JP4102878B2 - High-temperature circulating fluidized bed particle velocity measuring device - Google Patents

Description

The present invention relates to the inside of a high-temperature circulating fluidized bed for measuring the particle moving speed of a high-temperature circulating fluidized bed in a gasifier that generates high-temperature gas by a fluidized bed using particles, or a combustion apparatus that uses a fluidized bed. on that equipment be measured particle circulation rate.

  Fluidized bed utilizing treatment equipment is used in various fields in which particles are put into a fluidized state and various substances are mixed therein, and the substances are treated. In particular, the particles are mixed with substances at high temperatures. The high-temperature treatment is used as a coal combustion device, a coal gasification device, as a waste treatment device, or as a drying device for various substances.

  FIG. 3 schematically shows an example of a waste pyrolysis gasification furnace using a conventional fluidized bed, in which a particulate fluidized medium 2 is accommodated in the gasification furnace 1, and an air blower disposed below is disposed. Air is supplied from the nozzle 3 into the fluidized particles 2 at a high pressure so that the fluidized particles 2 are in a fluid state. Waste 4 such as a resin material is supplied from the side wall of the gasification furnace 1 into the fluidized particles 2 in a fluid state, and after the first ignition, the fluidized particles 2 and the like are heated by the combustion reaction heat. As a result, a part of the combustion reaction of the waste 4 continues, and the waste 4 thrown into the gasification furnace 1 forms a high-temperature circulating fluidized bed together with the high-temperature fluidized particles 2 in the furnace and is stirred in the furnace. It is decomposed and gasified while circulating while being mixed.

  Combustion exhaust gas and cracked gas due to the combustion reaction as described above in the gasification furnace 1 rise in the furnace together with fluid particles and combustion residue, and enter the cyclone solid-gas separator 6 from the upper discharge port 5. A solid material mainly composed of the fluidized particles 2 is separated and dropped, and is stored in a loop seal chamber 7 which is a storage chamber disposed below and is a backflow circulation prevention chamber. The part where the fluid particles move from the solid-gas separator 6 into the lower chamber is referred to as a downcomer section 8.

  The fluidized particles 2 in the loop seal chamber 7 are again introduced into the gasification furnace 1 from the fluidized particle introduction holes 9 and circulate by repeating the above-described operation. A gas mainly composed of cracked gas is discharged from an exhaust port 10 at the top of the cyclone solid-gas separator 6 and used as fuel for a gas turbine or a boiler combustor, thereby generating electric power and further hot water. Effective use of energy by supply etc. is planned.

  In such a high-temperature circulating fluidized bed process, it is extremely important to know how the fluidized particles are flowing in order to perform desired process control. The solid component of the waste is gradually mixed into the fluidized particles and the fluidized material is increased. On the other hand, the original fluidized particles are gradually refined into a powder and are reduced by being discharged to the outside together with the gas. Since these states vary greatly depending on the type of waste and the treatment state in the gasification furnace 1, in order to perform a desired gasification treatment in the gasification furnace, the amount of the fluid medium that is currently flowing must be detected. Therefore, it is important to perform control such as addition or extraction of fluidized particles, adjustment of waste input amount, adjustment of furnace air supply amount, and the like.

  As described above, various methods have been proposed and used as means for detecting the circulating amount of fluidized particles, and the fluidized particles in the gasifier may be detected directly, but the most stable in the fluidized particle circulation path. The amount of flowing particles present in a unit time in the gasification furnace 1 is also detected by measuring the velocity of the flowing particles flowing down in the downcomer section 8 that is flowing.

In order to detect the velocity of the flowing particles in the downcomer unit 8, it has been proposed to use an optical sensor such as a photoelectric sensor, a photoelectric switch, an infrared sensor, or a laser sensor. It has also been proposed to measure the weight of fluid particles and the like present in the loop seal chamber below the downcomer section with a load cell (Japanese Patent Laid-Open No. 2003-185116).
JP 2003-185116 A

  Various methods have been proposed as described above as a method for measuring the particle circulation rate in the high-temperature circulating fluidized bed, but both are insufficient as a reliable and practical method for measuring the amount of particle circulation at high temperatures, The method has not yet been established, and the development of a more reliable and practical method for measuring the amount of particle circulation is desired. In particular, in the method using an optical sensor, the rate of descent at the downcomer can be measured by using the light emission of particles in a combustion furnace, but the light emission is not so large in a gasification furnace where the reaction process is performed at a relatively low temperature. It cannot be used. Further, when measuring the weight with a strain gauge or the like, there is a problem that the temperature dependency of the sensor is high and correction is difficult.

Therefore, the present invention can reliably and easily measure the circulation rate of particles in a high-temperature circulating fluidized bed, and is not particularly dependent on the light emission in the furnace, and can be applied to a relatively low temperature gasification furnace. and to provide a particle circulation rate measuring TeiSo location at high temperature circulating fluidized bed that can.

In order to solve the above-mentioned problem, the high-temperature circulating fluidized bed particle circulation velocity measuring apparatus according to the present invention provides a high-temperature circulating fluidized bed for high-temperature treatment of fluidized particles and a processing substance in a fluidized state, and Circulation of fluidized particles that circulates fluidized particles by a separator that separates the fluidized particles and gas components, and a downcomer unit that returns the fluidized particles separated by the separator from the separator to a lower part of the high-temperature circulating fluidized bed. A cooling heat supply pipe, an oxygen supply pipe , an upstream optical fiber probe, and a downstream optical fiber probe are arranged in the path at intervals from the upstream side, and the cold supply pipe and the oxygen supply pipe Any one of the above is selected and used .

  Another high-temperature circulating fluidized bed particle circulating velocity measuring device according to the present invention is the high-temperature circulating fluidized bed particle circulating velocity measuring device, wherein the heat supply source, the upstream optical fiber probe, and the downstream optical fiber probe are It is arranged in the downcomer section.

  Another high-temperature circulating fluidized bed particle circulating velocity measuring device according to the present invention is the above-described high-temperature circulating fluidized bed particle circulating velocity measuring device, wherein the heat supply source is a cold supply pipe for flowing a low-temperature gas therein. is there.

  Another high-temperature circulating fluidized bed particle circulating velocity measuring device according to the present invention is the high-temperature circulating fluidized bed particle circulating velocity measuring device, wherein the low-temperature gas is a low-temperature nitrogen gas.

  Since this invention was comprised as mentioned above, the circulation speed of the particle | grains in a high temperature circulating fluidized bed can be measured reliably and easily. In particular, since it does not depend on the light emission in the furnace, there is an advantage that it can be applied to a gasifier having a relatively low temperature.

The present invention reliably and easily measures the circulation rate of the particles, and can be applied to a relatively low temperature gasification furnace without depending on the light emission in the furnace. A high-temperature circulating fluidized bed for high-temperature treatment in a state; a separator for separating the fluidized particles and gas components from the upper part of the high-temperature circulating fluidized bed; and the separator from the separator to the lower part of the hot circulating fluidized bed. In the circulation path of the fluidized particles that circulate the fluidized particles by the downcomer unit that returns the separated fluidized particles, the cooling heat supply tube, the oxygen supply tube , the upstream optical fiber probe, and the downstream optical fiber in that order from the upstream side The problem has been solved by arranging the probes at intervals and selecting and using either the cold supply pipe or the oxygen supply pipe .

  FIG. 1 shows an example in which the embodiment of the present invention is applied to a downcomer section 8 in an external circulation type fluidized bed gasification furnace using a high-temperature circulating fluidized bed as shown in FIG. The part which the solid content isolate | separated with the solid-gas separator, ie, the fluid medium which has a fluid particle as a main component, flows down from the upper direction in Fig.1 (a) is shown.

  In the example shown in FIG. 1, in order from the upstream side of the downcomer section 8, a cooling heat source such as a cooling heat source supply pipe 15 for cooling the fluidized particles, and oxygen are blown into the fluidized particles to heat the fluidized particles. The oxygen supply pipe 16 that heats the flowing particles by burning a part of surrounding unburned components and generated gas, the distance L1 below the oxygen supply pipe 16, and the cold heat source supply pipe 15 to L2 An upstream temperature detecting optical fiber 17 arranged at a distance of L2 and a downstream temperature detecting optical fiber 18 at a distance Lv downstream from the upstream temperature detecting optical fiber 17 are arranged as an optical fiber probe for temperature detection. Of optical fiber.

  The cooling heat source supply pipe 15 can be supplied with nitrogen gas cooled by opening the valve 19 or with cooling water by releasing the valve 23. When supplying nitrogen gas or water, the cooling heat source is supplied. The flowing particles flowing down around the supply pipe 15 and the like are cooled. In addition, oxygen or air is supplied to the oxygen supply pipe 16 by opening the valve 20, and oxygen or air is injected into the downcomer section 8 from a nozzle hole 21 formed in the pipe to oxidize combustion or the like. The flowing particles flowing down this part by the reaction can be heated instantaneously.

  Both the upstream temperature detecting optical fiber 17 and the downstream temperature detecting optical fiber 18 are optical fibers of an optical fiber type temperature measuring device that has been widely used heretofore. Various optical fiber temperature measuring devices can be used. For example, an optical fiber temperature measuring device for measuring the temperature in a high-temperature furnace as disclosed in Japanese Patent Application Laid-Open No. 2000-54013 can be used. Even a relatively low temperature substance that can detect the radiation and measure the temperature is preferable.

  In the apparatus as described above, when cooling the flowing particles, the valve is opened to supply the cooled nitrogen gas or water into the cold heat source supply pipe. Thereby, the cold heat source supply pipe 15 and the like are immediately cooled, and the fluid medium mainly composed of surrounding fluid particles is cooled. The fluid medium cooled in this manner descends and reaches the periphery of the upstream temperature detection optical fiber 17, and the upstream temperature detection optical fiber 17 detects a rapid temperature drop of the surrounding fluid medium. Further, when the cooled fluid medium descends and reaches the periphery of the downstream temperature detecting optical fiber 18, a rapid temperature drop is detected from the luminance change of the surrounding fluid medium. The flowing particles emit a considerable amount of light by radiation even at several hundreds of degrees C. according to the Stefan-Boltzmann rule, and the wavelength distribution of the radiation light varies depending on the temperature difference, so that the above temperature drop can be easily detected.

  Since the distance Lv between the upstream temperature detecting optical fiber 17 and the downstream temperature detecting optical fiber 18 is accurately measured in advance, the downstream temperature detecting optical fiber 17 is detected after the temperature drop is detected by the upstream temperature detecting optical fiber 17. By measuring the time difference until the temperature drop is detected at 18, the velocity of the flowing particles flowing down the downcomer portion 8 can be detected. In addition, by detecting the velocity of such fluidized particles, the amount of fluidized media such as fluidized particles that circulate and flow per unit time can be known, thereby performing additional supply of fluidized particles or adjustment of extraction, If necessary, it is possible to control the amount of processing waste put into the gasification furnace.

  On the other hand, when detecting the velocity of the flowing particles flowing down the downcomer portion, when not using the cold source as described above, the valve 20 is opened and oxygen or air below the lower explosion limit is supplied to the oxygen supply pipe 16. Then, it is ejected from the nozzle hole 21 into the downcomer portion 8. As a result, the gas around the nozzle hole 21 is ignited and burned, or the fluid particles etc. are locally and rapidly oxidized by the temperature, and the fluid particles etc. are immediately heated to a high temperature.

  The fluid medium such as fluid particles that have become high in this manner descends, and when reaching the periphery of the upstream temperature detection optical fiber 17 in the same manner as described above, the upstream temperature detection optical fiber 17 has a brightness of the surrounding fluid medium. A rapid temperature rise is detected from the change. Further, when the heated fluid medium falls and reaches the periphery of the downstream-side temperature detecting optical fiber 18, a rapid temperature rise of the surrounding fluid medium is again detected by the change in luminance. Accordingly, the velocity of the flowing particles flowing down the downcomer portion 8 is detected by measuring the time of the flowing particles required to pass the distance Lv between the upstream temperature detecting optical fiber 17 and the downstream temperature detecting optical fiber 18. And can be used for various controls similar to those described above.

  As shown in FIG. 1, when both the cold supply pipe 15 and the like as a cold supply source and the oxygen supply pipe 16 as a hot supply source are arranged and any one is selected and used as necessary, A cold heat supply pipe is disposed upstream so that the oxygen supply pipe 16 is not exposed to high temperatures when used. Further, in the example shown in FIG. 1, an example in which both the cold heat supply source such as the cold heat supply pipe 15 and the oxygen supply pipe 16 are provided in advance is shown, but either one is selected and arranged, and only that is used. Of course, it may be measured.

  The supply of cold heat, such as the supply of nitrogen to the cold supply pipe, and the supply of oxygen to the oxygen supply pipe 16 are sufficient for only the short time required for the temperature measurement as described above, and therefore the valves of the respective pipes are used. The speed detection can be performed only by a short time opening that is pulse-operated.

  Further, various heat sources and various heat source supply means can be adopted as the cold heat supply source and the warm heat supply source. For example, as shown in FIG. 2, a heat source fluid supply pipe 22 is disposed upstream of the downcomer unit 8. Thus, it is possible to supply a low-temperature fluid or a high-temperature fluid by opening the valve 23. Here, when the low-temperature fluid is supplied to the heat source fluid supply pipe 22, it acts in the same manner as when the low-temperature nitrogen is supplied to the cold heat source supply pipe 15 in the embodiment shown in FIG. Further, when the high-temperature fluid is supplied to the heat source supply pipe 22, it acts in the same manner as when oxygen is supplied to the oxygen supply pipe 16 in the above embodiment, so that the upstream-side temperature detecting optical fiber 16 and the downstream-side temperature are the same as described above. From the temperature change detection time difference with the detection optical fiber 17, the velocity of the flowing particles flowing down the inside is detected.

  INDUSTRIAL APPLICABILITY The present invention can be used in a wide range of fields such as a coal combustion device, a coal gasification device, a waste treatment device, and a drying device that perform processing by putting a processing substance in a high-temperature fluidized bed.

It is explanatory drawing of the Example of this invention, (a) is a schematic diagram of a principal part, (b) is sectional drawing of the BB part of (a), (c) is sectional drawing of the CC part, (D) is sectional drawing of the DD part, (e) is sectional drawing of the EE part. It is a schematic diagram of the other Example of this invention. It is a figure which shows the example of the gasification apparatus using the hot circulating fluidized bed to which this invention is applied.

Explanation of symbols

8 Downcomer section 15 Cold source supply pipe 16 Oxygen supply pipe 17 Optical fiber for upstream side temperature detection 18 Optical fiber for downstream side temperature detection 19 Valve 20 Valve 21 Nozzle hole

Claims (4)

A high-temperature circulating fluidized bed for high-temperature treatment of the fluidized particles and the processing substance in a fluidized state; a separator for separating the fluidized particles and gas components from the upper part of the high-temperature circulating fluidized bed; and the high-temperature circulating fluidized bed from the separator In the circulation path of the fluidized particles for circulating the fluidized particles by the downcomer part for returning the fluidized particles separated by the separator to the lower part of the tube , a cooling heat supply pipe, an oxygen supply pipe, and an upstream optical fiber in order from the upstream side A high-temperature circulating fluidized bed particle circulation rate measuring device , wherein a probe and a downstream optical fiber probe are arranged with a space therebetween, and either the cold supply pipe or the oxygen supply pipe is selected and used. . The high-temperature circulating fluidized bed particle circulation rate measuring apparatus according to claim 1, wherein the cold heat supply pipe, the oxygen supply pipe , the upstream optical fiber probe, and the downstream optical fiber probe are arranged in the downcomer section. Wherein the cold supply pipe, hot circulating fluidized bed particles circulation rate measuring apparatus according to claim 1, wherein the score flow of cold gas in the interior. 4. The high-temperature circulating fluidized bed particle circulating velocity measuring apparatus according to claim 3, wherein the low-temperature gas is a low-temperature nitrogen gas.

Images