RU2244878C2 - Igniter (versions) - Google Patents

Abstract

FIELD: combustion control processes; lighting-up stabilizing the flame of burners of thermal power units.

SUBSTANCE: according to first version, proposed igniter includes plasmatron and auxiliary lighting-up injector mounted in such position that its jet of spraying intersects plasma jet of plasmatron. Lighting-up injector may be made in form of pneumohydraulic injector which is connected with autonomous fuel source or may take fuel from jet of main injector. Igniter may be provided with fuel thermal preparation chamber where plasmatron and lighting-up injector are located in one end other is located in zone of spray of main injector. According to other version, igniter is provided with casing having holes; it is made for of semicylinder.

EFFECT: low cost due to reduced power of plasmatron.

4 cl, 7 dwg

Description

The group of inventions relates to the field of combustion control and can be used for ignition and stabilization of the flame of burners of heat power plants burning various types of fuel.

A firing device for a kindling burner of a power plant containing a plasmatron is known (Plasma oil-free kindling of boilers and stabilization of the combustion of a pulverized coal torch. MF Zhukov, EI Karpenko, BC Peregudov et al. Edited by V.E. Messerle, BC Peregudova . - Novosibirsk: Science. Sib. Publishing company of the Russian Academy of Sciences. 1995. S. 98).

The disadvantage of designs with plasma ignition of the main burner is the large required power of the plasma torch, which complicates the power supply system of the plasma torch and increases the cost of installation.

Closest to the proposed is the ignition device for a burner of a power plant, containing a plasmatron and means for supplying fuel to the torch of the plasma torch through an annular space covering the plasma torch (WO 90/08289, F 23 D 1/00, F 23 Q 13/00, publ. 26.07 .1990). In this device, as an additional fuel, a pulverized coal mixture is used, which is also the working fuel of the boiler unit.

The known design is not suitable for working with liquid fuel, which requires a special device for spraying, and when passing through the annular space around the plasma torch, droplets of fuel will become larger, and their ignition and flare formation will be less effective.

The technical result of the group of inventions is to increase the efficiency of the ignition device on liquid fuel, as well as expanding the range of ignition devices.

This result is achieved in that in the ignition device for a burner of a power plant according to the first embodiment, comprising a plasma torch equipped with an auxiliary ignition device installed at the output of the plasma torch with the possibility of intersection of its torch with the plasma torch of the plasma torch, according to the invention, the auxiliary device is made in the form of a fuel nozzle installed with the possibility of fuel selection from the spray torch of the fuel of the main burner.

The fuel nozzle may be a pneumohydraulic nozzle.

In addition, the device can be equipped with a thermal fuel preparation chamber, at one end of which there is a plasmatron and a fuel nozzle, and its opposite open end is designed to be placed in the zone of the fuel spray of the main burner.

The indicated result is also achieved by the fact that the ignition device for the burner of the heat and power plant according to the second embodiment, containing a plasmatron, is equipped with a casing with holes made in the form of a half cylinder, mounted at the outlet of the plasma torch and designed to accommodate at least part of it in the spray torch coaxially with him and intended to accommodate, at least part of it in the spray torch of the main burner.

Figure 1 shows the location of the ignition device according to the first embodiment in the installation pipe; figure 2 - node 1 in figure 1; figure 3 - pneumohydraulic nozzle; figure 4 - diagram of the selection of fuel from the spray torch of the main burner; figure 5 - arrangement of the ignition device with a camera for thermal preparation of fuel; figure 6 - camera thermal preparation of fuel; Fig.7 - ignition device according to the second embodiment.

The ignition device (charger) for a kindling burner of a power plant according to the first embodiment of the invention comprises a plasmatron 1, an ignition fuel nozzle 2 (Fig. 1), which can be made pneumohydraulic with the possibility of adjusting the geometric parameters of the torch by changing the input pressure of the fuel and gas and setting the output nozzle 3 of various shapes (FIG. 3). In addition, the charger is equipped with a chamber 4 for thermal preparation of fuel, at one end of which there is a plasma torch 1 and an ignition device in the form of a fuel nozzle 2, and the opposite end of the chamber 4 is designed to be placed in the zone of the spray of fuel of the main heated burner (Fig. 6). The charger is located in the installation pipe 5, passing either parallel to the main fired burner, or at an angle to it (Fig. 1).

The initiating device for igniting the torch of the main burner is the plasma torch 1. Air or any other substance is used as the working fluid. When voltage is applied to the electrodes of the plasma torch 1, a torch is formed at its output containing ionized dissociation products with high chemical activity and initiating the combustion of the fuel mixture. Plasmatron 1 is installed in the memory. The kindling burner may include several memories with plasmatrons 1, fed sequentially (in time) from one power supply, which is located near the boiler unit.

In addition to fuel oil, gas, diesel fuel, kerosene and other combustible products can be used as ignition fuel.

The ignition device according to the first embodiment operates as follows.

When voltage is applied to the electrodes of the plasma torch 1, a torch is formed at its output, containing ionized products of dissociation of the working fluid, which are highly active and initiate the combustion of the fuel mixture exiting the fuel nozzle 2 and falling into the torch zone of the plasma torch 1 (see Fig. 2). A torch is formed on the nozzle 2, intersecting with the torch of the plasma torch 1, as a result, a stable high-temperature torch is formed.

In order to optimize the conditions for igniting a fuel oil flame of a boiler unit or other heat engineering device, the fuel nozzle 2 flame is organized with a predetermined distribution of parameters over the flame space (temperature distribution, size and concentration of fuel particles, etc.). This is achieved by spraying fuel using a pneumatic-hydraulic nozzle 2 equipped with a profiled nozzle 3 (figure 3). By changing the flow rate and pressure of the fuel and atomizing gas, as well as the shape of the nozzle 3, the desired size and spatial distribution of the fuel droplets can be achieved.

Autonomous power supply of the fuel injector 2 may be associated with technical difficulties (the need to clean the fuel pipelines in the interval between switching on, additional automation devices, etc.). In some cases, it is possible to take fuel from the spray torch of the main burner (figure 4). In this case, part of the fuel is taken out by a trap 6 installed in the spray torch, and enters the pneumohydraulic nozzle 2, which acts as an ejector, sucking in the fuel and spraying it with gas.

In order to increase the convenience of operation, the plasma torch 1 and nozzle 2 are placed at the end of the pipe 7 located outside the boiler unit (Fig. 6), and the open end of the pipe 7 is placed inside the boiler unit at a distance of 100-1000 mm from the torch of the main fuel oil nozzle 8 of the ignition burner (Fig. 5).

In this case, the cooling conditions of the plasma torch 1 and the fuel channels of the fuel nozzle 2 are simplified. The fuel is supplied to the fuel nozzle 2 in such a quantity as to ensure the permissible temperature of the gas in the flame tube 7 with a lack of oxidizer. When leaving the flame tube 7, the products of incomplete combustion and thermal decomposition combine with the oxygen of the blast air and burn out, forming a high-temperature stable flame.

According to the second embodiment of the invention (Fig. 7), at the outlet of the plasma torch 1, a casing is mounted coaxially with it, for example, in the form of a cylinder or half cylinder 9 with holes or slots, which is placed in the spray torch of the main burner. Part of the fuel enters through the holes into the cylinder, where it is ignited by a plasma torch. Combustion products exit both along the axis of the cylinder and through openings on the opposite side. In the case of using a half cylinder 9, the fuel penetrating through the holes is ignited by the jet, and the flame propagates in the direction of movement of the fuel droplets. A cylinder or a half cylinder 9 heated by a plasma jet also contributes to ignition of the fuel. The casing may also have a different shape, for example, with a cross section in the form of a trapezoid, ellipse, etc.

In this embodiment of the device, favorable conditions are created for combustion, to prevent the ignition device from breaking down into the fuel torch of the main burner, and to stabilize the flame.

Claims (4)

1. The ignition device for the burner of a power plant, containing a plasma torch, equipped with an auxiliary ignition device installed at the output of the plasma torch with the possibility of intersection of its torch with a flame torch of the plasma torch, characterized in that the auxiliary ignition device is made in the form of a fuel nozzle mounted with the possibility of taking fuel from fuel spray torch of the main burner. 2. The ignition device according to claim 1, characterized in that the fuel nozzle is a pneumohydraulic nozzle. 3. The ignition device according to claim 1, characterized in that it is equipped with a thermal fuel preparation chamber, at one end of which there is a plasmatron and a fuel nozzle, and its opposite, open end, is designed to be placed in the zone of the fuel spray of the main burner. 4. An ignition device for a burner of a heat power plant containing a plasma torch, characterized in that it is provided with a casing with holes made in the form of a half cylinder, mounted at the exit of the plasma torch and designed to accommodate at least part of the main burner in the spray of fuel.

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