RU2532051C1 - Continuous burning heating boiler - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: invention relates to thermal power engineering, namely, to heating systems using solid fuel, and may be used for the creation of solid fuel continuous burning heating devices. The heating boiler comprises a body, made of several panels connected to each other via a sealant with lock joints, at the same time in the front panel there are holes made with gas tight loading and ash doors, a heat exchanger comprises two side and one upper hollow panels, having inlet and outlet nozzles, some of which are connected to each other, in the upper panel there is an air intake hole with a gate controlled by a heat controller, connected via an air duct with an air distributor, the air distributor comprises a base from a plate with a hole in the centre with a nozzle installed above it for fixation of the air duct, having holes in the side surface, it is equipped with a movable ring with a fixator relative to the nozzle and response holes, and also an additional plate with a hole in the centre, fixed under the main plate, besides, the movable ring has a gap relative to the nozzle, the area of the cross section of which makes 20-25%, and the area of the hole in the additional plate is around 45% of the area of the nozzle hole, in the upper part of the rear cover there is an additional hole for discharge of smoke gases, in which there is a smoke gate installed, having a manual and an automatic drive from a heat controller installed on the stack.

EFFECT: simplified design, increased stability of efficiency at different modes of the heating boiler operation, and also improved manufacturability and cheaper production.

3 cl, 2 dwg

Description

The invention relates to a power system, and in particular to solid fuel heating systems.

A long-burning heating boiler with a fuel hopper and an automatic fuel supply system with a water temperature regulator / 1 / is known, in which air is supplied to the lower part of the combustion chamber and fuel is periodically added to it, thereby increasing the burning time of the boiler. The disadvantage of this heating boiler is the complexity, high cost and practical inapplicability for firewood of a non-standardized shape and size, as well as the possibility of an emergency when uncontrolled loading of fuel into the furnace in case of a malfunction of the automation and the dependence of the boiler's performance on energy supply.

Known heating boiler long burning / 2 /, comprising a housing, self-regulating height duct and air distributor. This boiler implements a method of burning solid fuel, which includes the supply of air gases through a variable section, depending on temperature, an opening in the upper part of the combustion chamber, a self-regulating height duct and an air distributor directly to the fuel, and removal, after the oxidation reaction, through a chimney to the upper part of the combustion chamber of a mixture of air and flue gases. In this heating device, fuel burnup occurs from top to bottom, as the air distributor moves under its own weight, and the combustion rate is controlled by the amount of air supplied.

However, in the considered device, due to design features, the burning duration reaches only a few tens of hours. In particular, this is due to the fact that such a device has a relatively small thermal performance per unit volume of the body. And the design of the air duct and the air distributor does not exclude the possibility of unstable operation of the heating boiler (especially when burning fuel with high and inhomogeneous humidity) due to its failures in the burned-out part of the fuel, with the occurrence of an emergency or spontaneous extinction of fuel and the boiler stops. In addition, the specified boiler has a low maintainability.

The closest analogue, selected as a prototype, is a heating boiler / 3 / long burning, which implements a method of burning fuel from top to bottom. The specified boiler includes a detachable housing, a heat exchanger placed in the plane of connection of the two parts of the housing, an air duct, an air distributor and a temperature regulator with an inlet air damper actuator.

The disadvantages of this boiler include the complexity of the design of the heat exchanger and air distributor, as well as the need to organize additional traction in the chimney during the ignition of the boiler and the inability to ensure close to optimal flue gas temperature in the chimney in the entire range of generated heat capacities.

The aim of the invention is to eliminate the disadvantages of the prototype, namely, simplifying the design, increasing the stability of efficiency under various modes of operation of the heating boiler, as well as improving the manufacturability of its manufacture and the cost of production.

This goal is achieved by the fact that the heating boiler contains a housing consisting of several panels interconnected through a seal with lock connections, while the front panel has holes with gas-tight loading and ash doors, the heat exchanger consists of two side and one upper hollow panels, having inlet and outlet nozzles, some of which are interconnected, in the upper panel there is an air inlet opening with a damper controlled by a thermostat connected through an air duct to an air distributor containing a base from a plate with a hole in the center with a pipe mounted above it for fixing the duct, having holes in the side surface, a movable ring with a retainer relative to the pipe and return holes, and also an additional plate with a hole in the center, fixed under the main plate, moreover, the movable ring has a gap relative to the nozzle, the cross-sectional area of which is 20-25%, and the area of the hole in the additional plate is about 45% of the area of the nozzle opening, in The upper part of the rear cover has an additional hole for the removal of flue gases, in which a smoke damper is installed, which has a manual and automatic drive from a thermostat mounted on the chimney.

The invention is illustrated in figure 1, 2. Figure 1 shows a longitudinal section of the boiler, and figure 2 is a transverse. Figure 1-2 indicates: a housing consisting of an upper heat exchange panel 1, side heat exchange panels 2, a front panel 3, a rear panel 4, a base 5. On the front panel 3 there is a loading door 6, an ash door 7. In the upper panel 1 a cylindrical cavity 10 is made for accommodating the air duct 19, the inlet 11, the outlet pipe 12, the inlet pipes 13. On the rear panel 4 there are upper 14 and lower 15 openings with pipes for exhaust gases, and a shutter is located in the upper pipe 14 for exhaust gases 16. Side heat exchange panels 2 comprise input 17 and output 18 tubes. The panels are connected by lock joints 20, through the seal 21. The air distributor contains a main plate 22, an additional plate 23, a pipe 24, a movable ring 25, a cable 26, a cable wire 27. The temperature controller 28 is connected to the shutter 29. Thermal insulation panels, top 30 and side 31 .

The upper heat exchange panel 1 is made of steel with the necessary heat resistance and corrosion resistance. On the rear side of the panel 1, input 13 and output 12 nozzles are made. If necessary, a hot water circuit can be mounted inside the panel 1, the nozzles of which are also displayed on the rear side of the panel 1. In the center of the panel 1, a cylindrical cavity 10 is located in which the duct 19 is placed (when compressed), and the inlet is made in the upper surface 11 in the form of a branch pipe. Side heat exchange panels 2 are made of steel with the necessary heat resistance and corrosion resistance. They have input 18 and output 17 nozzles. The inlet pipes 18 are connected to the heating system, and the outlet pipes 17 to the inlet pipes 13 of the upper panel 1. To increase the thermal power of the boiler, the surfaces of the side and upper panels from the side of the combustion chamber can be coated with additional fins. The front 3 and rear 4 panels and the base 5 are made three-layer from the outer case element, thermal insulation 8 and the inner screen 9. At the base 5, the thermal insulation is denser to prevent significant deformation under the mass of loaded firewood. Boot 6 and ash 7 doors are made with a seal that prevents air leakage during the combustion process. The panels 1-4 and the base 5 are interconnected by the same type of locking joints 20 through the seal 21. For this purpose, ledges are made on the strips 20 and the panels, which mutually engage when connecting the corresponding elements. The damper 16 has a manual and automatic drive from a thermostat located on the pipe above the boiler. This thermostat does not have fundamental features and can be performed, for example, on the basis of a bimetallic plate. The temperature controller 28 can also be made on the basis of a bimetallic plate or a hydraulic actuator. The temperature controller 28 is mechanically connected to the valve 29, which may also have a manual actuator. Air duct 19 may be made of corrugated pipe, for example, of heat-resistant silica fabric impregnated with silicone, and reinforced with a heat-resistant steel spiral. The plate 22 of the air distributor, depending on the configuration and size of the heater, can be made round, square or rectangular with a hole in the center. A pipe 24 is attached to it. A pipe 24 with holes in the lower part located on opposite sides is designed to drain air from the duct 19 under the additional plate 23, above the plate 22 and between the plates 22, 23. To adjust the ratio of the volumes of air entering under the plate 22 and above it, a movable ring 25 is used, having holes matching the same holes in the pipe 24, the movable ring having a gap relative to the pipe, the cross-sectional area of which is 20-25% of the area of the hole in the plate 22. Depending on the type of fuel and its humidity, the position of the ring 25 adjusts the coefficient of excess air. For example, for coal or peat briquettes, this coefficient is set more. For this, the holes in the pipe 24 and the ring 25 (depending on the position of the ring) can be completely blocked by the deaf part of the walls of the pipe and the movable ring, partially or completely open. The holes in the pipe and ring can be made, for example, rectangular on a quarter of a circle each on opposite sides of the corresponding element. The area of these openings is chosen so as to ensure that the volume of air necessary for burning the combustible gases generated during the combustion of the fuel and its pyrolysis passes through the lower ones. To fix the movable ring 25, small indentations are made in its lower part, and a protrusion corresponding to them on the plate 22. The additional plate 23 is intended for heating passing between the air plates and is made of a more heat-resistant material than the other elements of the air distributor. The distance between the plates 22 and 23 is chosen so as to ensure that about 55% of the air passing through the pipe 24 passes between the plates. The area of the hole in the plate 23 is about 45% of the area of the hole in the pipe 24. The purpose of the heat-insulating panels 30, 31 is obvious from their name and fundamental features in the proposed design do not have.

The heating boiler operates as follows. Using the cable 26 passing through the cable wire 27, the air distributor rises to the upper position and is fixed in this position, by fixing the end of the cable for the corresponding hook on the housing. If there is an excess amount of ash in the boiler, then it is removed through the ash door 7. Through the loading door 6, fuel 32 is loaded, in particular, wood 32. The shutter 16 is moved to the open position. Then the fuel is ignited, the air distributor is lowered onto the fuel, the shutter 29 is opened, the actuator of the thermostat 28 is set to the desired temperature of the coolant, and the loading door 6 is closed. Next, the flue gas damper 16 is transferred to automatic control from a flue gas temperature controller. After closing the door 6, the air in the combustion chamber will enter the combustion zone through the inlet 11, the duct 19, the pipe 24, the holes in the plates 22, 23. In this case, part of the air passing between the plates 22 and 23 is heated, while cooling these plates. Another part of the air (about 25-35%) through the nozzle and holes in the plates 22 and 23 enters under the plate 23. Between the plates 22 and 23, about 35-45% of the air passes. Another part of the air (from 20 to 40%, depending on the position of the movable ring 25 relative to the nozzle 24) enters over the air distributor and is used to burn combustible gases generated during the combustion of the fuel and its pyrolysis. Next, the flue gases enter the upper hole for removal of flue gases 14 and after a short time the chimney is heated. After heating the chimney pipe to the required temperature and stabilizing the draft in it, the flue gas thermostat turns the damper to a close position, thereby reducing the flow of hot flue gases through the upper hole 14. At the same time, the flue gas flow through the lower smoke hole increases by the same amount 15. But already cooled down flue gases will be discharged through the lower opening, which will transfer their heat to the heat carrier through heat-exchange surfaces. During combustion, the flue gas temperature regulator will maintain the flue gas temperature close to the minimum required (ensuring the normal operation of the chimney), automatically changing the ratio of hot and cooled flue gases leaving the chimney through the upper and lower openings. At the same time, almost the entire volume of the loaded fuel is in the hot gas zone, due to this it warms up well, and thereby its combustion conditions are improved, including by heating the air entering the combustion zone in the distributor. In addition, almost during the entire period of fuel combustion in the hot gas zone, all the heat transfer surfaces of the side 2 and top 1 panels are located, which improves the heat transfer conditions and ensures the stability of their functioning conditions, which favorably affects the efficiency of the boiler and its life.

Due to the specifics of the gas dynamics of the air and flue gas flows in the upper combustion heaters, fuel burnup occurs mainly on one side of the air distributor. And with a rigid duct structure, the air distributor freezes. And then either its failure in the burned-out part of the fuel, or the extinction of the fuel and the boiler stopping. In the described construction, due to the flexibility of the duct 19, the plate 22 is tilted towards the burnt part of the fuel and the distribution of air in the combustion chamber changes. As the heated air tends to the top, more air begins to flow under the upper part of the tilted disk, and less air under the lower part. Due to this, the burnup of the upstream part of the fuel is accelerated and the plate 22 is almost completely aligned. If the fuel is uniform (in density, humidity, styling), the burnout will occur with a small step to the base of the combustion chamber. If in the process of burning fuel inside it there will be places with increased humidity or density, then burnout of fuel slows down in this place, plate 22, leaning on this unburned part of the fuel, tilts more towards the better burning part of the fuel. Due to this, conditions are created for the burning out of a wetter or denser area of fuel. And after its combustion, the plate 22 is again leveled, and without failures of the air distributor, the fuel continues to burn in the previous mode. This ensures a more uniform combustion of fuel having various inhomogeneities.

In the described boiler, the simplification of the design is achieved by simplifying the air distributor, reducing its mass, and also making the housing in the form of panels connected during assembly to each other. In addition, the implementation of the housing from individual panels allows you to partially or fully automate the manufacture of structural elements, improve the quality of their manufacture and reduce the cost of production. This ensures high maintainability of the boiler, including due to the possibility of replacing a failed element, and the possibility of preventive maintenance, to increase the life of the boiler. The implementation in the boiler design of a mechanism to maintain a given flue gas temperature allows for high boiler efficiency in a wide range of generated heat capacities.

In general, in a heating boiler of the proposed design due to stabilization of combustion parameters at all stages of fuel combustion, regardless of its composition, humidity and density, an increase in its efficiency and reliability is achieved and it becomes possible to increase the volume of the boiler, the volume of fuel loaded and, as a consequence, the duration of combustion.

The development level (after testing the prototype) is at the stage of development of a model range of heating boilers of various capacities and duration of combustion and preparation for their serial production.

Information sources

1. The journal "Energy Saving", 2005, No. 1, p. 65-67.

2. Eurasian patent No. 005303 of 12/10/2004

3. RF patent No. 2459145 dated 08/20/2012

Claims (3)

1. A long-burning boiler comprising a housing with a removable back cover having a flue gas outlet in the lower part, openings with gas tight loading and ash doors on the front of the casing, and an air inlet in the upper part of the casing connected through an air duct to an air distributor, and a thermostat with a shutter above the air intake opening, characterized in that the housing contains several panels connected through gas-tight seal with lock joints, while the exchanger consists of two side and one upper hollow panels having inlet and outlet nozzles, some of which are interconnected, the air distributor contains a base of a plate with an opening in the center with a nozzle for fixing the duct having holes in the side surface mounted above it, equipped with a movable ring with a retainer relative to the nozzle and mating holes, as well as an additional plate with a hole in the center, fixed under the main plate, and the movable ring has a clearance relative to In particular, the nozzle, the cross-sectional area of which is 20-25%, and the hole area in the additional plate is about 45% of the hole area in the nozzle, in the upper part of the back cover there is an additional hole for exhaust fumes, in which the smoke damper is installed, which has manual and automatic drive from a thermostat mounted on a chimney. 2. The long-burning heating boiler according to claim 1, characterized in that the upper heat exchanger panel inside contains an additional heat exchanger connected to the hot water circuit. 3. The long-burning heating boiler according to claim 1, characterized in that the thermostat of the smoke damper is made on the basis of a bimetallic plate.

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