RU2066035C1 - Cross-flow heat exchange apparatus - Google Patents

Abstract

FIELD: heat-power engineering; heat exchangers for gaseous heat-transfer agent at high temperature differential. SUBSTANCE: cross-flow heat exchange apparatus has stack of plates with discontinuous longitudinal fins forming separate sections on surface of plate at similar pitch which reduces from section to section in way of motion of heat-transfer agent. Section located at heat-transfer agent outlet may be additionally provided with turbulizing notches. EFFECT: enhanced efficiency. 2 cl, 3 dwg

Description

 The invention relates to heat engineering, namely to heat exchangers with a large temperature difference between the two environments at the entrance to the heat exchanger.

 Known plate cross-flow heat exchanger (AS 1598592, class F 28 D 9/00, 1988), containing a package of flat sheets and corrugated plates placed between the sheets with the formation of central and peripheral channels for the flow of heat-exchanging media, and the channels are equipped with two-tee spacers , the number of which in the peripheral channels is increased.

 The disadvantage of this technical solution is the low reliability of the apparatus with a large temperature difference of the media at the inlet to the apparatus and a large unevenness of the temperature fields in the heat exchanger. This temperature unevenness leads to cracking of welded and soldered joints and to a decrease in the efficiency of the apparatus.

 Known plate cross-flow heat exchanger (application Germany N 3345558, class F 28 D 9/02, 1985) containing a package of plates with longitudinal ribs, and the heat exchange surface formed between the ribs of the channels changes in the direction of movement of the coolant. As calculations and experiments show, the known technical solution does not lead to the desired alignment of the temperature field in the body of the plates and in the cross section of the flows at the outlet of the heat exchanger channels.

 To reduce the thermal stress in the design of the heat exchanger and maintain its efficiency, as well as to equalize the temperature field at the outlet of the apparatus and in the body of the plates, it is proposed to increase the degree of intensity of the heat exchange process not across, but along the flow of heat-exchanging media by making longitudinal ribs intermittent with the formation of separate sections with the same finning step in each of them and decreasing from site to site in the direction of movement of the coolant.

 The degree of intensification of the heat transfer process can be increased both separately for cooling or cooled media, and for both together, both by increasing the heat transfer surface, and by performing, for example, at the sections located at the outlet of the apparatus, cuttings.

 Figure 1 presents a diagram of the inventive heat exchanger; in FIG. 2 is a top view of one of the plates of the inventive heat exchanger, from which it is seen how the individual sections are made and how the pitch between the ribs in them decreases; Fig.3 notches in the ribs in the last section.

 The cross-precision heat exchanger comprises plates 1 for a flow of a cooled medium and plates 2 for a flow of a cooling medium. To increase the degree of intensification of the heat transfer process and increase the strength, and hence the reliability of the apparatus, ribs 3 are made in plates 1 and 2, the number of which is increased in the heat carrier flow by installing additional ribs 4 and 5. The ribs can be intermittent and broken into separate sections with the same step in them, which decreases from site to site in the direction of movement of the coolant.

 With a step that varies in the flow, the sections can be performed both in the cooled or cooling media, and in both media simultaneously. On the edges of the sections located at the exit of the apparatus, notches 6 can be made.

 When the media flows between plates 1 and 2, heat exchange occurs between them, the degree of intensification of which increases along the stream. This leads to equalization of the temperature field both in the body of the plates and in the cross section of the heat fluxes at the outlet of the channels of the heat exchanger. In turn, this alignment of temperature fields will not only simplify the assembly technology of the plate package, but also use it in heat transfer with a significant difference in the temperatures of the flows at the inlet to the heat exchanger. YYY2

Claims (2)

 1. Cross-precision heat exchanger containing a package of plates with longitudinal ribs, moreover, the heat exchange surface of the channels formed between the plates changes in the direction of movement of the coolant, characterized in that the longitudinal ribs are intermittent with the formation of separate sections with the same fin pitch on each of them and decreasing from site to site in the direction of movement of the coolant.  2. The apparatus according to claim 1, characterized in that the ribs in the areas located at the outlet of the coolant are made with notches.

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