Varical - Modular Thermal Energy Buffering System
For energy generation in the heating sector, a decentralised heat supply plays an increasingly important role. Often, several energy sources are used in the building, which contribute to the heat and power supply in parallel or alternatively under certain conditions.
Since the supply of renewable energy is also very variable both in the daytime and in the season, a good storage capacity with low heat losses and good stratification are important. When retrofitting in buildings to achieve the greatest potential for climate protection, a small space is an important factor as larger volumes increase the potential for saving CO2 and costs.
VARICAL—the modular buffer storage system—has been developed for this application. Which offers great advantages in in terms of space requirements, ease of installation and set up especially with limited access.
VARICAL is awarded with the Innovation Award 2017 by the OTTI-symposium for thermal solar energy.
Areas of application
- Solar heat
- biomass
- heat pump
- district heating
- combined heat
- power plant
- power-to-heat
Easy access modular system
The individual modules can be taken through 70 cm wide doors and usually also through the narrow hallways and entrances typical of existing buildings.
Space-saving installation
With VARICAL, it is often possible to install volumes which take up only half of the space in comparison to a multi store arrangement.
Steel-pressure accumulator
The modular buffer storage can be pressurised as usual buffer storage up to 3 bar operating pressure so that heat generators and heating circuits can be directly connected without the need for heat exchanges and transfer losses.
Flexible integration
The 5 connections on each side of the tank allow the use as a heating buffer or in combination with a fresh water station in a wide range of applications.
Innovative heat insulation system with LEEPS insulation and optional VIP vacuum insulation
Thanks to the heat-proof LEEPS insulation with a very good insulation value and the joint insulation of all modules, heat losses are kept very low. The air chambers inside the insulation shells also have a good insulating effect. The heat losses can be reduced further to very low values using the optional vacuum isolation panels (VIP), which can be pushed into the air chambers.
Integrated By-pass for quick heat delivery
If the heat generator is connected on one side of the storage tank and the heating circuit on the other side of the same pipe, the water from the heat generator can flow directly into the heating circuit without any mixing losses. Only the water, which the heating circuit does not need, flows through the slots of the loading and unloading pipe into the buffer storage. This is particularly important for heat pumps, where any degree of cooling by mixing should be avoided.
Proven and well thought-out sealing system
A special sealing system has been developed and carefully tested to permanently seal the pipe ducts. It seals the individual modules at the pipe passages by means of flat and lamella seals and is based on proven long-life elastomers in combination with stainless steel sleeves.
The slats seal without pressure during filling and emptying. As the pressure increases, the sealing function increases. The sealing system was successfully tested at a different pressures in a pressure-change testing device at the ITW of the University of Stuttgart.
Controlled loading and unloading
The loading and unloading pipes, which extend through the entire storage length, enable a cleanly layered loading and unloading through special inlet and outlet openings for the buffer water with flow deflection.