RU2773426C1 - Plate type air cooling unit - Google Patents

Abstract

FIELD: heat engineering.

SUBSTANCE: invention relates to the field of heat engineering and can be used in heat exchange devices of air cooling. In the plate type air cooling unit, the distribution and assembly chambers have a tubular shape with holes along the generatrixes for the passage of the cooled product, the corrugated plates are stitched in a direction perpendicular to the plane of the plates, and are provided with perimeter seals at the points of passage through the plates, on one side the distribution and assembly chambers have threaded shanks, clamping bushings and clamping nuts, and on the other, opposite side, they have support rings and are connected to fittings, pressure frames are adjacent to the side corrugated plates, interconnected by threaded ties. In addition, transverse corrugations are made on the plates of the apparatus in the form of rollers on the side of the air passage, which are vortex generators, and on the side of the passage of the cooled product, there are longitudinal corrugations, which are spacing elements.

EFFECT: increase in the efficiency of the device, its maintainability and ensuring a decrease in the cooling temperature of the product.

4 cl, 8 dwg

Description

The invention relates to heat exchange devices, where atmospheric air cools liquid media, and can be used in chemical, petrochemical, energy and other industries.

Known air-cooling devices of horizontal, zigzag and tent types [1], including heat exchange sections with finned tubes, chambers for inlet and outlet of the cooled flow, a diffuser, a fan with an electric motor, louvers for the passage and regulation of the cooling air flow. The disadvantages of the known air coolers (AVO) are uneven distribution of the cooled flow through the pipes of the heat exchange sections and the cooling air flow over the cross sectional area of the heat exchange sections, which adversely affects the efficiency of heat transfer. In addition, known air coolers have high aerodynamic resistance of rows of finned tubes, large dimensions, weight, bulkiness, metal consumption, significant capital costs in the manufacture and operation of air coolers. Requires a large area for placement of air coolers on the operational site. Repair of heat exchange sections is a rather complicated and time-consuming operation involving lifting mechanisms.

Known apparatus for air cooling [2] with a heat transfer surface of ribbed vertically oriented tubes in the heat exchange sections. The device [2] occupies a smaller area on the operational site, has better maintainability, but to varying degrees, it has the same disadvantages as the known devices [1], noted above.

The closest in technical essence to the proposed invention is an air cooler, including corrugated plates connected in pairs, forming alternating channels for the passage of cooling air and cooled product flows, distribution and collection chambers, fittings, a fan with an electric motor [3] - prototype. The amount of heat transferred per unit mass of the heat-transfer surface in the device [3] is much higher than in known air coolers with finned tubes. The device [3] is more compact and less metal intensive.

The disadvantage of the known device [3] is that its design is non-separable, and this makes it difficult to carry out repairs. Another disadvantage of the device [3], as well as other known air coolers [1, 2] with a heat transfer surface of finned tubes, is that they operate according to the “cross current” or “mixed current” heat carrier flow patterns. This does not allow cooling the technological product to the lowest possible temperatures determined by the temperature of the cooling coolant - atmospheric air and leads to the need to develop the heat transfer surface area and increase the air flow rate pumped through the air cooler.

The technical problem to be solved by the present invention is the need to improve the efficiency of the device, its maintainability, to ensure the cooling of the technological product to the lowest possible temperatures.

This problem is solved by the fact that the plate air cooler, including corrugated plates connected in pairs, forming alternating channels for the passage of cooling air and cooled product flows, distribution and collection chambers, fittings, a fan with an electric motor, paired connections of corrugated plates are made using gaskets made of elastic material along the perimeter of the plates and are detachable, the outer side walls of the air channels are formed by solid, air-tight spacers between pairs of corrugated plates connected to each other, and air-permeable spacers are installed on the sides of the air inlet and outlet of the air channels, distribution and collection chambers have a tubular shape, openings along the generatrices for the passage of the cooled product, pierce the corrugated plates in the direction perpendicular to the plane of the plates and are equipped with seals around the perimeter in the places of passage of the Without a plate, on one side, the distribution and collection chambers have threaded shanks, clamping bushings and clamping nuts, and on the other, opposite side, they have support rings and are connected to fittings, clamping frames connected to each other by threaded ties adjoin the side corrugated plates.

In addition, a confuser is installed in the plate air cooler on the side of the cooling air outlet, in the narrow part of which a fan is located, the transverse corrugations on the plates are located in the direction perpendicular to the direction of air flow, the longitudinal corrugations are located in the direction of air flow, and the transverse corrugations are made in in the form of rollers on the sides of the plates facing the channels for the passage of air and are turbulators for air flows in the channels, and the longitudinal corrugations are made on the sides of the plates facing the channels for the passage of the cooled product and are spacer elements, the corrugated plates are made with a flare.

Unlike the known device [3], the implementation of pairwise connections of corrugated plates is detachable using gaskets made of elastic material around the perimeter of the plates, the presence between pairs of interconnected corrugated plates of solid, air-tight spacers forming the outer side walls of the air channels, and air-permeable spacers on the sides of the air inlet and outlet in the air channels, the tubular shape of the distribution and collection chambers, having holes along the generators for the passage of the cooled product and piercing the corrugated plates in the direction perpendicular to the plane of the plates, in the presence of seals along the perimeter in the places of passage through the plates , allows the proposed plate-type air-cooling apparatus to operate according to the best thermally technical “counterflow” scheme, when heat carriers exchanging heat move in opposite directions. In this case, it is possible to cool the technological product to extremely low temperatures, as close as possible to the temperature of the cooling atmospheric air.

The presence in the proposed lamellar air-cooling apparatus of threaded shanks, clamping bushings and clamping nuts on one side of the distribution and collection chambers, and on the other, opposite side, where they are connected to fittings, support rings, clamping frames adjacent to the side corrugated plates and connected between each other with threaded ties, ensures the tightness of the channels for the passage of the cooled product by tightening the threaded connections. The device is completely collapsible, which ensures its high maintainability and interchangeability of the constituent structural parts.

The use of a confuser installed on the side of the cooling air outlet and connected with the fan with its narrow part provides a much more uniform distribution of the cooling air through the air channels than when using a diffuser on the side of the air inlet to the channels in a known device [3]. Studies show that for the proposed option for placing the diffuser and fan, the thermal efficiency of the device can increase by 7÷9%. Placing the fan on the side of the cooling air outlet from the channels also has the advantage that it helps to reduce the aerodynamic resistance of the air channels of the device due to less vortex formation in the air flow relative to the diffuser inlet.

Longitudinal and transverse corrugations on the plates in the proposed device, in addition to their direct purpose, also perform the functions of stiffeners. The transverse corrugations have a small height, are elements of discrete roughness that turbulize the air flow and intensify its heat exchange with the plate wall, and can be applied to the surface of the plates, for example, by surfacing. The implementation of transverse corrugations in the form of rollers with rounded shapes allows you to achieve the best match between the increase in the intensity of heat transfer and the increase in the aerodynamic resistance of the cooling air flow that accompanies this increase. Studies show that the shape of turbulent elements of discrete roughness has little effect on the intensity of heat transfer of the coolant flow around them, but significantly affects the flow resistance. All corrugated plates are of the same type, interchangeable and manufactured using one die. On the side corrugated plates of the device, transverse corrugations may not be performed.

The presence of flanging on corrugated plates ensures the fixation of gaskets made of elastic material around the perimeter of the plates, which facilitates assembly of the device. In addition, the flanging prevents the gaskets from being squeezed out during an unscheduled increase in pressure in the channels for the passage of the cooled product.

Thus, the distinctive features of the invention allow to solve the problem.

Comparative analysis of the proposed technical solution with the prototype shows that the proposed device meets the criterion of invention "novelty".

The design of the well-known [1,2,3] and other air coolers does not allow them to be used for work according to the "counterflow" scheme.

All this allows us to conclude that the proposed technical solution meets the criterion of the invention "significant differences".

The invention is illustrated by drawings: Fig. 1-8.

In FIG. 1 shows a general view of a plate air cooler; in fig. 2 is a left side view of FIG. one; in fig. 3 - corrugated plate; in fig. 4 is a left side view of FIG. 3; in fig. 5 - chamber seals in places of passage through the plates; in fig. 6 - element I in FIG. 2; in fig. 7 - element II in FIG. 2; in fig. 8 - a solid impermeable spacer and a permeable spacer assembly.

The plate air cooler includes corrugated plates 1, detachably connected in pairs using gaskets 2 made of elastic material located along the perimeter of the plates 1. The plates 1 connected in pairs form alternating channels 3 for the passage of cooling air and channels 4 for the passage of cooled air. product. The outer side walls of the air channels 3 are formed by solid, air-tight spacers 5 between pairs of corrugated plates 1 detachably connected to each other. , impervious to air, spacers 5 with the help of pins 7. The tubular distribution 8 and assembly 9 chambers stitch the corrugated plates 1 in the direction perpendicular to the plane of the plates and have holes 10 along the generators. The holes 10 connect the cavities of the chambers 8 and 9 with the cavities of the channels 4 and serve for the passage of the cooled product. In places where the distribution 8 and collection 9 chambers pass through the corrugated plates 1, there are O-rings 11 made of an elastic material. The tight fit of the ring seals 11 to the surfaces of the corrugated plates 1 of the tubular chambers 8 and 9 and the sealing of the channels 4 for the passage of the cooled product are ensured by means of movable internal 12 and external 13 spacers with bevelled ends. On the inner spacers 12 there are holes 14 for the passage of the cooled product. On the side of the inlet 15 and outlet 16 fittings, the distribution 8 and assembly 9 chambers are rigidly connected to the support rings 17 and are equipped with movable support bushings 18 with bevelled ends. On the other, opposite side, the distributing 8 and assembly 9 chambers have threaded shanks 19, movable clamping bushings 20 with beveled ends, washers 21 and clamping nuts 22. Tightening the clamping nuts 22 with the necessary tightness puts all seals 11 into working condition and seals the channels 4 for the passage of the cooled product. The channels 4 are sealed along the perimeter by tightening the nuts 23 on the threaded couplers 24 connecting the clamping frames 25 adjacent to the side corrugated plates 1.

At the exit side of the cooling air channels 3, a confuser 26 is installed, connected by its narrow part to a fan 27 driven by an electric motor 28.

On the corrugated plates 1, the corrugations are made in the form of rollers 29 (transverse corrugations) on the sides of the plates facing the channels 3 for the passage of air, and in the form of ribs 30 (longitudinal corrugations) on the sides of the plates facing the channels 4 for the passage of the cooled product. Flanging 31 is made along the perimeter of the corrugated plates 1.

Corrugated plates 1 are made of sheet metal or plastic by stamping or drawing.

The plate air cooler works as follows.

When the fan 27 is turned on, driven by the electric motor 28, atmospheric cooling air begins to move through channels 3, along the perimeter of which there are air-permeable 6 and deaf 5 spacers connected to each other by means of pins 7. In the space of the confuser 26, the channel air flows are collected into one common flow, which, passing through the fan 27, is released into the atmosphere. The cooled product enters through the inlet fitting 15 into the distribution chamber 8, from where it flows through the holes 10 and further through the holes 14 in the movable internal spacers 12 into channels 4. In the channels 4, the movement of the cooled product is carried out in the direction opposite to the direction of movement of the cooling air in parallel channels 3. In the process of movement of product and air flows, heat is exchanged between them through the walls of plates 1 separating them. under turbulent conditions of its motion. As a result, the intensity of heat transfer from the product in the channels 4 to the air in the channels 3 increases. An additional function of the transverse corrugations 29, as well as the longitudinal corrugations 30 and the flanging 31, is to increase the rigidity of the plates 1, which makes it possible to make the plates thin-walled with less material for manufacturing. The cooled product from the channels 4 through the holes 14 in the movable internal spacers 12, covering the collection chamber 9, the holes 10 in the wall of the collection chamber 9 enters the cavity of the collection chamber 9, from where it is directed to the outlet fitting 16, through which it is removed from the apparatus. The tightness of the channels 4 for the cooled product at the junctions with the distribution 8 and the team 9 chambers is ensured through the use of ring seals 11 made of elastic material, as well as internal 12 and external 13 spacer bushings, support rings 17, support bushings 18, threaded shanks 19 with clamping nuts 22, washers 21 and clamping sleeves 20. The tightness of the channels 4 along their perimeter is ensured by the use of gaskets 2 made of elastic material between the plates 1 and threaded ties 24 with nuts 23, tightening the package of pairs of interconnected plates using clamping frames 25.

Thermal expansions of the elements of the proposed device are compensated both due to their free movement, and, in part, due to their elastic deformation.

The plate air cooler will find application for working conditions when the pressure of the cooled product does not differ much from atmospheric pressure, with relatively small temperature differences of heat carriers, and a limited area for placing the device.

The proposed device has the following advantages:

- the design is simple and technologically advanced;

- high maintainability;

- high degree of unification;

- countercurrent movement of heat carriers;

- cooling of the technological product to a temperature as close as possible to the temperature of the cooled atmospheric air;

- increased thermal efficiency due to the high uniformity of the distribution of heat carrier flow rates along the flow channels.

To illustrate the advantages of the proposed device, let's compare the temperature performance of a serial air cooler with finned tubes, operating according to the scheme of cross-countercurrent movement of heat carriers, and the proposed plate air cooler, operating according to the counterflow scheme. In the apparatus, kerosene is cooled with an initial temperature of 104°C. The air temperature at the inlet to the apparatus is 26°C. In the first of these apparatuses, kerosene is cooled to 43°C at an outlet air temperature of 44.75°C. At the same flow rates of heat carriers in the proposed device, kerosene is cooled to 35°C, and the air, respectively, is heated to 47.2°C. The lower cooling temperature of kerosene in the proposed apparatus contributes to a significant reduction in storage losses of kerosene by reducing its evaporation. The metal consumption of the proposed device is more than 4 times lower in relation to air coolers with finned tubes.

Sources of information

1. Skoblo A.I., Tregubova I.A., Molokanov Yu.K. Processes and devices of the oil refining and petrochemical industries. M.: Chemistry, 1982. S. 501.

2. Patent RU No. 2075714, IPC F28D 1/04, publ. 03/20/1997.

3. Patent RU No. 2549059, IPC F28D 1/00, publ. 04/20/2015.

Claims (4)

1. Lamellar air cooler, including corrugated plates connected in pairs, forming alternating channels for the passage of cooling air and cooled product flows, distribution and collection chambers, fittings, a fan with an electric motor, characterized in that paired connections of corrugated plates are made using gaskets made of elastic material around the perimeter of the plates and are detachable, the outer side walls of the air channels are formed by solid air-tight spacers between pairs of corrugated plates connected to each other, while air-permeable spacers are installed on the sides of the air inlet and outlet of the air channels, distribution and collection chambers have a tubular shape, openings along the generatrices for the passage of the cooled product, pierce the corrugated plates in the direction perpendicular to the plane of the plates, and are equipped with seals around the perimeter at the points of passage through the plate walls, on one side of the distribution and collection chambers, threaded shanks, clamping bushings and clamping nuts are made, and on the other, opposite side, support rings are made and connected to fittings, in addition, clamping frames connected to each other by threaded ties are adjacent to the side corrugated plates . 2. Plate air cooler according to claim 1, characterized in that a confuser is installed on the outlet side of the cooling air channels, in the narrow part of which a fan is located. 3. Lamellar air cooler according to claim 1, characterized in that the transverse corrugations on the plates are located in the direction perpendicular to the direction of air flow, the longitudinal corrugations are located in the direction of air flow, and the transverse corrugations are made in the form of rollers on the sides of the plates facing into the channels for the passage of air, and are turbulators for air flows in the channels, and the longitudinal corrugations are made on the sides of the plates facing the channels for the passage of the cooled product, and are spacers. 4. Plate air cooler according to claim 1, characterized in that the corrugated plates are made with a flare.

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