UA68683A - Recuperation heat-exchange apparatus - Google Patents

Abstract

Recuperation heat-exchange apparatus "pipe in pipe" comprises an inner and an outer pipes. The outer pipe is made of flexible material, and the end surfaces are sealed with split tightening elements.

Description

Description of the invention

The proposed invention relates to energy, and specifically to equipment for the exchange of heat 2 energy between different flows of substances, which are used mainly in refrigeration equipment. This equipment can be used as heat exchange devices such as subcoolers, condensers, evaporators, liquid coolers, etc.

Known heat exchange devices in the form of sections made of a tube bundle placed in a body made of a metal pipe of a larger diameter. With a slight thermal load, the section is made not from a bundle of 70 pipes, but from one pipe, that is, as a "pipe in a pipe". Heat exchangers "pipe in a pipe" are made from separate sections, which are combined into a separate device with the necessary heat exchange surface, for example, as in a heat exchange device for cooling lubricant |Barenboim M.I. Improvement of the construction of the oil cooler attachment of the AN-260 screw compressor unit. Refrigeration equipment Mo1, 1992 p. 29 - analogues. 12 The disadvantages of such heat exchange devices are the complexity of manufacturing and operation due to the difficulty of cleaning the heat exchange surface from contamination, high consumption of metal per unit area of the heat exchange surface, as well as significant hydraulic resistance to the movement of the heat carrier circulating in the intertube space. The latter is due to the fact that the sections are connected by nozzles, in which the flow of the circulating coolant sharply changes the direction of movement, and this causes an increase in hydraulic resistance.

Known heat exchangers of the "pipe-in-pipe" type, welded from metal pipes concentrically inserted into each other. Inlet and outlet fittings are welded to the ends of the pipes for connecting to the corresponding elements of the installation in which they are used, for example, for cooling water or another liquid. Such heat exchangers are made direct or coil. (Zelikovsky, I.H., Kaplan, L.G. Small refrigeration machines and installations: Reference book. 3rd ed., revised and updated - M. Agropromizdat, 1989 - 672 p.: illus. fig. 6-23, p. .254 - prototypes.

Coil heat exchangers are much more difficult to manufacture due to the need to manufacture a coil at the same time from two concentrically installed one-to-one pipes. After that, before welding, they should be cleaned of the filler, which, of course, is used during the preparatory work for the manufacture of the coil. For such heat exchangers, pipes are mainly made of one brand of metal, which is due to the need to simplify welding work, as well as to ensure the same coefficient of thermal expansion. with

Despite the fact that they have a much lower hydraulic resistance to the movement of the substance circulating in the intertube space, a (5...1095) lower metal capacity compared to the heat exchangers described in ee, analog, they are also difficult to manufacture and operate. require a large consumption of metal per unit of surface area of the heat exchange, and also have a length limitation due to the fact that the outer and inner pipes are in different temperature conditions, and this causes temperature stresses that can lead to the destruction of the device.

The invention is based on the task of reducing the metal capacity of the heat exchanger and facilitating operation by simplifying the cleaning of the heat exchange surface from deposits of impurities of various nature, such as hardness salts (scale), tartar, and the like, as well as ensuring durability at З 70 long length of the heat exchange surface device c The problem is solved due to the fact that in a heat exchanger of the "pipe-in-pipe" type, which

"Iz" consists of an inner pipe placed in an outer pipe of a larger diameter, the outer pipe is made of flexible material, and the end surfaces are sealed with detachable sealing elements.

The proposed technical solution from the reviewed literary sources is not known to us, it allows to obtain a positive effect in the form of a reduction in the metal capacity of the heat exchange device, ensuring durability for b devices of great length and simplifying the cleaning of the outer side of the heat exchange surface.

Ge | The schematic diagram of variants of the heat exchange device is presented in Fig. 1.

Fig. 1 shows the version of direct, Fig. 2-3 - coil heat exchangers, and Fig. 4 and 5 - options for possible fastening of fittings and sealing elements of the heat exchange apparatus. o 20 The heat exchanger consists of an inner pipe 1, made of a material with a low thermal resistance. Such a material can be metal, for example, steel, aluminum, copper, titanium, and others. Fittings 2 of any known design are attached to the ends of the metal c" pipe 1, for example by welding, for example as shown in Fig.4. An outer pipe 3 made of a flexible material with high thermal resistance, such as polyethylene, rubber, plastic, etc., is placed on the inner pipe 1. At the same time, the inner diameter 29 of the outer pipe must be larger than the largest outer diameter of the elements of the inner pipe. (it can be as the diameter of the innermost pipe, if the very end parts of the pipe are used as fittings 2, or, if welded fittings are used, then the largest diameter of these fittings). This requirement is necessary to ensure the ability to put on or take off the outer tube of the apparatus. The production of the outer pipe from a flexible material makes it easy to assemble the device, even if it has the form of a coil. Fittings 4 are located on the outer pipe 60. They are fixed in one of the known ways, for example, similar to the fitting for air supply to the car chamber with the help of a washer 5 and a nut 6 (Fig. 5). Sealing of the inter-pipe space from the end sides is performed by any known method of sealing end surfaces, for example, with the help of rubber rings that are pressed through the outer pipe with clamps 8.

The heat exchanger works as follows. because One of the substances, for example, refrigerant in the form of liquid or steam, is fed into the device through the fitting 2 of the internal metal pipe. Through the fitting 4 of the external pipe, another working substance is supplied, usually it can be water, or solutions of organic or inorganic substances, etc. If this substance is under high pressure, the outer pipe is reinforced with any reinforcing material. These working substances exchange heat through the wall of the inner tube.

Several inner pipes can be located in the middle of the outer pipe. This will somewhat complicate the design of the end seals of the heat exchanger, but, with an increase in the inner diameter of the outer tube, will significantly reduce its length at a fixed amount of transferred heat.

Over time, the outer surface of the inner pipe can become covered with various contaminants, for example, salts of 7/0 Hardness, grease, etc. This will lead to a significant decrease in the heat transfer coefficient due to the fact that the thermal conductivity coefficient 7) of these contaminants is significantly lower than that of the metal (if for metals X-15(titanium)...38O(copper), then for contaminants /- /X-0, 12(lubricant)...0.13...0.2(scale) W/(m'K)).

The heat exchange device becomes inoperable, i.e. unable to work in calculated modes, and requires cleaning of the heat exchange surface.

In the proposed technical solution, it is easy to implement, for example, in the simplest mechanical way, due to the possibility of removing the outer pipe, which does not cause difficulties, considering that it is made of flexible material, and the design of the sealing elements is collapsible.

The strength of the device is ensured by the elasticity of the outer pipe and seals, which compensates for the difference in length change due to the effect of the difference in temperature conditions in which the inner and outer pipes are located, and different coefficients of their temperature expansion.

The proposed heat exchange device makes it possible to significantly reduce the metal capacity, ensure the strength of the design of long devices, significantly reduce heat energy losses due to heat exchange with the environment, and in some cases to refuse the use of special heat-insulating material and performing insulation work, as well as to facilitate the cleaning of the external heat-exchange surface in case of its contamination. and Z new « 4... osno - lu tn shi 1 22002005 3Y---Ш05-- SY 55 7 and so

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Claims (3)

Formula of the invention (ee) 1. A recuperative heat exchanger of the "pipe-in-pipe" type, consisting of internal and external "o pipes, which differs in that the external pipe is made of flexible material, and the end surfaces are sealed with detachable sealing elements. 2. The recuperative heat exchanger of the "pipe in a pipe" type according to claim 1, which is characterized by the fact that the inner diameter of the outer pipe is larger than the largest outer diameter of the elements of the inner pipe. 3. A recuperative heat exchanger of the "pipe-in-pipe" type according to claim 1, which is characterized by the fact that several internal pipes are located inside the outer pipe. . "» Official Bulletin "Industrial Property". Book 1 "Inventions, useful models, topographies of integrated microcircuits", 2004, M 8, 15.08.2004. State Department of Intellectual Property of the Ministry of Education and Science of Ukraine. (o) (ee) (o) (ee) syu" 60 b5