RU2452905C2 - Water-heating boiler and method of its operation - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: boiler comprises a vessel made of two coaxial shells, in a circular space between which there are flue pipes of a convective bundle and a circuit of coolant heating, a combustion chamber formed by a cavity of an internal shell, a working thermostat, a recirculation pump, a fuel hopper and a burner with a cone-shaped element. In the lower part of the circular space of coaxial shells the boiler comprises a vertical shell, which communicates with the combustion chamber on top, a vortex combustion chamber placed in the vertical shell, where the specified burner is installed, a flame reflector, an automatic unit for supply of a fuel-air mixture, a vacuum-vortex gateway, an air gate. During boiler operation air from a supercharging fan is supplied to the vacuum-vortex gateway and through it into a pneumatic drive cavity, and the other part of air from the vacuum-vortex gateway under pressure arrives into a pneumatic conveyor, tangentially via a channel arranged at the angle of 45 degrees, fuel is supplied into a created zone of pneumatic conveyor evacuation, where fuel and air are mixed, and the fuel and air mixture is supplied under pressure into the burner.

EFFECT: invention provides for more efficient operation of a boiler.

6 cl, 8 dwg

Description

The invention relates to designs of boilers, methods for their operation and is intended for heating water, can be used in autonomous heat supply systems with natural or forced circulation of the coolant.

A well-known hot water boiler containing a housing made of two coaxial shells, in the annular space between which there are smoke tubes of the convective beam and the heating circuit of the coolant, and a combustion chamber formed by the cavity of the inner shell (see RU 2186302 C2, published on July 27, 2002).

The known boiler has a number of disadvantages, namely, the boiler operation process is not optimized, uncontrolled heating of the coolant, increased fuel consumption, uneven heating of the internal elements of the boiler, increased emission of carbon monoxide (CO ₂ ).

Known hot water boiler, selected as a prototype for the largest number of matching features and the achieved technical result (see RU 2296920 C1 published 2007.04.10), comprising a housing made of two coaxial shells in the annular space, between which there are smoke tubes of the convection beam and the circuit heating medium, a combustion chamber formed by the cavity of the inner shell, a working thermostat, a fuel hopper and a burner located in the combustion chamber and connected by an automatic feeding system and fuel to the fuel hopper and automatic feeding of combustion air from supercharging fan. The automatic fuel supply system is made in the form of a conveyor, driven by a gear motor, and a working thermostat through a programmable controller controls the supply of electric current to the fan and gear motor.

The well-known boiler has several disadvantages, namely the complexity and unreliability of the automatic fuel supply system: fuel is supplied by a screw conveyor, and air is supplied by a boost fan through different channels:

- fuel and air are supplied to the burner through different channels, due to which the fuel supply channel is under pressure created by the boost fan, which prevents the passage of fine fuel into the cavity of the fuel supply channel. As a result, a small fraction of fuel accumulates in the area of entry into the screw conveyor, forming a vault, which periodically leads to a cessation of fuel supply. This problem has been partially solved constructively: by installing an expensive gateway or installing an airtight hopper. Thus, the design of the boiler is much more complicated, leading to an increase in its cost. In addition, due to the presence of constant friction against the fuel, the gateway wears out after a certain time, the seal of the hopper hatch loses its properties or breaks, as it is constantly in the area of mechanical impact (during refueling of the hopper), which requires constant maintenance and repair;

- a large energy consumption for transporting fuel to the burner due to the high friction force, since the fuel is fed into the burner by a screw conveyor over a sufficiently large distance from the bottom up, which often leads to jamming and failure of the screw conveyor itself (twisting of the screw, separation cantilever support, combustion of an electric motor, etc.);

- the complexity and metal consumption of the burner: the burner is constantly located inside the furnace and seated on a heat-resistant sealant, thereby occupying most of the furnace space;

- low reliability of the burner (due to the reverse flame, the burner bottom burns out and the support sleeve at the end of the auger conveyor burns out);

- the impossibility of using other types of fuel, except granular, as the burner is fixed and is constantly inside the furnace.

The objective of the proposed technical solution is to eliminate all of the above disadvantages of the prototype, as well as optimizing the operation of the boiler, reducing fuel consumption, its cost.

The technical result is achieved in that the boiler contains a housing made of two coaxial shells, in the annular space between which there are smoke tubes of the convective beam and the heating circuit of the coolant, a combustion chamber formed by the cavity of the inner shell, a thermostat, a recirculation pump, a fuel hopper and a burner with a cone-shaped element. In the lower part of the annular space of the coaxial shells, the boiler contains a vertical shell, connected to the combustion chamber from above, a vortex combustion chamber located in the vertical shell, in which the mentioned burner, flame reflector, automatic fuel-air mixture supply unit, including a cantilever-screw feeder-doser, is installed , vacuum-vortex lock, pneumatic air damper, pneumatic conveyor. In this case, the coaxial shells are located horizontally, and the axis of the inner shell is shifted upward relative to the axis of the outer shell. The burner with a vortex combustion chamber is removable and connected via annular couplings through a cavity in the boiler body to the automatic fuel-air mixture supply unit, and smoke tubes are arranged in rows on planes perpendicular to the axes of the horizontal shells, while the axes of the smoke tubes continue to extend through the axis of the holes hatches designed for cleaning smoke tubes, a flame reflector is located in the upper part of the combustion chamber.

The method of operation of the proposed boiler consists in supplying solid fuel to the burner inlet located in the combustion chamber, manually firing it with air supply to the combustion chamber, switching to automatic fuel and air supply to the burner, removing flue gases through smoke tubes, while the fuel is burned in a burner installed in a vortex combustion chamber and before supplying fuel and air are pre-mixed, for which the air from the boost fan is fed into the vacuum-vortex lock and through it into the pneumatic cavity of the drive, and the other part of the air from the vacuum-vortex lock under pressure enters the pneumatic conveyor, tangentially, through a channel made at an angle less than 45 °, fuel is introduced into the created rarefaction zone of the pneumatic conveyor, where fuel and air mix and the air-fuel mixture is supplied under pressure in the burner installed in the vortex combustion chamber.

The technical essence of the boiler is illustrated by drawings,

where figure 1 is a front view of the boiler;

figure 2 is the same, rear view;

figure 3 - the internal arrangement of structural elements of the boiler;

figure 4 - automatic node supply of the fuel-air mixture;

figure 5 - arrangement of smoke tubes;

figa is a diagram of sections aa, bb, bb of the location of the smoke tubes;

6 is a control panel of the operation of the boiler;

Fig.7 - node circulation-recirculation;

Fig. 8 is a lever system for controlling an atmospheric valve.

The boiler includes a housing 1 made of two horizontally aligned coaxial shells 2.

The axis of the inner horizontal shell is offset above the axis of the outer horizontal shell.

The cavity of the inner shell forms a combustion chamber 45 with an atmospheric valve 4 and an atmospheric channel 59 connecting the combustion chamber to the flue gas outlet duct 26.

The outer horizontal shell at the back and front is blanked by welded sheets, and in front is closed by a door 5 (Fig. 1, Fig. 3, Fig. 5) with a viewing window 40 (Fig. 1, Fig. 3, Fig. 5).

In the annular space between the shells in the lower part there are a heating medium heating circuit 7 (Fig. 3) and smoke tubes of the convective beam (Fig. 3, Fig. 5, Fig. 5a): 6 for downward flow and 6a for upward flow.

Smoke tubes 6, 6a (FIG. 3, FIG. 5, FIG. 5a) are arranged in rows on perpendicular planes to the axes of the horizontal shells, with the extension of the axes of the smoke tubes 6, 6a passing through the axis of the holes 41 (FIG. 5, FIG. 5a) ) hatches 29 ((Fig. 1, Fig. 2, Fig. 3, Fig. 5, Fig. 5a), designed for cleaning smoke tubes from ash deposits. Also in the annular space between the shells in the lower part there is one vertical shell 3 ( Fig. 3, Fig. 5, Fig. 5a) connecting horizontal shells 2 and forming a space for the burner representing oboj vortex combustion chamber 8 (Figures 3, 5, 5a) with a conical element 9 (3. 5).

The design of the vortex combustion chamber is made in accordance with patent RU No. 2372555, publ. 11/10/2009.

The vortex combustion chamber is multistage with at least two steps, the steps being separated by baffles made in the form of rings mounted on the shell, while the passage area of the annular baffles decreases towards the exit of the combustion products.

The cavity of the vertical shell 3 communicates with the combustion chamber 45 from above and from below with an ash pan. Above the vertical shell 3 (FIG. 3), a flame reflector 39 (FIG. 3, FIG. 5) is located in the cavity of the inner shell forming the combustion chamber.

The burner is a vortex combustion chamber 8 (Fig. 3, Fig. 5, Fig. 5a) with a removable cone-shaped element 9 (Fig. 3, Fig. 5) located in the cavity of the vertical shell 3 (Fig. 3, Fig. 5, Fig. .5a), is connected with the automatic unit for supplying the fuel-air mixture 10 (Fig. 3) through the cavity 11 (Fig. 3) in the boiler body using a pneumatic conveyor 12 (Fig. 3).

The cavity 11 (figure 3) is the inner space of the pipe, which connects the vertical and outer shells and is designed to pass the pneumatic conveyor 12. (figure 1, figure 3, figure 4)

The chimney 38 (Fig. 5) is attached to the flue gas outlet duct 26 (Fig. 2, Fig. 3).

On the front side of the housing 1, a handle 36 is fixed (Fig. 8) connected by a lever system to an atmospheric valve 4 (Fig. 3, Fig. 5). The force from the handle 36 (Fig. 8) to the atmospheric valve 4 (Fig. 3, Fig. 5) is transmitted through the bracket 64 (Fig. 8), the rod 62 (Fig. 8) with a lock nut 63 (Fig. 8), a two-arm lever 60 (Fig. 8) and the support of the two shoulders of the lever 61 (Fig. 8).

The automatic fuel-air mixture supply unit 10 (Fig. 4) consists of a screw feeder-dispenser 13, driven by a geared motor 14, a vacuum-vortex lock 15, a boost fan 16, an air damper 43 with an air actuator 17 and a pneumatic conveyor 12.

To supply air from the boost fan 16 to the cavity of the vacuum-vortex lock 15 there is a channel 53.

The vacuum-vortex gateway contains a channel 52 for supplying air to the cavity of the pneumatic actuator 17 through the channel 47 in it.

The pneumatic actuator 17 (figure 4) contains a piston 51, which is connected with the valve 43 (gate). The seal 49 performs the function of a guide flap 43, which is located in the cavity of the pneumatic conveyor 12. The volume of air passing through the gap "a" created by the flap 43 for idle is regulated using the adjusting screw 44 and lock nuts 46. Channel 48 is made over the seal 50 of the pneumatic actuator air removal.

The screw feeder-doser 13 is seated on a bearing 55, receives rotational movement from the gear motor 14 through sprockets 56, 57 and chain transmission 58.

Fuel is supplied to the vacuum-vortex gateway 15 from the accumulator 5 4. The fuel is supplied from the fuel hopper (not shown in the drawings).

The working thermostat 18 (Fig.6) through a programmable controller controls the supply of electric current to the boost fan 16 (Fig.1, Fig.3) and the gear motor 14 (Fig.1, Fig.2, Fig.3, Fig.4) .

On the rear surface of the housing (Fig. 7) there are pipes for the outgoing 19 and 20 incoming coolant flow, a 3-way valve 21, a circulation pump 22 and a coarse filter 23, as well as an emergency pressure relief valve 23a (Fig. 2) and a pipe 24 (figure 2) draining water from the boiler.

In the front part of the boiler body, the firebox door 5 (Fig. 1) with a window 40 (Fig. 1, Fig. 5) and an ashpit door 25 (Fig. 1) are suspended on hinges.

On the rear surface of the housing there is a flue gas outlet duct 26 (FIG. 2, FIG. 3) with a door 27 (FIG. 2) for cleaning soot and an ashpit door 28 suspended on hinges (FIG. 2).

In the upper part of the body there are hatches 29 (Fig. 1, Fig. 2, Fig. 3, Fig. 5a (A-AB-B)) for cleaning the convective part from ash deposits.

(figure 3, figure 5) 41 - holes in the hatch 29 for cleaning the convective part (smoke tubes) from ash deposits).

The boiler contains an operation control panel 30 (FIG. 2, FIG. 5), comprising a thermomanometer 31, a thermometer 32 for the coolant effluent, a thermometer 33 for the coolant inlet flow, a working thermostat 18 (FIG. 6), an emergency thermostat 34 (FIG. 6 ) and the mode switch of the boiler 35 (Fig.6).

On the outer surface of the housing is thermal insulation 42 (Fig. 3) made of mineral wool, closed on top with a removable decorative cladding of sheet steel 1.

On the front side of the housing is fixed a handle 36 (Fig. 8), connected by a system of levers to the atmospheric valve 4 (Fig. 3, Fig. 5). The force from the handle 36 to the atmospheric valve 4 is transmitted through the bracket 64 (Fig. 8), the rod 62 (Fig. 8) with the lock nut 63, and the two shoulders of the lever 60 (Fig. 8).

From the bottom to the ash pan, the boiler supports 37 are rigidly attached (Fig. 1, Fig. 2, Fig. 3, Fig. 5).

The firebox door, flue gas outlet duct and fuel supply system are coated with heat-resistant paint.

The screw feeder-dispenser 13 (Fig. 4) is seated on a bearing 55 (Fig. 4), receives rotational movement from the geared motor 14 (Fig. 4) through sprockets 56, 57 (Fig. 4) and a chain gear 58 (Fig. 4). four).

To regulate the temperature of the coolant, a three-way valve 21 is used (Fig.7).

The emergency thermostat 34 (Fig.6) is designed to open the power circuit of the boiler when the temperature of the heating medium is exceeded, set by the operating thermostat 18 (Fig.6).

The hot water boiler operates as follows.

The hot water boiler by means of pipes for the outgoing 19 (Fig. 7) and incoming 20 (Fig. 7) coolant flows is connected to a heating system containing a circulation pump 22 (Fig. 7).

A fuel hopper or soft container (not shown) is filled with fuel, mainly wood pellets.

The door of the furnace 5 opens (Fig. 1) and the cone-shaped element 9 (Fig. 3, Fig. 5) of the burner - vortex combustion chamber 8 (Fig. 3, Fig. 5) is removed for visual inspection of the filling of the burner cavity with fuel.

The switch 35 (6) of the boiler modes is rotated to the position "fuel supply mode". After filling the vortex combustion chamber 8 (Fig. 3, Fig. 5, Fig. 5a) with fuel, the boiler switch 35 (Fig. 6) is rotated to the STOP position, the fuel is poured with the kindling liquid.

Then opens the atmospheric valve 4 (Fig. 3, Fig. 5), designed to remove flue gases into the chimney 38 (Fig. 5), bypassing the smoke tubes 6, 6a (Fig. 3, Fig. 5, Fig. 5a). The fuel in the burner is ignited - a vortex combustion chamber 8 (Fig. 3, Fig. 5, Fig. 5a). After the formation of stable combustion around the entire perimeter of the burner - the vortex combustion chamber, the furnace door 5 and the atmospheric valve 4 are closed, and the boiler mode switch 35 is turned to the “fan” position.

After a few minutes, to control the ignition, the atmospheric valve 4 opens (Fig. 3, Fig. 5), then the door 5 of the furnace is visually checked for the presence of stable combustion over the entire surface of the fuel.

Next, with the help of the holder (capture) conical element 9 is installed on the burner - a vortex combustion chamber. The furnace door 5 closes, the atmospheric valve 4 is moved to the “closed” position, the boiler mode switch 35 is rotated to the “automatic boiler operation” position.

Flue gas movement S-shaped. Flue gases rise to the flame reflector 39 (Fig. 5) of the furnace, then along the surface of the furnace wall and further through the smoke pipes 6 pass down to the ash pan and through the smoke pipes 6a rise up, through the cavity of the convection hatch and through the pipe into the smoke pipe 38 .

Maintaining the desired temperature of the coolant is carried out by a working thermostat 18 located under the control panel 30 (Fig. 1, Fig. 2, Fig. 3) by operation. When the set boiler heating temperature is reached, the operating thermostat 18 switches off the boost fan 16 and the gear motor 14 through the programmable controller (the power supply circuit opens). After the coolant has cooled by 7-10 ° C from the set value, the circuit is closed and the burner is automatically ignited by feeding the fuel-air mixture.

Automatic node supply of the fuel-air mixture works as follows (figure 4). The air from the supercharger fan 16 tangentially (through the channel 53) enters the cavity C of the vacuum-vortex lock 15, then part of the air through the channel 52 and 47 enters the cavity A of the pneumatic actuator 17 of the valve 43. Under air pressure, the piston 51 together with the valve 43 rises to the extremely upper position until it stops in the seal 50. The air in the cavity B under the action of the piston 51, through the channel 48 is removed to the outside. The seal 49 functions as a guide flap 43. After the flap 43 has reached its highest position, the air pressure in the cavity C will begin to rise. Air, performing a rotational-translational movement from a cavity C through a channel K at a certain angle, starts to flow into a cavity D of a pneumatic conveyor 12 at a high speed. Compressed air, at the outlet of a channel K, expands sharply under the action of centrifugal force, thereby creating a rarefaction zone E According to the signal from the programmable controller, the screw feeder-dispenser 13 begins to supply fuel located in the accumulator 54 to the rarefaction zone E. Under the influence of the vortex created by the air flow, the fuel rotates noe movement, under the influence of centrifugal force thrown into the high pressure zone D and further along the pneumatic conveyor 12 into the burner - vortex combustion chamber 8.

The screw feeder-metering device, which is mounted on the bearing 55, receives rotational movement from the gear motor 14 through sprockets 56, 57 and chain gear 58. The screw of the metering feeder is made without support on the shaft end.

To regulate the temperature of the coolant, a three-way valve 21 is used.

If the temperature limit value of the heating medium by 8-10 ° C exceeds the temperature reading set by the operating thermostat 18, the emergency thermostat 34 is activated, opening the boiler power circuit.

In the event of an emergency stop, it is necessary to wait for the coolant temperature to drop (mainly to 70-75 ° C), unlock the emergency thermostat 34, and the system should automatically restart and return to the set temperature mode.

Thus, the claimed technical solution allows for the implementation of the tasks.

The design of the inventive boiler contains a vertical shell, which is an additional furnace space, due to which the surface of the heating medium is increased.

Inside the vertical shell is a burner-vortex combustion chamber, which is removable. When the burner is removed, the furnace space increases and it becomes possible to use other types of fuel (firewood, briquettes, etc.).

The design of the burner - the vortex combustion chamber has effective technical and economic indicators. Equipping the burner - a vortex combustion chamber with annular partitions allows increasing the degree of fuel combustion in the vortex chamber due to the fact that the annular partitions provide an increase in the centrifugal force with which the burning fuel is pressed against the walls of the shell, thereby minimizing the possibility of the unburnt fuel element being released into the atmosphere.

The use of a cone-shaped element and a burner - a vortex combustion chamber allows more flexible distribution and achievement of an optimal combustion mode, in connection with which there is a more complete combustion of gases, including sulfur compounds, as a result of which emissions of harmful gases into the atmosphere are reduced. In this case, the minimum amount of ash (about 0.001-0.005%) is formed in the furnace, which characterizes a high degree of combustion. Boiler efficiency increases.

The design of the automatic fuel-air mixture supply unit significantly increases the reliability of the boiler:

- replacement of the screw conveyor supplying fuel and a separate air channel (according to bl.analog) to a pneumatic conveyor and the combined supply of the fuel-air mixture through a pneumatic conveyor to the burner - a vortex combustion chamber greatly simplifies the design of the boiler, increases its reliability;

- eliminates the possibility of a reverse flame entering the firebox through the fuel supply channel;

- a separate air channel has been eliminated (according to the analogue), which is periodically clogged with unburned fuel residues, due to which the fuel burns when there is a lack of air, thereby increasing harmful emissions into the atmosphere;

- the flame reflector reduces the local heat load on the inner horizontal shell.

The claimed technical solution of the boiler and method of operation

- increases the reliability of the boiler by eliminating from the design of the boiler wear of unreliable elements and the optimal layout of its individual parts;

- reduces the material consumption of the boiler due to the design features of the execution of both individual structural elements, and their mutual arrangement and interaction, the use of heat and chemical resistant materials of the boiler;

- reduces the amount of harmful emissions into the atmosphere, including sulfur compounds, by ensuring optimal conditions for fuel combustion;

- increases the efficiency of the boiler up to 95% compared with the efficiency of the closest analogue - 93% (see Appendix 1. Technical specifications bl. analogue).

The claimed technical solution meets the criterion of "novelty", presented to the invention, since the prior art has not identified technical solutions that have a set of features inherent in the claimed boiler water-heating boiler and the way it works to achieve the stated goals.

The claimed technical solution meets the criterion of "inventive step" for inventions, because from the prior art did not reveal technical solutions that match the distinctive features of the claimed solution and it does not follow explicitly from the prior art.

The claimed technical solution meets the criterion of "industrial applicability" to the invention, because it can be made by known methods and from known means. The claimed technical solution was tested and showed the achievement of the declared results during trial operation: heating several industrial buildings and structures in rural areas.

Claims (6)

1. The boiler is a hot-water boiler containing a housing made of two coaxial shells, in the annular space between which there are smoke tubes of the convective beam and a heating medium heating circuit, a combustion chamber formed by the cavity of the inner shell, a thermostat, a recirculation pump, a fuel hopper and a burner with a cone-shaped element , characterized in that it contains in the lower part of the annular space of the coaxial shells a vertical shell, communicating from above with the combustion chamber, placed in a vertical shell This includes a vortex combustion chamber in which the aforementioned burner is installed, a flame reflector, an automatic fuel-air mixture supply unit, including a cantilever-screw feeder-dispenser, a vacuum-vortex lock, an air-operated choke with a pneumatic drive, and a pneumatic conveyor. 2. The boiler according to claim 1, characterized in that the coaxial shells are arranged horizontally, while the axis of the inner shell is shifted upward relative to the axis of the outer shell. 3. The boiler according to claim 1, characterized in that the burner with a vortex combustion chamber is removable and connected via annular couplings through a cavity in the boiler body to the automatic fuel-air mixture supply unit. 4. The boiler according to claim 1, characterized in that the smoke pipes are arranged in rows on planes perpendicular to the axes of the horizontal shells, while the extensions of the axes of the smoke pipes pass through the axis of the holes of the hatches intended for cleaning the smoke pipes. 5. The boiler according to claim 1, characterized in that the flame reflector is located in the upper part of the combustion chamber. 6. The method of operation of the boiler according to claim 1, which consists in supplying solid fuel to the burner inlet located in the combustion chamber, manually firing it with air supply to the combustion chamber, switching to automatic supply of fuel and air to the burner, removing flue gases through smoke tubes, characterized in that the fuel is burned in a burner installed in a vortex combustion chamber, and before being fed, the fuel and air are pre-mixed, for which the air from the boost fan is supplied to the vacuum-vortex gateway and through first into the cavity of the pneumatic drive, and the other part of the air from the vacuum-vortex lock under pressure enters the pneumatic conveyor, tangentially, through the channel, made at an angle less than 45 °, fuel is introduced into the created discharge zone of the pneumatic conveyor, where fuel and air mix and fuel air mixture under pressure into a burner installed in a vortex combustion chamber.

Images