| 摘要 |
The freeze-protected heat exchanger comprises a fluid supply header for receiving a pressurized heated fluid and a drain chamber coextending with the fluid supply header for collecting and draining cooled fluid. A plurality of heat exchanger tubes extends radially from the fluid supply header and drain chamber, and each comprise outer and inner pipes. The outer pipe has a heat-conductive wall, a proximal end in fluid communication with the drain chamber and a distal closed end. The inner pipe is disposed coaxially within the outer pipe, has a proximal end in fluid communication with the fluid supply header and comprises a plurality of first orifices through which the inner pipe is in fluid communication with the outer pipe. At least one second orifice through which the drain chamber is in fluid communication with the fluid supply header opens in the drain chamber. In freeze-protected operation, heated fluid from the fluid supply header is supplied to the inner pipes, heated fluid from the inner pipes is transferred to the respective outer pipes through the first orifices, heat from the heated fluid in the outer pipes is transferred to the outside, for example to a flow of air, through the heat-conductive walls of the outer pipes, cooled fluid from the outer pipes is collected and drained through the drain chamber, the second orifice produces a jet of heated fluid in the drain chamber to prevent the formation of ice preferably in the area of the drain outlet, and heat from the fluid supply member is also transferred to the drain chamber by conduction and radiation. The invention also relates to a face and by-pass heat exchanger unit including the above described freeze-protected heat exchanger.
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