JP2017203434A - Furnace operating method in waste treatment facility and waste treatment facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a furnace operating method in a waste treatment facility and the waste treatment facility that can operate a supercharger in a stable state in a region where surging is prevented.SOLUTION: A furnace operating method in a waste treatment facility that has a heat treatment furnace for incinerating sludge and the like includes: a compression process of compressing combustion air by using a compressor; a preheating process of preheating the combustion air compressed in the compression process by using potential heat of exhaust gas guided to a flue of the heat treatment furnace; a compression power generation process of transmitting power to the compressor by rotating a turbine by using the combustion air preheated in the preheating process; a combustion air supply process of supplying the combustion air discharged from the turbine in the compression power generation process to the heat treatment furnace; and a control process of controlling a flow rate and/or temperature of the combustion air flowing into the turbine to a target flow rate and/or target temperature on the basis of properties or treatment amount of the sludge and the like so as not to cause an operation point of the supercharger to fall into a surge region.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for operating a waste treatment facility and a waste treatment facility.

  Various sewage is purified by biological treatment using microorganisms and then discharged into rivers or reused. A large amount of sludge generated by such biological treatment is dehydrated and then buried in a final disposal site, or is incinerated or melted.

  Patent Document 1 discloses a combined facility that effectively uses the exhaust gas of a fluidized incinerator in a waste incineration facility and the high-temperature exhaust of a gas turbine in a gas turbine generator as heat sources.

  The combined facilities are equipped with a fluid incinerator, a white smoke prevention heat exchanger, an exhaust gas / smoke treatment facility, and a gas turbine power generator having a compressor, a combustor, and a regenerator, and regenerate the exhaust gas from the fluid incinerator. After being used as a heat source for compressed air for gas turbines, it is configured to be sent to a heat exchanger for preventing white smoke, and the exhaust of the gas turbine is sent to a fluidized incinerator as combustion air It is configured as follows.

  Patent Document 2 discloses an energy efficiency that can be applied to a normal pressure incinerator and a pressurized incinerator, and does not require a blower that generates compressed air for combustion or compressed air for white smoke prevention and supplies it to a preheater. An excellent waste treatment facility is disclosed.

  The waste treatment facility preheats the compressed air for combustion supplied to the fluidized bed incinerator by continuous gas-gas heat exchange between the fluidized bed incinerator and the exhaust gas from the fluidized bed incinerator. The turbine is rotated by the first preheater and the compressed air for combustion which is heated by the first preheater and goes to the fluidized bed incinerator, and the compressed air supplied to the first preheater by the compressor by this rotation. A first supercharger for generating and blowing air, and a first start-up air supply device that is provided upstream of the first preheater and rotates the turbine at the start of operation. And

JP 2003-56363 A Japanese Patent No. 4831309

  An abnormal phenomenon called surging may occur in the turbocharger. Surging means that when the flow rate to the compressor is reduced, the compressor stalls and the flow rate and pressure fluctuate periodically and the entire gas flowing through the system consisting of the compressor and piping vibrates violently in the direction of flow. It is a phenomenon.

  When surging occurs, the entire system including the compressor may vibrate and become unstable, and the compressor and piping system may be damaged. Therefore, it is necessary to operate in a region where surging does not occur. Therefore, the supercharger used for the composite equipment and the waste treatment equipment described in the above-mentioned patent document needs to have characteristics that can be operated in a region where surging does not occur.

  However, it is difficult to design and manufacture a turbocharger having arbitrary characteristics, and select a model with the characteristics that best fits a facility equipped with a heat treatment furnace such as a fluidized incinerator from several existing models. It was necessary to incorporate. Therefore, if a deviation from the design value of temperature or flow rate occurs after the equipment is constructed, it may be difficult to operate in a stable state in a region where surging does not occur.

  In addition, in a waste treatment facility equipped with a heat treatment furnace that incinerates sludge and other waste, the supply of combustion air depends on properties such as the moisture content and the amount of heat retained by the heat treatment furnace. In such a case, it may be difficult to operate in a stable state in a region where surging does not occur.

  In view of the above-described problems, an object of the present invention is to provide a method for operating a waste treatment facility and a waste treatment facility capable of operating a supercharger in a stable state in a region where surging does not occur. is there.

  In order to achieve the above-mentioned object, the first characteristic configuration of the furnace operation method of the waste treatment facility according to the present invention incinerates waste such as sludge as described in claim 1 of the claims. A method for operating a waste treatment facility including a heat treatment furnace, wherein a compression step of compressing combustion air with a compressor of a supercharger, and combustion air compressed in the compression step A preheating process that preheats by the combustion heat in the furnace and / or the retained heat of the exhaust gas guided to the flue, and the combustion air preheated in the preheating process rotates the turbocharger turbine to transmit power to the compressor. A compression power generation step, a combustion air supply step for supplying combustion air exhausted from the turbine in the compression power generation step to the heat treatment furnace, and a property or throughput of the waste heat-treated in the heat treatment furnace And a control step of adjusting the flow rate and / or temperature of the combustion air flowing into the turbine to the target flow rate and / or target temperature so that the operating point of the supercharger does not enter the surge region. In the point.

  The flow rate of combustion air flowing into the turbine based on the property or amount of waste heat treated in the heat treatment furnace in the control process in order to appropriately heat treat according to the property or amount of waste heat treated in the heat treatment furnace And / or the temperature is adjusted to the target flow rate and / or the target temperature. For example, the flow rate of combustion air can be reduced or the moisture content can be reduced when performing low-load operation for heat-treating flammable waste with low moisture content or partial-load operation for heat-treating less waste than the rated treatment amount. If the temperature of the combustion air needs to be raised when performing high-load operation that heats waste that is high and difficult to burn, make sure that the operating point of the turbocharger does not enter the surge region in the control process. The flow rate and / or temperature of the combustion air flowing into the turbine is adjusted. As a result, the turbocharger can be operated in a stable state in a region where surging does not occur.

  In the second characteristic configuration, as described in the second aspect, in addition to the first characteristic configuration described above, the control process may include a part of the combustion air compressed in the compression process in the preheating. It is in a point including a bypass ventilation process supplied to the compression power generation process without passing through a process, and a flow rate adjustment process for adjusting a supply amount of combustion air to the preheating process.

  The bypass air blow process and the flow rate adjustment process are included in the control process that is the first characteristic configuration described above. When a bypass air blowing process is performed in which part of the combustion air compressed in the compression process is supplied to the compressed power generation process without going through the preheating process, the energy input to the turbine is reduced and the combustion air is compressed by the compressor. The air pressure ratio decreases. As a result, the amount of combustion air can be reduced without the operation point of the supercharger entering the surge region. At this time, of the combustion air output from the compressor, the supply amount of combustion air adjusted by the flow rate adjustment process is supplied to the preheating process, and the remaining combustion air is bypassed to the compression power generation process by the bypass air blowing process. The

  In the third feature configuration, as described in claim 3, in addition to the second feature configuration described above, the control step is a pressure which is a ratio of the pressure on the outlet side to the pressure on the inlet side of the compressor. The flow rate adjusting step is performed such that the operation point of the supercharger does not enter the surge region indicated in the compressor map of the supercharger, using the ratio and the flow rate of the combustion air as an index.

  The compressor map shows the turbine efficiency and operable range on a two-dimensional coordinate with the air flow on the horizontal axis and the pressure ratio on the vertical axis. Surging occurs when the operating point of the turbocharger moves further to the left. The boundary line of the surge area is a performance curve shown on the left edge of the operable area as a surge line. In the control process, the operating point of the turbocharger determined by the pressure ratio and the flow rate of combustion air is set so that it does not move to the left side of the surge line indicated in the compressor map of the corresponding turbocharger. A flow rate adjusting step is executed so as to correspond to the operation point.

  In the fourth characteristic configuration, as described in claim 4, in addition to the second or third characteristic configuration described above, the flow rate adjusting step is performed between an inlet port of the turbine and an outlet port of the compressor. In a bypass air passage that is connected in between and bypasses the preheating step, a bypass air amount adjusting step that adjusts a bypass air amount supplied to the compression power generation step without going through the preheating step and / or the compressor to the preheating step And a preheating air amount adjusting step of adjusting the amount of combustion air supplied to the preheating step on the downstream side of the inlet of the bypass air passage.

  The flow rate adjustment process that is the second characteristic configuration described above includes a bypass air volume adjustment process and / or a preheated air volume adjustment process. The bypass air volume adjustment process adjusts the bypass air volume supplied to the compression power generation process without going through the preheating process so that the operating point of the turbocharger does not enter the surge region, and the preheating air volume adjustment process burns into the preheating process. The supply amount of the working air is adjusted, and either one or both are adjusted.

  In the fifth feature configuration, in addition to any one of the second to fourth feature configurations described above, the combustion air exhausted from the turbine is further preheated to perform the heat treatment. Including a re-preheating step for supplying to the furnace, and the control step is to compensate for temperature fluctuations of the combustion air due to the flow rate adjusting step by adjusting a heat exchange amount in the re-preheating step.

  Even if the temperature of combustion air output from the turbine falls below the target temperature as a result of adjusting the operating point of the turbocharger so that it does not enter the surge region by the flow adjustment process, heat exchange in the re-preheating process By adjusting the amount, the combustion air at the target temperature can be supplied to the heat treatment furnace.

  A first characteristic configuration of a waste treatment facility according to the present invention is a waste treatment facility including a heat treatment furnace for incinerating waste such as sludge as described in claim 6, wherein the heat treatment furnace A first heat exchanger that preheats combustion air with the internal combustion heat of the furnace and / or the retained heat of the exhaust gas guided to the flue, and a turbine that rotates with the combustion air preheated with the first heat exchanger, A turbocharger including a compressor for supplying combustion air to the first heat exchanger by rotation of the turbine, and the supercharger based on properties or throughput of the waste heat-treated in the heat treatment furnace And a control mechanism that adjusts the flow rate and / or temperature of the combustion air flowing into the turbine to the target flow rate and / or the target temperature so that the operating point does not enter the surge region.

  A control mechanism is provided to appropriately heat-treat according to the properties or the amount of waste heat-treated in the heat treatment furnace. In the control mechanism, the flow rate and / or temperature of the combustion air flowing into the turbine is adjusted to the target flow rate and / or the target temperature based on the property or throughput of the waste heat-treated in the heat treatment furnace. As a result, the turbocharger is operated in a stable state in a region where surging does not occur.

  According to the second characteristic configuration described in claim 7, in addition to the first characteristic configuration described above, the control mechanism is connected between an inlet port of the turbine and an outlet port of the compressor. A bypass air passage that bypasses the first heat exchanger, a flow rate adjusting mechanism that adjusts an air amount supplied to the first heat exchanger and / or an air amount supplied to the bypass air passage, and the flow rate adjusting mechanism. And a control unit for controlling.

  The control mechanism includes a bypass air passage, a flow rate adjusting mechanism, and a control unit. The flow rate and / or temperature of the combustion air flowing into the turbine is adjusted to the target flow rate and / or target temperature while the flow rate adjusting mechanism is adjusted by the control unit so that the operating point of the turbocharger does not enter the surge region. The

  In the third feature configuration, in addition to the second feature configuration described above, the control unit includes a storage unit that stores a compressor map of the supercharger, and the compressor Using the pressure ratio, which is the ratio of the pressure on the outlet side to the pressure on the inlet side, and the flow rate of combustion air as an index, the operation point of the supercharger does not enter the surge region shown in the compressor map. The flow control mechanism is controlled.

  The control unit captures where the turbocharger operating point specified by the pressure ratio and flow rate is in the compressor map stored in the storage unit, and based on the result, the operating point is a surge in the compressor map. The flow rate adjusting mechanism is controlled so as not to move to the left side of the line, and the flow is changed to an operating point where the flow rate and / or temperature of the combustion air flowing into the turbine becomes the target flow rate and / or the target temperature.

  In the fourth feature configuration, as described in claim 9, in addition to the first or second feature configuration described above, the flow rate adjustment mechanism includes a first damper mechanism provided in the bypass air passage, and / or Or it is in the point comprised by the 2nd damper mechanism with which the air outlet path of the said compressor and the said 1st heat exchanger were provided in the downstream from the inlet_port | entrance of the said bypass air passage.

  By adjusting the opening degree of the first damper mechanism, the bypass flow rate of the combustion air is adjusted, and by adjusting the opening degree of the second damper mechanism, the supply amount of the combustion air to the first heat exchanger is adjusted.

  In the fifth feature configuration, in addition to any one of the first to third feature configurations described above, the flow rate adjusting mechanism includes a first damper provided in the bypass air passage. It is in the point comprised by the mechanism and the pushing air blower which pre-compresses combustion air and supplies it to the said compressor.

  By adjusting the opening of the first damper mechanism, the bypass flow rate of the combustion air is adjusted, and the supply amount of the combustion air to the first heat exchanger is adjusted by the amount of air blown by the pusher blower.

  In addition to any one of the second to fifth feature configurations described above, the sixth feature configuration further includes preheating combustion air exhausted from the turbine, and performing the heat treatment as described in claim 11. A second heat exchanger supplied to the furnace, wherein the control unit compensates for temperature fluctuations in the combustion air by the flow rate adjusting mechanism by adjusting a heat exchange amount in the second heat exchanger. is there.

  Even if the temperature of the combustion air output from the turbine falls below the target temperature as a result of adjusting the operating point of the turbocharger so that it does not enter the surge region by the flow rate adjusting mechanism, the second heat exchanger By adjusting the amount of heat exchange, the combustion air at the target temperature can be supplied to the heat treatment furnace.

  As described above, according to the present invention, it is possible to provide a method for operating a waste treatment facility and a waste treatment facility capable of operating a supercharger in a stable state in a region where surging does not occur. Became.

Explanatory drawing of the method of operating a waste treatment facility and the waste treatment facility according to the present invention Illustration of compressor map Explanatory diagram of furnace operation method for waste treatment facilities based on compressor map Explanatory drawing of the furnace operation method of a waste treatment facility which shows another embodiment, and a waste treatment facility Explanatory drawing of the furnace operation method of a waste treatment facility which shows another embodiment, and a waste treatment facility

  Hereinafter, embodiments of a method for operating a waste treatment facility and a method for operating a waste treatment facility according to the present invention will be described.

  FIG. 1 shows a waste treatment facility 100 for incinerating waste such as sludge. The waste treatment facility 100 includes a sludge storage tank 1 in which sludge as an incinerator is stored, a sludge charging mechanism 11, a fluidized bed incinerator 2 which is an example of a heat treatment furnace, an exhaust gas treatment facility, and the like. Yes.

  The fluidized bed incinerator 2 heats the sludge supplied from the sludge input mechanism 11 to the fluidized bed formed by the high temperature air supplied from the air supply mechanism 3 and heats the gasified sludge in the fluidized bed. This is a heat treatment furnace for burning in the free board section 20 formed in the upper space. A temperature raising burner 21 for heating the inside of the furnace at the time of start-up is disposed below the free board portion 20, and an auxiliary burner 22 is provided to supplement the amount of heat necessary for the combustion of sludge after the temperature of the furnace is raised.

  In order along the flue 10 of the fluidized bed incinerator 2, the first heat exchanger 5 that preheats the combustion air by the retained heat of the exhaust gas, the dust collector 6 that collects dust, and the exhaust gas by spraying an alkali agent A flue gas treatment tower 7 or the like for neutralizing the acidic gas component therein is disposed.

  At the downstream side of the flue gas treatment tower 7, an induction blower 8 that attracts the exhaust gas from the flue 10 and maintains the inside of the furnace at a negative pressure is provided, and the exhaust gas attracted by the induction blower 8 is purified by each exhaust gas treatment facility. After that, it is exhausted from the chimney 9.

  The air supply mechanism 3 includes a pusher blower 30, a supercharger 40, and a first heat exchanger 5. Combustion air preliminarily compressed to 1 to 19 kPa by the pusher blower 30 is supplied to the air supply port of the compressor 40c constituting the supercharger 40 via the air passage 31, and is reduced to 0.1 to 0.3 MPa by the compressor 40c. The compressed air is preheated by the first heat exchanger 5 and then supplied to the turbine 40t. The compressed air exhausted from the turbine 40t is supplied to the air supply mechanism 23 formed at the bottom of the fluidized bed incinerator 2. The

  The air compressed by the compressor 40c is heat-exchanged with the exhaust gas at 800 to 1000 ° C. by the first heat exchanger 5 and preheated to 500 to 750 ° C. and then supplied to the turbine 40t.

  When the compressed air preheated by the first heat exchanger 5 is supplied to the turbine 40t, the turbine 40t is rotationally driven, and the compressor 40c connected to the turbine 40t is further driven by the drive shaft 40s. The compressed air of 400 to 650 ° C. and 0.02 to 0.04 MPa discharged from the turbine 40t is supplied to the fluidized bed incinerator 2 as fluidizing air, that is, combustion air, to form a fluidized bed. In addition, the pressure demonstrated in this specification is a gauge pressure.

  Since the combustion air pre-compressed by the pusher blower 30 is supplied to the compressor 40c of the supercharger 40, the air compressed not only by the compressor 40c but also by the pusher blower 30 is preheated by the first heat exchanger 5. Become so. Thereby, the expansion work of the turbine 40t becomes equal to or greater than the compression work of the compressor 40c, and combustion air can be supplied at a pressure higher than the aeration pressure loss when forming the fluidized bed in the fluidized bed incinerator 2. It becomes like this.

  When the fluidized bed incinerator 2 is started up, it is necessary to form the fluidized bed exclusively with the forced blower 30. However, the ventilation resistance of the supercharger 40 is small, and the temperature of the supercharger 40 is increased as the temperature is raised by the start-up. The power cost reduction effect due to operation can be obtained, and the power consumption required for the pusher blower 30 can be greatly reduced.

  A bypass air passage 51 that bypasses the first heat exchanger 5 is provided between the inlet port of the turbine 40t and the outlet port of the compressor 40c, and the first damper mechanism 51D is provided in the bypass air passage 51. In addition, a second damper mechanism 52D is provided on the downstream side of the inlet of the bypass air passage 51 in the air passage 52 that connects the outlet port of the compressor 40c and the first heat exchanger 5.

  A flow meter Qs that measures the flow rate of combustion air is installed in the air passage 31, a pressure gauge Pis that measures the inlet pressure is installed in the inlet port of the compressor 40c, and an outlet pressure is measured in the outlet port of the compressor 40c. A pressure gauge Pos is installed.

  In addition, an oxygen gas sensor Sg that measures the concentration of oxygen gas contained in the exhaust gas is installed at the outlet of the freeboard unit 20, and the inlet air temperature of the turbine 40 t, the inlet air temperature of the air supply mechanism 23, the temperature of the freeboard unit 20, A plurality of temperature sensors for measuring the furnace outlet temperature and the like are arranged.

  A control unit 53 for controlling the above-described waste treatment facility is provided. The control unit 53 includes an input unit for inputting various sensor signals and the like, an arithmetic unit for executing a predetermined control calculation based on a signal input from the input unit, and a control signal for various actuators based on the calculation result. The computer includes an output unit that outputs data and a storage unit that stores control data and the like.

  Properties of the sludge to be treated, target treatment amount (t / day), oxygen concentration contained in the exhaust gas flowing into the flue 10, the flow rate Q of combustion air supplied from the forced air blower 30, the inlet port pressure of the compressor 40c A plurality of signals such as Pi and outlet port pressure Po are input to the input unit, and control calculation is performed in the calculation unit based on these input signals, and the amount and flow rate of air flow from the output blower 30 from the output unit based on the calculation result A control signal for controlling the opening degree of the adjusting mechanisms 51D and 52D, the amount of sludge input through the sludge input mechanism 11, and the like is output. The storage unit is used as a working area for control calculation by the calculation unit, and is also used as a storage area for a control program executed by the control unit 53 and a compressor map described later.

  The target processing amount is configured to be manually input from an operation panel provided in the input unit, and the property of sludge is grasped by manual input from the operation panel, control calculation by the control unit 53, or the like. For example, the retained heat amount of sludge is calculated by the control unit 53 based on the input amount of sludge into the furnace, the amount of combustion air, and the furnace temperature, and the moisture content of the sludge is obtained by manual input from the operation panel.

  The control unit 53 appropriately controls the fluidized bed incinerator 2 by performing feedback control of the amount of sludge input and the rotational speed of the forced blower 30 based on the oxygen concentration of the exhaust gas detected by the oxygen gas sensor Sg and the temperature in the furnace. It is configured to maintain a stable combustion state.

  For example, the control unit 53 calculates the target air amount to be supplied into the furnace by performing, for example, PID calculation based on the deviation between the oxygen concentration of the exhaust gas detected by the oxygen gas sensor Sg and the target oxygen concentration. A combustion air amount required for complete combustion is calculated based on a theoretical air amount assumed in advance according to the target processing amount of sludge input from the input unit, and the value of the flow meter Qs becomes the calculated combustion air amount. Thus, the inverter 30a which is a drive circuit of the pusher blower 30 is controlled.

  FIG. 2 shows an example of a compressor map showing the operating characteristics of the supercharger 40. The compressor map is a characteristic diagram showing the operating point of the supercharger 40 and the efficiency of the supercharger 40 with respect to the operating point in a two-dimensional coordinate system in which the horizontal axis is the flow rate Q and the vertical axis is the pressure ratio Po / Pi. There are equal efficiency curves L 1, L 2, L 3,... (Indicated by broken lines in the figure) that are more efficient at the center and are distributed radially, and extend obliquely to the left end of the equal efficiency curve. The region on the left side of the dashed line M is a surge region where surging occurs.

  The supercharger 40 is selected and selected so that it can be operated at an efficient operating point corresponding to the standard flow rate of combustion air supplied to the target fluidized bed incinerator 2 and the standard preheat amount. The compressor map data of the supercharger 40 is stored in a memory provided in the control unit 53.

  In the fluidized bed incinerator 2, the operating point P is set when the rated target throughput (t / day) is operated at the standard combustion air amount and preheating temperature. The operating point P is designed to move on the feeder operating line A.

  However, when the heat transfer coefficient of the first heat exchanger 5 is higher than the design value, the supercharger operating line shifts upward, the operating point P1 moves on the supercharger operating line A1, and the first heat When the heat transfer coefficient of the exchanger 5 is lower than the design value, the supercharger operating line shifts downward and the operating point P2 moves on the supercharger operating line A2.

  When the operating point P moves on the supercharger operating line A, if the properties (moisture content or heat amount) of the sludge to be incinerated change or the target processing amount (t / day) changes, along with it The required amount of combustion air varies from Q1 to Q2, and the operating point P moves on the supercharger operating line A.

  For example, when a partial load operation is performed in which the target processing amount (t / day) is reduced to 80% of the rated value, the required amount of the combustion air amount is reduced and moves to the left on the supercharger operation line A. At this time, surging occurs when the operating point P ′ moves to the left of the boundary line M.

  As shown in FIG. 3, in such a case, when the heat exchange amount of the first heat exchanger 5 is decreased, the supercharger operation line A is shifted to the supercharger operation line A ″ so that the same flow rate is obtained. Since the corresponding operating point is shifted from P ′ to P ″, the occurrence of surging can be avoided. As indicated by the thick arrows in FIG. 3, the flow rate can be reduced while avoiding the occurrence of surging by gradually reducing the heat exchange amount of the first heat exchanger 5.

  Similarly, when the flow rate Q is decreased from the operating point P1 when the turbocharger operating line A is moved to A1 in FIG. 2, there is a high possibility of entering the surge region, and the flow rate Q is constant. However, if the amount of heat exchange in the first heat exchanger 5 is increased, there is a high possibility that the operating point P1 moves upward and enters the surge region.

  Even in such a case, when the heat exchange amount of the first heat exchanger 5 is decreased, the supercharger operation line A1 is shifted to the supercharger operation line A, and the operation point corresponding to the same flow rate is P1. Therefore, the occurrence of surging can be avoided.

  In order to adjust the heat exchange amount of the first heat exchanger 5, the opening degree of the first damper mechanism 51D and / or the second damper mechanism 52D is adjusted.

  That is, the flow rate and / or temperature of the combustion air flowing into the turbine 40t is set so that the operating point of the supercharger 40 does not enter the surge region based on the property or the amount of waste heat-treated in the heat treatment furnace. A control mechanism 50 for adjusting the target flow rate and / or the target temperature is provided.

  That is, the control mechanism 50 controls the bypass air passage 51, the flow rate adjusting mechanism that adjusts the air amount supplied to the first heat exchanger 5 and / or the air amount supplied to the bypass air passage 51, and the flow rate adjusting mechanism. The control unit 53 is configured.

  The flow rate adjusting mechanism includes a first damper mechanism 51D and / or a second damper mechanism 52D, and a pusher blower 30 that pre-compresses combustion air and supplies it to the compressor 40c.

  The control unit 53 includes a storage unit that stores a compressor map of the supercharger 40, and a pressure ratio Po / Pi that is a ratio of the pressure Po on the outlet side to the pressure Pi on the inlet side of the compressor 40c and the flow rate Q of the combustion air. The control program configured to control the flow rate adjusting mechanism is executed so that the operating point of the supercharger 40 does not enter the surge region indicated in the compressor map, using as an index.

  As described above, the furnace operation method of the present invention is executed in the waste treatment facility controlled by the control unit 53 described above.

  That is, a compression process in which combustion air is compressed by the compressor 40c of the supercharger 40, and combustion air compressed in the compression process is held in the furnace heat of the heat treatment furnace 2 and / or in the exhaust gas that is led to the flue A preheating step for preheating by heat, a compression power generation step for rotating the turbine 40t of the supercharger 40 with combustion air preheated in the preheating step to transmit power to the compressor 40c, and an exhaust from the turbine 40t in the compression power generation step The operating point of the supercharger 40 does not enter the surge region based on the combustion air supply process for supplying the burned combustion air to the heat treatment furnace 2 and the properties or throughput of waste heat treated in the heat treatment furnace 2 The control method of adjusting the flow rate and / or temperature of the combustion air flowing into the turbine 40t to the target flow rate and / or the target temperature, and a method for operating a waste treatment facility It is executed.

  In the control step, the flow rate and / or temperature of the combustion air flowing into the turbine is adjusted to the target flow rate and / or target temperature based on the properties or throughput of the waste heat-treated in the heat treatment furnace 2. For example, the flow rate of combustion air can be reduced or the moisture content can be reduced when performing low-load operation for heat-treating flammable waste with low moisture content or partial-load operation for heat-treating less waste than the rated treatment amount. If the temperature of the combustion air needs to be raised when performing high-load operation that heats waste that is high and difficult to burn, make sure that the operating point of the turbocharger does not enter the surge region in the control process. The flow rate and / or temperature of the combustion air flowing into the turbine is adjusted. As a result, the turbocharger can be operated in a stable state in a region where surging does not occur.

  In the control process, the bypass air blowing process that supplies part of the combustion air compressed in the compression process to the compressed power generation process without going through the preheating process, and the supply amount of combustion air to the preheating process are adjusted. The flow rate adjusting step is performed.

  When a bypass air blowing process is performed in which part of the combustion air compressed in the compression process is supplied to the compressed power generation process without going through the preheating process, the energy input to the turbine 40t is reduced and the compressor 40c The pressure ratio of the combustion air decreases. As a result, the amount of combustion air can be reduced without the operating point of the supercharger 40 entering the surge region. At this time, of the combustion air output from the compressor 40c, the supply amount of combustion air adjusted by the flow rate adjustment process is supplied to the preheating process, and the remaining combustion air is bypassed to the compression power generation process by the bypass air blowing process. Is done.

  Furthermore, in the control process, the operating point of the supercharger 40 is excessively determined using the pressure ratio Po / Pi, which is the ratio of the pressure Po on the outlet side to the pressure Pi on the inlet side of the compressor 40c, and the flow rate Q of the combustion air. The flow rate adjustment process is executed so as not to enter the surge region indicated in the compressor map of the feeder 40.

  Further, in the flow rate adjustment process, a bypass that is connected between the inlet port of the turbine 40t and the outlet port of the compressor 40c and that bypasses the preheating process and supplies the compressed power generation process without passing through the preheating process. Bypass air volume adjustment process for adjusting the air volume and / or preheating air volume adjustment for adjusting the supply amount of combustion air to the preheating process in the air flow path 52 from the compressor 40c to the preheating process downstream from the inlet of the bypass air flow path The process is executed.

  The above-described flow rate adjustment process includes a bypass air volume adjustment process and / or a preheating air volume adjustment process. The bypass air volume adjustment process adjusts the bypass air volume supplied to the compression power generation process without going through the preheating process so that the operating point of the turbocharger does not enter the surge region, and the preheating air volume adjustment process burns into the preheating process. The supply amount of the working air is adjusted, and either one or both are adjusted.

Still another embodiment will be described.
FIG. 4 includes a second heat exchanger 4 that further preheats the combustion air exhausted from the turbine 40t and supplies the combustion air to the fluidized bed incinerator 2, and the control unit 53 controls the combustion air generated by the flow rate adjusting mechanism. It is preferable that the temperature fluctuation be compensated by adjusting the amount of heat exchange in the second heat exchanger 4.

  That is, it includes a re-preheating step in which the combustion air exhausted from the turbine 40t is further preheated and supplied to the heat treatment furnace 2, and the control step takes into account the temperature fluctuations in the combustion air caused by the flow rate adjustment step and the heat in the re-preheating step. Compensate by adjusting the exchange amount.

  Even if the temperature of the combustion air output from the turbine 40t is lower than the target temperature as a result of adjusting the operating point of the supercharger 40 so as not to enter the surge region by the flow rate adjusting mechanism, the second heat exchanger By adjusting the heat exchange amount at 4, the combustion air at the target temperature can be supplied to the heat treatment furnace.

  As shown in FIG. 5, if the hot air furnace 54 is provided in the bypass air passage 51, the hot air furnace 54 can quickly start up the fluidized bed incinerator 2.

  First, the second damper mechanism 52D is closed and the first damper mechanism 51D is opened, and the combustion air from the pusher blower 30 is heated in the hot air furnace and supplied to the turbine 40t.

  The amount of air distribution to the first heat exchanger 5 is increased by gradually increasing the opening of the second damper mechanism 52D and gradually decreasing the opening of the first damper mechanism 51D according to the degree of temperature rise in the furnace. During the steady operation, the hot stove 54 is stopped to reduce fuel consumption.

  When the fluidized bed incinerator 2 is started up, the waste heat of the furnace cannot be used, and pressure loss due to ventilation of the air passage or the heat exchanger also occurs. However, if the second damper mechanism 52D is closed and the first damper mechanism 51D is opened and the first heat exchanger 5 is bypassed when the fluidized bed incinerator 2 is started up, the blower path can be shortened. Furthermore, by providing the hot air furnace 54 to heat the combustion air, it is possible to supply heat to the turbine 40t and to raise the temperature of the fluidized bed incinerator 2.

  Without providing the hot air furnace 54 in the bypass air passage 51, when the fluidized bed incinerator 2 is started up, the second damper mechanism 52D is closed and the first damper mechanism 51D is opened to bypass the first heat exchanger 5 only. But you can.

  In the above-described embodiment, the configuration in which the first heat exchanger 5 is provided on the upstream side of the flue 10 has been described. However, the first heat exchange is performed so that the combustion air is preheated by the in-furnace combustion heat of the heat treatment furnace. The vessel 5 may be installed on the free board unit 20.

  Although embodiment mentioned above demonstrated the case where the fluidized-bed type incinerator 2 was employ | adopted as a heat treatment furnace, the incinerator to which this invention is applied is not restricted to the fluidized-bed type incinerator 2, Similarly, the present invention can be applied to other types of industrial furnaces such as a shaft furnace having a large airflow pressure loss. For example, a coke bed is formed at the bottom, and a heat treatment furnace or scrap that melts by pouring sludge from above the shaft furnace in which the tuyere that supplies combustion air to the coke bed is formed is melted by charging. The present invention can also be applied to a cupola or the like.

  Each of the above-described embodiments is an example of the present invention, and the present invention is not limited by the description. The specific configuration of each part can be appropriately changed and designed within the range where the effects of the present invention are exhibited. Needless to say.

1: Sludge storage tank 2: Fluidized bed incinerator 5: First heat exchanger 30: Pusher blower 40: Supercharger 40t: Turbine 40c: Compressor 51: Bypass air passage 51D: First damper mechanism 52: Air passage 52D : Second damper mechanism 53: Control unit 100: Waste treatment facility

Claims (11)

A furnace operation method for a waste treatment facility equipped with a heat treatment furnace for incinerating waste such as sludge,
A compression process in which combustion air is compressed by a turbocharger compressor;
A preheating step in which the combustion air compressed in the compression step is preheated by the in-furnace combustion heat of the heat treatment furnace and / or the retained heat of the exhaust gas guided to the flue;
A compression power generation step of rotating the turbocharger turbine with combustion air preheated in the preheating step and transmitting power to the compressor;
A combustion air supply step of supplying the combustion air exhausted from the turbine in the compression power generation step to the heat treatment furnace;
The flow rate and / or temperature of the combustion air flowing into the turbine is controlled so that the operating point of the supercharger does not enter the surge region based on the properties or the throughput of the waste heat treated in the heat treatment furnace. A control process for adjusting to a target flow rate and / or a target temperature;
Of waste treatment facilities including The control step includes
A bypass air blowing step for supplying a part of the combustion air compressed in the compression step to the compression power generation step without going through the preheating step;
A flow rate adjusting step for adjusting a supply amount of combustion air to the preheating step;
The method for operating a waste treatment facility according to claim 1, comprising: The control step includes
Using the pressure ratio, which is the ratio of the pressure on the outlet side to the pressure on the inlet side of the compressor, and the flow rate of combustion air as an index, the operating point of the supercharger is in the surge region indicated in the compressor map of the supercharger The furnace operation method for a waste treatment facility according to claim 2, wherein the flow rate adjustment step is performed so as not to enter. The flow rate adjusting step includes
A bypass air volume that is connected between the turbine inlet port and the compressor outlet port and that bypasses the preheating step and adjusts the bypass air amount supplied to the compression power generation step without passing through the preheating step. Adjustment process and / or
4. The disposal according to claim 2, further comprising a preheating air amount adjustment step of adjusting a supply amount of combustion air to the preheating step on a downstream side of an inlet of a bypass air passage in a ventilation passage from the compressor to the preheating step. How to operate a waste treatment facility. A re-preheating step of further preheating the combustion air exhausted from the turbine and supplying the combustion air to the heat treatment furnace,
5. The waste treatment facility according to claim 2, wherein the control step compensates for a temperature variation of the combustion air caused by the flow rate adjustment step by adjusting a heat exchange amount in the re-preheating step. How to operate the furnace. A waste treatment facility equipped with a heat treatment furnace for incinerating waste such as sludge,
A first heat exchanger that preheats combustion air using in-furnace combustion heat of the heat treatment furnace and / or retained heat of exhaust gas guided to a flue;
A turbocharger comprising: a turbine rotating by combustion air preheated by the first heat exchanger; and a compressor for supplying combustion air to the first heat exchanger by rotation of the turbine;
The flow rate and / or temperature of the combustion air flowing into the turbine is controlled so that the operating point of the supercharger does not enter the surge region based on the properties or the throughput of the waste heat treated in the heat treatment furnace. A control mechanism for adjusting to a target flow rate and / or a target temperature;
Waste treatment facility equipped with. The control mechanism is
A bypass air passage connected between an inlet port of the turbine and an outlet port of the compressor, and bypassing the first heat exchanger;
A flow rate adjusting mechanism for adjusting an air amount supplied to the first heat exchanger and / or an air amount supplied to the bypass air passage;
A control unit for controlling the flow rate adjusting mechanism;
A waste treatment facility according to claim 6.   The control unit includes a storage unit that stores a compressor map of the supercharger, and uses a pressure ratio that is a ratio of an outlet side pressure to an inlet side pressure of the compressor and a flow rate of combustion air as an index, and The waste treatment facility according to claim 7, wherein the flow rate adjusting mechanism is controlled so that a supercharger operating point does not enter a surge region indicated in the compressor map.   The flow rate adjusting mechanism includes a first damper mechanism provided in the bypass air passage and / or a first air passage provided between the outlet port of the compressor and the first heat exchanger on the downstream side of the inlet of the bypass air passage. The waste treatment facility according to claim 7 or 8, comprising a two-damper mechanism.   The said flow volume adjustment mechanism is comprised in the 1st damper mechanism with which the said bypass ventilation path was equipped, and the pushing air blower which precompresses combustion air and supplies it to the said compressor. Waste disposal equipment. A second heat exchanger for further preheating combustion air exhausted from the turbine and supplying the combustion air to the heat treatment furnace;
The waste treatment according to any one of claims 7 to 10, wherein the control unit compensates for a temperature variation of combustion air by the flow rate adjusting mechanism by adjusting a heat exchange amount in the second heat exchanger. Facility.

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