A double pipe for a heat exchanger includes an inner pipe disposed in an outer pipe. In a straight-pipe portion of the double pipe, the inner pipe has a plurality of protruding parts extending in a helically offset manner along a longitudinal direction, an inner-circumferential surface of the outer pipe directly contacts the protruding parts, and outer-side channels are partitioned at a plurality of locations in a circumferential direction of the double pipe. The protruding parts are curved to protrude radially outward. In a cross section of the straight-pipe portion orthogonal to the longitudinal direction, the inner-circumferential surface of the outer pipe is circular, and an average value of D/L values of all the outer-side channels is 0.09-0.20, wherein D is defined as a maximum depth of each of the outer-side channels and L is defined as an arc length of each of the outer-side channels in the circumferential direction.

A flow reactor is structured to increase the overall heat transfer coefficient, which represents the efficiency of heat exchange with respect to a reactive fluid to be treated. This flow reactor is provided with three flow passages, which are a first flow passage, a second flow passage, and a third flow passage which spirally circulate within a space formed between an inner tube and an outer tube. The flow passages are compartmented by an inner heat transfer body and an outer heat transfer bodies. The heat transfer bodies spirally circulate, have a screw-like cross-sectional shape in an axial cross-sectional view, and are assembled in a screw-like configuration. By changing the shapes of a male-thread portion and a female-thread portion, the flow passage area of the first flow passage is changed, the second flow passage and the third flow passage are spirally formed, and heat exchange and reaction take place through the heat transfer bodies.

A cooling channel structure includes a tubular member with openings at both ends. In an inner portion or on a surface of the tubular member, as cooling channels for flowing a cooling medium for cooling the tubular member, provided are a plurality of spiral outer surface-side channels located on an outer surface side of the tubular member, at least one inner surface-side channel located on an inner surface side of the tubular member, and a plurality of folded channels, respectively, connecting the plurality of outer surface-side channels and the at least one inner surface-side channel on one end side of the tubular member.

Polymeric tube-in-shell heat exchangers with twisted tubes are provided. The heat exchanger may include one or more polymeric tube bundles, wherein each of the one or more polymeric tube bundles includes at least one tube twisted about its length or at least one pair of tubes twisted or wound around each other. The presently disclosed polymeric tube-in-shell heat exchangers with twisted tubes may be especially suited for applications where the use of polymer tubes offers advantages, such as in the case of acid solutions, food and beverage fluids, and carbon capture applications where the use of metal heat exchangers destroy the amines used for capture.

A refrigeration cycle device has a compressor, a radiator, an auxiliary heat exchanger, a decompressor, an evaporator, and an interior heat exchanger. The auxiliary heat exchanger performs a heat exchange between refrigerant and air and causes the refrigerant to radiate heat. The evaporator performs a heat exchange between air and refrigerant after being decompressed in the decompressor before the air is heated in the auxiliary heat exchanger. The interior heat exchanger has a first heat exchanging portion and a second heat exchanging portion and performs a heat exchange between refrigerant flowing in the first heat exchanging portion and refrigerant flowing in the second heat exchanging portion. The first heat exchanging portion is disposed in a refrigerant path between the radiator and the decompressor and is connected to the auxiliary heat exchanger in series. The second heat exchanging portion is disposed in a refrigerant path between the evaporator and the compressor.

Vapor flow-diverting devices that re-direct upwardly flowing vapor, for example, in a downward direction across condenser tubes disposed in the upper or top section of a vapor-liquid contacting apparatus, are described. These devices are particularly beneficial in tubular condensers within distillation columns and may be used in combination with other associated equipment (e.g., a deflector plate and divider plate) as well as in combination with the tube surface enhancements to improve the heat transfer coefficient.

A double pipe type heat exchanger includes an inner pipe having a first flow path defined therein and an outer pipe arranged around the inner pipe to define a second flow path between the inner pipe and the outer pipe. The inner pipe includes a spiral groove formed on an outer circumferential surface of the inner pipe to extend along a longitudinal direction of the inner pipe. The outer pipe includes a reduced diameter portion protruding inwardly so that the inner surface of the outer pipe is intermittently contacted with the outer circumferential surface of the inner pipe.

The production method for producing a rifled tube, which includes a plurality of first helical ribs on its inner surface, includes: a steps of: preparing a steel tube; and producing a rifled tube by performing cold drawing on a steel tube by using a plug which includes a plurality of second helical ribs, the plug satisfying Formulae and:

0.08 <W×(A−B)×N/(2π×A)<0.26  (1)

0.83<S×(A−B)×N/(2×M)<2.0  (2) where, W is a width of a groove bottom surface of the helical groove; A is a maximum diameter of the plug; B is a minimum diameter of the plug; N is a number of the second helical ribs; S is the width of the groove bottom surface; and M is a pitch of adjacent second helical ribs.

Disclosed herein is a double tube for heat exchange. The double tube for heat exchange includes: a spiral pipe having ridges and valleys alternately formed on a circumferential surface thereof along a spiral track thereof and guiding a first fluid to flow therethrough; an outer pipe receiving the spiral pipe axially inserted thereinto and guiding a second fluid to flow along the circumferential surface of the spiral pipe in an axial direction such that the second fluid exchanges heat with the first fluid; and a resistance member protruding from the spiral pipe or the valleys to increase residence time of the second fluid in the valleys on the circumferential surface of the spiral pipe and to support the ridges adjacent thereto. Unlike typical double tubes, the double tube for heat exchange can improve heat exchange efficiency between a second fluid flowing inside an outer pipe and a fluid flowing inside a spiral pipe axially inserted into the outer pipe to increase residence time of the second fluid inside the outer pipe by virtue of a spiral shape of the spiral pipe; can improve flow directionality of the second fluid through formation of the grooves in valleys of the spiral pipe along a spiral track of the valleys; can reduce flow-induced noise through expansion of a space defined between an end joint of the outer pipe and the inner pipe to reduce the pressure of the second fluid; and further improve heat exchange efficiency through resistance members protruding from the valleys to increase residence time of the second fluid.

There is provided a heat exchanger adapted to exchange heat between a first fluid and a second fluid. The heat exchanger comprises an outer tubular body, an inner body, a first inlet, a first outlet, a second inlet and a second outlet. The outer tubular body has an inner surface. The inner body is arranged inside the outer tubular body and has an outer surface facing the inner surface of the outer tubular body, leaving free a gap between the inner surface of the outer tubular body and the outer surface of the inner body. The first inlet and the first outlet are arranged to provide a first flow path for the first fluid from the first inlet to the first outlet via a first channel and via a second channel. The second inlet and the second outlet are arranged to provide a second flow path from the second inlet to the second outlet for the second fluid in the gap between the inner surface of the outer tubular body and the outer surface of the inner body. The outer tubular body comprises the first channel. The inner body comprises the second channel. The inner body and the second channel are rotatable relative to the outer tubular body and the first channel.