The present invention relates to a multicircuit heat exchanger, i.e. a heat exchanger capable of circulating more than two media. Through delimiting zones in the heat exchanger package, a further medium can be placed in heat exchange with one of the two media normally being circulated. Several such delimited zones may be arranged in the same heat exchanger package, and the zones may even overlap each other for mutual heat exchange.
In today""s conventional heat exchangers, two media are circulated in heat exchange with each other. There is, however, a requirement for circulating further media in the exchanger, e.g. for additional heating.
The present invention eliminates the above limitation of the prior art by providing delimited zones or islands in the heat exchanger. Inside these zones, a further medium may be circulated and be in heat exchange with one of the other media.
The present invention thus provides a multicircuit heat exchanger comprising plates with a pattern of grooves and inlet and outlet connections. The plates are placed in a package and brazed together to form separate ducts for two media between alternate pairs of plates.
According to the invention, at least one delimited zone is defined between alternate pairs of plates, to block off a first medium whereas a second medium is allowed to flow through. The delimited zone has an inlet and an outlet for circulation of a further medium under heat exchange with said second medium.
The invention is defined by the accompanying claim 1, whereas advantageous embodiments are stated in the dependent claims.