RU2341732C2 - Hot water boiler - Google Patents

Abstract

FIELD: heat-power engineering.

SUBSTANCE: boiler consists of a furnace, convection area with ducts forming a flue, heat-exchanging tube hydraulic system consisting of individual convection and radiation tube sections connected to each other subsequently in water flow direction and opposite to flue gas direction. Connection of heat exchanging tubes in sections and connection of sections to each other is made in the form of loops so that end of one tube in a section is connected with the beginning of the other tube which is adjacent, and the end of one section is connected with the beginning of the other one. Tangential-slot reducing piece made in the form of a rectangular cross-section tube the inlet and outlet ends of which are placed tangentially in walls of two adjacent tubes is used for connecting two adjacent tubes. Bigger size of tangential-slot reducing piece cross section is directed along the tube length. Cross section area of tangential-slot reducing piece channel is equal to cross section area of each tube being connected. Hydraulic system of heat exchanging tubes consists of two independent strings - left one and right one located symmetrically.

EFFECT: improving heat exchange efficiency, reducing fuel consumption, ensuring fail-safety, reliability and long service life of the boiler operating on any fuel type under conditions of water treatment system non-availability.

6 dwg

Description

The claimed technical solution relates to the field of power engineering, in particular to the so-called small boiler plants, and can be used in various industries and utilities that have a need for thermal energy, for example, for heating (hot water) of residential buildings, as well as buildings and structures socio-social, industrial and agricultural purposes.

Known boilers produced by the domestic industry (Biysk boiler plant, LLC Izhevsk boiler plant and other catalogs).

They are vertically arranged one-, two-, three-row sections connected in parallel through the water, while in the sections the flame tubes are also connected in parallel. The movement of gases, as a rule, is one-way, at best, two-way with dividing walls-screens. An economizer (flue gas heat recovery) is rare, at best it is a multi-row bundle of pipes connected in parallel, which are very quickly clogged with soot and do not work. The operation of such boilers is characterized by low efficiency, significant overuse of coal, and instability. The service life of such boilers due to the high accident rate (clogging and burning of pipes) is from one to three years.

Known hot water boiler (RF patent No. 2241913, IPC 7 F24H 1/12, publ. 10.12.04), which is partially devoid of the above disadvantages. The boiler contains furnace and convection parts, which are formed by screens made of pipes, and have a common ceiling screen, horizontal input and output collectors. Each of the screen tubes has inlet and outlet bypass pipes, the ends of the screen tubes of the furnace and convection screens are muffled. The nozzles are located on opposite sides of the diameter of the screen tube, tangentially to the axes of the screen tubes.

The disadvantages of the described hot water boiler are that the convective part for utilizing the heat of the flue gases is not sufficiently developed, the parallel connection of the flame (radiation and convective) pipes does not provide a sufficiently high water velocity, there is no rotational movement of water through the collectors that may clog, the parallel pipe connection is not gives an early assessment of the condition of the pipes with respect to scale formation.

Also known is a hot water boiler (RF patent No. 2059537, publ. 08/18/92) containing a combustion chamber shielded by pipes and a convective tube bundle equipped with an economizer and a twisting device for water flow in the form of bypass pipes connecting adjacent pipe screens, convective beam and the economizer and located tangentially to their axes, while all boiler pipes are made straight.

The disadvantages of the known boiler are also the insufficient development of convective areas, unidirectional movement of water in the pipes, which reduces the efficiency of heat transfer from flue gases to water.

The closest in essential features to the claimed technical solution is a boiler (RF patent No. 213406, publ. 20.07.99), adopted as a prototype. The device contains a brickwork made of fireclay bricks, a furnace, gas ducts, autonomous convective and furnace radiation modules in the form of tube screens with collectors and drainage, connected to each other in series through water and opposite the flow of flue gases, two side convection modules installed in the lowering shafts screens - ceiling, frontal and side. Two side convective modules in the lowering shafts are made in the form of two paired four-way screens, and the remaining furnace radiation screens are connected to each other in a chain - single-color: side four-way, front two-way, second side four-way and ceiling two-way. In the lowering and lifting tubes of the screens, swirlers are coaxially mounted on both sides.

Its drawbacks are that when the working agent (water) is distributed from the collector through the pipes, the rhythm of water movement is disrupted in each tube screen, it is additionally turbulized in the longitudinal plane of the pipe section at the entrance to it, forming vortices opposite to the water movement, as a result of which it slows down in transitions from the collector to each of the pipes, it loses its longitudinal (along the pipe) speed and the speed of twisting. An increase in water pressure only enhances these negative effects. All this leads to a decrease in the speed of movement of water as a whole in the hydraulic heat transfer system and, as a result, requires double, build, etc. to increase the heat transfer surface. screens. All this complicates the entire heat exchange system, further increases its hydraulic resistance, makes it cumbersome, contributes to the deposition of salts and contaminants from the water, leading to clogging of the system and accidents. With such a complicated system, it is impossible to control the boiler resistance, which allows continuous assessment of the condition of the internal cavities of the pipes and timely measures to eliminate the emergency. It is not possible to carry out periodic non-stop cleaning of the boiler.

The installation of turbulators-swirls in the form of a helical metal strip in the pipes does not solve the problem of movement of the working agent with swirling along the entire path of its movement, while reducing the cross sections of the pipes, increasing their resistance, complicating the design, leading to clogging of the pipes with accumulating deposits.

Ultimately, the design of the hot-water boiler adopted as a prototype is low-efficient, does not ensure trouble-free and stable operation, it is uncontrolled.

The objectives of the invention are to increase the efficiency of heat transfer by organizing countercurrent movement of heat carriers - flue gases and water, reducing fuel consumption, ensuring trouble-free, stability and durability of a boiler on any type of fuel in the absence (or unsatisfactory operation) of water treatment systems.

These tasks are achieved by the fact that in the boiler containing the lining, a furnace, a convection compartment with channels made in it, forming a chimney, a hydraulic system of heat exchange pipes, consisting of separate convective and radiation sections in the form of pipe sections with air ducts and drainage connected to each other according to the invention, the connection of heat-exchange pipes in sections and sections between one another and in series with respect to water and opposite to the course of the flue gases, including the upper, front, internal, external and rear sections It is made loop-like, so that the end of one pipe in the section is connected to the beginning of the other adjacent pipe and the end of one section is connected to the beginning of the other section, and a tangential-gap adapter is used to connect two adjacent pipes to each other.

These tasks are also achieved by the fact that the tangential-slot adapter is made in the form of a tube with a rectangular section, the input and output ends of which are cut tangentially into the walls of two adjacent pipes, while the larger cross-section of the tangential-slot adapter is directed along the generatrix along the length of the pipe.

These tasks are also achieved by the fact that the cross-sectional area of the channel of the tangentially slotted adapter is equal to the cross-sectional area of each of the connected pipes.

These tasks are also achieved by the fact that the hydraulic system of the heat exchange tubes consists of two independent branches - left and right, located symmetrically.

The claimed technical solution is illustrated by drawings, where figure 1 shows a longitudinal section of a boiler; figure 2 is a section along AA in figure 1; figure 3 is a section along the BB in figure 1; figure 4 is a diagram of the interaction of flows of coolants - water and flue gases; figure 5 is a cross section of a tangential-gap transition between the pipes; figure 6 is a tangential-gap transition between the pipes in a perspective view.

The inventive hot water boiler consists of a lining 1, divided by a wall 2 of refractory material into the furnace compartment (furnace) 3 and the convection compartment 4 (Figs. 1, 2, 3). The furnace compartment 3 contains a grate 5, on which solid fuel 6 is placed, and a front opening 7 to provide access to oxygen of the air necessary for combustion (FIGS. 1, 2). In the convection compartment 4, with the help of partitions 8 of staggered refractory material, a chimney 9 is formed, the channels of which are interconnected with the furnace 3. The chimney 9 has an opening 10 for the exit of flue gases and is equipped with windows 11 for removing soot and ash. Windows 11 provide the ability to remove soot without stopping the boiler. Arrows 12 show the movement of flue gases obtained from the combustion of solid fuel through the chimney 9 to the opening 10 (Fig.1, 3).

Arrows 13 show the movement of an air stream carrying the amount of oxygen necessary for combustion.

The main component of the boiler, providing heat exchange between flue gases and water, is the hydraulic pipe system, which is the same for the furnace compartment 3 and the convection compartment 4 of the boiler.

The hydraulic system of pipes consists of two independent branches - left a and right b (Fig.1, 2), located mirror-image. Moreover, each branch has an independent cold water inlet 14a and 14b (or return) and hot water outlets 15a and 15b with corresponding shutoff valves (Figs. 1, 2).

The hydraulic pipe system is equipped with drainage and flushing nozzles 16 and nozzles for the release of air (air vents) 17 (Fig.2, 3).

Each of the branches of the hydraulic pipe system consists of separate sections (pipe screens) 18-22, connected in series and arranged in such a way as to provide a counterflow between the directions of movement of the flue gases and water (Fig. 4). Some sections of both branches installed in the combustion zone (at the end of the water course) are radiation ones, they perceive mainly radiant energy. These include: ceiling sections 22a, 22b (FIG. 4), rear radiation sections 21a, 21b (FIG. 4), internal sections 20a, 20b (FIGS. 2, 4). The remaining sections along the flue gas perceive heat due to convection. These are the external sections 19a, 19b (Fig. 4) and the rear sections 18a, 18b (Figs. 1, 2, 3, 4).

Each section consists of interconnected horizontal pipes, which ensures cross-flow interaction for individual pipes in the section and counterflow for sections and the boiler as a whole.

The connection of two adjacent pipes in the section is provided using a tangentially slotted adapter 23 (Fig.3, 5, 6), which allows you to create a rotational movement of water at each transition. 5, 6 show two adjacent pipes 24 in sections connected by a tangentially slotted adapter 23.

The tangential-slot adapter 23 is made in the form of a tube with a rectangular (slot) section, the input and output ends of which are tangentially cut into the walls of two adjacent pipes 24. Moreover, the larger cross-sectional dimension of the tangential-slot adapter 23 is directed along the generatrix pipe 24, and its transverse area the cross-section is equal to the cross-sectional area of the pipe 24.

The hot water boiler operates as follows.

Solid fuel 6 is burned on the grate 5 in the furnace compartment 3 of the boiler under the action of an air stream, shown by arrows 13, delivering the required amount of oxygen to the combustion zone (Fig. 1). The flue gases resulting from combustion through the chimney 9 from the furnace compartment 3 are sent to the convection compartment 4, first to its side compartments (Fig. 3), along arrow 12, then to the labyrinth formed by partitions 8 made of refractory material, and then to opening 10 for the exit of flue gases.

Towards the flow of flue gases simultaneously along two branches (a and b) of the hydraulic pipe system, a flow of movement of heating (network) water (Fig. 1) is organized sequentially in all sections to the outlets of the heated water 15.

The hot water boiler was tested in the boiler room No. 1 of the village of New construction of the Kemerovo region in the heating season of 2005-2006.

Using the inventive hot water boiler allows you to get the following technical effect:

- to ensure the orderly movement of the working agent (water) in the entire system of heat exchange pipes with a constantly renewed swirl of water at each transition from pipe to pipe;

- increase the speed of movement of water in the pipes, and taking into account the countercurrent movement of heat carriers - heating (flue gases from fuel combustion) and heated (water) - increase heat transfer (heat transfer) by reducing the temperature of flue gases. The heat removed (transmitted), as is known, is determined by the formula

Q = Δt · G,

where Q is the removed (transmitted) heat;

Δt - temperature gradient - the difference between the temperature of the heating and heated fluids, constant throughout the path of the interaction of flows;

G is the mass of the coolant (water);

- all of the above allows you to increase the efficiency of the boiler with the same value of the surface of heat transfer (heating);

- the organization of renewable rotational movement when the working agent (water) flows from one pipe to another (adjacent), and without changing the direction of rotation, it allows mixing of water layers with a characteristic movement of the colder layers from the center to the walls, and heated, on the contrary, from the walls to the center;

- ensuring the rotational movement of water in the pipes allows you to reduce (or completely eliminate) deposits on the walls of the pipes, which is of particular value of the claimed technical solution in terms of ensuring the stability of the boiler, increasing efficiency and increasing the service life without water treatment;

- the claimed technical solution makes it possible to control the internal hydraulic resistance of the boiler, which allows you to continuously evaluate the condition of the internal cavities of the pipes during operation and take timely measures that exclude an emergency;

- to provide the possibility of timely non-stop cleaning of the boiler from soot and dust deposits.

The claimed technical solution allows to increase the efficiency of the heat transfer process, reduce fuel consumption, ensure trouble-free, process stability and durability of the boiler on any type of fuel in the absence (or unsatisfactory operation) of water treatment systems.

Claims (1)

A water boiler containing a lining, a furnace, a convection compartment with channels made in it, forming a chimney, a hydraulic system of heat exchange pipes, consisting of separate convective and radiation sections in the form of pipe sections with air ducts and drainage, connected to each other in series through water and opposite to the way flue gases, while the sections are, including the upper, front and rear sections, characterized in that the connection of the heat exchange pipes in the sections and sections between them is made loop-like that the end of one pipe in the section is connected to the beginning of the other adjacent pipe and the end of one section is connected to the beginning of another section, and for connecting two adjacent pipes to each other, a tangential-slot adapter is used, while the tangential-slot adapter is made in the form of a tube with a rectangular section, the input and output ends of which are tangentially cut into the walls of two adjacent pipes, while the larger cross-section of the tangential-slot adapter is directed along the generatrix along the length of the pipe, and the cross-sectional area of the tang channel the genial-slot adapter is equal in cross-sectional area to each of the connected pipes, and the hydraulic system of the heat-exchange pipes consists of two independent branches - left and right, located symmetrically.

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