Aufgrund der Entwicklung eines COVID-19-Impfstoffs und seiner besonderen Anforderungen rücken transportable Tiefkühllager immer mehr in den Fokus der kommenden Distribution. Dementsprechend wird der Markt derzeit mit Lösungen überschwemmt, so dass es zunehmend schwieriger wird, ein geeignetes von einem ungeeigneten Produkt zu unterscheiden. Mit unserer Übersichtsseite schaffen wir Klarheit und zeigen die wichtigsten Merkmale, die ein Tiefkühllagerraum haben sollte.
The larger the external surface area and the greater the temperature differences between the ambient temperature and the storage temperature, the greater the heat input. Good insulation is therefore essential for cryogenic storage. One option is to increase the wall thickness, but above a certain point this hardly brings any improvement in percentage terms and also limits the storage volume. Combinations of PU foam and integrated vacuum panels provide a remedy, resulting in low wall thicknesses with high insulation values. The outer surface is significantly influenced by the geometry. It therefore makes sense to keep the ratio of volume to surface area as small as possible. The quotient of external surface area and storage volume, the so-called specific surface area, is used as a reference value. To illustrate this, consider several individual refrigerators compared to a large storage room. As a rule, larger appliances are more efficient than smaller ones. But even if many fridges are operated in the same way as one storage room, they differ considerably in terms of energy consumption because the individual fridges have a much larger specific surface area than the storage room. This can account for a factor of 10 in energy consumption.
Nature provides a perfect example here. If you look at two different penguin species based on their habitats, you can see how drastic this influence is:
Powerful and efficient refrigeration technology is important for deep-freeze storage. The energy input from the environment (transmission), the waste heat from the electrical installation and the loading and unloading lead to a corresponding power requirement. In addition, humidity must be constantly removed from the cold room.</p
When it comes to refrigeration technology, it is also important to ensure that it does not fall under the applicable regulations or is regulated by them. This currently relates to the Global Warming Potential (GWP) value, which will be reduced to an average of around 500 by 2030 as a result of the quota system of the European F-Gas Regulation and already prohibits refrigerants with a GWP of over 2500 for normal applications.
We deliberately use the natural refrigerant ambient air for cooling. This makes you future-proof and environmentally friendly. What's more, you don't need any additional safety measures as with other natural refrigerants such as ethane, ammonia and CO2.
The low-temperature refrigerant R23 with a GWP value of 14900 can still be used due to an exemption. However, this is definitely not advisable. It is currently massively affected by the shortage due to the quota regulation. New systems with this refrigerant are questionable and harmful to the environment. To make the environmental impact tangible, we compare the CO2 equivalent of one kilo of R23 with the distance a car could travel to emit the same amount of CO2. In concrete terms, this means that a single kilo of R23 has as much global warming potential as the amount of CO2 a car would emit if it travelled around the world twice. We deliberately use the natural refrigerant ambient air for cooling. This makes you future-proof and environmentally friendly. What's more, you don't need any additional safety measures as with other natural refrigerants such as ethane, ammonia and CO2.
Opening the access to the storage room creates a short, large air flow that brings a lot of warm air into the cold room. This has a drastic effect, especially in low-temperature applications, as the difference in density between the storage room and the anteroom is high due to the temperature difference. This means that the cold air falls into the anteroom when the door is opened. By integrating an airlock, which is tempered as a buffer zone only by transmission and convection from the cold room, the influence of loading/unloading remains low.
Conventional cooling systems require an evaporator in the cold room. This is equipped with a fan and a fan heater and must be thermally defrosted at regular intervals. Both components and the defrosting process generate a lot of heat in the cold room. In addition, no active cooling can take place during defrosting. With open cold air coolers, an evaporator is no longer necessary, which eliminates these heat sources and enables continuous cooling. This makes the low-temperature storage room with cold air coolers more efficient. In addition, all electrical installations should be well thought out and suitable for the storage temperature.
Refolution supported me in the technical verification of the design and dimensioning of a cooling system with natural refrigerant for a new freeze-drying plant.
I was very pleased with the immediate support and expertise of the Refolution team. Thank you very much for your help.
