JP2016183616A - Fluid bed incineration facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluid bed incineration facility which enables stable and easy operation control even when a processed object changes its characteristics without causing enlargement and complication of the facility and cost increase.SOLUTION: A fluid bed incineration facility includes: a fluid bed incinerator 1 which incinerates a processed object while flowing the processed object with circulation air A; an air preheater 2 which conducts heat exchange between a flue gas B discharged from the fluid bed incinerator 1 and the circulation air A; and a preheating air duct 9 which supplies the circulation air A, which has been subjected to heat exchange in the air preheater 2, to the fluid bed incinerator 1. Stirling engine generators 10 are attached to the preheating air duct 9.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a fluidized bed incineration facility that incinerates an object to be treated while flowing with a fluidizing air supplied to a fluidized bed incinerator.

  As such a fluidized bed incineration facility, for example, Patent Document 1 discloses a fluidized bed furnace that burns an object to be treated such as sewage sludge by flowing air, and combustion exhaust gas discharged from the fluidized bed furnace and fluidized. An air preheater that exchanges heat with industrial air, a dust collector that removes dust from the combustion exhaust gas discharged from the air preheater, and a turbocharger that generates compressed air from the combustion exhaust gas removed from the dust collector ( A pressurized flow furnace installation with a turbocharger is described. The compressed air generated by the supercharger is supplied as fluidizing air to the fluidized bed furnace through the air preheater.

JP 2014-190572 A

  By the way, in such a fluidized bed incineration facility, the retained heat of the combustion exhaust gas discharged from the fluidized bed furnace and the combustion exhaust gas discharged from the air preheater is recovered by a waste heat boiler, or the dusted combustion exhaust gas is removed from the outside. The heat is recovered from the circulating water of the flue gas processing tower that performs the processing to discharge the water.

  However, especially when the material to be treated is sewage sludge, if the water content of the dewatered sludge decreases due to the improvement of the capacity of the dewatering equipment, self-burning operation that does not require auxiliary fuel in the fluidized bed furnace becomes possible. The amount of heat that can be recovered from the combustion exhaust gas may increase because the temperature becomes too high. When the amount of heat of the combustion exhaust gas increases in this way, the temperature of the fluidized air preheated in the air preheater also rises, resulting in a further increase in the combustion temperature of the fluidized bed furnace.

  Here, as a means for dealing with such an increase in the amount of heat for incineration, for example, water can be sprayed into the fluidized bed furnace to suppress the combustion temperature, but the amount of combustion exhaust gas increases due to the evaporated spray water. For this reason, the exhaust gas treatment equipment such as the dust collector must be enlarged. In addition, although there is a means to lower the temperature of the fluidized air preheated in the air preheater, it is difficult to control the operation stably, and the equipment is complicated if the fluidized bed furnace is made into a boiler structure to increase the amount of heat recovery. In addition, the cost increases.

  In addition, sewage sludge is often intensively treated, and fluctuations in sludge properties such as moisture content and calorific value are larger than before, and fluidized bed incineration equipment can be operated stably. It's getting harder. These problems become more conspicuous especially in the above-described pressurized fluidized furnace equipment that supplies compressed air generated by combustion exhaust gas as fluidized air to a fluidized bed furnace.

  The present invention has been made under such a background, and can stably and easily control the operation even if the properties of the object to be processed fluctuate without causing an increase in size, complexity, and cost of equipment. It aims to provide a fluidized bed incineration facility.

  In order to solve the above-described problems and achieve such an object, the present invention provides a fluidized bed incinerator that burns while moving a material to be treated by fluidizing air, and a combustion exhausted from the fluidized bed incinerator. An air preheater for exchanging heat between the exhaust gas and the fluidizing air; and a preheating air duct for supplying the fluidizing air heat-exchanged in the air preheater to the fluidized bed incinerator. A plurality of Stirling engine generators are attached to the air duct.

  As is well known, a Stirling engine generator, for example, connects a displacer piston and a power piston housed in a cylinder to a crankshaft, and uses one end of the cylinder as a heater part (heating part) and the other end as a cooling part. As described above, the crankshaft is rotated by the volume change of the gas in the cylinder due to the temperature difference, and power is generated by the generator connected to the crankshaft.

  Accordingly, in the fluidized bed incinerator having the above-described configuration, a plurality of such Stirling engine generators are attached to the preheated air duct for supplying the fluidized air heat-exchanged in the air preheater to the fluidized bed incinerator. When the combustion temperature rises and the amount of heat of the combustion exhaust gas increases, the Stirling engine generator is started to cool the fluidizing air so that the combustion temperature in the fluidized bed incinerator and the exhaust gas temperature of the combustion exhaust gas can be quickly increased. While stabilizing, surplus heat can be recovered as electric power.

  In addition, by adjusting the number of Stirling engine generators to be activated in accordance with the combustion temperature, it is possible to easily and finely cope with changes in the combustion temperature due to fluctuations in the properties of the workpiece. Moreover, it is only necessary to install multiple Stirling engine generators in the preheating air duct, so a large exhaust gas treatment facility is required as in the case of spraying water into the fluidized bed incinerator, or the inside of the fluidized bed incinerator is a boiler structure. As is the case, the equipment is less complicated.

  Further, since the Stirling engine generator is attached to the clear fluid air preheated by the air preheater, even if the heater portion of the Stirling engine generator is directly exposed to the fluid air and heated, for example, combustion As in the case of recovering heat by exposing the heated part to exhaust gas, damage such as wear does not occur due to particulate components in the combustion exhaust gas. For this reason, a heating part can be penetrated in a preheating air duct, a Stirling engine generator can be attached, and it becomes possible to aim at heat recovery by efficient power generation.

  In addition, by attaching a plurality of Stirling engine generators at intervals in the flow air supply direction in the preheating air duct, when the inner diameter of the preheating air duct is small, the Stirling engine power generation is performed in the preheating air duct as described above. Even when the heating part of the machine is installed through, the heating parts can be prevented from interfering with each other and more efficient heat recovery can be performed, and the flow of flow air in the preheating air duct can be prevented. Absent.

  Further, when mounting a plurality of Stirling engine generators at intervals in the flow air supply direction in this way, the Stirling engine generators adjacent to each other in the flow air supply direction are connected to each other in the circumferential direction of the preheating air duct. By attaching to different positions, it is possible to prevent the stirling engine generator located on the supply direction side from being hindered from being heated by the flow air and to further stabilize the flow of the flow air in the preheating air duct. . Similarly, when a plurality of Stirling engine generators are installed at intervals in the flow air supply direction, among the plurality of Stirling engine generators, the Stirling engine generator located closest to the air preheater side is fluidized to the fluidized bed. By providing a control means for sequentially starting the Stirling engine generator in the flow air supply direction toward the incinerator side, heat recovery can be achieved from the higher temperature flow air, and it is efficient. When the Stirling engine generator is additionally activated, the amount of heat of the flowing air supplied to the already activated Stirling engine generator does not fluctuate, so that stable power generation can be performed.

  Therefore, in particular, the above-described configuration of the present invention is such that the air for flow is supplied to the air preheater via the supercharger driven by the combustion exhaust gas discharged from the air preheater. This is effective when applied to a pressurized fluidized-furnace facility because the combustion temperature in the fluidized-bed incinerator tends to be high.

  In the present invention, it is essential that a plurality of Stirling engine generators are attached to the preheated air duct, but this does not prevent the Stirling engine generators from being attached to other locations. For example, in addition to the preheated air duct, other Stirling engine generators are attached to the fluidized bed incinerator, and the temperature of the combustion exhaust gas varies depending on the properties of the material to be treated even though the temperature of the preheated fluidizing air is low. If it is high, heat recovery may be performed by starting another Stirling engine generator.

  As described above, according to the present invention, it is possible to easily and quickly cope with a change in the combustion temperature of a fluidized bed incinerator due to a change in properties of an object to be processed without causing an increase in size and complexity of equipment. Therefore, it becomes possible to perform stable operation control of the fluidized bed incineration facility.

It is the schematic of the fluidized-bed incineration equipment which shows one Embodiment of this invention. It is the (a) top view and (b) side view of the preheating air duct in embodiment shown in FIG.

  1 and 2 show one embodiment of a fluidized bed incineration facility of the present invention. The disclosed technology is not limited to the following embodiments, and various modifications can be made without departing from the spirit of the present invention. In FIG. 1, reference numeral 1 denotes a pressurized fluidized bed incinerator that combusts while flowing a workpiece. The fluidized bed incinerator 1 is filled with a fluidized medium, and the fluidized bed incinerator 1. Processed materials such as sewage sludge, human waste sludge, food waste, garbage and municipal waste supplied inside are being fluidized with a fluid medium by high-temperature, high-pressure fluid air A supplied from the hearth. It is heated and burned. The fluidized bed incinerator 1 includes an auxiliary combustion device and a start burner (not shown), a thermometer that measures the combustion temperature, exhaust gas temperature, pressure, and the like in the furnace, and outputs to a control means of the incineration equipment (not shown). Instrumentation equipment such as a pressure gauge is provided.

  The high-temperature combustion exhaust gas B generated by burning the object to be processed in the fluidized bed incinerator 1 is supplied to the shell and tube type air preheater 2 and supplied to the fluidized bed incinerator 1, for example. This air is heated and heated to a high temperature. The combustion exhaust gas duct connecting the combustion exhaust gas outlet of the fluidized bed incinerator 1 and the air preheater 2 is provided with a thermometer (not shown) that measures the combustion exhaust gas temperature and outputs it to the control means.

  The combustion exhaust gas B heated in the air preheater 2 in this way is supplied to the dust collector 3 to remove dust and the like contained in the combustion exhaust gas B. The dust collector 3 is, for example, a bag filter having a large number of bottomed cylindrical ceramic filters. When the flue gas B passes through the ceramic filter having minute pores, dust or the like in the flue gas B is captured. The combustion exhaust gas B is cleaned by collecting and removing dust.

  The combustion exhaust gas B purified in the dust collector 3 is supplied to the supercharger 4. The supercharger 4 includes a turbine that is supplied with the purified flue gas B and rotated at a high speed, and a compressor that is coaxially connected to the turbine and that rotates at a high speed and generates high-pressure compressed air. It is a well-known so-called turbocharger provided. The compressor of the supercharger 4 is supplied with air C sucked through a filter or the like, and the compressed air generated in the compressor is supplied to the air preheater 2 as the flow air A, as described above. Heat is exchanged with the combustion exhaust gas B.

  The combustion exhaust gas B that has generated compressed air in the supercharger 4 in this manner is supplied to the white smoke prevention heat exchanger 5 and exchanged heat with the white smoke prevention air D, and then in the smoke treatment tower 6. By spraying caustic soda water and water, impurities and the like are removed and cooling treatment is performed. Further, the cooled combustion exhaust gas B is supplied to the chimney 7, mixed with the white smoke prevention air D heat-exchanged by the white smoke prevention heat exchanger 5 and heated to prevent generation of white smoke. It is discharged outside.

  A preheating air duct 9 is connected in series to a supply pipe 8 that supplies the fluidizing air A heat-exchanged in the air preheater 2 to the fluidized bed incinerator 1. A plurality of Stirling engine generators 10 are attached. The preheating air duct 9 is attached in the middle of the supply pipe 8 when the pipe diameter of the supply pipe 8 is smaller than the length of the heater portion 10A of the Stirling engine generator 10 or when the pressure loss becomes too large. In addition, the central portion is formed in a cylindrical shape having a diameter larger than that of the supply pipe 8, and both end portions are formed in a tapered truncated cone shape and are connected to the supply pipe 8 in an airtight manner.

  In the Stirling engine generator 10, for example, a displacer piston and a power piston connected to a crankshaft are accommodated in a cylinder as described above, and one end of the cylinder is used as the heater part (heating part) 10A. At the same time, the other end is a cooling unit 10B that is cooled by being supplied with cooling water, and a generator 10D is connected to a case 10C in which the crankshaft is accommodated. The Stirling engine generator 10 of the present embodiment allows the heater portion 10A to penetrate from the outside of the preheating air duct 9 to the inside, and the cooling portion 10B, the case 10C, and the generator 10D are positioned outside the preheating air duct 9. Thus, the preheated air duct 9 is airtightly attached.

  Furthermore, in this embodiment, a plurality of (for example, four as shown in FIG. 2) Stirling engine generators 10 are provided in the supply direction F of the flow air A in the preheating air duct 9 as shown in FIG. It is attached at intervals. Of these, the Stirling engine generators 10 adjacent to each other in the supply direction F of the flow air A are attached to different positions in the circumferential direction of the preheating air duct 9.

  Specifically, the plurality of Stirling engine generators 10 of the present embodiment are arranged at equal intervals in the supply direction F as shown in FIG. 2, and those adjacent to the supply direction F are preheated air ducts. In the circumferential direction 9, the positions are shifted at equal intervals. In addition, these Stirling engine generators 10 are moved around the preheated air duct 9 by shifting the position in one circumferential direction toward the supply direction F (clockwise as viewed from the supply direction F in this embodiment). In other words, they are arranged in a spiral shape.

  In such a fluidized bed incineration facility, during normal operation, fluidized air A preheated from the air preheater 2 to a certain preheating temperature (for example, 650 ° C.) is supplied to the fluidized bed through the supply pipe 8 and the preheated air duct 9. When supplied to the incinerator 1 and the object to be treated is combusted at a constant combustion temperature, combustion exhaust gas B having a constant exhaust gas temperature is also generated. It should be noted that the Stirling engine generator 10 is stopped at the start of the fluidized bed incineration facility to reduce the amount of auxiliary fuel used at the start-up, as well as when the normal operation is performed in which each temperature is constant and stable.

  Here, the combustion temperature of the fluidized bed incinerator 1 becomes higher than the above-mentioned constant combustion temperature (for example, 850 ° C. or higher) due to fluctuations in the properties of the supplied object to be processed, or the exhaust gas temperature of the combustion exhaust gas B is increased. When the temperature becomes higher than the certain exhaust gas temperature (for example, 840 ° C. or higher), this is detected by the thermometer provided in the fluidized bed incinerator 1 or the combustion exhaust gas duct, and is controlled by the control means. First, among the plurality of Stirling engine generators 10, one Stirling engine generator 10 closest to the air preheater 2 is started to generate electricity using the flow air A as a heat source and the temperature of the flow air A is constant as described above. The preheating temperature is maintained at or lower than the predetermined preheating temperature.

  Further, when the Stirling engine generator 10 closest to the air preheater 2 is started in this way, the combustion temperature and the exhaust gas temperature do not decrease, or the combustion temperature and the exhaust gas temperature do not stop rising, and a higher combustion temperature (for example, 860 ° C.). When the exhaust gas temperature (for example, 850 ° C. or higher) is reached, start one Stirling engine generator 10 located on the air preheater 2 side next to the Stirling engine generator 10 on the most air preheater 2 side. Lower the temperature of the flow air A. As described above, the Stirling engine generator 10 is sequentially activated from the air preheater 2 side in accordance with the combustion temperature of the fluidized bed incinerator 1 and the exhaust gas temperature of the combustion exhaust gas B, thereby reducing the temperature of the fluidizing air A. The temperature and exhaust gas temperature are returned to the above-described constant combustion temperature and exhaust gas temperature.

  Such a Stirling engine generator 10 has a short start-up time from the state in which the rotation of the crankshaft is stopped and stopped, and a high follow-up performance of temperature control. Even if the temperature or exhaust gas temperature rises, it can respond quickly. In addition, since a plurality of Stirling engine generators 10 are attached to the preheating air duct 9, the number of Stirling engine generators 10 to be activated is adjusted according to the combustion temperature and the exhaust gas temperature, so that the combustion temperature and the exhaust gas temperature are adjusted. It is possible to stabilize in response to changes in the size easily and finely. Furthermore, it is possible to efficiently recover surplus heat as electric power without increasing the size of the exhaust gas treatment facility and complicating the structure of the fluidized bed incinerator 1.

  Further, in the fluidized bed incineration facility having the above configuration, such a Stirling engine generator 10 is provided in the exhaust passage of the combustion exhaust gas B from the fluidized bed incinerator 1 to the air preheater 2 to reduce the exhaust gas temperature. Is not attached to the preheating air duct 9 provided in the supply pipe 8 of the flowing air A from the air preheater 2 to the fluidized bed incinerator 1, and does not reduce the preheating temperature of the flowing air A by combustion. The previous clear flowing air A is used as a heat source.

  For this reason, even if the heater part 10A penetrates the preheating air duct 9 and is directly exposed to the combustion air A as in the present embodiment, it is caused by the particle components in the combustion exhaust gas B as in the case of being exposed to the combustion exhaust gas B. It is possible to control the combustion temperature and the exhaust gas temperature that are stable over a long period of time without causing the heater portion 10A to be worn and damaged. Further, since the heater unit 10A can be directly exposed to the combustion air A to generate power, efficient heat recovery can be promoted.

  In particular, as in the present embodiment, in the pressurized flow furnace equipment in which the flow air A is supplied to the air preheater 2 via the supercharger 4 driven by the combustion exhaust gas B discharged from the air preheater 2. Since the fluidizing air A pressurized by the supercharger 4 is supplied to the fluidized bed incinerator 1, the combustion temperature in the fluidized bed incinerator 1 and the exhaust gas temperature of the combustion exhaust gas B tend to be high and fluctuate. large. Therefore, it is effective to stabilize the combustion temperature and exhaust gas temperature by applying the above configuration to such a pressurized fluidized furnace facility.

  On the other hand, in the present embodiment, a plurality of Stirling engine generators 10 are attached at intervals in the supply direction F of the flowing air A in the preheating air duct 9 and the Stirling is performed when the inner diameter of the preheating air duct 9 is small. Even if the heater unit 10A of the engine generator 10 is inserted through the heater unit 10A, the heater units 10A of the Stirling engine generator 10 adjacent to the supply direction F can be prevented from interfering with each other.

  For this reason, even when the heater portion 10A penetrates so as to protrude beyond the center of the preheated air duct 9 as shown in FIG. 2A in particular, a plurality of Stirling engine generators 10 are produced without causing interference. It is possible to achieve a reliable heat recovery by arranging the. In addition, the stable flow of the flowing air A in the preheating air duct 9 can be prevented from being disturbed as in the case where the heater portion 10A protrudes at the same position in the supply direction F. Further, by controlling the Stirling engine generator 10 thus spaced in the supply direction F by the control means so as to start from the Stirling engine generator 10 on the most air preheater 2 side as described above, It is efficient because heat can be recovered from the air A for flow. In addition, the Stirling engine generator 10 is additionally started by sequentially starting the Stirling engine generator 10 positioned toward the fluidized bed incinerator 1 side from the Stirling engine generator 10 positioned closest to the air preheater 2 side. At this time, since the amount of heat of the flowing air A supplied to the Stirling engine generator 10 already started does not fluctuate, stable power generation can be performed.

  In the present embodiment, the plurality of Stirling engine generators 10 are attached at intervals in the supply direction F of the flowing air A, and the Stirling engine generators 10 adjacent to the supply direction F are also attached. They are attached to different positions in the circumferential direction of the preheating air duct 9. Accordingly, the heater section 10A of the Stirling engine generator 10 adjacent to the supply direction F side (fluidized bed incinerator 1 side) by the heater section 10A of the Stirling engine generator 10 on the front side (air preheater 2 side) in the supply direction F. It is possible to prevent a situation in which the heating by the flowing air A is hindered, and to achieve more reliable heat recovery. Further, the flow of the flowing air A in the preheating air duct 9 can be further stabilized.

  In particular, in the present embodiment, the Stirling engine generator 10 is spirally disposed in the preheating air duct 9 as described above, and the Stirling engine generator 10 on the supply direction F side until this spiral makes one turn. The heater part 10A of the next Stirling engine generator 10 does not protrude on the opposite side to the supply direction F of the current. For this reason, at least at the other end side of the cylinder of the Stirling engine generator 10, the heater unit 10 </ b> A can be exposed to the high-temperature flowing air A, and more efficient heat recovery can be achieved.

  In the present embodiment, a preheating air duct 9 having a diameter larger than that of the supply pipe 8 is connected to the supply pipe 8 that supplies the flowing air A from the air preheater 2 to the fluidized bed incinerator 1. However, if the supply pipe 8 has a sufficiently large diameter, a plurality of supply pipes 8 themselves are used as preheating air ducts without connecting such a preheating air duct 9 separately. A Stirling engine generator 10 may be attached.

  Similarly, when the supply pipe 8 has a sufficiently large diameter or the preheating air duct 9 has a sufficiently large diameter, a plurality of Stirlings are arranged on the same position in the supply direction F or on a straight line along the supply direction F. An engine generator 10 may be attached. 1 and 2, the preheating air duct 9 extends in the vertical direction, but a plurality of Stirling engine generators 10 may be attached to the preheating air duct 9 extending in the horizontal direction.

  In addition, a plurality of Stirling engine generators 10 are attached to the preheating air duct 9 for supplying the fluidizing air A heat-exchanged in the air preheater 2 to the fluidized bed incinerator 1 as shown in FIG. 11, another Stirling engine generator may be attached to the fluidized bed incinerator 1.

  For example, as shown in the figure, if another Stirling engine generator 11 is installed near the exhaust part of the combustion exhaust gas B at the top of the fluidized bed incinerator 1, the temperature of the preheated fluid air A is low, When the temperature of the combustion exhaust gas B is high due to the properties of the object to be treated, the temperature of the combustion exhaust gas B can be increased without lowering the temperature of the flow air A more than necessary by starting the other Stirling engine generator 11. It is possible to perform heat recovery as well as lowering the temperature.

  In this embodiment, the starting condition of the Stirling engine generator 10 is set to the combustion temperature of the fluidized bed incinerator 1 or the exhaust gas temperature in the combustion exhaust gas duct, but it flows to the preheating air duct 9 and the supply pipe 8. A thermometer for measuring the temperature of the working air A can be provided, and the temperature of the flowing air A can be used as a starting condition.

DESCRIPTION OF SYMBOLS 1 Fluidized bed incinerator 2 Air preheater 3 Dust collector 4 Supercharger 5 White smoke prevention heat exchanger 6 Flue gas processing tower 7 Chimney 8 Flowing air A supply pipe 9 Preheating air duct 10 Stirling engine generator 10A Heater part 10B Cooling section 10C Case 10D Generator 11 Other Stirling engine generator A Flowing air B Combustion exhaust gas C Atmosphere D White smoke prevention air F Supply direction

Claims (6)

  A fluidized-bed incinerator that combusts while flowing an object to be treated by fluidizing air, an air preheater that exchanges heat between the combustion exhaust gas discharged from the fluidized-bed incinerator and the fluidizing air, and the air A preheating air duct for supplying the fluidizing air heat-exchanged in a preheater to the fluidized bed incinerator, wherein a plurality of Stirling engine generators are attached to the preheating air duct. Layer incineration equipment.   The fluidized-bed incinerator according to claim 1, wherein the plurality of Stirling engine generators are attached at intervals in the supply direction of the flowing air in the preheating air duct.   The fluidized bed incinerator according to claim 2, wherein the Stirling engine generators adjacent to each other in the supply direction of the flow air are attached to different positions in the circumferential direction of the preheating air duct.   From among the plurality of Stirling engine generators, the Stirling engine generator is sequentially activated in the flow direction of the flowing air from the Stirling engine generator located closest to the air preheater toward the fluidized bed incinerator. The fluidized-bed incinerator of Claim 2 or Claim 3 provided with the control means to perform.   5. The air preheater is supplied to the air preheater via a supercharger driven by the combustion exhaust gas discharged from the air preheater. Fluidized-bed incineration equipment as described in one.   The fluidized bed incinerator according to any one of claims 1 to 5, wherein the fluidized bed incinerator is provided with another Stirling engine generator.

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