. Additionally, optional equipment like UV sterilisation, anti-pollen filter, exhaust attenuators and exhaust air louvers or air side louvers are available.
Operating characteristics of hybrid dry coolers
JAEGGI hybrid coolers can be operated like conventional dry coolers without wetting the heat exchangers. The energy is dissipated to the ambient air via convection. At high external temperatures or higher plant loads, wetting the heat exchangers increases the
hybrid cooler’s performance by a factor of two or three compared to dry operation: The system is then cooled by a combination of convection and evaporation. Both modes offer an excellent dry cooler performance with a small footprint and low operating costs.
Hygiene Compliance Testing of the Units
In pursuit of the highest possible safety compliance of its Hybrid Dry Coolers, JAEGGI had the sophisticated design of its units officially inspected by an independent body. As part of the hygiene compliance inspection, the Hygiene Institute of the Ruhr (Institute of Environmental Health & Toxicology) has confirmed the compliance of the units with the relevant requirements of VDI 2047-2.
Independent from this, JAEGGI naturally takes the requirements of the relevant laws and standards of other countries into consideration when constructing their units. In particular, JAEGGI has engaged with independent advice from one of the co-authors of ACOP L8 to ensure that their Hybrid Dry Coolers remain fully compliant with all current UK guidelines. It has been confirmed, both in the laboratory and in measurements in the field, that JAEGGI units do not generate any measurable aerosols when used as specified, and are thus tested for legionella-safety.
HYBRIMATIC – Intelligent control saves operating costs
The efficient operation of hybrid dry coolers depends very much on the intelligence and strategy of their functional control. The built-in control continually controls all the significant parameters and automatically adapts the operating mode to the current system state. This guarantees a smooth and efficient unit operation and compliance with the predicted consumption values.
The HYBRIMATIC is designed as a programmable logic controller and allows for the control of the cooling water outlet temperature, wetting water management, output of operational and fault signalling and communication with building management systems. In addition, the HYBRIMASTER controller also maximises energy efficiency and water conservation for hybrid coolers installed in parallel, thus contributing to reducing your operating costs.