RU2739877C1 - Furnace burners unit for fire tests - Google Patents

Abstract

FIELD: power engineering.

SUBSTANCE: invention relates to the field of power engineering. Burner assembly for fire tests comprises at least two burners. Each burner is equipped with fuel line for liquid fuel supply and air pipeline for supply of pre-dried air. At that, electric ignition is installed on one constantly operating burner. Distance between burners is selected based on guaranteed ignition of fuel-air mixture at supply of fuel to burner adjacent to operating one. Each fuel line is equipped with fuel supply valve, and air supplied by air pipeline is pre-drained.

EFFECT: invention allows reducing consumption of used fuel and avoiding spontaneous flame attenuation.

3 cl, 2 dwg

Description

The invention relates to the field of construction, in particular to furnaces for testing building structures and engineering equipment, and can be used for certification of building products for fire resistance and fire hazard.

The fire resistance of building components is mainly measured in accordance with standard fire resistance tests, that is, in accordance with the requirements of prescribed heating conditions, pressure conditions, load conditions and fire conditions. It is checked whether components such as walls, columns, beams and floors can meet the requirements for stability, integrity, thermal insulation, etc. When certifying building structures for fire resistance, special furnaces are used that create conditions typical for a fire, namely temperature and fire effects on the tested structures or equipment. For this, installations with a fire zone are used, equipped with burners operating on liquid fuel, for example, diesel fuel. Such burners generate one or more flames in the fire zone using diesel fuel and an oxygen source such as air, for example.

CN 206269126, Priority 11/29/2016, describes a fuel burner for a test bench, which includes a fire detector, an ignition sensor, a diesel fuel supply pipe and an air supply pipe located at the burner inlet. The nozzle sleeve is fixed to the burner. There is a nozzle that is connected to the diesel fuel supply pipe. The air diffuser is fixed to one side of the nozzle outlet and has a ring-like shape, with the air outlet holes in the air outlet being evenly distributed, and the size of each air outlet increasing towards the outer radius. The flame outlet pipe is installed at the outlet end of the burner, and is tapered inward. The disadvantage of the proposed useful model is the need to regulate the temperature of the outgoing flame depending on the supplied fuel and air.

This disadvantage is solved in the patent CN 203965359, priority 07.07.2014, which describes a test furnace. The test furnace includes a furnace body, furnace bottom, oil supply pipe, built-in burner and furnace temperature thermocouple, and a flue duct. The furnace body is protected by refractory materials including the assembled furnace walls and connectors, and the assembled furnace walls are connected by connectors. The furnace body is provided with burner mounting holes and the furnace body. The furnace floor is rigidly connected to the bottom of the furnace body.

The liquid fuel supply pipe is located outside the furnace body and surrounds the furnace body. The liquid fuel supply pipe is in communication with the fuel tank.

The nozzle of the built-in burner is made facing inside the furnace body and is mounted on the oil supply pipe through the burner mounting hole on the furnace body and communicates with the liquid fuel supply pipe.

The control and data acquisition device includes a central processing unit, a flame control circuit, a temperature measurement acquisition circuit and an offset. For temperature control, a central processor is provided, which is electrically connected to an electronic servo valve and an igniter on the built-in burner. Furnace temperature control is controlled by the flame control loop, that is, the central processor sends instructions to control the opening and closing of the electronic servo valve on the built-in burner via feedback from the data collector. The decrease in the internal temperature of the furnace body is controlled only by reducing the amount of supplied oil. Additionally, water circulation in a pipe located in the smoke outlet is used to change the temperature inside the oven.

The main disadvantage in the proposed utility model is the need for constant temperature control of the torches of the flame of the burners. Regulation is carried out by changing the amount of fuel supplied to the burners due to feedback. At the same time, in order to achieve the required temperature, a signal is sent from the central processor about an alternating increase or decrease in the amount of fuel supplied to the burners. This leads to a large waste of fuel.

Also the quality of the supplied air has a strong influence on the flame temperature. This is due to the fact that if the correct combination of fuel and oxygen is not maintained, the burner can enter a phase of substoichiometric combustion, in which there is not enough oxygen to completely burn the fuel. Substoichiometric combustion can lead to instability of the burner flame and, if not corrected in time, the burner flame can completely disappear. This is called flame extinction.

The problem solved by the present invention is to create a block of burners that allows, without additional adjustment, to create a stable, predetermined maximum heat release on each burner used.

The technical result is the economy of fuel consumed during the tests.

The problem is solved, and the technical result is achieved by the fact that the block of burners of the furnace for firing tests contains at least two burners. Each of the burners is equipped with a fuel line for supplying liquid fuel and an air line for supplying air. Moreover, the electric ignition is installed on one burner constantly operating in the block. The distance between the burners is chosen on the basis of guaranteed ignition of the fuel-air mixture when fuel is supplied to the burner adjacent to the operating one. Each fuel line is equipped with a fuel supply valve. In this case, the air supplied by the air duct is pre-dried.

In particular, diesel fuel is used as fuel.

It is preferred that the burners are pre-set for maximum heat generation upon complete combustion of the supplied fuel.

The presence of two or more burners in the burner block of the firing test furnace makes it possible to stepwise change the amount of heat release, while the amount of heat released is known in advance and is stable.

The fact that the electric ignition is installed on one permanently operating burner in the block makes it possible to constantly maintain the burner block in working order. At the same time, the fact that the distance between the burners is selected on the basis of guaranteed ignition of the fuel-air mixture when fuel is supplied to the burner adjacent to the operating one allows increasing or decreasing the total heat release from the burner block as necessary. This is done by turning on or off the fuel supply valve, which is supplied with the fuel line of each burner in the block.

The pre-dried air supplied by the air duct ensures the quality of the supplied air, the absence of moisture in it, and, as a result, the impossibility of spontaneous extinction of the burner flame.

The use of diesel fuel makes it possible to pre-adjust and obtain a stable heat release from the flame of each burner.

Pre-configured burners for maximum heat release during complete combustion of the supplied fuel allow maximum fuel savings during testing.

In the following, the claimed invention is illustrated by a detailed description of a specific, but not limiting present solution, an example of its implementation and the accompanying drawings, in which:

Fig. 1 is a schematic representation of an embodiment of a block of three burners;

Fig. 2 is a schematic diagram of a block of three burners.

In the example shown, the burner block of the fire test furnace is made of three, horizontally arranged in a row, burners 1. However, it is possible to use a different number of burners 1. The arrangement of burners 1 can be different, for example, vertical or diagonal.

The burners 1 are installed in the wall of the furnace chamber, which has, for example, brickwork 2, a first 3 insulating lining layer and a second 4 insulating lining layer.

The burners 1 are installed in such a way that the flame of the torch of each burner 1 is directed into the fire chamber of the furnace. The distance at which the burners 1 are installed is selected from the condition under which guaranteed ignition of the fuel-air mixture is ensured when fuel is supplied to adjacent burners 1 that are constantly operating. In a specific example, these are side burners 1, while the central burner 1 is constantly operating.

A fuel line 5 and an air line 6 are connected to each burner 1. A fuel supply valve 7 is installed on each fuel line 5, and an air supply valve 8 is installed on each air line 6. It should be noted that the supplied air is pre-dried in an air dryer, not shown in the drawings.

The formation of a directed torch of burners 1 is carried out by reducing the area of atomization of the fuel-air mixture leaving the nozzles of burners 1 by using guide cylinders 9 located in the furnace wall and protruding beyond the level of internal thermal insulation of the furnace walls (see Fig. 1).

Constantly working, in a specific example, this is the central burner 1 is equipped with an electric ignition 10. For the operation of the electric ignition 10, the power cable 11 is connected to it.

The burner block 1 is operated as follows. Each burner 1 is preliminarily adjusted for maximum heat release in terms of fuel consumption at a given amount of supplied air or in terms of air consumption at a given amount of supplied fuel, which ensures complete combustion of the supplied fuel.

Constant combustion of the central burner 1 torch is maintained by the constantly supplied fuel and dry air to the burner at preset flow rates, calculated and adjusted for the maximum heat release, and by constantly operating electric ignition 10 of the combustible mixture at the outlet from the guide cylinder 9 of the central burner 1.

At the same time, a constant supply of dried air is made to the side burners 1, regardless of the fuel supply.

Regulation of the power of heat release in the fire space of the furnace is carried out by turning on / off the burners 1 located in the blocks next to the operating burners 1, by turning on / off the fuel supply to each burner 1.

The presence of several blocks, each of which is made, as in the given example of three burners 1, in one test furnace allows to obtain a high variability in the regulation of the heat release power, which makes it possible to provide a given thermal regime in the furnace combustion chamber.

At the same time, there is no need to adjust the amount of fuel and air supplied during the test.

It should be noted that the pre-dried air supplied by the air duct ensures the absence of moisture in it, which prevents the spontaneous extinction of the flame of burners 1.

Using, while maintaining a predetermined temperature regime in the fire space of the furnace, the "on / off" modes of burners 1, tuned for maximum heat release, without the use of adjusting the supply of air and / or fuel supplied to the burner, during the tests significantly reduces the consumption of fuel used, which allows achieve the stated technical result.

Claims (3)

1. A block of burners of a furnace for firing tests, containing at least two burners, each of which is equipped with a fuel line for supplying liquid fuel and an air line for supplying air, characterized in that the electric ignition is installed on one burner constantly operating in the block, the distance between the burners is selected from calculating the guaranteed ignition of the air-fuel mixture when fuel is supplied to the burner adjacent to the operating one, each fuel line is equipped with a fuel supply valve, and the air supplied by the air line is pre-dried. 2. The block of burners of the furnace for firing tests according to claim 1, characterized in that diesel fuel is used as fuel. 3. The block of burners of the furnace for firing tests according to claim 1, characterized in that the burners are preset for maximum heat release upon complete combustion of the supplied fuel.

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