Double-pipe stream heat exchanger
SUBSTANCE: double-pipe heat exchanger for liquid and gaseous media, which contains a heat exchange pipe and an external turbulence promoter dividing inter-tube space into inlet and outlet cavities, which are concentrically located in the cylindrical housing. On the turbulence promoter surface there are the holes serving as medium injection to the cavity between the heat exchange pipe and external turbulence promoter. Inside the heat exchange pipe there concentrically located is an internal turbulence promoter dividing inter-tube space into inlet and outlet cavities and having the holes on the surface, which serve as medium injection into the cavity between the heat exchange pipe and the internal turbulence promoter. Use of the invention will allow intensifying heat exchange due to almost complete removal of a boundary layer from outer and inner surfaces of the heat-conducting pipe with heated (or cooled) medium.
EFFECT: increasing heat transfer coefficient between heat carrier and heated medium up to 10 times and more; reduction of the required heat exchange surface corresponding to it, length of stream heat exchangers, their weight and overall dimensions.
The claimed invention relates to heat exchange apparatus and can be used in various industries, agriculture and communal farms.
Known heat exchangers of the type "pipe in pipe", consisting of two pipes, one of which, of smaller diameter, concentrically located inside another, larger diameter annular gap, called the annular space (Bajan P.I. and other Reference heat-exchange apparatus. M. engineering, 1989, p.56, (figure 1.15), b). The inner tube is pumped liquid, for example, a higher temperature (hot), and the annular space fluid of lower temperature (cold). Thus the wall of the inner tube is heated and transfers heat to the cold fluid, which has as a consequence the temperature rises. The direction of heat transfer may be such as described above, or in the opposite direction depending on the ratio of the temperatures in the inner tube and in the annular space.
Note. The term "liquid" hereinafter refers to the environment in liquid or gaseous state.
The efficiency of heat transfer depends mainly on the thickness of the boundary layer fluid, i.e. the layer adjacent to the wall, with comparatively with the main stream of small thickness and remaining practically the automatic stationary relative to the wall. Up to 95% or more thermal resistance with heat transfer from the liquid to the wall (or Vice versa) is thermal resistance of exactly the boundary layer. And if its any way to remove or at least significantly reduce its thickness, thermal resistance of the heat transfer from the liquid to the wall will be reduced many times and becomes comparable to thermal resistance of the wall. Since the pipes in heat exchangers are typically made from metals, thermal resistance of the wall close to zero, and when the wall thickness of a few millimeters when calculating the overall heat transfer coefficient him (thermal resistance of the wall) usually do not take into account.
To improve the efficiency of heat transfer strive in one way or another to reduce the thickness of the boundary layer.
The simplest and most affordable way to increase the turbulence of the fluids on both sides of the wall (i.e. from the side of the coolant and the heated (or cooled) by the environment).
When increasing the turbulence of a fluid particle from the main thread penetrate the part of the boundary layer, which is adjacent to the main thread, and some part of it involved a total chaotic motion. This reduces the thickness of the immobile or sedentary part of the boundary layer, which reduces thermal resistance is of boundary layer and to increase the overall heat transfer coefficient, i.e. to increase the efficiency of heat exchange.
The increase in turbulence can be achieved by increasing the speed of the fluid, creating different shapes and sizes of projections and depressions on the walls separating the flows of the fluids, installed on the inner and outer pipes turbulized elements.
It should be noted that the increase in speed has its negative sides.
First, the growth of turbulence in a first approximation proportional to the growth rate, and the hydraulic resistance increases when it is proportional to the square of the growth rate. I.e. there is a certain limit, after which, it becomes disadvantageous, if not impossible, to further increase speed.
Secondly, it reduces the contact time of the fluid in the heat transfer, which makes it necessary in some cases to increase the heat exchange surface.
Therefore, strive to enhance the turbulent flow of liquids not to increase speed, and to use other, the above-mentioned methods in turbulence.
Known heat exchangers of the type "pipe in pipe", in which the inner tube is wound wire having different steps of winding and configuration. The drawback of such heat exchangers is a slight increase of turbulence with the growth of hydraulic resistance (patent RU №2121122).
Known as the heat exchangers, on the inner tube which is installed, for example, the welding of spiral ribs, the height of which is almost equal to the distance from the inner pipe to the outer. Such ribs largely increase the turbulence in the annular space compared to the winding wire. In addition, they increase the area of thermal contact between the wall of the inner tube with the liquid annulus, i.e. increases the efficiency of heat transfer (patent SU # 800566).
The drawbacks of such heat exchangers are the following:
not all of the liquid in the annular cavity engages in a helical movement - a large portion of it flows through the annular gap between the spiral ribs and the wall of the outer pipe;
the increase in the fluid velocity, turbulence occurs only at a few percent, at least several tens of percent, since the elevation angle of helix of small ribs. And with the increase of the elevation angle of the hydraulic resistance increases much faster growth of turbulence and increasing the amount of fluid begins to flow through the annular gap;
- the heat transfer from the fluid in the inner pipe to the wall remains relatively low level, which determines the efficiency of heat transfer in General.
A known heat exchanger "pipe in pipe" patent SU # 1222207. Inthis heat exchanger inside the inner pipe installed turbulent insert in the form of a twisted coil line strip of sheet metal with the turbulent petals along its longitudinal edges. This insertion causes a twisting of the fluid along a helical line, significantly increases the turbulence of the liquid in the pipe and the heat transfer from the fluid to the wall.
However, this analog has the following disadvantages:
not all of the liquid in the pipe engages in a helical movement (only approximately 20-30%), which can significantly increase the turbulence of the fluid, and hence the amount of heat transfer;
- due to insufficient development of turbulence reduction of the thickness of the turbulent boundary layer occurs by a small amount (a few percent). Its thermal resistance is high, and heat dissipation is increased slightly.
A known heat exchanger pipe in pipe" patent SU # 510634.
The heat exchanger comprises a cylindrical housing, located on its axis of the heat exchange tube with wavy turbulization having radial holes. The tabs turbulizer is directed along the longitudinal axis of the pipe. At the ends of the turbulizer installed mechanical plugs.
When the flow of fluid in the annulus, it passes through the holes in turbolister and comes in the form of separate streams on the outer surface of the wall of the tubes, thereby intensively washing away the boundary layer at the area of impact of the jets. Due to this several times increases the heat transfer from the LM the bones to the wall of the tubes.
This heat exchanger is adopted for the prototype.
However, it has the following disadvantages:
- turbulization difficult to make, especially for small diameter (10-30) mm;
- the heat transfer from the fluid flowing inside the tubes, remains low, and this can significantly increase the efficiency of heat transfer in General (not more than twice, as in a conventional heat exchanger of the tube-in-tube heat transfer efficiency from the liquid filling the annular space to the wall of the tubes and the fluid inside the tubes to the wall about the same).
The aim of the present invention is more significant increase of heat transfer coefficient in a few times. This in turn will allow the same time to reduce the length of the heat exchanger and, therefore, also, at times to reduce its dimensions and weight, although to a lesser extent than the decrease in length.
This goal is achieved due to the fact that the heat exchanger pipe for liquid and gaseous media containing concentrically located within the cylindrical housing of the heat exchange pipe and the outer turbulator dividing the annular space into the input and output cavities. On the surface of the turbulizer holes that serve as the input medium in the cavity between the heat e is constant pipe and outer turbulization. Inside the heat pipe is concentric inner turbulator dividing the annular space into the input and output cavity and having on the surface holes that serve as the input medium in the cavity between the heat pipe and the inner turbulization.
The device proposed heat exchanger is shown schematically in figure 1 and figure 2.
Figure 1 shows a longitudinal section of the heat exchanger, figure 2 - cross section a-a figure 1.
The heat exchanger pipe for liquid and gaseous media, includes: a cylindrical housing 4, concentrically located therein heat exchange tube 8 and the outer turbulator 6, which divides the annular space into the input 7 and output 3 cavity. On the surface of the outer turbulizer 6 holes 5, serving as an input medium in the cavity 3 between the heat exchanger tube 8 and outer turbulization 6. Inside the heat pipe 8 is concentric inner turbolister 2, which divides the annular space into input 1 and the output 9 of the cavity and having on the surface of the hole 12, serving as an input medium in the cavity between the heat exchange pipe 8 and the inner turbulization 2. The size of annular gap annulus, and the diameters of the holes 12, 5, located on the inner and outer energizers 2 and 6 are determined by thermal and hydraulic calculations Approximate the total area of the holes 12 should be 10-20% less than the cross-sectional area of the annular gap annulus between the heat exchange pipe 8 and the inner turbulization 2. The total area of the holes 5 should be 10-20% less than the cross-sectional area of the annular gap annulus between the heat exchanger tube 8 and outer turbulization 6. To achieve the maximum heat transfer coefficient perforated portions of the inner and outer turbulizer 2 and 6 should be located along the length opposite each other on the plot intensive (working) heat transfer. Position 10, 11, 13, 14, 15, 16 - the seals.
Does the heat exchanger is as follows. The inner turbolister 2 through the input cavity 1, enters the environment, such as hot fluid filling the internal space turbulizer 2 passes to the holes 12 and goes through them in the output cavity 9 of the tubes 8. The speed of the liquid in the holes depends on the pressure in the inner turbolister 2. For example, at a pressure of 0.5 MPa speed will be about 30 m/s When the pressure change rate will vary proportionally to the square root of the magnitude of the pressure change.
Streams of liquid at a speed given for the example above, reaching the walls of the tubes 8, intensely wash the boundary layer in the zone of action of the jets (it's a stain in the form of a circle with a diameter equal to about 4-6 diameters of the jet). Hot liquid when it comes into contact directly with the wall heat e is tion of the pipe 8, and the local heat transfer coefficient is increased tenfold. When frequent location of holes on the inner turbolister 2, the boundary layer on the inner surface of the wall of the tubes 8 in the zone of action of the jets from the holes is almost completely removed. And on this site in General, the heat transfer coefficient will increase tenfold. This implies a corresponding reduction of heat transfer surface (i.e. the length of the pipes).
A similar pattern is observed when the flow of the cold liquid as the heat transfer fluid through the inlet cavity 7 in the cylindrical body 4. Only cold coolant enters first in the annulus annulus between the outer turbulization 6 and the cylindrical housing 4, and then passing through the holes 5 in the outer turbulator 6, washes the outer surface of the tubes 8.
As a result, the coefficient of heat transfer from the coolant to the heated (or cooled) environment as a whole also increased tenfold, closer in magnitude to the coefficient of heat transfer by conduction through the wall of the tubes 8.
The use of the invention makes it possible to intensify the heat transfer due to the almost complete removal of the boundary layer with the outer and inner surfaces of conductive heat the pipe with the heated (or cooled) environment. This entails an increase of the heat transfer coefficient between the coolant and the heated (or cooled) by environment up to 10 or more times, suitably reducing the required heat exchange surface, the length of the inkjet heat exchangers, their weight and dimensions.
The heat exchanger pipe for liquid and gaseous media containing concentrically located within the cylindrical housing of the heat exchange pipe and the outer turbulator dividing the annular space into the input and output cavity and having on the surface holes that serve as the input medium in the cavity between the heat pipe and the outer turbulization, characterized in that the heat exchange pipe is concentric inner turbulator dividing the annular space into the input and output cavity and having on the surface holes that serve as the input medium in the cavity between the heat pipe and the inner turbulization.
FIELD: power engineering.
SUBSTANCE: heat exchanger comprises a vessel with the first and second channels for coolants and spherical heat transfer elements placed in spherical holes. Channels are separated with a heat transfer surface, inlet and outlet nozzles of the first channel, inlet and outlet nozzles of the second channel. Spherical heat transfer elements are placed in spherical holes on the heat transfer surface and on the inner surface of the vessel.
EFFECT: invention makes it possible to improve heat transfer from a heat transfer surface that separates channels of a heat exchanger.
FIELD: power engineering.
SUBSTANCE: heat exchange pipe, in which a channel is made with protrusions and grooves, besides, the channel is made with geometric ratios: h/D=0.03, l1=(90-100)/h, l2=(90-100)h, where h - protrusion height, mm D - inner diameter of a heat exchange pipe, mm l1 - protrusion length, mm l2 - groove length, mm.
EFFECT: invention makes it possible to increase energy efficiency due to reduction of hydraulic resistance.
FIELD: power industry.
SUBSTANCE: tubular heat exchanger includes tubes with ribs. Tubes pass in some axial direction and are equipped with heat exchange ribs. Each rib includes a heat exchanger surface that envelopes a tube and passes in some radial direction relative to the tube and has relief shape, thus forming grooves located at some distance from each other in radial direction. Grooves of a rib have dimensions, such as width and depth, which are reduced as far as they are located at some distance from the tube in radial direction, thus providing direction of fluid medium around the tube.
EFFECT: creation of a shaped rib structure for a heat exchanger tube, which allows increasing heat exchange between air and fluid medium circulating in the tube without deterioration of head loss.
9 cl, 10 dwg
SUBSTANCE: heat exchanger contains pipeline made in the form of wall of a through cavity with outer surface and end sections. Also it contains external heat transfer elements attached to one end section. Wall of the through cavity of another end section is made in the form of an enveloping element of a through opening that is formed in the wall of the room. At that external heat transfer elements are made in the form of facing elements of the wall of the room being made from steel plates, pipes, channel sections, angle elements or bars. End sections are fastened to each other by metal fixing device.
EFFECT: improving efficiency of heat transfer from heat exchanger to ambient air enlarging functional capabilities of heat exchanger and the number of hardware.
SUBSTANCE: pipeline is made in the form of wall of a through cavity with outer surface and end sections. Besides external heat transfer elements are made and attached to one end section. Wall of a through cavity of another end section is made in the form of an enveloping element of a through opening, which is made in the wall of the room. At that external heat transfer elements are made in the form of facing elements of the wall of the room being made from steel plates, pipes, channel sections, angle elements or bars. End sections are fastened to each other by metal fixing device.
EFFECT: improving efficiency of heat transfer from heat exchanger to ambient air enlarging functional capabilities of heat exchanger and the number of hardware.
SUBSTANCE: pipeline is made by manufacturing a wall of a through cavity with outer surface, end sections and an intermediate section that is arranged between end sections. Besides, external heat transfer elements are made, which are attached to end sections. The wall of the through cavity of the intermediate section is made in the form of an enveloping element of a through opening, which is made in the wall of the room.
EFFECT: enlarging the number of hardware; improving heat transfer efficiency from heat exchanger to ambient air.
SUBSTANCE: heat exchanger includes a pipeline made in the form of a wall of a through cavity with outer surface, end sections and an intermediate section that is arranged between end sections. Besides, it includes external heat transfer elements that are attached to end sections. Wall of through cavity of the intermediate section is made in the form of an enveloping element of a through opening that is formed in the wall of the room.
EFFECT: enlarging the number of hardware, namely, creating a new site; improving heat transfer efficiency from heat exchanger to ambient air.
SUBSTANCE: in an air heater made using a laser prototyping method, consisting of a matrix made from ceramic material and containing longitudinal channels with different cross section configuration, working media distributing/collecting headers with their inlet/outlet branch pipes, heating gas distributing/collecting headers include air and gas tubes passing through them, the external surface of which has fins; at that, fins are oriented in the direction of radii of headers.
EFFECT: reduction of energy losses, increase in heat release, reduction of metal consumption and improvement of compactness.
SUBSTANCE: heat exchanger is designed for heating-cooling of circulating flows of liquid or gas by thermoelectric batteries and may find application in power, chemical, petrochemical, food and other industries. The heat exchanger is made in the form of a forward-flow pipe from a rectangular profile, the width of which complies with width of contact plates of the thermoelectric battery, and inner surfaces are used for heat transfer to a heated (cooled) flow, with transverse partitions installed inside the pipe, which partially cover its throughout section. In the heat exchanger a rectangular profile is applied with the ratio of inner section sides within the limits of 0.2-1, and transverse partitions are made in the form of a bundle of cylindrical rods that close thermal flows of opposite walls of the pipe and installed in a corridor or staggered order perpendicularly to flow direction, besides, the rods are either tightly mounted into opposite walls of the pipe, or are installed on one or several longitudinal plates, pressed with rods into the inner cavity of the pipe.
EFFECT: high ratio of heat transfer from plates of a thermoelectric battery to a heated flow without considerable increase of aerohydrodynamic resistance to its motion.
SUBSTANCE: flat tubes, heat exchangers of flat tubes and their manufacturing methods are described and illustrated. Flat tubes can be made from one, two or more fragments of sheets. A shaped insert that is non-detachable from the flat tube or made from other sheet can be used to form several passages through the flat tube. Flat tubes can be made from relatively thin material and can be reinforced by means of material bends of flat tube and/or insert in the areas subject to actions of higher pressures and temperatures. Besides, relatively thin material of flat tube can have a corrosive layer allowing the material to withstand the failure due to corrosion. Heat exchangers having such flat tubes connected to composite tubes are also described, as well as the methods, which can be provided for such tubes which can be equipped with fins.
EFFECT: easier manufacture and assembly of heat exchangers.
23 cl, 106 dwg
FIELD: heat exchanging facilities for use in different industries.
SUBSTANCE: invention is designed for use in heat exchanging devices, particularly those with two non-communicating flows of heat carriers with heat exchange through wall. Proposed heat exchanger consists of housing accommodating thin-walled hollow elements with clearances in between, hollow ribs opening into said clearances and passing through inner space of thin-walled hollow elements being made in form of hermetically sealed flat spaces arranged in tandem and interconnected by circular channels, and ribs are made so that in any two adjacent thin-walled hollow elements single rib in one of elements is arranged along axis of heat exchanger, and other element has several ribs arranged over periphery of thin-walled hollow elements.
EFFECT: intensification of heat exchange, reduced overall dimensions and mass of device.
2 cl, 2 dwg
FIELD: heat engineering; production of methods and the equipment for production of finned pipes of cooling apparatuses or containers.
SUBSTANCE: the invention is intended for application in heat engineering, in particular, at production of finned pipes of cooling apparatuses or containers used for storage of spent fuel of nuclear reactors, and also other materials or objects being the powerful heat sources. The method of production of a heat-exchanging pipe provides for introduction of a core and ribs inside a tubular billet. At that on the internal surface of the tubular billet and on the external surface of the core there are preliminary made hollow longitudinal grooves. The ribs produced separately from the core are made in the form of a strip consisting of two layers, joint among themselves on edges in longitudinal direction or in the form of hollow pipes of oval cross-section, which before installation in the grooves are deformed creating inside excessive pressure, then insert them in the grooves and relieve the pressure. At that the pressure is chosen so, that the relative change of the maximal overall dimension of each rib in transversal direction is equal to: δ≥δmin,
where δ is the value of the relative change of maximum overall dimensions of a rib in the transversal direction, δmin - minimum value of a relative change of the maximum overall dimensions of the rib in the transversal direction, at which assembly of a pipe and creation of elastic deformations in the ribs are ensured. The invention ensures efficient heat sink cooling in large-sized pipes with their internal ribbing and simultaneous simplification of production.
EFFECT: the invention ensures efficient heat sink cooling in large-sized pipes with their internal ribbing and simultaneous simplification of production.
FIELD: heat-exchange equipment.
SUBSTANCE: heat-exchange apparatus has supplying and removing collectors integrated by group of heat-exchange tubes having protrusions at their surfaces. Protrusions are made in form of sheets connected by their side surfaces with surface of tube along the length being equal to 1,5-3,0 thickness of sheets. Protrusions are disposed tangentially to surface of tube tat the points of connection of those sheets with tubes. Several sheets are fastened to tube along the perimeter of cross-section to overlap each other. Protrusions on surfaces of heat-exchange tubes are made in form of several sheets of different lengths being fastened along their side surfaces by welding or soldering along the whole length of surfaces of heat-exchange tubes. Protrusions in form of sheets fastened to surfaces of heat-exchange tubes can be also made to have slots and curves relatively sheets at adjacent, neighboring parts.
EFFECT: improved efficiency of heat exchange; provision of adjustment of heat flow.
7 cl, 12 dwg
FIELD: heat power engineering.
SUBSTANCE: method comprises setting the core and ribs into the piping blank. The core is hollow, and each of the ribs are made of a hollow body defined by the rotation of a figure composed of the straight sections interconnected to form a hexagon. After setting the ribs, they are subjected to the flexible deformation by bringing the sides of the rib together. The sides of the ribs are perpendicular to the axis of the pipe and point in the direction of the pipe axis.
EFFECT: enhanced efficiency.
FIELD: the invention is designed for application in the field of heat-and-power engineering namely in finned heat-exchanging tubes of a gas air cooling apparatus.
SUBSTANCE: the apparatus has the body of a heat exchanging tube and an exterior finning which form in the transverse cooling flow of the exterior heat exchanging environment plots of shading of various intensity in a conditioned flatness normal to the vector of the mentioned flow of the exterior heat exchanging environment and passing through the central longitudinal axle of the tube: complete aerodynamics shading corresponding to the square of projection on the referred flatness of the unit of the length of the actual body of the tube without taking the finning into consideration and incomplete aerodynamics shading corresponding to the total square of projections on the referred flatness of the plots of finning of the unit of the length of the finned tubes limited from each side with a conditional direct line tracing along the tops of the fins minus the square of complete shading produced by the body of the tube without taking the finning into consideration. At that the connection of the squares of projections on the referred flatness of the plots of shading of various intention to their sum forms correspondently (0,30-0,80): 1 and (0,21-0,79):1 and the medium value along the radius of finning of the specific square of aerodynamics shading on the plots of projection of finning on the referred flatness on the unit of the length of the tube composes 0,08-0,55.
EFFECT: allows to increase thermal aerodynamics characteristics of finned heat exchanging tubes and thermal effectiveness of the apparatus in the whole and also to decrease metal consuming and the dimension of the construction of the beam of heat exchanging tubes of the gas air cooling apparatus.
15 cl, 4 dwg
FIELD: heat-exchanging equipment, particularly for combustion engine radiators and for other heat-exchanging facilities using gaseous coolant.
SUBSTANCE: heat-exchanger comprises coolant pipes and cooling plates provided with corrugations and cuts. The pipes are formed of brass and copper corrugations extend in longitudinal direction. The corrugations are used as turbulence promoters and define channels for gaseous coolant circulation. The plates are formed of copper strip.
EFFECT: increased heat dissipation.
FIELD: heating engineering, particularly tubular air heater production.
SUBSTANCE: method involves bending metal strip to form tube and performing longitudinal welding thereof. Before strip folding identical depressions with predetermined geometrical parameters are formed on strip surface corresponding to inner tube surface. The strip edges adapted for following welding are free of above depressions. The depressions are formed by cold stamping along the full tube length.
EFFECT: increased manufacturability, possibility to produce tube of small diameter.
FIELD: mechanical engineering, particularly support metal structures used in air cooling plants.
SUBSTANCE: support structure comprises rod-like post members and cross-bars. The cross-bars form horizontal grid-like structure with three longitudinal and transversal belts creating support parts for heat-exchanging sections of gas air-cooling plant supporting. The grid-like structure also creates chambers for fans installation. The fans are mounted on support plates suspended by rigid braces forming four-disc three-dimensional system. The posts include posts of two kinds, namely intermediate and corner ones. Intermediate posts are flat V-shaped. Corner posts are three-dimensional and consist of vertical branches and two inclined branches adjoining lower part of vertical branch. The inclined branches are arranged in two mutually perpendicular planes. Intermediate post and corresponding parts of longitudinal belt form triangle so that distance between post branch ends corresponds to distance between adjacent support plates of chamber for fan installation. Angle between inclined and vertical branches of corner post is determined from a given relation.
EFFECT: reduced material consumption and labor inputs for support structure and support structure components erection.
8 cl, 3 dwg
FIELD: heating engineering.
SUBSTANCE: developed heat-exchange surface can be used in heat exchangers, steam and hot water boilers, and boilers-exhausts. Developed heat-exchange surface has heat-exchange surface and set of hollow rods disposed inside holes of heat-exchange surface. Edges of rods are plugged at the sides from where the heat is supplied. Set of hollow rods can be disposed along both sides of heat exchange surface or only at the side from where the heat is supplied. Heat-exchange surface has cylindrical or flat shape.
EFFECT: improved accrual of heat exchange.
7 cl, 12 dwg
FIELD: heat power engineering.
SUBSTANCE: invention can be used in thermoelectric plants and boiler rooms, at transportation and storage of materials whose viscosity depends on temperature. According to invention, proposed device contains pump, external heater, suction branch pipe, pressure pipeline and jet head, and guide member. Guide member is made of cylindrical, conical pipes or their combination, including telescopic pipes and is provided with blind, plate and separate baffles. Guide member is arranged in reservoir between its bottom and surface of fuel oil in reservoir.
EFFECT: increased area of fuel oil heating (in reservoir) to temperature not lower than required temperature without additional consumption of power.
5 cl, 7 dwg