CN2290016Y

CN2290016Y - No-baffle varying-area channel axial flow heat exchanger

Info

Publication number: CN2290016Y
Application number: CN 96245049
Authority: CN
Inventors: 岑汉钊; 江楠; 钱颂文; 李雪梅; 何强民
Original assignee: South China University of Technology SCUT
Current assignee: South China University of Technology SCUT
Priority date: 1996-11-01
Filing date: 1996-11-01
Publication date: 1998-09-02
Anticipated expiration: 2006-11-01

Abstract

The utility model provides a no-baffle varying cross section tube axial flow heat exchanger. The partial contact and the non-contact points of the varying cross-section of the varying cross section tube are vertically and laterally spaced mutually, which can act an action of mutual support. Thus a support between tubes of a traditional baffle plate or a baffle rod, etc. is saved. When the structure of the utility model is adopted, because the cross sections of the tube pass and the shell pass formed by the varying cross section tube are changed continuously, the fluid turbulent motion degree is increased, the tube pass and the shell pass are intensified as well as transferring heat, and the total heat transfer coefficient is obviously increased. The baffle plate is not arranged, which enables the metal consumption to be reduced. The axial flow and the tubes are mutually supported, which effectively prevents the destruction caused by the vibration of tubes.

Description

No baffle plate varying cross-section duct axial flow heat exchanger

The utility model relates to shell-and-tube heat exchanger, specifically is meant a kind of no baffle plate varying cross-section duct axial flow heat exchanger.

Shell-and-tube heat exchanger is a kind of heat transmission equipment that is widely used in the technical process of industrial departments such as chemical industry, oil refining, power, atomic energy, food and refrigeration.For supporting pipes and the speed that increases shell-side fluid to improve heat-transfer effect, the researcher has designed the baffle shell-and-tube heat exchanger that the polylith deflection plate is installed in housing.Though this heat exchanger adaptability is strong, treating capacity is big, also can use under high-temperature and high-pressure conditions, and this heat exchanger structure is compact inadequately, and the metal wastage of unit heat-transfer area is bigger, and the flow-induced vibration takes place pipe easily, and heat transfer efficiency also remains to be improved.

The fluid oscillation that brings for the baffle arrangement that overcomes baffle shell-and-tube heat exchanger destroys, early seventies U.S. Philps Petroleum Company has designed deflection rod heat exchanger, promptly rod-type baffling circle is installed at heat exchanger shell pass, come supporting pipes and disturbance fluid with rod-type baffling circle, thereby raising heat transfer efficiency, in the tube bank every heat-transfer pipe on, down, a left side, the right side has all obtained reliable supporting, the lateral flow that becomes baffle heat exchanger is into being parallel to the axial flow of pipe, eliminated the root that produces the flow-induced vibration, but the required rod-type baffling number of turns order of this heat exchanger more (more than the number of general deflection plate many), the metal material consumption is big.

The purpose of this utility model is to overcome the deficiencies in the prior art part, designs a kind ofly not only to have made heat-transfer pipe obtain secure support but also save material and no baffle plate varying cross-section duct axial flow heat exchanger that heat transfer efficiency is improved.This heat exchanger had both been eliminated the viscous flow dead band phenomenon that exists when deflection plate is arranged, and had fundamentally solved the vibration of pipe generation flow-induced, prevented the destruction that heat exchanger produces because of vibration.

The purpose of this utility model realizes by following design:

A kind of no baffle plate varying cross-section duct axial flow heat exchanger of mainly forming by heating surface bank and heat exchanger shell, it is characterized in that, need not deflection plate and make the heating surface bank of supporting and constituted by some variable cross-section heat-transfer pipes that axially discontinuously the circular section become on-circular cross-section along heat-transfer pipe, the variable cross-section heat-transfer pipe of different cross section shape in shell side, be in contact with one another and not the contact position the locus vertical, horizontal all mutually separately.

The utility model is a kind of shell-and-tube heat exchanger that need not to be provided with support between pipes such as deflection plate or rod-type baffling circle, and it relies on the changing unit in heat-transfer pipe cross section to support mutually and formation flow-disturbing runner.When its cross sectional shape ovalize and major axis scope are during to the difference of twice tube pitch and pipe external diameter, to form contact between the variable cross-section heat-transfer pipe with mutual support greater than the pipe external diameter.In this heat exchanger the fluid of tube side and shell side all along tubular axis to flowing, the cross section axially constantly changes along it in the heat-transfer pipe, shell side cross section also longshore current body flow direction constantly changes, increased the less turbulence that tube side and shell-side fluid flow, the convection heat transfer' heat-transfer by convection of tube side and shell side is strengthened simultaneously, and can too not increase its fluid flow pressure and fall, obtain the ratio that higher heat transfer coefficient and pressure fall with activation.

The utility model compared with prior art has following advantage:

1, heat-transfer pipe adopts varying cross-section duct, when fluid flows through varied cross section, can cause additional eddy current, causes boundary layer separation, has increased the less turbulence of fluid, thereby has strengthened intraductal heat transfer.

2, utilize support mutually between the varying cross-section duct different cross section, saved traditional deflection plate or rod baffle supporting arrangement, thereby significantly reduced the consumption of metal.

3, the varying cross-section duct different cross section mutually support place form shell side flow-disturbing runner, increased turbulent flow body traverse degree, shell side is conducted heat is also strengthened.

4, shell-side fluid is an axial flow, make same section each several part all keep flowing uniformly, the viscous flow dead band that has existed when having avoided deflection plate is arranged, and fundamentally eliminated the flow-induced vibration that pipe produces, prevented the destruction that heat exchanger produces because of vibration effectively.

Fig. 1 is a no baffle plate varying cross-section duct axial flow heat exchanger schematic diagram;

Fig. 2 is the stringing mode schematic diagram of no baffle plate varying cross-section duct axial flow heat exchanger.

The utility model will be further described in conjunction with following embodiment and the accompanying drawing that provides thereof:

As shown in Figure 1, the design specification and the shell-and-tube heat exchanger of the prior art of no baffle plate varying cross-section duct axial flow heat exchanger are similar, for example: the comb mode is consistent with the comb mode of shell-and-tube heat exchanger, the position of heat-transfer pipe variable cross-section part is also similar with the distance between plates position of shell-and-tube heat exchanger, all can make the reasonably design of conducting heat according to technological requirement.The tube bank of no baffle plate varying cross-section duct axial flow heat exchanger is made up of the varying cross-section duct 4 of some same sizes, and guarantees that by location-plate 6 and banding circle 5 pipe different cross section part supports mutually, and the two ends of varying cross-section duct 4 are fixed on the tube sheet 7.1 is bobbin carriage among Fig. 1, and 2 for taking over, and 3 is housing.Variable cross-section heat-transfer pipe 4 is the axial of the general heat transfer pipe in edge, by designing requirement, in certain location pipe is depressed into on-circular cross-section by the circular section, make between the heat-transfer pipe of different cross section shape and be in contact with one another or do not contact, as shown in Figure 2, the variable cross-section heat-transfer pipe in shell side, be in contact with one another with the locus vertical, horizontal of contact position not all mutually separately.For example: when the noncircular sectional shape ovalize, oval major axis scope is greater than pipe external diameter poor to twice tube pitch and pipe external diameter.Rely on the contact position between the variable cross-section heat-transfer pipe to support mutually, thereby traditional deflection plate or rod baffle bracing or strutting arrangement have been saved, the equipment metal wastage of making significantly reduces, constantly change owing to the inside and outside cross section of varying cross-section duct again, increased the less turbulence that fluid hose is interior, pipe is outer, tube side and shell side are conducted heat to be strengthened simultaneously, and because shell side is that axial flow and pipe way support mutually, prevented to vibrate the flutter failure that produces, the viscous flow dead band when also having avoided having deflection plate to exist because of flow-induced.

Claims

1, a kind of no baffle plate varying cross-section duct axial flow heat exchanger of mainly forming by heating surface bank and heat exchanger shell, it is characterized in that, need not deflection plate and make the heating surface bank of supporting and axially discontinuously the variable cross-section heat-transfer pipe of circular section variable cross-section is constituted along heat-transfer pipe by some, the variable cross-section heat-transfer pipe of different cross section shape in shell side, be in contact with one another and not the contact position the locus vertical, horizontal all mutually separately.

2, a kind of no baffle plate varying cross-section duct axial flow heat exchanger according to claim 1, when it is characterized in that being the variable cross-section heat-transfer pipe ovalize of on-circular cross-section, this transverse scope is greater than pipe external diameter poor to twice tube pitch and pipe external diameter.