RU178049U1 - Heater - Google Patents

Abstract

The utility model relates to fire heating devices for fluids and can be used in the oil, chemical and other industries for heat treatment of liquids having limitations on the maximum heating temperature. The technical problem solved by the utility model is to simplify the design, increase efficiency and reliability heater operation. A heater containing a heat pipe with turbulent rings placed in it, a convection chamber, a burner device, adjoin it to the end of the flame tube, a gas outlet adjacent to the other end of the flame tube, a shirt in which an intermediate liquid coolant and a section of a food coil made of series-connected straight pipes are connected, which is connected in series with another section of a food coil placed in a convection chamber and made of straight pipes sequentially interconnected, forming a bundle and having a spiral wire winding on the outer surface, characterized in that it is convective The chamber is placed in the part of the flame tube adjacent to the gas outlet and opposite to the burner device, tubes are placed in the flame tube at an angle to the horizontal, which are fixed in the openings in the wall of the flame tube and open ends into the jacket. In addition, the heater is characterized in that the rings -turbulators are placed with a step t = 0.4D and have a height d = 0.93D, where D is the inner diameter of the flame tube, and the protrusions-turbulators on the product pipes have a height h = 0.015d and a step t = 10h, where d is the equivalent diameter beam of direct grocery pipes with ktsii coil disposed in the convection chamber. 5 ill.

Description

The utility model relates to fire heating devices for fluids and can be used in the oil, chemical and other industries for the heat treatment of thermolabile and thermally unstable liquids having technological and other restrictions on the maximum heating temperature.

A known heater [1], where the source of heat is the products of fuel combustion, moving in a horizontal duct along the forward and reverse passages, and the heated liquid product is fed into a bundle of product pipes placed above the duct. Grocery pipes and a gas duct are placed in a housing filled with an intermediate liquid coolant. The heater contains heat exchange tubes fixed by the ends in the lower and upper flat walls of the duct. The presence of a large number of heat exchange tubes complicates and increases the cost of the heater design. A large number of welds connecting the heat exchange tubes with the walls of the duct reduces the reliability of the heater. The lower flat wall of the duct may burn out due to the formation of a stable vapor film in local depressions on the wall. The heater has a high metal consumption and dimensions. A liquid heater [2] is also known, comprising a housing filled with a liquid intermediate coolant immersed in the last heat pipe and a horizontal food pipe made with at least one vertical channel, the walls of which are fastened by an edge to the pipe. The heater is difficult to manufacture. At high pressure of the heated product, the walls of the vertical channels should be thick. High specific costs of metal per unit of transmitted heat capacity.

The closest in technical essence to the proposed utility model is a heater containing a flame tube with turbulent rings placed in it, a convection chamber, a burner device adjacent to the end of the flame tube, a gas outlet adjacent to the other end of the flame tube, a jacket in which the intermediate liquid coolant and a section of a food coil made of straight pipes connected in series to each other, which is connected in series with another section of a food coil placed in a convection chamber and made of straight pipes sequentially interconnected, forming a bundle and having a spiral wire winding on the outer surface, [3] - prototype.

In the known device, ring-turbulators in diametric sections of the flame tube and protrusions-turbulators in the form of wire winding on the pipes of the section of the product coil in the convection chamber can intensify the heat transfer of the combustion products of fuel and thereby improve the overall dimensions of the heater. The disadvantage of the heater is the high temperature of the housing wall, which stimulates an increase in heat loss to the environment. With increased heat loads, a steam “cap” above the intermediate liquid coolant may form in the upper part of the volume of the jacket of the heat pipe due to the presence of external heat supply through the wall of the shirt, which will lead to a sharp increase in the temperature of the wall of the shirt in the area of the “cap” and possible wall damage along this reason. In severe temperature conditions, the rear end wall of the casing also works, since a high-temperature flow of fuel combustion products flows at right angles to it and the heat flux comes from radiation from the volume of the flame tube. All this reduces the efficiency and reliability of the heater. In addition, the heater is difficult to manufacture and difficult to repair.

The technical problem to which the proposed utility model is aimed is to simplify the design, increase the efficiency and reliability of the heater.

The essence of the utility model consists in the fact that in a heater containing a flame tube with turbulent rings placed in it, a convection chamber, a burner device adjacent to the end of the flame tube, a gas outlet adjacent to the other end of the flame tube, a jacket in which the intermediate liquid is placed the coolant and the section of the food coil made of straight pipes connected in series to each other, which is connected in series with another section of the food coil placed in the convection chamber Here, made of sequentially connected straight pipes forming a bundle and having a spiral wire winding on the outer surface, the convection chamber is placed in the part of the flame tube adjacent to the gas outlet and opposite to the burner device, tubes which are fixed at an angle to the horizontal are placed in the flame tube in the holes in the wall of the flame tube and open ends enter the shirt. The heater is made so that the turbulator rings are placed with a step t _to = 0.4D and have a height d = 0.93D, where D is the inner diameter of the flame tube, and the protrusions on the product tubes have a height h = 0.015 eq and a spiral pitch t _in = 10h, where deq is the equivalent diameter of the direct product tube bundle of the coil section located in the convection chamber.

In contrast to the known device, the placement of the convection chamber in the part of the flame tube adjacent to the gas outlet and opposite to the burner device allows to reduce the hydraulic resistance to the flow of fuel combustion products, since there is no 180 ° flow rotation. At the same time, a shirt with an intermediate coolant becomes the outer element of the heater, which helps to reduce heat loss to the environment. Placement in the flame tube at an angle to the horizontal of the tubes, which are fixed in the holes in the wall of the flame tube and open ends enter the jacket, increases the surface area of the heat transfer from the combustion products of the fuel to the intermediate liquid coolant, which, being in the tubes, has the ability to move from bottom to top when heating up. In addition, the tubes serve as protection for the product pipes of the coil section located in the convection chamber from the hard heat radiation of the flame plume. As a result, the likelihood of local overheating of the heater elements is reduced.

Placement in the flame tube of turbulizer rings with a step of t _k = 0.4D and a height of d = 0.93D, and on direct product pipes of a coil section placed in a convection chamber, of turbulence protrusions of height h = 0.015d _equiv and a spiral pitch of t _in = 10h, provides the best match between the increase in the heat transfer intensity achieved with this and the increase in hydraulic resistance of the flow of fuel combustion products [4].

All this together leads to a simplification of the design, increasing the efficiency and reliability of the heater. The heater is more technologically advanced in manufacture. Ease of disassembling and inspection of the elements ensures high maintainability of the heater.

A comparative analysis of the proposed technical solution with the prototype shows that the claimed device meets the criterion of "novelty."

Known heaters [1, 2] have increased metal consumption and dimensions, since the heat exchange processes in them have a low intensity. The structural complexity of these heaters and the presence of a large number of welds adversely affects the manufacturability of their manufacture and reduces reliability.

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

In FIG. 1 shows a longitudinal section of the proposed heater; in FIG. 2 is a cross section AA in FIG. one; in FIG. 3 is a transverse section bB in FIG. one; in FIG. 4 - remote element I in FIG. one; in Fig.5 - remote element II in Fig. one.

The heater contains a flame tube 1, inside which a convection chamber 2 is located on part of its length 2. In the holes of the flame tube 1 are fixed at an angle to the horizontal of the tube 3, which are connected with open ends to a jacket 4 filled with an intermediate liquid coolant. A burner device 5 is adjacent to the flame tube 1. Turbulent rings 6 are placed along the entire length of the flame tube 1. From the side opposite to the burner device 5, a gas outlet 7 is adjacent to the portion of the flame tube 1 in which the convection chamber 2 is located. In the shirt 4 there is a section 8 of the grocery coil. Section 8 with a flange outlet 9 is connected to another section 10 of the food coil, which is located in the convection chamber 2. Sections 8 and 10 of the coil are predominantly double-threaded for the heated product. The pipes of the section 10 of the product coil have turbulent protrusions 11, which are mainly made in the form of weld ribs with a section profile close to a semicircle.

In order to ensure a high level of intensification of convective heat transfer and a moderate increase in the hydraulic resistance of the flow of fuel combustion products with respect to pipes with a smooth surface, turbulent rings 6 in the flame tube 1 are placed with a step t _to = 0.4D and have a height d = 0 , 93D, where D is the inner diameter of the flame tube, and the protrusions - turbulators 11 on the product pipes 10 have a height h = 0.015d _equiv and a step t _in = 10h, where d _equiv is the equivalent diameter of the straight product pipe bundle of the coil section located in the convection the camera.

Housing cylindrical elements of the heater are made detachable for the possibility of extracting sections 8 and 10 of the food coil and the convenience of repair work. In the design of the heater, the number of welds is minimized and standard and standardized products are widely used.

The tubular heater operates as follows. The combustion products resulting from the combustion of fuel in the burner device 5 enter the flame tube 1, where they are cooled by transferring heat by radiation and convection through the wall of the flame tube to the intermediate liquid heat carrier located in the jacket 4. Heat is transferred from the intermediate heat carrier through the walls of the pipe - studs of section 8 the product coil is transferred to the heated product. The presence of turbulizer rings 6 in the flame tube 1 leads to the formation of microvortices in the near-wall zone of the flow of combustion products and thereby intensifies convective heat transfer. The combustion products also give part of their heat to the intermediate liquid coolant through the walls of the transversely streamlined tubes 3. The inclined (relative to the horizontal) arrangement of the tubes 3 provides a stable circulation of the intermediate liquid coolant in the shirt-tube system and reliable cooling of their walls. Then, the combustion products enter the convection chamber 2, where heat is transferred to the heated product through the pipe walls of the product coil section 10, and also through the wall of the portion of the flame tube surrounding the convection chamber 2, into the jacket 4 with an intermediate liquid coolant. The presence of protrusions-turbulators 11 on the pipes of section 8 of the food coil can significantly intensify the convective heat transfer of combustion products with the walls of the pipes. From the convection chamber 2, the combustion products enter the gas outlet 7, from where they are removed to the atmosphere.

The direction of movement of the heated product through the pipes of the sections of the product coil can be different. An advantageous variant of the direction of movement for a product such as oil, which can form coke deposits on the heat exchange surface, is shown by arrows in FIG. 1. The heated product enters first into section 8 of the food coil, where it is heated under conditions of a “soft” temperature regime. Then the product enters the section 10 of the grocery coil, where it is heated to a given final temperature. In section 10, at an elevated temperature of the product, its viscosity decreases, which contributes to an increase in the heat exchange intensity of the product stream with the pipe walls. This allows you to maintain the wall temperature of the pipes of section 10 of the food coil below a value acceptable under the conditions of minimizing coke deposits on the heat exchange surface.

The advantages of the proposed heater are:

- structural simplicity, simpler manufacturing and repair technologies;

- a small number of components in the design, while the components are predominantly unified and standard products;

- less metal, which is due to the use of techniques and means of intensification of heat transfer of the combustion products of fuel with heat transfer surfaces;

- less hydraulic resistance along the path of combustion products, since there are no turns that change the direction of flow;

- less heat loss to the environment from the surface of the heater;

- lower specific capital and operating costs, due to the simplicity of the heater design and the recommended optimal sizes of turbulators located on the heat exchange surfaces;

- high reliability due to the relatively low operating temperatures of the structural elements of the heater and the lack of high thermal stresses in them.

For example, a heater with a thermal power of 2 MW, designed to heat a water - oil emulsion to a temperature of 90 ° C, has a diameter of the flame tube of 630 mm and its length of 11,300 mm. Thermal efficiency is 90% at rated thermal power. Water is used as an intermediate heat carrier. Compared with the known analogues manufactured by the industry, the proposed heater has an average of four times the magnitude of the ratio of the nominal thermal power to its total weight.

Information sources

1. USSR copyright certificate No. 1561612, M. cl. F22B 7/00 of 10/05/1987.

2. USSR author's certificate No. 1668827, M. cl. F24P 1/14 dated 05/10/1989.

3. Patent for the invention of PU No. 2256846, M. cl. F22B 7/00 of 03/01/2004. Published July 20, 2005, bull. No. 20.

4. Kalinin E.K., Dreitzer G.A., Yarkho S.A. Intensification of heat transfer in the channels. 3rd ed., Revised. and add. M .: Mechanical Engineering, 1990.p. 193-196.

Claims (2)

1. A heater containing a flame tube with turbulent rings placed in it, a convection chamber, a burner adjacent to the end of the flame tube, a gas outlet adjacent to the other end of the flame tube, a jacket in which an intermediate liquid coolant and a food coil section are made from straight pipes connected in series to each other, which is connected in series with another section of the food coil placed in the convection chamber and made of connected in series interconnected straight pipes forming a bundle and having a spiral wire winding on the outer surface, characterized in that the convection chamber is placed in the part of the flame tube adjacent to the gas outlet and opposite to the burner device, in the flame tube placed tubes that are fixed in holes in the wall of the flame tube and open ends enter the shirt. . 2. The heater according to claim 1, characterized in that the baffle-ring has a step _to t = 0,4D and have a height d = 0,93D, where D - internal diameter of the flame tube and the baffle, the protrusions on the product pipes have a height h = 0.015d _eq and step t _in = 10h, where d _eq is the equivalent diameter of the direct product tube bundle of the coil section located in the convection chamber.

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