RU145536U1 - AIR COOLING UNIT TYPE ABOOV - Google Patents

Abstract

1. An air cooling apparatus comprising at least a heat exchange section provided with heat exchange surfaces made of finned carrier tubes, with distributing and collecting manifolds adjacent to them for the cooled product, and an associated fan unit for supplying a cooling medium to the heat exchange surface characterized in that the heat exchange surfaces are made of finned flat oval or elliptical bearing tubes fixed in tube sheets installed in the distributing and collecting manifold ah.2. The apparatus according to claim 1, characterized in that the tube sheet is provided with a steel tube plate with holes repeating the external contour of the supporting tubes fixed therein. 3. The apparatus according to any one of paragraphs. 1 or 2, characterized in that the outer fins of the supporting pipes contain transverse plate fins with a closed outer and inner contour. 4. The apparatus according to claim 3, characterized in that the total height of the ribs of the supporting pipes is constant. The apparatus according to claim 3, characterized in that the external contour of the ribs repeats the outline of the cross section of the supporting pipe. 6. The apparatus according to claim 3, characterized in that the supporting pipe is made bimetallic. 7. The apparatus according to claim 1, characterized in that the heat exchange section and the fan unit are combined into a monoblock supporting metal frame structure. The apparatus according to claim 7, characterized in that the heat exchange section is removable.

Description

Purpose and scope

The utility model relates to the field of heat power engineering, namely to air cooling devices and can be applied in power engineering, chemical, oil and gas processing and other industries. The utility model can be used to create new designs.

State of the art

A horizontal air cooler of the discharge or suction type is known, consisting of separately mounted on a modular frame with racks of heat exchange and air distribution parts, respectively including a bundle of pipes with distribution chambers installed on the supporting elements of the vertical load-bearing walls, one of which is floating, and drive fans with air distribution boxes, in which the heat exchange part of the apparatus is equipped with counterbalance-compensators ver bending loads, while its supports are made in the form of frame power elements located along the length of the tube bundle, rigidly fixed to the supporting elements in the transport position and rigidly fixed at one end to allow longitudinal movements relative to the supporting elements of the remaining part of the tube bundle from the side of the floating chamber from its temperature deformations in the working position (patent for the invention of the Russian Federation No. 2087822).

Devices of this type are convenient to maintain, but bulky and occupy large areas, are characterized by increased metal consumption, are ineffective and consume a lot of energy.

For intensification of heat transfer processes in heat exchangers, for example, developed surfaces, including finned heat transfer tubes, are used.

From publications of patents for utility models of the Russian Federation No. 66801 and 66494, solutions are known for monoblock and block-modular designs of air-cooling units, consisting of fully prefabricated modules, including a cooling surface in the form of a heat-exchange section, which is a tube bundle assembled from mainly finned bearing pipes of circular cross section and having input and output chambers containing tube sheets, in which, mainly by welding, pipes with a slope in their axial direction are attached. One of the chambers is made floating and from the side of which the beam is installed with the possibility of longitudinal movement with its thermal elongation. The design of the tube bundle is selected depending on the parameters and type of product being cooled. The intensification of heat transfer in the apparatus is ensured by reducing the aerodynamic drag of the flow part of its fan unit (s) by optimizing its geometry.

Among the shortcomings of the above solutions of air-cooling units are cumbersome and difficult to manufacture, due to increased requirements for the design of the tube bundle depending on the parameters of the refrigerated product, as well as the insufficient thermal efficiency of the equipment, due to the design of the supporting pipe.

The closest adopted for the prototype, in terms of the essential features, to the claimed solution of the utility model include the design of an air gas cooling apparatus known from the publication of the patent for the invention of the Russian Federation No. 2283989, characterized in that the gas air cooling apparatus contains at least a horizontally located section heat exchange provided with heat exchange surfaces formed by finned carrier tubes, with distributing and collecting manifolds adjacent to them for the cooled the product, and the associated fan unit for supplying a cooling medium to the heat exchange surface, and at the same time, includes a multi-row bundle of finned, supporting tubes of circular cross section, containing rows of supporting tubes (bundle) with different finning coefficients. At least two adjacent, the first along the annular medium and following it, rows of pipes are made with finning coefficients of a smaller value than the finning coefficients of a part of the rows of bundle pipes that follow along the annular medium, and at least part of the bundle tubes, or at least one of its rows is made with a variable finning coefficient along the length of the pipe. The disadvantages of this solution include the bulkiness of the structure, the difficulty in manufacturing and limited thermal efficiency. The large length of the pipes, as well as the large dimensions and weight of the apparatus as a whole lead to a large consumption of material. At the same time, the relatively high power consumption of the fan drive is caused by the high aerodynamic resistance of the air when it moves through a bundle of heat exchange tubes according to the above design. In addition, the cooling air has an uneven velocity field, which does not allow the efficient use of the entire heat exchange surface.

At the same time, the disadvantage of all known air-cooling units (ABO) with a finned round tube is the need for spatial separation (position fixation) in a large number of places to prevent tube deflection, the intermediate supports should be located at a distance of no more than 1.8 m from each other, and this accordingly leads to an increase in the mass of the equipment, its dimensions and the complexity of the assembly.

Utility Model Essence

The technical task of the claimed technical solution is to offer an easy-to-operate and assembly design, preferably a modular block design, ABO with low power consumption and high heat efficiency.

The technical result achieved by this utility model is to increase the heat and aerodynamic characteristics of an air-cooling apparatus, increase the area of the heat-exchange surface of the apparatus, reduce energy consumption, increase the rigidity of the structure and the reliability of the apparatus.

The claimed technical result is achieved by using an air cooling apparatus comprising at least a horizontally located heat exchange section, provided with heat exchange surfaces made of finned carrier tubes, with distributing and collecting manifolds adjacent to them for the cooled product, and a fan a unit for supplying a cooling medium to the heat exchange surface, characterized in that the prototype in that the heat exchange surfaces are made of flat oval or ellipse iCal finned supporting tubes fixed to tube sheets installed in the collecting and distributing as collectors.

The tube sheet can be equipped with a steel tube plate with holes repeating the external contour of the heat exchange tubes fixed in them.

The outer fins of the supporting tubes may preferably comprise transverse plate ribs with a closed outer and inner contour. Moreover, the total height of the ribs of the supporting pipes is preferably constant, and the outer contour of the ribs follows the outline of the cross section of the supporting pipe.

In one embodiment of the utility model, the support tube may be bimetallic.

The supporting metal structure ABO is mainly made of carbon steel, in the form of a parallelepiped of a block structure or can be assembled from profile elements (channels, I-beams, box-shaped profiles, corners, sheets, etc.).

The choice of the design of additional devices, such as an air heater, humidifier, and louvre devices, is usually based on the requirements for the temperature regime maintained in ABO during operation.

Other ABO characteristics are usually selected in accordance with the regulatory characteristics established, for example, GOST Ρ 51364-99 “Air-cooled devices” and ISO 13706-2006 “Air-cooled devices”).

Brief Description of the Drawings

The utility model is illustrated by drawings, where:

FIG. 1 - air cooling apparatus with flat oval or elliptical finned heat exchange tubes with an oval-shaped carrier (type ABOOB), where, a) a cross-section, b) a longitudinal section;

FIG. 2 - Heat transfer tube, where a) side view, b) longitudinal section cutout

FIG. 3 - Cross-section of a heat exchange tube with an oval-shaped carrier, where a) with a flat-oval carrier, b) with an elliptical carrier pipe:

It should be noted that the accompanying drawings illustrate only one of the most preferred embodiments of the utility model and cannot be considered as limitations on the content of the utility model, which includes other embodiments.

Utility Model Feasibility

As shown in FIG. 1-3 drawings, ABO, according to a utility model, contains a housing 1, made mainly of carbon steel, in the form of a parallelepiped of block construction or assembled from profile elements (channels, I-beams, box-shaped profiles, corners, sheets, etc.), in the internal volume which, in its upper part, there is a heat exchange section 2 with a heat exchange surface 3 made of plane-oval or elliptical finned heat-exchange supporting tubes 5, with adjacent pipes of distributing and collecting headers (in the drawing ah not shown) for the product. The design of the heat exchange surface is selected depending on the parameters and type of product being cooled according to the results of thermohydraulic calculations. ABO is equipped with at least one fan 4, for supplying to the heat exchange surfaces 3 of a cooling medium (mainly atmospheric air). Based on practical application, the maximum number of fans in the ABO design, as a rule, does not exceed six, however, their number is determined taking into account the required operational characteristics of ABO and operating conditions. The fans 4 are equipped with an AC electric drive (not shown in the drawings) with the possibility of starting and shutting down, as well as changing the rotation speed depending on operating conditions, for example, when the ambient temperature changes below or above the threshold value and / or the temperature indices of the cooled medium deviate from preset thresholds.

In accordance with the drawings shown in FIG. 1-3, the heat exchange pipe is a finned, namely, transversely finned, pipe containing a carrier pipe 5 with ribbing on the outer surface, consisting of flat transverse ribs 6 with a closed external and internal circuit, repeating the outline of the cross section of the carrier pipe 5. The ribs 6 are evenly distributed in the longitudinal direction with the formation of a gap 7 between adjacent ribs. The height of the rib is selected depending on thermal calculations, taking into account the required operational characteristics of the structure. In practice, the choice of rib height in the range from 5 mm to 17 mm and rib thickness from 0.35 mm to 0.9 mm is most preferred. Moreover, within the design, the selected rib height is constant.

The cross section of the carrier pipe is close to oval in shape, moreover, in the solution shown in FIG. 3a) the support pipe is made with a plano-oval cross-sectional contour, and in FIG. 3b) - with an elliptical contour of the cross section. ABO heat exchange sections with an oval-shaped support pipe (ABOOB type), in this case, with a flat-oval or elliptical support pipe, have a high degree of heat transfer surface development due to the elongated shape of the support pipe. And the use of finned tubes in the design, according to the utility model, on the one hand enhances the degree of development of the heat exchange surface due to the ribs, and on the other hand, it allows to increase the heat transfer rate and is an additional factor in increasing heat transfer efficiency, improving weight and size characteristics, ABO solutions according to the utility model .

For example, when calculating the surface area of the apparatus F, m indirectly by the formula:

where

D is the measured outer diameter of the finned tube, m;

H - measured rib height, m;

Sp is the measured thickness of the ribs at the apex, m;

S0 is the measured distance between the ribs, m;

L is the measured length of the finned part of the pipe, m;

t is the actual linear number of edges, pcs .;

π is the actual number of pipes in the apparatus, excluding plugged ones, pcs.

with a pipe length of 8 m and a finning coefficient of 20, the surface area of a typical air-cooling apparatus with 267 pipes, 25 mm in diameter is 3477.4 m ² , whereas in case of use, the replacement ABO according to the utility model, for carriers pipes with a flat oval cross-section of 25 × 45 mm with a reduced number of pipes - 207 pcs., the surface area is already 4802.4 m, which is 38% more and provides a significant advantage from the point of view of increasing the efficiency of the heat exchange process of finned tubes with a flat-coiled pipe carrier oh, in comparison with traditional circular tubes. Obviously, for a carrier pipe with an elliptical cross-section, the surface area of the finned tube will be close to the above calculated values for a carrier pipe with a flat oval cross-section.

Additionally, in the process of condensation of products, the apparatus, according to a utility model, is more efficient and preferable from the point of view of an increased internal contact surface and distribution of the vapor-liquid mixture inside the pipe, because the process of condensation of the product occurs to a greater extent in the wall areas, and the inner perimeter of a flat oval or elliptical pipe is larger than a round one. Moreover, during condensation in a flat oval and elliptical pipe, the formed liquid layer overlaps the inner surface of the pipe to a lesser extent than in round ones, allowing the product then condense over large areas, preventing the liquid film from evaporating and forming a “dry wall”. A comparison of the perimeters of a typical air-cooled apparatus with a round finned tube and an apparatus according to a utility model with a flat oval tube based on the above example of calculating the surface area of the apparatus F shows: the total perimeter of the contact of the product with the pipe wall 2 mm thick in a typical apparatus is 140.915 m, while the replacement according to the utility model, his apparatus is 177.142 m, which is 25% more.

At the same time, according to the utility model, ABO, due to the use of a flat oval or elliptical shape of both the supporting pipes and the external fins, has low aerodynamic resistance to the air flow of cooling air, due to the reduction (narrowing) of the size along the pipe width and, as a consequence, the reduction of the surface resistance in the transverse direction, and, accordingly, and reduce the power spent on purging the coolant. This allows you to achieve at least 20-30% of energy saving indicators during operation of air-cooling units according to the utility model.

So, when calculating the performance indicators of air-cooled apparatuses using finned tubes with a circular supporting tube with an outer diameter of 25 mm and ABO according to a utility model using finned tubes of elliptical cross-section, with dimensions of 16 mm and 30 mm, and with ribs of the same configuration , the rated fan power in the first case amounted to 5.8 kW, and in the case of a supporting tube according to the utility model - 4.1 kW, which indicates a significant reduction in the power consumption of the structure and increased its energy efficiency. It is also obvious that by increasing the energy efficiency of the structure, in order to achieve the design capacity of the air-cooling apparatus, a smaller number of finned tubes with a flat-oval and elliptical bearing tube will be required, which allows the production of compact designs of air-cooling apparatus based on them and helps to reduce the material consumption of the structure.

As finned heat transfer pipes, bimetallic pipes (carrier pipe - steel, fins - aluminum), as well as pipes made of aluminum, or other finned tubes known from the prior art applicable in the specified equipment in this technical field can be used. The use of the above materials allows to reduce the material consumption of heat transfer sections and contributes to the creation of compact solutions with high heat transfer efficiency. Depending on the operating conditions of the heat exchanger pipe and the cooled medium flowing inside its carrier pipe, the material design of the heat exchanger pipe may vary.

Preferably, the finned tubes are fixed in the tube sheets by flaring at least one groove, and can also be further fixed in the tube sheets by welding.

According to a utility model, ABO can be manufactured and used both with an internal air recirculation system, which allows to further substantially reduce the dimensions of the ABO casing in width, for example, from 4.5 m to 3 m due to its placement in the existing ABO casing, and with an external air recirculation system most widely used in industry.

The heat exchange section and the fan unit are preferably combined into a monoblock by a supporting metal frame structure. At the same time, the heat exchange section is removable and may contain the number of rows of finned carrier pipes ranging from 1 to 10 with their length L from 3 m to 16 ms by the number of strokes in the pipe space from 1 to 40. The number and geometry of the placement of heat exchange pipes is selected in depending on the parameters and type of refrigerated product according to the results of thermohydraulic calculations.

The air cooling apparatus, according to the presented utility model, works as follows:

The cooled product (liquid, gas, steam or mixtures thereof) is supplied through the pipe of the distributing collector to the pipe space of the heat exchange surface and flows through finned flat oval or elliptical pipes fixed by flaring, with the formation of a bundle of finned heat transfer pipes, in the pipe grids of the manifolds of the manifolds. When a cooling coolant (air) is supplied to a bundle of finned heat-exchange pipes, through which a cooled product is transported under pressure (the product is supplied to the system by pumps), the tube bundle flows around the air and contact heat exchange with cooling of the product.

At the same time, ABOOV has a number of advantages, and due to the use of plane-oval or elliptical finned supporting tubes according to the utility model, the following is achieved:

- a 10-30% reduction in the power consumption of the fans required for pumping cooling air by improving the aerodynamic conditions around the finned heat-exchange tubes flowing around the beam with cooling coolant;

- reducing the dimensions of the apparatus, by increasing the total area of the heat exchange surface of the beam, using the shape of the ribbed carrier pipes according to the utility model and the possibility of a more dense placement of pipes in the beam, respectively;

- reducing the mass of the apparatus and the complexity of its assembly, due to the absence of the need for spatial separation (position fixation) of heat exchange tubes of a flat oval or elliptical shape, as well as materials used in the construction.

According to the utility model, ABO is easy to manufacture, has increased heat and aerodynamic characteristics, increased heat exchange surface area, increased energy efficiency (reduced energy consumption), increased rigidity and reliability due to the use of finned oval or elliptical finned heat exchange tubes, materials used, and a block-modular design solution.

ABO according to a utility model may further comprise

- internal / external recirculation system (if necessary);

- a set of blinds (if necessary);

- a heater, humidifier and other additional systems and devices designed for the effective functioning of ABO in various operating conditions.

Claims (8)

1. An air cooling apparatus comprising at least a heat exchange section provided with heat exchange surfaces made of finned carrier tubes, with distributing and collecting manifolds adjacent to them for the cooled product, and an associated fan unit for supplying a cooling medium to the heat exchange surface characterized in that the heat exchange surfaces are made of finned flat oval or elliptical bearing tubes fixed in tube sheets installed in the distributing and collecting manifold ah. 2. The apparatus according to claim 1, characterized in that the tube sheet is provided with a steel tube plate with holes repeating the external contour of the carrier tubes fixed to them. 3. The apparatus according to any one of paragraphs. 1 or 2, characterized in that the outer ribbing of the supporting pipes contains transverse plate ribs with a closed outer and inner contour. 4. The apparatus according to claim 3, characterized in that the total height of the ribs of the supporting pipes is constant. 5. The apparatus according to claim 3, characterized in that the outer contour of the ribs repeats the outline of the cross section of the carrier pipe. 6. The apparatus according to p. 3, characterized in that the supporting pipe is made bimetallic. 7. The apparatus according to claim 1, characterized in that the heat exchange section and the fan unit are combined into a monoblock supporting metal frame structure. 8. The apparatus according to claim 7, characterized in that the heat exchange section is removable.