Sectional heating radiator
FIELD: power industry.
SUBSTANCE: sectional heating radiator includes supply and discharge aluminium headers for heat carrier passage and aluminium tubular sections as heat sinks; the new feature is that external and internal surfaces of heat sinks, as well as internal surfaces of supply and discharge headers are provided with coating from aluminium oxide, which is applied by plasma chemical method; at that, coating thickness of external surfaces of heat sinks is 5…10 mcm, and that of internal surfaces of headers is 20…100 mcm.
EFFECT: increasing radiation coefficient, which allows reducing the surface area of radiators, reducing the number of sections or heat carrier flow rate, reducing corrosion and erosion wear and improving ornamentality without any additional coating.
The invention is intended for use in heating engineering, in particular in the sectional aluminum radiators for hot water Central heating residential, public and industrial buildings.
There are various designs of heat exchangers (radiators), connecting to the Central heating system, basic elements of which is a channel for passage of the heat carrier and heat-release surface. Heat exchange device may be performed, for example, in the form of a pipe located on the edges (see author's certificate 1461570, MCL421D 53/02). Its disadvantage is the low heat dissipation because the area of the heat-release surface of the partition is too small.
The closest technical solution is a sectional radiator home heating system, aluminum extruded profiles, containing inlet and outlet manifolds (see patent application EN 2008101572). The inner surface of the channels of the radiator for corrosion protection equipped with corrosion-resistant coating, and the outer heat-release surface of the radiator covered with powder paint. The disadvantage of the prototype is the low heat dissipation, associated with a low heat transfer coefficient of the material of the heat sink, and a small service life of the radiator, which is due to the lack of erosion the th protection of internal channels, which moves the coolant - water containing large amounts of chloride and other chemical compounds and mechanical impurities (sand).
The objective of the invention is to improve the heat transfer of the aluminum heat sink and increases service life by reducing erosive wear.
This object is achieved in that in the known radiator containing inlet and outlet aluminum reservoir for the passage of coolant and aluminum tubular sections as heatsinks, according to the invention the outer and inner surfaces of the heat sinks, as well as the inner surface of the inlet and outlet manifolds are made with a coating of aluminum oxide deposited by plasma-chemical method, and the thickness of the coating outer surfaces of the heat sinks is 5 to 10 μm, and the inner surfaces of the collector - 20...100 microns.
It is known that when heated bodies radiate energy. The amount of heat transferred by radiation becomes significant at higher temperatures or under conditions when the heat transfer by other means is difficult, in particular when the free convection (see Mukhachev GA, Shchukin VK Thermodynamics and heat transfer. - M.: Higher. HQ., 1991. - 480 C.). Radiation opaque bodies has a superficial character, i.e. the radiation energy of the particles in the surrounding environments, which gets only emitted a thin surface layer. Radiation is estimated surface density of the radiation flux that is, the body's Ability to radiate energy can be characterized by the degree of blackness of the body
where: ε is the degree of blackness;
E - flux density of the radiation of a real body;
E0the flux density of black-body radiation.
The degree of blackness depends on the nature of the body, temperature, surface roughness, and for metals from surface oxidation. Oxide film on the metal surface has a significant impact on its degree of blackness. The formation of oxides on the polished surface of the aluminum increases its degree black from 0.05 to 0.8, and more.
The emissivity of a real body is defined as:
where the Co - factor black-body radiation, (5,67 W/m2To4),
ε is the degree of blackness.
The authors tested (heat transfer) emissivity coatings of aluminum oxide having a different thickness. The aluminum surface of the heat sink on delivery have degree black ε=0,1. On the outer surface of the heat radiator inflicted oxide coating of different thickness. Measuring the degree of blackness was performed on thermogravimetry TRM-I. the Results of the measurements are presented in the table.
|No. of samples||1||2||3||4||5||6||7|
|The coating thickness, microns||3||5||10||15||20||25||30|
|The degree of blackness ε||0,30-0,75||0,84-0,85||0,82-0,84||0,79-0,81||0,71-0,75||0,67-0,70||0,55-0,60|
Experimental research has shown that when the thickness of the coating is from 5 to 10 μm, the heat sink surface has the highest degree of blackness 0,82-0,85 with variation across the sample surface is not more than 5%.
When the coating thickness is less than 5 μm, the degree of blackness has a large spread on the surface of the sample (up to 50%)due to uneven coating.
With the increase of coating thickness more than 10 μm, a decrease in the degree of blackness, due to the lower thermal conductivity of the coating, i.e. a decrease in the temperature of the surface is resti.
An example of a specific implementation.
Parts aluminum radiator aluminum alloy AD-1 (two manifold and tubular sections are immersed in different baths with alkaline aqueous electrolyte (Si2O3+KON) and treated under different technological regimes. The junction point of the collectors with tubular sections, and location of the alleged connection of the radiator with external pipes, inlet coolant, isolate the fluoropolymer film. To detail secures the electrode to which is supplied a positive voltage potential from installing plasma-chemical oxidation, and tub - negative. Oxidation leading to alternating current.
Coating on interior and exterior surfaces of the heat sinks heatsink thickness of 5 to 10 μm was carried out under the following conditions oxidation: the current density i=15A/DM2; the ratio of the cathodic and anodic component of the current Ik/Iaor =0.6; processing time t=20 minutes
A coating of aluminum oxide of a thickness of 20 to 100 μm on the inner surfaces of the reservoir to increase its hardness and, therefore, reduce erosive wear was formed when the current density i=25A/DM2, the ratio of the cathodic and anodic component of the current Ik/Ia=1, the processing time t=50 min Hardness collectors in this mode of application is 25 HPa, C is the account of the translation of the β-phase of Al 2O in α-phase.
In the operation of the radiator such hardness reduces its thickness due to erosion wear of not more than 5 μm in the year (depreciation collector without covering up to 0.5 mm per year).
After coating, washing and Stripping of the joints, parts arrive at the Assembly.
Sectional heating radiator made of aluminium alloy with a coating of aluminum oxide surfaces of the heat sinks with a thickness of 5 to 10 μm has a degree of blackness, increased to 0.85, which reduces the area of the radiators-radiators, i.e. to reduce the number of sections or reduce the coolant flow. The oxide coating of the inner surfaces of the collectors reliably protects the radiator from the erosive wear in a long time.
This radiator does not require additional decorative coating outer surfaces, so as aluminum oxide performs this function.
Sectional radiator, containing inlet and outlet aluminum reservoir for the passage of coolant and aluminum tubular sections as heatsinks, characterized in that the outer and inner surfaces of the heat sinks, as well as the inner surface of the inlet and outlet manifolds are made with a coating of aluminum oxide deposited by plasma-chemical method, and the thickness of the p the closure of the outer surfaces of the heat sinks is 5-10 microns, and the inner surfaces of the collectors of 20-100 μm.
FIELD: power industry.
SUBSTANCE: plated element for heat exchanger includes core material and one or more layers of side material laminated on one of its sides or both of its sides. Multiple small grooves (B) which are periodic and arc-shaped in longitudinal direction of side material are formed on surface of side material (A). Grooves are spread to external peripheral edge of side material and have curvature radius of 800-1500 mm and period (D) of 1-8 mm in the above direction. Roughness of surface of side material (A) comprises 1-15 mcm as per the average at 10 roughness points (Rz). Side material is made by cutting the ingot into material of the specified thickness and alignment in horizontal position with longitudinal direction of the cut material. Centre of rotating disc device corresponds to ingot centre as to width. Occurrence of bad adhesion between material of core and side material is prevented due to controlling the state of surface and flatness of side material.
EFFECT: improving corrosion resistance of plated element and increasing the heat exchanger obtaining process efficiency.
8 cl, 7 dwg, 1 tbl, 14 ex
FIELD: heat exchange.
SUBSTANCE: cylindrical cooler comprises solid radiator made of an alloy with shape memory effect. The radiator is shaped into a cylinder. The cylinder is preliminary rolled with respect to the axis of rotation in the thermoplastic region by an angle close to the limit one. At a critical temperature, the cylinder is unrolled. The cylindrical shape of the radiator is recovered under the action of thermoelastic force. When the temperature of the cylinder exceeds the critical temperature, the cylinder cools and absorbs the excess of heat.
EFFECT: enhanced efficiency.
SUBSTANCE: invention refers to heat exchangers and can be used in such industries as metallurgy, machine industry and processing of agricultural products. There proposed is method for manufacturing heat-retaining element with coating from high-radiating material at least on one of the surfaces of the main part of the element, which consists in the surface treatment with liquid representing water solution containing high-temperature binding substance and polyamine hardener or silicate of alkali element, and application by plastering, sputtering or dipping to the above pre-treated surfaces of the coating made from material the thermal emissivity of which in far-infrared region is higher than that of material from which the main part of the element is made. At that, the above coating material is applied in a layer 0.02 to 3 mm thick. There also proposed is heat-retaining element with coating from high-radiating material, which is made as per the described method; at that, material from which the main part of element is made is chosen form the group including refractory material, ceramic material, iron or steel; cross section of element can be round, square, rectangular, rhomb-shaped, hexagonal or multangular, and the element itself can be made in the form of honeycomb, tube with rectangular cross section, ball, ellipsoid or plate, with one or several inner holes, and cross section of the above holes can be round, square, rectangular, rhomb-shaped, hexagonal or multangular.
EFFECT: heat-retaining element contributes to increase of heat exchange function and thus to energy saving.
7 cl, 7 dwg
FIELD: power industry.
SUBSTANCE: electric air heater includes housing with inlet and outlet holes, inlet and support tube sheets in which there longitudinally installed are tubular heating elements which are equipped with current leads, and current leads and connecting straps fixed on the side of inlet hole in tube sheet and passing with a gap through electrically-insulating assemblies of support sheets. Exit sections of heating elements are equipped with converging diaphragms, and current connecting straps consisting at least of three pieces are made in the form of expansion loop and rigidly installed on ends of heating elements, between which drain holes are made; at that, expansion joints are bent towards exit section.
EFFECT: decrease in temperature of each plate of connecting strap, reduction of pressure pulsation and the appropriate structural vibrations leads to decrease in racking alternate loads on them, increases service life of connecting straps, electrically insulating sleeves, tubular heating elements and the whole electric heater.
FIELD: power industry.
SUBSTANCE: heat generator includes a housing with heated air inlet and outlet holes and nozzle of fuel combustion device, tubular flue gas channel arranged inside the housing and made in the form of heat exchange tubes equipped on the outside with profiled screens and attached to each other by caps, and convective heat exchanger with installed heat exchange elements, gas distributing heads and a stack; at that, convective heat exchanger is two-pass; flue gas duct, the first and the second pass of convective heat exchanger is located in series along heat generator housing; upper distribution head of the first pass is connected to the last heat exchange tube in the direction of flue gases; separately located upper distribution head of the second pass is connected to the stack; lower distribution head which is common for both passes is provided with a condensate discharge nozzle, and nozzle of fuel combustion device, the first heat exchange tube in flue gas direction and a return bend adjacent to it are provided with flanges.
EFFECT: improving heat engineering and hydrodynamic properties, increasing efficiency coefficient of heat generator.
9 cl, 3 dwg
SUBSTANCE: inventions are intended for being used in heating equipment, and namely in heating radiators-convectors for water central heating systems and attachment methods of register tube in the hole of tubular header. Heating radiator-convector includes upper and lower tubular headers made of aluminium profile, connected with a number of vertical aluminium fin tubes of register by means of short tubular elements tightly sealed on one side by means of press fitting in register tubes, and on the other side - in holes of header by means of a sealing element located between the end of tubular element protruding to the header cavity and its inlet to header hole; at that, each tubular element is made in the form of a branch pipe having taper and cylindrical parts, on external surfaces of which there is at least one annular groove; at the point where cylindrical part is changed into taper one, there is a flange located between register tube edge and header, and sealing element is made in the form of inlet hole of an adapter sleeve pressed in the edge of inlet header hole and conjugated with annular flat surface of flange and cylindrical surface of branch pipe, the protruding end of which is flared by means of access on the side of taper part of branch pipe. Besides upper and lower headers at the attachment points of branch pipes have longitudinal flat sections the thickness of which is more than thickness of round walls, and finning of each aluminium register tube is made in the form of longitudinal radial plates located symmetrically relative to the tube axis, and front and rear planes of finning comprise at least with two plates adjacent to them the closed air channels interconnected with atmosphere at the level of upper and lower headers. Attachment method of register tube in the hole of tubular header of heating radiator-convector, which is implemented by means of intermediate element having taper surfaces with inverse taper by leading the end of intermediate element inside the header and its elastoplastic release; at that, intermediate element is made in the form of a branch pipe having taper and cylindrical parts; internal channel of branch pipe in the zone where its end is led into the header cavity is abruptly converging; plastic release is made by pushing the working puncheon via internal channel of branch pipe on the side of its taper part till the puncheon falls to the header cavity, and removal of working puncheon from the header cavity is performed by emptying.
EFFECT: inventions allow increasing strength of radiator-convector, simplifying manufacturing and assembly method thereof, increasing processibility and intensification of heat transfer.
9 cl, 7 dwg
SUBSTANCE: invention related to heat and power industry, particularly automated gas heaters and can be used primary for heating of gas and liquid hydrocarbon products transported with pipelines. Heater contains a case with horizontal connector. Firing volume in the case separated with a air valve liner, connected with recuperative air heater, located over the case, under fixed on it exhaust pipe, inlet and outlet collectors and a heat exchanger, burners, connected with a bending, a bottom plate with a fitting for water stem condensate discharge. The binding inlet fitting connected to heat exchanger outlet collector. Burners located over the bottom plate, and burner holes axis for fuel-air mixture discharge directed to the bottom plate. The inlet and outlet collectors and the heat exchanger executed as a horizontal heated pipeline, locate coaxial to the case horizontal connector. Burners located in the detachable case top part on entrance length of liners dislocation, in line to the heated pipeline.
EFFECT: efficiency and reliability increase, also consumption decrease in a heater manufacture process.
2 cl, 6 dwg
FIELD: mechanics, heating.
SUBSTANCE: proposed convector incorporates a heat exchanger with a pipe accommodating heat exchange plates attached thereto. The heat exchange pipe upper arm end part frontal projection features L-shape, while that of the pipe lower arm end can be either L-shape or rectilinear. The convector side wall features two recesses arranged one above the other. The casing depth s-to-casing height h can make either s/h=0.35 to 0.45 or s/h=0.2 to 0.3. the q-to-h ratio, that is the distance between the upper and lower pipe end hole axes-to-casing height ratio, can make either q/h=1.1 to 1.4 or q/h=0.75 to 0.95. The heat exchanger pipe upper and lower arms can be rectilinear. The aforesaid side wall recess can be elongated both upward and downward. The proposed heat exchanger can incorporate one heat exchange unit, or two parallel heat exchange units arranged one above the other. Note that the proposed heat exchange can also incorporate the upper and lower heat exchange units and, at least two intermediate heat exchange units. The convector casing is made from one-piece work part furnished with the top angular openings between the upper and side walls. Every aforesaid opening accommodates an angular fastener covering it, every side wall being furnished with ledges facing the upper wall, while every fastener inside part is provided with the first and second retainers. The aforesaid angular fastener is furnished with a lengthwise grove to receive the convector casing upper wall end face, the said groove being arranged between the second retainers and the lengthwise edge of the angular fastener one side. The angular fastener second lengthwise edge is provided with a shoulder. Note that a slit is arranged between the aforesaid ledge and each first retainer to receive the wall end face of the casing side wall connected with the casing upper wall. Note that the aforesaid slit is arranged at an angle to the aforesaid shoulder corresponding to that between the connected casing walls and that the second retainers are provided with beards to get engaged with the casing side wall. The proposed method of producing the aforesaid casing incorporates cutting one blank from a metal sheet, cutting air release holes in the aforesaid blank, nearby the upper wall, shaping the casing front and upper walls by bending. At least, one side of the said blank is furnished with angular openings. The side walls are bent to form openings between adjacent end faces of the upper wall and the side walls. Now, the upper wall is rigidly coupled with the side walls and the aforesaid openings are covered with the casing angular fasteners.
EFFECT: expanded performances of convectors, lower labour input in producing them.
17 cl, 58 dwg
FIELD: the invention is designed for using in heating technique namely in central heating systems of residential constructions and civic buildings.
SUBSTANCE: the heating appliances for central heating systems consists of sections formed by tubular heat-release elements for heat-carrying agent and finning. At that the sections are additionally provided with front low-temperature prefabricated screen-contours with vertical through channels, the middle, the low and the upper and correspondingly the rear convection contours with finning, generators and air humidifiers and the tubular heat-release elements are connected with radially located plate fulfilled in crossed form on which the middle, the low and the upper prefabricated screen-contours are fixed and correspondingly the rear convection contours. At that the generators are located in external connections between sections and the air humidifiers are located in the vertical through channels of the upper low-temperature screen-contour. At that the marginal section is provided with a socket.
EFFECT: simplifies the construction of heating appliances, increases intensification of heat exchange, improves adaptability to manufacture and operational hygienic indices of heating systems.
FIELD: fluid heaters.
SUBSTANCE: heater comprises housing made of base and heat insulating wall provided with a burner, heat exchanging module made of axially aligned inner and outer pipes with plug from the side of the burner, combustion passage, inlet and outlet collectors, and chimney. The heat exchanging module has baffles interposed between the inner and outer pipes from both sides of the plug. The baffles form passages for the flow of fluid to be heated. The passages are interconnected. The combustion passage is mounted inside the heat exchanging module. The air duct is defined by the space between the heat exchanging module and heat insulating wall. The valve is mounted from the side of the burner and made for permitting rotation around its axis. The inlet and outlet collectors are connected with the passages of the heat exchanging module from the side of the burner. The passages for fluid to be heated can be in communication through both the opening in the baffles and through additional heat exchanging members mounted in the space of the inner pipe of the heat exchanging module. The outer side of the inner pipe of the heat exchanger is stiffened. The sides of the housing and additional heat exchanging members can be detachable.
EFFECT: enhanced efficiency.
7 cl, 5 dwg