The shell side structure of shell-and-tube heat exchanger has multiple, what use always in industry is the shell-and-tube heat exchanger of arc baffling dividing plate supporting tube bank, abbreviate baffling dividing plate shell-and-tube heat exchanger as, shell-side fluid comes and goes the baffling motion in the intercropping of baffling dividing plate, the shell-and-tube heat exchanger that screen supporting tube bank is also arranged, China Patent No. is: the shell-and-tube heat exchanger of ZL93243442.8 and cavity ring supporting tube bank, China Patent No. is: 89218385.3, the shell-side fluid of the two kinds of heat exchangers in back is an axial flow, abbreviates shell side axial flow type shell-and-tube heat exchanger as.When cold and hot two logistics volume flows little, and temperature rise and temperature drop are bigger, and cold and hot both sides heat transfer temperature difference hour, above-mentioned heat exchanger all exists following different defective, (1) the heat transfer temperature difference utilization rate of its baffling dividing plate shell-and-tube heat exchanger is low, and often monoshell journey even bivalve journey also are difficult to finish the heat transmission tasks; (2) common shell side axial flow type shell-and-tube heat exchanger mostly is monoshell journey structure, and heat-transfer pipe mostly is plain tube, and therefore when shell both sides logistics capacity is little, if will obtain suitable flow velocity, shell directly will be very little, and the heat exchanger draw ratio is too big, can't settle in industrial system.Owing to above reason, often need many baffling dividing plate shell-and-tube heat exchanger series connection just can finish the heat exchange task in the industry, the equipment investment height, floor space is many, and fluid impedance losses is big.
Purpose of the present invention is exactly in order to solve and to overcome existing heat exchanger heat transfer temperature difference effective rate of utilization under above-mentioned special operation condition condition low, be difficult to finish the heat transfer task, demand is with a plurality of heat exchanger series operations, thereby cause the heat exchanger fluid drag losses big, the operation energy consumption height, equipment investment is big, perhaps the housing draw ratio is excessive, the problem that can't in industrial system, settle and shortcoming, a kind of heat transfer temperature difference effective rate of utilization height that has is invented in research, only need separate unit or two heat exchanger operations, the heat exchanger fluid resistance is little, operation energy consumption is low, low equipment investment, be easy in industrial system, implement the convergent-divergent tube, full counterflow bivalve journey axial flow-type heat exchanger and the heat-exchange method thereof of arrangement.
The present invention realizes by following technical proposals, the structural representation of convergent-divergent tube, full counterflow bivalve journey axial flow-type heat exchanger as shown in Figure 1, its A-A to view as shown in Figure 2, the convergent-divergent pipe as shown in Figure 3, support is shown in Fig. 4～5 between screen formula pipe, and this heat exchanger longitudinally is divided into double-current journey with heat exchanger shell by longitudinal baffle on diameter, and the shell-side fluid runner is the outer wall by heat-transfer pipe, the inwall of housing, the bivalve journey that longitudinal baffle and two ends tube sheet constitute axially come and go runner; It is mainly by heat exchanger shell 1, longitudinal baffle 2, scaling type heat-transfer pipe 3, support 4 between screen formula pipe, two ends tube sheet 5, sealing two ends lid 6, shell side is imported and exported pipe 7,8 and tube side import and export pipe 9,10 connect and compose jointly, its mutual alignment and annexation are: in heat exchanger shell 1, many convergent-divergent heat-transfer pipe 3 is uniform vertically, and weld mutually or expanded joint with housing 1 two ends tube sheet 5, longitudinal baffle 2 is imported and exported pipe 7 near shell side, the tube sheet of 8 one ends, and the inner walls of pasting mutually at the diameter place of tube sheet is tightly connected, housing is divided into two journeys, and longitudinal baffle 2 is having one section breach with other end tube sheet junction stream, constitute the return flow path of shell side runner, two ends end socket lid 6 is connected to form the backflow route of tube side runner and imports and exports pipe 9 with two ends tube sheet 5,10, support 4 equidistantly is placed in interbank vertically and is connected with convergent-divergent heat-transfer pipe 3 between screen formula pipe becomes support between the pipe of heat-transfer pipe, support is divided into vertical grid and two kinds of horizontal grid between screen formula pipe, when shell side is axially settled with two kinds of screens alternate lay with realize to heat-transfer pipe laterally and longitudinal register, prevent tube bundle vibration; Wherein: convergent-divergent heat-transfer pipe 3 is to constitute with continuous contraction and expansion pipeline section by repeating, the pipe thickness uniformity, and the inside and outside both sides of pipe scaled waveform symmetry, support is that convergent-divergent Guan Shangyi the lath more than the rib spacing constitutes by width between screen formula pipe.
The heat-exchange method of this heat exchanger: shell-side fluid is along import and suction casing 1, flow passage vertically, afterbody indentation, there baffling at longitudinal baffle 2 returns, flow passage vertically again, flow out housing from exporting 8 then, tube side fluid enters end socket lid 6 along import 9, and enter tube side from tube sheet 5, making inverse axial flow with shell-side fluid flows, turn back at another end socket lid place, make the two-tube-pass axial flow, flow out tube side from exporting 10 then, tube side and shell-side fluid are done full counter-current flow heat exchange in heat transfer process; Its key is to adopt the convergent-divergent pipe of the concavo-convex finned surface symmetry in the inside and outside both sides of pipe, to two side liquids while augmentation of heat transfer, and by bivalve journey structure, make shell two side liquids when volume flow is not high, also can obtain suitably flow velocity, make that heat transmitter also can obtain higher overall heat-transfer coefficient under full counter-current condition, and the heat transfer temperature difference utilization rate of heat exchanger can reach 100%, by screen as support between the pipe of convergent-divergent tube bank, fluid resistance is little, and shell-side pressure drop is low.
The present invention compared with prior art, have following advantage and beneficial effect: (1) this heat exchanger is the full contra-flow heat exchanger that adopts enhanced type convergent-divergent heating surface bank and bivalve pass heat exchanger structure to form, tube side and shell-side fluid are full countercurrent flow in heat transfer process in the heat exchanger, the heat transfer temperature difference utilization rate reaches 100%, has avoided the little shortcoming of the effective heat transfer temperature difference of cross-flow heat exchange in the prior art; Keep high flow velocities simultaneously, obtain higher overall heat-transfer coefficient; (2) owing to support convection cell drag losses between the screen pipe is little, the heat exchanger shell pass pressure drop is low, required fluid carries power consumption little, so it is little that this heat exchanger shell pass axial flow structure has fluid impedance losses, the operation advantage of low energy consumption, avoid the high-drag that baffling dividing plate convection cell causes in prior art loss, can save operation energy consumption greatly; (3) heat exchanger adopts the convergent-divergent pipe as heat-transfer pipe, can also can obtain the good heat transfer strengthening effect under the not high condition of flow velocity, and this helps to shorten heat-transfer pipe length, and the long shortcoming of pipe range when avoiding using plain tube is easy to settle in industrial system; (4) owing to adopted efficient heat conducting tube and the full countercurrent heat exchange method of bivalve journey axial flow, the heat transfer property of heat exchanger significantly improves, especially under turbulent-flow conditions (Re number＞5000), adopt the vertical fluid that flows in the inside and outside both sides of scaling type heat-transfer pipe of the concavo-convex finned surface symmetry in the inside and outside both sides of pipe to make to strengthen heat convection, can obtain two-sided good heat transfer strengthening effect, both sides fluid heat transferring film coefficient is higher; Can significantly reduce required heat exchange area, invest can have by a relatively large margin than the heat transmission equipment of prior art and reduce, volume compact is convenient to the I﹠M of equipment simultaneously.