Method and cryogenic cooling plant products REALIZING coupling between the cryogenic system of a tunnel and a refrigeration system is added via a condenser outside the tunnel

The invention relates to a cooling system or cryogenic freezing of products comprising a cryogenic tunnel, notable in that: - it has an exchanger / condenser external to the tunnel, wherein it carries all or part of the cold gases resulting from the vaporizing the cryogenic fluid operated in the tunnel, allowing these gases to yield to the condenser at least a portion of their frigories, before being discharged to the outside; - is arranged inside the tunnel, preferably in its inlet region, an exchanger / cooling coil, cooling coil forming part, with said condenser, a mechanical refrigerating system.