RU2597355C1 - Fire-tube multiple pass boiler - Google Patents

Abstract

FIELD: heat engineering.

SUBSTANCE: present invention relates to heat engineering, namely to devices intended for water heating. Multiple pass fire-tube boiler includes housing with cover at the inlet and discharge branch pipe of exhaust gases at the outlet. Boiler comprizes fire furnace pipe and fire pipes of combustion products, covering the fire furnace pipe. On the housing wall there are inlet and outlet water branch pipes. Fire pipes from the side of branch pipe for discharge gases are included in a pipe wall and are connected by this wall with the body in front of said branch pipe, on the other side they are connected to the other pipe wall with flange and fixed in the housing. On the side of flange attachment of fire pipes with the body, fire furnace pipe is connected with front cover with possibility of disconnection. Cover is manufactured as water-cooled together with fire furnace pipe to make therewith a single water-cooled structure. This structure is fixed in the boiler housing with possibility of independent extraction of the fire pipes, fixed in the housing of the boiler independently of the fire furnace pipe. Cover is connected with the flange of the boiler housing through a heat-resistant sealing gasket, providing for temperature changes of the fire furnace pipe and fire pipes in independent parts of the boiler.

EFFECT: when using the invention design simplification and reliability in operation is provided, as well as comfort at work in cleaning and repairs as fire furnace pipe as well as fire pipes.

1 cl, 2 dwg

Description

The present invention relates to heat engineering, and in particular to devices designed for heating water.

It is known that the development of boiler technology goes in the direction of increasing the capacity of boilers, reducing their metal consumption, increasing thermal efficiency and durability, simplifying installation work and reducing installation time. The metal consumption of the boiler is determined by the ratio of the mass of the metal part to its heat output. In modern designs of steam boilers, this figure reaches 1.4-1.6 against 5-5.5 in boilers of an old design. A weak link in old boilers is the lack of thermal compensation of some of their structural elements relative to others. As a result, individual parts are not able to elongate relative to others freely when heated from exposure to high temperatures that arise during operation. This leads to stresses in the structure and to the violation of their connections. These boilers include fire tube boilers, some types of water tube boilers with direct boilers (boilers V.G. Shukhov, A.I. Lukin and others). In essence, the boiler consists of a steel cylinder mounted on cast-iron supports, of which two are movable to compensate for the elongation of the drum when heated. Inside the drum there is one or two flame tubes rigidly fixed in its niches. At the beginning of the flame tubes is a firebox designed to burn fuel. Outside, the boiler is encased. Between the inner side walls of the lining and the drum there remains a space forming two parallel gas ducts, separated below by an incomplete longitudinal partition. The drum is filled to a certain level with water. The heating surface is the surface of the flame tubes and the outer side surface of the drum, washed by gases. Flue gases at the exit from the chimneys are directed through the boiler flues and, having given off the heat of the outer surface of the drum, are emitted into the atmosphere through a smoke exhaust or chimney. Fire tube boilers are characterized by high thermal rigidity due to uneven heating of the flame tubes and the drum itself, with which they have a rigid connection. To compensate for the extension of the flame tube, its surface is made wavy, which is achieved by a complex technological operation. But the main disadvantages of all these boilers are the oversized dimensions and difficulties of repairing and inspecting the fire tube because of the difficulty in accessibility to both it and its working elements.

Known fire tube smoke boiler (Patent RU 2206022, IPC F22B 7/12, publ. 06/10/2003), which inherently represents a fire tube multi-pass boiler. It contains a boiler body, a heat pipe located in it, and heat pipes of the second stroke, and a third stroke of combustion products, forming the heat part enclosing the heat pipe. At the same time, the space between the boiler body and the outer shell is used as the path of the combustion products, and the boiler body, washed from the inside by the heated boiler water, has a fin on the outside for better heat transfer.

The disadvantages of the designs of this type of boilers is that they have oversized dimensions, and the heat pipe and the fire tube part, wrapping it around and forming the number of pipe passages, are made as a one-piece and integral structure in the boiler body. This creates inaccessible conditions for their repair and inspection.

Known three-way fire tube boiler (RF Patent No. 2336460, IPC F22B 7/00, publ. 10/20/2008), which, in essence, represents a fire tube multi-pass boiler. It contains a boiler body, a heat pipe and heat pipes located in it, the corresponding number of strokes of the combustion products, covering the heat pipe, the space between the body of the boiler and the outer shell is formed in the form of a third stroke of the products of combustion, and the boiler body, washed inside the heated boiler water, has fins on the outside. Moreover, the heat pipe and the flame tubes of the second stroke are closed on the one hand by the front cover and connected to the flange, which are fixed in the boiler body, forming a single structure, and on the other, end with the transitional floating head, and the heat pipes are fixed in the tube sheet, which is connected to case. In this case, the housing at the inlet has the aforementioned front cover, and at the outlet there is a flue gas outlet pipe, and it contains water inlet and outlet pipes that are located on its wall. It should be noted that swirl tubes are installed in the flame tubes of the second stroke from the exit side of the cooled combustion products.

This invention is selected as a prototype, as it is aimed at solving the same problem as the claimed invention, and has the greatest number of common essential features with it. However, the prototype has significant drawbacks, namely oversized dimensions and the difficulty of inspecting the heat pipe and heat pipes from the stamped bottom side, as well as the inability to repair the tube plate with the heat pipes welded into it from the stamped bottom side. This is due to the fact that the heat pipe and flame tubes of the second stroke are closed on one side by a front cover and connected to a flange that is fixed in the boiler body, forming a single structure inserted into the boiler body, and when disassembling the flange connection, take out such a one having significant overall dimensions the design is extremely difficult and heavy. For this reason, removing this part for cleaning and repair is a labor-intensive process; it is also difficult to keep such a structure in equilibrium during repair and cleaning. The design of the connection of such a part being removed to the boiler fixed to the boiler body on the flange is unsuccessful, since this connection of a large diameter should provide a density from the flow of water between the body and the part being removed, which is difficult to implement in practice. In addition, the removable part is mounted on this flange cantilever, which with its mass will create significant bending stresses on the flange. This reduces the reliability and performance of the structure.

The objective of the present invention is the modernization of the existing fire tube multi-way boiler by achieving a technical result, which consists in simplifying the design and forming from it one-piece during operation and collapsible in the manufacture and repair of the structure, providing easy access to the flame tube and to its fire tube during repair and pipe cleaning.

The problem is solved as follows. In the well-known fire tube multi-way boiler, comprising a housing with a cover at the inlet and a flue gas outlet pipe at the outlet, a heat pipe and combustion pipes placed therein, covering the heat pipe and installed in tube boards, as well as water inlet and outlet pipes, located on the wall of the boiler body, while the flame tubes from the side of the exhaust gas pipe are included in the tube board and connected to the boiler body in front of the pipe, and on the other hand they are connected to another pipe with a flange and it is fixed in the boiler body, and on the side of the flange fastening of the heat pipes with the boiler body, the heat pipe is connected to the front cover with the possibility of separation with the said flange. ACCORDING to the present invention, the cover is made water-cooled in one piece with the heat pipe, forming it has a single water-cooled design, which is fixed in the boiler body with the possibility of independent extraction of heat pipes from it, fixed in the boiler body independently of the heat pipe, and the lid is connected to the flange of the boiler body through a heat-resistant sealing gasket that provides temperature changes to the flame tube and flame tubes in the boiler parts independent of each other.

The applicant has conducted a patent search on this subject. He showed that the claimed combination of the claimed essential distinguishing features has not been identified, and therefore, the proposed invention can be considered new.

The claimed invention has an inventive step, because for a specialist it does not logically follow from the prior art, but rather contradicts the current practice of designing multi-pass fire tube boilers. So in the well-known fire-tube boilers, their designs always sought the heat pipe and heat pipes formed by the corresponding number of strokes of the products of combustion and covering the heat pipe with the latter, to form in the form of an integral one-piece design in which the mentioned structural elements are fixed in the boiler body depending on friend and usually on the flange of the boiler body. Therefore, this removable part has the appearance of a cantilever structure, which complicates both its removal from the boiler body and the subsequent repair and pipe cleaning.

In our case, the opposite is true. In the claimed invention, the heat furnace tube together with the front cover is made of a water-cooled one-piece design with the ability to be removed from the body regardless of the heat pipes, fixed independently from the heat furnace pipe in the boiler body in the tube boards. This allowed us to create convenience for its repair and cleaning. In addition, in our case, the reliability of the operation of the boiler is increased, since the placement of the flame tubes in the boiler body in the fixed part of the boiler makes it possible to significantly facilitate the removable part, and the unified welded construction of the removable part connected to the single structure of the boiler body does not, as, for example, in the prototype, a flange connection in contact with water. Moreover, it became possible to provide isolation to structural changes with different thermal elongations, namely, a heat pipe, which is affected by the temperature of the torch and heat pipes, which are affected by a much lower temperature of the exhaust gases. This became possible due to, as noted earlier, the implementation of the heat pipe in one piece with the front cover in the form of a water-cooled design and the connection of the cover with the flange of the boiler body at the same time, in which the heat pipes are fixed through a gasket that seals the connection between the heat pipe and the boiler body with heat pipes and compensating for various temperature elongations of these parts of the boiler. In this case, the heat pipe has a free extension in the boiler body, and through the gasket, the flame tubes and the boiler body elongate independently towards the flue gas outlet pipe.

The invention is illustrated by drawings, where in FIG. 1 shows a section through a multi-pass multi-pass boiler, and FIG. 2 - removable heat boiler furnace pipe.

The proposed fire tube multi-way, for example, three-way, the boiler contains a housing 1. In the housing 1 there are flame tubes 7, mounted on the side of the pipe 3 of the combustion products from the boiler in the tube board 8, and from the side of the boiler cover 2 are fixed in the boiler body 1 in the tube board - flange 9. The inner part of the boiler body 1 is formed by a shell 13. The lid 2 of the boiler is made water-cooled in one piece with the flame tube 6, forming a single water-cooled structure with it, which is inserted along the guides (not shown) in the inner echayku 13 of the body 1 of the boiler. Moreover, the front cover 2 of the boiler is connected to the flange 9 of the boiler body 1 through the gasket 10. This gasket is heat-resistant, sealing and is able to provide temperature changes to the flame tube 6 and flame tubes 7 in independent parts of the boiler. The heat furnace tube 6 connected to the cover 2 is made of a single water-cooled design (Fig. 2). This design is fixed in the boiler body 1 with the possibility of extraction from it. The gasket 10, which serves to seal the connection of the lid 2 and the boiler body 1, as noted, is also heat-resistant. The temperature extensions of the flame tube 6 and boiler parts located in the housing 1, exposed to different temperatures, respectively, from the torch of the burner 11 to the flame tube 6 and combustion products to the flame tubes 7, are not rigidly connected into a single welded structure and do not create mutual deformations relative to each other and structural stresses.

It should be noted that through the front cover 2, a burner 11 is introduced into the heat pipe 6 to form a torch for burning the corresponding fuel (not shown in the drawing). The resulting torch gives off heat in the flame tube 6, then the combustion products enter the gap between the outer shell of the flame tube 6 and the inner shell 13 of the boiler body 1 (second gas passage), then to the flame tubes 7 (third gas passage) and to the exhaust branch 3 gases from the boiler.

The principle of operation of the proposed fire tube multi-pass boiler is as follows:

- a mixture of fuel with air by the burner 11 is fed into the heat pipe 6, where it burns, giving part of the heat to the cooling pipe water;

- combustion products from the flame furnace tube 6 enter the flame tubes 7. The number of strokes of the combustion products may be two or three. In this case, for example, it is shown that there are three of them. Cooled combustion products enter the pipe 3 of the exhaust gas outlet to the outlet of the housing, i.e. boiler;

- water through the pipe 4 enters the water part of the boiler body 1, and then into the heat pipe 6 of the boiler (the piping connecting the water space of the boiler body 1 and the heat pipe 6 is not shown in the drawing), where it is heated. Water leaves the boiler through pipe 5;

- when a difference in thermal heating occurs between the flame tube 6 and the flame tubes 7, their mutual change of lengths occurs, which is compensated independently, since it does not have a rigid connection.

To clean the boiler, the cover 2 with the heat pipe 6 is disconnected from the boiler body 1 along the flange 9, the heat pipe 6 is removed from the body 1 of the boiler, all boiler heating surfaces become fully accessible. Then they are cleaned mechanically, for example, to shine.

For the repair of the boiler, the entire design of the inner surface, including welding seams, also becomes available almost 100%. It should be noted that the back cover of the boiler (not shown in the drawing) is mounted on a flange connection, which also provides full access to the boiler from the rear.

Thus, it was possible to modernize the design of the fire tube multi-flow boiler, providing thermal elongation of the boiler elements in it, reducing, and in some cases eliminating thermal stresses in the boiler body due to the difference in the relative elongation of its structural parts, which are affected by different temperatures. At the same time, it was possible to reduce the weight of the removable parts of the boiler, since the heat pipe and the heat pipes are fixed independently in the boiler body. This facilitates the work on cleaning and repairing the boiler, and also eliminates the use of a stamped bottom on the back of the flame tube. At the same time, it simplifies the design and provides access for inspection and repair of all welds of the flame tube by 100%. Also, the placement of flame tubes in the housing provides access for inspection and repair of welds between the pipes and tube boards both from the side of the boiler cover and from the side of the flue gas outlet pipe at the boiler outlet, since the back cover with the flue gas outlet pipe is attached to the boiler body through a flange connection (not shown).

Claims (1)

A multi-way fire tube containing a housing with a lid at the inlet and a flue gas outlet pipe at the outlet, a heat pipe and combustion pipes placed in it, enclosing a heat pipe and installed in tube boards, as well as water inlet and outlet pipes located on the wall of the housing, while the flame tubes from the side of the exhaust gas pipe are included in the pipe board and are connected to the housing in front of the pipe, and on the other hand they are connected by another pipe board to the flange and are replicated in the housing, and on the side of the flange fastening of the flame tubes with the housing, the flame tube is connected to the front cover with the possibility of separation with the said flange, characterized in that the cover is made water-cooled in one piece with the flame furnace pipe, forming with it a single water-cooled design, which fixed in the boiler body with the possibility of independent extraction of heat pipes from it, fixed in the boiler body independently of the heat pipe, and the cover is connected to the boiler body flange through a heat-resistant sealing gasket that provides temperature changes to the flame tube and flame tubes in boiler parts independent of each other.

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