US Patent 9328978 Heat exchanger

The invention relates to a heat exchanger 10, comprising: a first unit 12 having a first conduit 16 for passing a flow of a first fluid through the first unit 12; a second unit 14 having a second conduit 28 for passing a flow of a second fluid through the second unit 28, wherein the flow of the first fluid is isolated from the second unit 14 and the flow of the second fluid is isolated from the first unit 12; and, a third conduit 40 connecting the first 12 and second 14 units, wherein the third conduit 40 is for carrying a flow of an intermediate fluid between the first 12 and second 14 units so as to transfer heat between the first fluid and the second fluid, when in use.