Flow-area-variable backflow plate-fin heat exchanger and control method thereof

Abstract

The invention discloses a flow-area-variable backflow plate-fin heat exchanger and a control method thereof. The flow-area-variable backflow plate-fin heat exchanger comprises a high-temperature region heat exchange core body A, a medium-temperature region heat exchange core body B and a low-temperature region heat exchange core body C. The three regions are connected through a first core body middle flow guide device and a second core body middle flow guide device. The two core body flow guide devices are right trapezoid flow guide devices formed by welding obtuse-angled triangular flow guide devices and right-angled triangular flow guide devices in a brazing manner. The channel widths of the high-temperature region heat exchange core body, the medium-temperature region heat exchange core body and the low-temperature region heat exchange core body are successively decreased from top to bottom. Compared with a manner that plate-fin heat exchangers of different sizes are connected in series in the field of phase-change heat exchange, the flow-area-variable backflow plate-fin heat exchanger has the beneficial effects that machining is easy, materials are saved, and pipe connection is simple, the heat exchanger is especially applied to a deeply-low-temperature mixing working medium cooling system; heat preservation of the high-low temperature regions is more reasonable, and heat preservation materials are saved; and downward falling film boiling and upward concentration can be achieved by arranging the flow-area-variable backflow plate-fin heat exchanger in an inverted manner.

Description

technical field [0001] The invention relates to the subject field of engineering thermophysics and energy utilization, in particular to a counterflow plate-fin heat exchanger with variable flow area and a control method thereof. Background technique [0002] The plate-fin heat exchanger has the characteristics of compact structure, easy to realize large-scale, and high heat transfer efficiency. It has been widely used in petroleum, chemical industry, air separation, natural gas liquefaction, aerospace and other fields. [0003] Although the traditional plate-fin heat exchanger has made many changes in the flow channel arrangement, deflector design and fins, but one thing remains unchanged, that is, each flow in the heat exchange core of the heat exchanger The flow area is always constant. For the phase-change heat with a large difference in the specific volume of the inlet and outlet streams, if a single plate-fin heat exchanger with a constant flow area is used, it is diff...

AI Technical Summary

Problems solved by technology

The disadvantage of such a flow direction arrangement is that the flow direction of the low-pressure side is opposite to the direction of gravity, resulting in a relatively large pressure drop, which affects system performance.

However, this is limited by the current equal flow area, and it is impossible to reverse the flow direction of the condensation side and the boiling side

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