JP2021188897A - Temperature measuring device and burner - Google Patents

Abstract

To prevent corrosion of a temperature sensor.SOLUTION: A temperature measuring device is provided in a burner in which a fuel is injected to a combustion space so that a fire is formed and in which a circulation flow of a combustion gas is formed. The temperature measuring device includes a temperature sensor set in the outer surface of the burner and a temperature sensor cover over the outside of the temperature sensor.SELECTED DRAWING: Figure 1

Description

The present invention relates to a temperature measuring device and a burner.

In a device such as a combustor where high-temperature combustion is performed, the temperature may be measured by using a thermoelectric pair or the like for controlling the combustion state and protecting each member. For example, Patent Document 1 discloses a temperature measuring device for measuring the temperature inside a heating furnace.

Japanese Unexamined Patent Publication No. 11-281494

By the way, at present, a burner that forms a flame by using oil coke as a fuel is considered, and even in such a burner, it is required to measure the surface temperature. However, when oil coke is burned, a corrosive substance such as vanadium is generated in the combustion gas. Such corrosive substances corrode the temperature sensor and interfere with continuous temperature measurement.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to prevent corrosion of the temperature sensor.

The present invention is provided in a burner in which fuel is injected into a combustion space to form a flame and a circulating flow of combustion gas is formed inside, as a first means for a temperature measuring device for solving the above problems. The temperature measuring device is provided with a temperature sensor installed on the outer surface of the burner and a temperature sensor cover covering the outside of the temperature sensor.

As a second means relating to the temperature measuring device, in the first means, the temperature sensor cover is erected from the outer peripheral surface of the burner and is joined to the side peripheral wall surrounding the temperature sensor and the side peripheral wall. The side peripheral wall is provided with a flange-shaped joint portion that comes into contact with the upper wall.

As a third means relating to the temperature measuring device, in the first or second means, the temperature sensor cover adopts a configuration in which the downstream side in the flow direction of the fuel is open with respect to the temperature sensor. do.

As a fourth means relating to the temperature measuring device, in any of the above-mentioned first to third means, the temperature sensor cover is filled with a heat-resistant material.

As a fifth means according to the temperature measuring device, in any one of the first to fourth means, a plurality of the temperature sensors are provided in the burner, and the temperature sensor cover comes into contact with the circulating flow of the combustion gas. A configuration is adopted in which the temperature sensor installed at the site is provided.

As the first means related to the burner, a preheating chamber in which fuel is injected into the combustion space and a circulation flow of combustion gas is formed inside, a temperature sensor installed on the outer peripheral surface of the preheating chamber, and the temperature sensor. A configuration is adopted in which a temperature sensor cover that covers the outside of the fuel is provided.

According to the present invention, corrosion of the temperature sensor can be prevented.

It is a schematic whole view of the burner which concerns on one Embodiment of this invention. It is a schematic diagram which shows the temperature measuring apparatus which concerns on one Embodiment of this invention. It is a schematic diagram which shows the temperature measuring apparatus which concerns on one Embodiment of this invention. It is sectional drawing in the temperature measuring apparatus which concerns on one Embodiment of this invention.

Hereinafter, an embodiment of the burner according to the present invention will be described with reference to the drawings.

A furnace opening 110 that communicates the inside and the outside is formed in the furnace wall 100 provided with the burner 1 according to the present embodiment. A throat is formed in the furnace opening 110 so as to increase the diameter toward the inside of the furnace.

The burner 1 is a device provided on the furnace wall 100 of the combustor and burns oil coke to form a flame in the combustor. The burner 1 includes a preheating chamber 2, an oil gun 3, a secondary air supply unit 4, a secondary air swirler 5, a thermocouple 6 (temperature sensor), a thermocouple cover 7 (temperature sensor cover), and casters. It is equipped with a metal fitting 8. Further, the thermocouple 6, the thermocouple cover 7, and the caster metal fitting 8 form the temperature measuring device S according to the present embodiment.

The preheating chamber 2 has a substantially cylindrical shape, and a fuel supply port is formed at a position eccentric to the lower side in the vertical direction at the upstream end portion. From the fuel supply port, oil coke as fuel and primary air for transporting the oil coke are injected into the preheating chamber 2. As a result, in the preheating chamber 2, the primary air flow path R1 is formed inside. Further, in the preheating chamber 2, a tertiary air supply port is formed at a position eccentric to the upper side in the vertical direction at the upstream end portion. In such a preheating chamber 2, a circulating flow R2 in which the combustion gas flows into the inside from the discharge port is formed in the space above the primary air flow path R1 in the vertical direction. The oil coke supplied to the preheating chamber 2 is in a state of being heated to about several hundred ° C. together with the primary air by a heater (not shown).

The oil gun 3 is a nozzle provided on the upper side in the vertical direction in the preheating chamber 2 and discharges heavy oil into the preheating chamber 2. The oil gun 3 is movable in the axial direction, for example, and discharges a highly ignitable liquid fuel such as heavy oil in a state of being projected toward the downstream side in the axial direction when the burner 1 is ignited.

The secondary air supply unit 4 is provided on the axis L on the outer peripheral side of the preheating chamber 2, and forms a secondary air flow path R3 with the furnace wall 100 on the outer periphery of the preheating chamber 2. The secondary air supply unit 4 supplies combustion air to the flame from the outside in the radial direction.

The secondary air swirler 5 is a blade row formed by a plurality of blade portions arranged in the circumferential direction about the axis L. The secondary air swirler 5 is provided on the downstream end side of the secondary air supply unit 4, and forms a flow swirling around the axis L in the injected secondary air. That is, the secondary air injected into the combustion space is a swirling flow centered on the axis L.

The thermocouple 6 is a temperature sensor having a thermocouple pad 6a at its tip. The thermocouples 6 are provided at three positions with respect to the preheating chamber 2 of the burner 1, and the thermocouple pads 6a are fixed to the outer peripheral surface of the preheating chamber 2 by welding. The thermocouple 6 is provided in the preheating chamber 2 near the discharge port on the side of the primary air flow path R1 and above the circulation flow R2. Such a thermocouple 6 transmits an electric signal based on the surface temperature of the preheating chamber 2 to an external control device.

As shown in FIGS. 2 to 4, the thermocouple cover 7 is a metal member provided so as to cover the thermocouple 6 on the outer peripheral surface of the preheating chamber 2 in which the thermocouple 6 is arranged. Further, a mortar-like heat-resistant caster (heat-resistant material) is filled between the thermocouple cover 7 and the outer peripheral surface of the preheating chamber 2, that is, around the thermocouple 6, which completely covers the thermocouple 6. It is said that. As shown in FIG. 2, there are two thermocouple covers 7 that cover two adjacent thermocouples 6 and one that covers one thermocouple 6 as shown in FIG. Such a thermocouple cover 7 has a side peripheral wall 7a and an upper wall 7b that abuts on the end of the side peripheral wall 7a and covers the thermocouple 6.

The side peripheral wall 7a is a member that is vertically erected from the outer peripheral surface of the preheating chamber 2 and surrounds the upstream side and the side of the thermocouple 6. That is, the side peripheral wall 7a is open because the wall portion is not formed on the downstream side of the thermocouple 6. The side peripheral wall 7a has a flange-shaped joint portion 7a1 protruding outward at the end portion on the side not in contact with the outer peripheral surface of the preheating chamber 2, that is, the entire circumference of the upper end portion. The side peripheral wall 7a is fixed by being welded to the outer peripheral surface of the preheating chamber 2.

As shown in FIG. 4, the upper wall 7b is a flat plate-shaped member that covers the thermocouple 6 surrounded by the side peripheral wall 7a from above (that is, the radial outside of the preheating chamber 2). The upper wall 7b has a size slightly smaller than the outer shape of the joint portion 7a1. The upper wall 7b is provided in contact with the joint portion 7a1 of the side peripheral wall 7a, and is welded to the outer edge of the joint portion 7a1.

As shown in FIG. 4, the caster metal fitting 8 is a substantially V-shaped member provided on the outer peripheral surface of the preheating chamber 2 and projecting outward in the radial direction of the preheating chamber 2. The caster metal fittings 8 are provided at a plurality of locations (in the present embodiment, two locations on the upstream side and two locations on the downstream side, for a total of four locations) in the thermocouple cover 7. The caster metal fittings 8 provided at the two locations on the upstream side are arranged so that the erected wall portions are oriented in the direction along the axis L. The caster metal fittings 8 provided at the two locations on the downstream side are arranged so that the erected wall portions intersect the axial center L.

At the time of ignition, the liquid fuel is injected into the combustion space with the oil gun 3 of the burner 1 protruding toward the downstream side. The liquid fuel is injected into the combustion space and ignited to form a flame in the combustion space.

Further, at the time of normal combustion, in the burner 1, the oil coke and the primary air pass through the primary air flow path R1 in the preheating chamber 2 and are injected into the combustion space. In addition, secondary air, which is combustion air, is simultaneously injected from the outer peripheral side. Further, the tertiary air is injected from above inside the preheating chamber 2. As a result, the combustion gas having a high temperature of 1000 ° C. or higher due to combustion in the combustion space flows into the preheating chamber 2. The combustion gas is a gas generated by burning oil coke and contains a corrosive substance such as vanadium dioxide.

Then, in the preheating chamber 2, the primary air and oil coke flowing in the primary air flow path R1 are in contact with and mixed with the combustion gas of the circulating flow R2, and the temperatures of the primary air and oil coke having a relatively low temperature are raised. Rise. Then, the combustion gas is again injected from the primary air flow path R1 into the combustion space together with the primary air and oil coke. As a result, the oil coke is supplied to the combustion space in a high temperature state, and easily volatilizes in the combustion space, so that combustion becomes easy.

In such a temperature measuring device S, the thermocouple 6 measures the temperature of the outer peripheral surface of the preheating chamber 2 and transmits it to an external control device. Since the thermocouple 6 is arranged in the vicinity of the circulating flow R2 of the combustion gas in the preheating chamber 2, it is exposed to the high temperature combustion gas. On the other hand, since the thermocouple 6 is covered with the thermocouple cover 7, the combustion gas does not come into direct contact with the thermocouple 6. Therefore, it is possible to prevent the thermocouple 6 from being corroded by a corrosive substance such as vanadium dioxide contained in the combustion gas.

Further, in the temperature measuring device S according to the present embodiment, the joint portion 7a1 is provided on the side peripheral wall 7a of the thermocouple cover 7. Therefore, welding between the joint portion 7a1 and the upper wall 7b becomes easy, and the thermocouple cover 7 can completely cover the thermocouple 6. This makes it possible to more reliably prevent the combustion gas from coming into direct contact with the thermocouple 6.

Further, in the temperature measuring device S according to the present embodiment, the side peripheral wall 7a is not formed on the downstream side of the thermocouple 6 and is in an open state. Therefore, it is easy to wire the thermocouple 6 from the open portion.

Further, in the temperature measuring device S according to the present embodiment, the inside of the thermocouple cover 7 is filled with mortar-shaped casters. This makes it possible to reliably prevent the thermocouple 6 from coming into contact with the high-temperature combustion gas on the outer periphery of the preheating chamber 2. Therefore, it is possible to more reliably prevent the thermocouple 6 from being corroded by a corrosive substance such as vanadium dioxide contained in the combustion gas.

Although the preferred embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to the above embodiment. The various shapes and combinations of the constituent members shown in the above-described embodiment are examples, and can be variously changed based on design requirements and the like without departing from the spirit of the present invention.

In the above embodiment, a plurality of thermocouples 6 are provided, and all thermocouples 6 are provided with thermocouple covers 7, but the present invention is not limited thereto. For example, the thermocouple 6 is provided only to the thermocouple 6 installed in the vicinity of the discharge port of the preheating chamber 2 and closest to the circulation flow R2 of the combustion gas (the upper portion in FIG. 1). May be provided.

Further, in the above embodiment, the thermocouple cover 7 is filled with casters, but the present invention is not limited to this. For example, in the thermocouple cover 7, when the downstream surface is sufficiently sealed, the inside of the thermocouple cover 7 may be hollow without filling the casters.

Further, in the above embodiment, the temperature measuring device S is provided in the burner 1, but the present invention is not limited to this. The temperature measuring device S can also be attached to the existing burner 1.

1 Burner 2 Preheating chamber 3 Oil gun 4 Secondary air supply unit 5 Secondary air swirler 6 Thermocouple 6a Thermocouple pad 7 Thermocouple cover 7a Side peripheral wall 7a1 Joint 7b Upper wall 8 Castor metal fittings 100 Thermal furnace wall 110 Thermal furnace opening L Axial center S temperature measuring device

Claims (6)

It is a temperature measuring device installed in a burner where fuel is injected into the combustion space to form a flame and a circulating flow of combustion gas is formed inside.
The temperature sensor installed on the outer surface of the burner and
A temperature measuring device including a temperature sensor cover that covers the outside of the temperature sensor. The temperature sensor cover has a side peripheral wall that is erected from the outer peripheral surface of the burner and surrounds the temperature sensor, and an upper wall that is joined to the side peripheral wall.
The temperature measuring device according to claim 1, wherein the side peripheral wall is provided with a flange-shaped joint portion that abuts on the upper wall. The temperature measuring device according to claim 1 or 2, wherein the temperature sensor cover is open on the downstream side in the flow direction of the fuel with respect to the temperature sensor. The temperature measuring device according to any one of claims 1 to 3, wherein the temperature sensor cover is filled with a heat-resistant material. A plurality of the temperature sensors are provided in the burner, and the temperature sensors are provided in the burner.
The temperature measuring device according to any one of claims 1 to 4, wherein the temperature sensor cover is provided on a temperature sensor installed at a portion of contact with the circulating flow of the combustion gas. A preheating chamber that injects fuel into the combustion space and forms a circulating flow of combustion gas inside.
A temperature sensor installed on the outer peripheral surface of the preheating chamber and
A burner including a temperature sensor cover that covers the outside of the temperature sensor.

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