International. Advansor reported on the development of a new Ultra module under overheating, which can provide energy savings of up to 30% and a payback time of up to 1 year if cooling systems are used.
The company explained that this new module has been used and tested in more than 30 facilities over the last year with customers such as Carrefour, where measurements show energy savings of more than 30% compared to the old cooling system.
The Ultra Low Overheating module allows evaporators to operate with a very low overheating setting without the risk of liquid CO2 returning to the compressors. Normally, the evaporation temperature can be increased by about 4-5 K, which provides an approximate energy saving of 10%.
However, depending on the geographical location and additional technology, such as parallel compression and ejectors, much greater savings can be obtained.
Positive side effects
A positive side effect when used in a supermarket is less defrosting of cupboards, where up to 75% less defrost has been measured.
For other sectors, there may be other positive side effects. For example, one nursery experienced much less dehumidification when storing potatoes, which ensured a higher weight and therefore a higher selling price. The stand-alone module is always tested at the factory and can be supplied attached to the cooling station or separately, allowing it to fit in narrow and small machine rooms, as it can be placed away from the plant itself. Advansor can calculate energy savings with the Advansor Energy Tool, which allows you to estimate the energy savings and payback time of certain projects.
Operation
The module consists of a suction accumulator, an internal heat exchanger and an ejector as an option.
The suction accumulator is used to capture any liquid that returns from the evaporators and to separate the gas from the liquid.
The main function of the internal heat exchanger is to evaporate and superheat the gas and liquid CO2 from the suction accumulator. The secondary function is to subcool the liquid line, which reduces the mass flow throughout the installation and reduces pressure drops.
The ejector is used to empty the liquid from the suction accumulator and, if a gas ejector is used, also to move the flash-gas from the MT compressors to the compressors in parallel.
If you don't have an ejector, the accumulated liquid evaporates into the internal heat exchanger.