Double-pipe heat exchanger
SUBSTANCE: double-pipe heat exchanger, in the internal pipe and in inter-pipe space of which screw inserts are installed. Inner space of the internal pipe and inter-pipe space between internal and external pipes represent screw cavities formed with walls of pipes and screw inserts. Screw inserts are installed so that an internal screw insert is connected mainly by welding or soldering to inner surface of the internal pipe. Screw insert in inter-pipe space is connected in the same manner to outer surface of the internal pipe and to inner surface of the external pipe. Materials of the internal pipe, screw inserts and points of joints of screw inserts with walls of the internal pipe shall have minimum thermal resistance. Flows of liquid or gaseous media in the internal pipe and in inter-pipe space flow along helical spirals.
EFFECT: invention allows shortening the length of double-pipe heat exchangers up to ten times and more and reducing the weight and overall dimensions of a heat exchanger.
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, is placed inside another larger diameter annular gap, called the annular space. The inner tube is pumped media (liquid or gaseous) for example, a higher temperature (hot), and the annular space environment with a lower temperature (cold). Thus the wall of the inner tube is heated and transfers heat to the cold environment, which thus temperature increases. 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.
The efficiency of heat transfer, in addition, depends on the degree of turbulence in the flow and viscosity of the media, the efficiency increases with increasing turbulence and reduce the viscosity.
If for specific environments to take the same initial temperature and therefore viscosity, and the diameters of the pipes, the only way to increase the efficiency of heat transfer between them will increase turbulence, Kataragama smooth pipes can only be achieved by increasing the speed of the media.
Improving the efficiency of heat transfer can reduce the required heat transfer area, to reduce the length of the heat exchanger, other dimensions and mass. But higher speed environments in pipes requires increasing the capacity of the pumps, which pump these fluids. If we consider that increasing the turbulence is proportional to the speed environment and the required capacity of the pump to the square of velocity, it is obvious that the increase of velocity environments has a certain limit, after which further increase in speed becomes unprofitable.
Therefore, strive to increase the turbulization due to installation in the inner tube and in the annular space of different types turbulized elements.
For example, the known heat exchangers "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 in turbulence with the growth of hydraulic resistance.
Also known heat exchangers, the inner tube which is installed, for example, by welding, 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 environment annulus, i.e. increase the efficiency of heat transfer.
The drawbacks of such heat exchangers are the following:
- not the whole environment in the annular cavity engages in a helical movement is part of it flows through the annular gap between the spiral ribs and the outer pipe;
- increase the fluid velocity, turbulence occurs only at a few percent, at least several tens of percent, since the elevation angle of helical ribs small, and with increasing elevation angle of the hydraulic resistance increases much faster growth of turbulence and increasing the amount of medium begins to flow through the annular gap;
- the heat transfer from the environment into the inner tube to its wall remains relatively low, as it determines the efficiency of heat transfer in General.
A known heat exchanger "pipe in pipe" patent # SU 1222207. In the 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 spiral line, significantly increases the turbulization of the environment in the inner pipe and the heat transfer from the environment to the wall.
The specified heat exchanger is adopted for the prototype.
However, he is pursuing the disadvantages:
- not all of the medium in the inner tube engages in a helical movement (only approximately 20-30%), which does not allow to reach the highest possible level of turbulence in the environment;
- large contact thermal resistance of the turbulent insert with the inner surface of the pipe (the turbulent insert touches the inner surface of the pipe only at certain points, and, by a simple pressing of it due to elastic forces. But such pressure is not quite securely and at any time may weaken i.e. thermal resistance of the contact area will increase and may become unacceptably large).
- large contact thermal resistance deprives the turbulent insert its essential function is to transfer heat from it to the wall of the inner tube due to the heat, (which is equivalent to increase the heat exchange surface of the inner pipe).
The aim of the present invention is more significant increase in the coefficient of heat transfer is not by tens of percent, and several times that, in turn, will allow the same time to reduce the length of the heat exchanger and, therefore, also in times to reduce its dimensions and weight, although to a lesser extent than the decrease in length.
Proposed by the present invention a heat exchanger tube in tube" differs from the prototype in that the internal issue is ransta inner pipe and the annulus between the inner and outer tubes are helical cavity, formed by the walls of pipes and screw inserts that are installed inside the inner tube and the inside of the annulus so that the internal screw insert is connected, particularly by means of welding or soldering, to the inner surface of the inner pipe, and screw the insert in the annular space is connected in the same manner with the outer surface of the inner pipe and the inner surface of the outer pipe, and the material of the inner pipe, screw inserts and joints screw inserts with the inner wall of the pipe must have a minimum thermal resistance.
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.
Figure 1: 1 - inner tube; 2 - outer tube; 3 - screw inserted into the inner tube; 4 - screw insert in the annular space; 5 - screw cavity in the inner pipe; 6 - screw cavity in the annular space; B - input medium in the inner tube; the output environment of the inner tube; D - input environment annulus; D - output environment of the annulus.
Figure 2: E - screw motion of the medium in the inner tube; W - helical flow in the annular space.
Has a heat exchanger as follows: in intova the cavity POS.1 comes hot environment and immediately acquires a helical movement, for example, clockwise. When moving environment washes the surface of the screw insert 3 and the inner surface of the pipe position 1 and transmits them warm. At the same time heat to the inner surface of the pipe item 1 is transferred by conduction through the screw insertion 3.
The efficiency of heat transfer from the fluid in the pipe position 1 to its wall in a first approximation proportional to the criterion of Reynolds (Re), and that, in turn, is proportional to the fluid velocity relative to the wall ceteris paribus. If the internal pipe set screw insert, the velocity of the medium inside it will be equal to the speed thereof at the entrance to the tube (i.e. in the direction of arrow B, figure 1) and the environment path is equal to the length taken of the pipe segment.
When installed, the insert, and when her step screw surface is equal to, for example, the inner diameter of the pipe POS.1 environment path relative to the wall is increased to 3.14 times. But to the whole environment, coming into the screw cavity POS.1 managed to pass this section of the pipe, the speed should increase also in 3.14 times. Proportionately increases the Reynolds criterion and, therefore, also proportional to and the heat transfer coefficient.
Thus, the coefficient of heat transfer from the fluid to the wall increases at least 3.14 times. In fact, the increase will be more, since when is the valuation were not taken into account two significant factors, to increase the heat transfer coefficient:
a) turbulization of the boundary layer at the inner wall of the pipe;
b) the heat transfer to the inner wall due to the heat coil insert.
To assess the degree of influence of these factors on the heat transfer coefficient increase is not exactly possible, but roughly this is 40-80%.
But, even without these two factors, the increase in heat transfer coefficient is very impressive. Moreover, it may increase several times. This should only reduce step screw insertion into the inner tube. For example, decreasing this step three times, about the same time will increase accordingly the velocity of the medium relative to the inner wall of the inner pipe, the Reynolds criterion and the overall heat transfer coefficient.
A similar pattern is observed in the annular space. I.e. with the set screw insert, depending on the internal diameter of the outer pipe and the pitch of the helical insert it increases the heat transfer coefficient from the wall of the inner pipe to the outside environment about the same time and from the environment in the inner pipe to the wall.
The use of the invention allows to intensify the heat transfer due to both improve hydrodynamic flow patterns and increase laptop is of waist environment, and due to the factor of the development of heat-exchange surface. This entails reducing the required length of the heat exchangers type "pipe" to ten or more times and a corresponding reduction in the mass and dimensions of the heat exchangers.
The heat exchanger pipe, the inner pipe and the annular space which has a screw insert, characterized in that the inner space of the inner pipe and the annulus between the inner and outer tubes are helical cavity formed by the walls of pipes and screw inserts installed in such a way that the inner coil insert is connected, particularly by means of welding or soldering, to the inner surface of the inner pipe, screw the insert in the annular space is connected in the same manner with the outer surface of the inner pipe and the inner surface of the outer pipe, and the material of the inner pipe, screw inserts and seats joints screw inserts with the inner wall of the pipe must have a minimum thermal resistance, the flow of fluids (liquid or gaseous) in the inner tube and in the annular space flow along the helical spirals.
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.
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.
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