JP2020085386A - Waste treatment equipment and operating method of waste treatment equipment - Google Patents

Abstract

To provide a waste treatment facility capable of rapidly reducing rotational frequency even when there is a risk that an operating region of a supercharger might reach an abnormally high rotation region under a situation where waste heat recovery amount of a heat exchanger becomes excessive.SOLUTION: A waste treatment facility includes: a heat treat furnace 2; a heat exchanger 5 preheating combustion air by using exhaust gas; and a supercharger 40 including a turbine 40t rotated by the preheated combustion air and a compressor 40c supplying the combustion air to the heat exchanger through the rotation of the turbine. The waste treatment facility further includes: an input heat amount adjustment mechanism 50 adjusting input heat amount of the combustion air to be supplied to the turbine; a pressure release mechanism 55 rapidly reducing driving force of the supercharger; and a control section 70 that controls the input heat amount adjustment mechanism 50 so that combustion air amount to be supplied to the compressor becomes target air amount and that monitors rotational frequency of the supercharger and activates the pressure release mechanism 55 when the rotational frequency exceeds a predetermined upper limit allowable value.SELECTED DRAWING: Figure 1

Description

The present invention relates to a waste treatment facility equipped with a heat treatment furnace for incinerating waste such as sludge and a method for operating the 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 dewatered, then landfilled in a final disposal site, or incinerated in a heat treatment furnace including a fluidized bed furnace and a shaft furnace.

In such a heat treatment furnace, it is necessary to supply a sufficient amount of combustion air into the furnace using a forced draft fan and to attract exhaust gas using an induced draft fan to maintain a negative pressure in the furnace. The power cost of the blower and the induced blower, that is, the electric power cost is very high.

Patent Document 1 proposes a waste treatment facility capable of operating a furnace while suppressing the power cost required for a forced draft blower. The waste treatment facility is a waste treatment facility including a heat treatment furnace including a fluidized bed furnace and a shaft furnace for incinerating waste such as sludge, and the heat of combustion in the furnace of the heat treatment furnace and/or the flue gas. A heat exchanger that preheats the combustion air by the heat of the exhaust gas that is guided to the turbine, a turbine that rotates by the combustion air that is preheated by the heat exchanger, and a compressor that supplies the combustion air to the heat exchanger by the rotation of the turbine. And a forced air blower for precompressing and supplying combustion air to the compressor.

In such waste treatment equipment, the compression work by the compressor is pushed up by the compression work by the compressor, so even if the loss such as ventilation pressure loss that occurs when supplying combustion air to the heat treatment furnace is subtracted, it is sufficient. Combustion air can be supplied, and the power of the forced draft fan required therefor can be sufficiently suppressed by providing the supercharger and the heat exchanger, and the power cost can be reduced as a whole.

JP, 2016-180528, A

In the waste treatment facility described above, the air pressure to be supplied by the forced draft fan is reduced as the amount of waste heat recovered by the heat exchanger is increased, and as a result, the power required for the forced draft fan is suppressed. If the amount of waste heat recovered by the heat exchanger becomes excessive, the rotation speed of the supercharger may exceed the upper limit rotation speed and rise.

Therefore, as shown in FIG. 3B, the inventor of the present application stably supplies the combustion air amount to the heat treatment furnace even in a situation where the waste heat recovery amount by the heat exchanger becomes excessive. As much as possible, a heat input amount adjustment mechanism that adjusts the heat input amount of the combustion air supplied to the turbine is provided, and the heat input amount adjustment mechanism is adjusted so that the combustion air amount supplied to the compressor becomes the target air amount. However, it is proposed to bypass the surplus.

For that reason, a flow rate adjusting valve that can adjust the flow rate of high-pressure air is used as a heat input adjusting mechanism.However, in the adjustment using the flow rate adjusting valve, the rotation speed of the supercharger rises abnormally due to the delay in response. There was a risk of damage to the supercharger.

When the rotation speed of the supercharger rises abnormally, for example, if a damper mechanism is provided between the forced draft fan and the compressor and the damper mechanism is closed, an abnormal phenomenon called surging occurs. There is a risk that the compressor and the piping system may be damaged.

The object of the present invention is to rapidly rotate the rotation speed even when there is a risk that the supercharger will operate in an abnormally high rotation range under the situation where the waste heat recovery amount by the heat exchanger becomes excessive. The present invention is to provide a waste treatment facility and a method of operating the waste treatment facility that can reduce the waste.

In order to achieve the above-mentioned object, the first characteristic configuration of the waste treatment facility according to the present invention is a heat treatment furnace for incinerating waste such as sludge and a combustion heat and/or a flue of the heat treatment furnace. A heat exchanger that preheats the combustion air by the retained heat of the exhaust gas that is introduced, a turbine that is rotated by the combustion air that is preheated by the heat exchanger, and the combustion air that is supplied to the heat exchanger by the rotation of the turbine. A waste treatment facility comprising a supercharger including a compressor, wherein a heat input amount adjusting mechanism for adjusting the heat input amount of combustion air supplied to the turbine and a driving force for the supercharger are set rapidly. A pressure release mechanism for reducing the amount of combustion air supplied to the compressor is adjusted so that the amount of combustion air supplied to the compressor is a target air amount, and the number of revolutions of the supercharger is monitored by monitoring the number of revolutions of the supercharger. When the rate of change of the rotation speed exceeds a predetermined upper limit allowable value, a control unit for activating the pressure release mechanism is provided.

If the amount of waste heat recovered by the heat exchanger becomes excessive and the amount of air supplied to the compressor, that is, the amount of air sucked in by the compressor, exceeds the target amount of air, the control unit supplies it to the turbine via the heat input adjustment mechanism. The heat input of the combustion air is adjusted. Further, when the rotational speed of the supercharger or the rate of change of the rotational speed exceeds a predetermined upper limit allowable value, the pressure releasing mechanism is operated by the control unit. As a result, the amount of air supplied to the compressor can be adjusted to the target amount of air, and it can be avoided that the supercharger is driven in an abnormally high rotation range that may cause damage.

In the second characteristic configuration, in addition to the above-described first characteristic configuration, the pressure release mechanism includes a bypass passage that directly guides the air delivered from the compressor and introduced to the heat exchanger to the delivery port side of the turbine. And an on-off valve mechanism provided in the bypass passage.

When the on-off valve mechanism provided in the bypass passage is opened, the air sent from the compressor and guided to the heat exchanger flows to the output port side of the turbine without heat exchange, and becomes the rotational power source for the supercharger. Since the hot compressed air is no longer supplied to the turbine, the rotational speed of the supercharger drops sharply.

The third characteristic configuration is, in addition to the above-described second characteristic configuration, provided with a flow rate adjustment mechanism in the bypass passage in parallel with the opening/closing valve mechanism, and the heat input amount adjustment by the bypass passage and the flow rate adjustment mechanism. The point is that the mechanism is configured.

By operating the flow rate adjustment mechanism with the on-off valve mechanism closed, the heat input amount of the combustion air supplied to the turbine can be adjusted with high accuracy, and the rotation speed of the supercharger or the change rate of the rotation speed can be set to a predetermined value. When the upper limit allowable value of is exceeded, the rotational speed of the supercharger can be rapidly reduced by opening the on-off valve mechanism.

In the fourth characteristic configuration, in addition to the first characteristic configuration described above, the pressure release mechanism is a bypass that directly guides the air guided from the heat exchanger to the introduction port of the turbine to the delivery port side of the turbine. And a switching valve mechanism provided in the bypass passage.

The air guided from the heat exchanger to the inlet port of the turbine is directly guided to the outlet port side of the turbine through the bypass passage, and the hot compressed air that serves as the rotational power source for the supercharger is not supplied to the turbine. The rotation speed of the feeder suddenly drops.

In the fifth characteristic configuration, in addition to the first characteristic configuration described above, a forced air blower for supplying combustion air to the compressor is provided, and the pressure release mechanism guides the forced air blower to the introduction port of the compressor. The point is that it is composed of a bypass passage that guides the generated air directly to the delivery port side of the turbine, and an opening/closing valve mechanism provided in the bypass passage.

The air guided to the compressor inlet port is directly guided to the turbine outlet port side via the bypass passage, and the hot compressed air that serves as the rotational power source for the turbocharger is no longer supplied to the turbine, which causes the turbocharger rotation. The number drops sharply.

In the sixth characteristic configuration, in addition to the first characteristic configuration described above, the pressure release mechanism includes an open path for discharging the air sent from the compressor and guided to the heat exchanger to the outside of the system, and the release path. It is composed of an on-off valve mechanism provided on the road.

The air sent from the compressor and guided to the heat exchanger is discharged to the outside of the system through the open path, and the high-temperature compressed air that serves as the rotational power source for the supercharger is no longer supplied to the turbine. Drops sharply.

The seventh characteristic configuration is that in addition to any one of the first to sixth characteristic configurations described above, the opening/closing valve mechanism is configured by a ball valve.

The on-off valve mechanism is required to rapidly reduce the rotation speed of the supercharger in an emergency to avoid damage to the supercharger. .. A ball valve is preferably used as such an on-off valve mechanism.

The operating method of the waste treatment facility according to the present invention is characterized by a heat treatment furnace for incinerating waste such as sludge, and a combustion heat of the heat treatment furnace and/or combustion heat of exhaust gas introduced to a flue. A supercharger including a heat exchanger for preheating the working air, a turbine rotated by the combustion air preheated in the heat exchanger, and a compressor for supplying the combustion air to the heat exchanger by the rotation of the turbine. A method for operating a waste treatment facility, comprising: a heat input amount adjusting mechanism for adjusting a heat input amount of combustion air supplied to the turbine; and a pressure releasing mechanism for rapidly reducing a driving force of the supercharger. Then, the rotation speed of the supercharger is monitored, and when the rotation speed or the rate of change of the rotation speed exceeds a predetermined upper limit allowable value, the pressure release mechanism is operated to increase the driving force of the supercharger. It is in the point of sudden drop.

As described above, according to the present invention, even when there is a risk that the supercharger will operate in an abnormally high rotation range under a situation where the waste heat recovery amount by the heat exchanger becomes excessive. It has become possible to provide a waste treatment facility and a method of operating the waste treatment facility that can rapidly reduce the rotation speed.

Explanatory diagram of a waste treatment facility and a method of operating the waste treatment facility according to the present invention (A), (b), (c) is a diagram explaining the Brayton cycle of a supercharger, (d) is a characteristic diagram which shows the correlation of blower power and waste heat recovery. (A) is explanatory drawing which shows the relationship of the rotation speed of a supercharger, a flow volume, and a pressure ratio, (b) shows a mode that a heat input amount adjustment mechanism is operated when waste heat recovery amount increases more than necessary power. Explanatory diagram of relationship between waste heat generation and waste heat recovery using heat exchanger Explanatory drawing of waste treatment equipment showing another embodiment of the pressure release mechanism Explanatory drawing of waste treatment equipment showing another embodiment of the pressure release mechanism Explanatory drawing of waste treatment equipment showing another embodiment of the pressure release mechanism Explanatory drawing of waste treatment equipment showing another embodiment of heat input adjustment mechanism Explanatory drawing of waste treatment equipment showing another embodiment of heat input adjustment mechanism Explanatory drawing of waste treatment equipment showing another embodiment of heat input adjustment mechanism Explanatory drawing of waste treatment equipment showing another embodiment of heat input adjustment mechanism Explanatory drawing of waste treatment equipment showing another embodiment of heat input adjustment mechanism

Embodiments of the waste treatment facility and the method for operating the waste treatment facility according to the present invention will be described below.

FIG. 1 shows a waste treatment facility 100 that incinerates waste such as sludge. The waste treatment facility 100 includes a sludge storage tank 1 in which sludge, which is a substance to be incinerated, is stored, a sludge input mechanism 11, a fluidized bed incinerator 2 which is an example of a heat treatment furnace, and an exhaust gas treatment facility. There is.

The fluidized bed incinerator 2 puts the sludge supplied from the sludge feeding mechanism 11 into the fluidized bed formed by the high temperature air supplied from the air supply mechanism 3 to heat the fluidized bed, and the gasified sludge is freeboarded. It is a heat treatment furnace that burns at 20. Below the freeboard section 20, a temperature raising burner 21 for heating the inside of the furnace at startup is arranged, and an auxiliary burner 22 for supplementing the amount of heat necessary for burning the sludge after the temperature of the furnace is raised.

Along with the flue 10 of the fluidized bed incinerator 2, the first heat exchanger 5 that preheats the combustion air by the heat of the exhaust gas, the dust collector 6 that collects soot dust, and the exhaust gas that sprays the alkaline agent in order. A flue gas treatment tower 7 and the like for neutralizing the acidic gas components therein is arranged.

At the downstream side of the smoke exhaust treatment tower 7, an induced air blower 8 that attracts the exhaust gas from the flue 10 to maintain a negative pressure in the furnace is provided, and the exhaust gas attracted by the induced air blower 8 is purified by each exhaust gas treatment facility. After being exhausted, the chimney 9 is exhausted.

The air supply mechanism 3 described above includes the forced air blower 30, the inverter 75, the supercharger 40, and the first heat exchanger 5. The supercharger 40 includes a compressor 40c and a turbine 40t that are integrally and rotatably connected by a drive shaft 40a.

The combustion air pre-compressed to about 5 kPa by the forced draft blower 30 is supplied to the air supply port of the compressor 40c constituting the supercharger 40 and compressed to about 100 to 300 kPa, and then supplied to the first heat exchanger 5. It

Combustion air that has been heat-exchanged with exhaust gas of 800 to 1000° C. in the first heat exchanger 5 and preheated to 500 to 750° C. is supplied to the turbine 40t in the subsequent stage, the turbine 40t is rotationally driven, and the drive shaft 40a and The connected compressor 40c is rotationally driven.

The compressed air of 400 to 650° C. and about 40 kPa discharged from the turbine 40t is supplied to the fluidized bed incinerator 2 as air for fluidization and combustion, and a fluidized bed is formed. The pressure described in this specification is a gauge pressure.

Since the combustion air pre-compressed by the forced air 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 forced air blower 30 is preheated by the heat exchanger 30. become. As a result, the expansion work of the turbine 40t becomes equal to or larger than the compression work of the compressor 40c, and the drive of the supercharger 40 is maintained. Therefore, the ventilation pressure loss in forming the fluidized bed in the fluidized bed incinerator 2 is less than The combustion air can be supplied at a high pressure.

As shown in FIG. 2( a ), the gas turbine and the supercharger are devices that operate according to the Brayton cycle, and the compression process in the compressor (1→2 in the figure) and the feed in the combustor or the heat exchanger are performed. It consists of a thermal process (2→3 in the figure) and an expansion process in the turbine (3→4 in the figure). Rotation is maintained when the expansion work in the turbine exceeds the compression work in the compressor.

However, as shown in FIG. 2(b), if a structure is adopted in which the air supply port of the compressor 40c is opened to the atmosphere and the outside air is directly sucked, the expansion work amount x in the turbine 40t causes a loss of ventilation pressure to the fluidized bed. When restricted by x1 and ventilation resistance x2, the expansion work amount x in the turbine 40t becomes smaller than the compression work amount y in the compressor 40c (x<y), and the drive of the supercharger 40 cannot be maintained.

Therefore, the forced air blower 30 is configured to supply air to the compressor 40c via the air passage.

As shown in FIG. 2C, since the combustion air precompressed by the forced air blower 30 is supplied to the air supply port of the compressor 40c, the compression work amount y in the compressor 40c is substantially equal to the precompression amount y1. Therefore, even if there is a ventilation pressure loss x1 to the fluidized bed and a ventilation resistance x2, the drive of the supercharger 40 can be maintained.

Moreover, since the discharge pressure by the forced draft blower 30 can be made lower than when the supercharger 40 is not used, the power consumption of the forced draft blower 30 can be reduced. However, at the initial stage of startup of the fluidized bed incinerator 2, it is necessary to raise the blast pressure in order to form the fluidized bed only by the forced draft blower 30, but the ventilation resistance of the supercharger 40 is small, and it depends on the startup. As the temperature rises, the power cost reduction effect of the supercharger 40 can be obtained.

The waste treatment facility 100 is provided with a control unit 70. The control unit 70 controls the rotation speed of the forced draft blower 30 based on the oxygen concentration of the exhaust gas detected by the oxygen gas sensor Sg provided at the outlet of the freeboard unit 20, so that the fluidized bed incinerator 2 is suitable. The supply amount of the combustion air is adjusted so that the combustion state is maintained.

The control unit 70 calculates the target air amount to be supplied into the furnace by performing a predetermined control 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.

The air amount required for complete combustion is set based on the theoretical air amount assumed in advance, and the reference oxygen concentration remaining in the exhaust gas at that time is calculated. Feedback calculation is performed so that the target air amount is decreased when the oxygen concentration of the exhaust gas detected by the oxygen gas sensor Sg is higher than the reference oxygen concentration, and the target air amount is increased when the oxygen concentration of the exhaust gas is lower than the reference oxygen concentration. Be done.

The control unit 70 calculates the target rotation speed of the forced draft fan 30 based on the deviation between the target air amount and the air amount detected by the flow meter Sq installed between the forced draft fan 30 and the compressor 40c, and the forced blower 30 is driven. The inverter 75 is controlled so that 30 becomes the target rotation speed.

By using the oxygen concentration contained in the exhaust gas as an index, it is possible to grasp the amount of combustion air that is appropriate for the organic components of the sludge burned in the fluidized bed incinerator 2, and set the target amount based on that index. As a result, the combustion air can be supplied without a significant excess or deficiency with respect to the required amount.

FIG. 2D shows the relationship between the amount of waste heat recovered by the first heat exchanger 5 and the power required for the forced draft blower 30 under the assumption that the amount of combustion air is kept constant. It is shown that the power required for the forced draft blower 30 decreases as the amount of recovery increases. When the amount of waste heat recovered by the first heat exchanger 5 increases, a sufficient amount of compressed air drawn in by the compressor 40c can be obtained, and the amount of air blown by the forced air blower 30 becomes unnecessary.

When the amount of waste heat recovered by the first heat exchanger 5 fluctuates rapidly in such a state, the control unit 70 can adjust the amount of air blown so that the amount of combustion air required for the fluidized bed incinerator 2 is adjusted. It may not be possible, and stable operation of the fluidized bed incinerator 2 may become difficult.

If the amount of waste heat recovered by the first heat exchanger 5 becomes excessively large, the response may be delayed, and the supercharger 40 may be driven in an abnormally high rotation range, resulting in damage.

Therefore, the heat input amount adjusting mechanism 50 and the inverter 75 that adjust the heat input amount to the turbine 40t are provided so that the air supply amount to the compressor 40c becomes the target air amount, and the driving force of the supercharger 40 is rapidly reduced. A pressure release mechanism 55 is provided.

The heat input amount adjusting mechanism 50 includes a bypass passage 51 that guides a part of the air sent from the compressor 40c and led to the first heat exchanger 5 directly to the sending port side of the turbine 40t, and a flow rate adjusting mechanism provided in the bypass passage 51. And a flow rate adjusting valve 52 which is As the flow rate adjusting valve 52, a needle valve capable of accurately adjusting the flow rate is preferably used.

The amount of heat input to the turbine 40t and the amount of air are adjusted by the flow rate adjusting valve 52 provided in the bypass passage 51. The preheated air sent from the turbine 40t and the air guided to the bypass passage 51 join and are supplied to the fluidized bed incinerator 2 as combustion air.

The pressure release mechanism 55 includes a bypass passage 54 that directly guides the air delivered from the compressor 40c and guided to the first heat exchanger 5 to the delivery port side of the turbine 40t, and an opening/closing valve mechanism 57 provided in the bypass passage 56. Has been done. As the opening/closing valve mechanism 57, it is necessary to rapidly reduce the rotation speed of the supercharger 40 in an emergency to avoid damage to the supercharger 40. Therefore, a ball valve having a characteristic that the ventilation resistance is low and the operation speed is fast. Is preferably used. In the present embodiment, since the bypass passage 54 is arranged in parallel with the bypass passage 51, the opening/closing valve mechanism 57 and the flow rate adjusting valve 52 are arranged in parallel in the common bypass passage.

When the amount of waste heat recovered by the first heat exchanger 5 becomes excessive and the amount of air supplied to the compressor 40c, that is, the amount of suction air by the compressor 40c exceeds the required amount, the heat input adjustment mechanism 50 supplies the turbine 40t with the heat. Heat input is adjusted. As a result, the rotation speed of the compressor 40c decreases, and the air supply amount can be adjusted to the target air amount.

In addition, when the amount of waste heat recovered by the first heat exchanger 5 becomes excessive and the supercharger 40 is driven in an abnormally high rotation range and may be damaged, compressed air is generated by the pressure release mechanism 55. It is possible to prevent the supercharger 40 from being opened and being driven in an abnormally high rotation range where it may be damaged.

More specifically, when the heat exchange amount in the first heat exchanger 5 increases and the air amount detected by the flow meter Sq rises above the target amount, the control unit 70 causes the air bypassed in the bypass passage 51. By adjusting the flow rate adjusting mechanism 52 so as to increase the amount, the heat input amount to the turbine 40t is decreased, and conversely, the heat exchange amount in the first heat exchanger 5 is decreased and detected by the flow meter Sq. When the amount of air is reduced below the target amount, the flow rate adjusting mechanism 52 is adjusted so as to increase the amount of air bypassed in the bypass passage 51, thereby controlling the amount of heat input to the turbine 40t to be increased.

Further, a revolution counter Sr for monitoring the revolution speed of the supercharger 40 is attached to the drive shaft 40a, and the control unit 70 controls the revolution speed of the supercharger 40 based on the output of the revolution counter Sr to a predetermined upper limit. When the value is exceeded, the pressure release mechanism 55 is controlled to operate. It is preferable to set the upper limit allowable value to a rotation speed that allows for a safety factor in the upper limit rotation speed of the supercharger 40.

It is also possible to estimate the rotation speed based on the performance characteristic curve shown in FIG. 3A showing the relationship between the pressure ratio (Po/Pi) of the supercharger 40 and the flow rate Q. It is possible to accurately capture the rotation speed by installing.

In the present embodiment, an example in which the pressure release mechanism 55 is controlled to operate when the rotation speed of the supercharger 40 exceeds a predetermined upper limit allowable value has been described. The pressure release mechanism 55 may be controlled to operate when the predetermined upper limit allowable value is exceeded. As the upper limit allowable value of the rotational speed change rate, a change rate can be set such that the upper limit rotational speed of the supercharger 40 reaches a rotational speed in which a safety factor is expected within a predetermined time. The term “within a predetermined time period” means a time period during which the rotation speed rapidly reaches the upper limit allowable value, and is preferably set to, for example, 3 seconds or less.

The heat input amount adjusting mechanism 50 is preferably controlled so as to operate without stopping the forced draft fan 30 when the forced draft fan 30 enters a preset low power state. This is because if the large-sized forced draft blower 30 is once stopped, it is difficult to immediately start it when necessary.

When the forced draft fan 30 enters a preset low power state, the state is maintained and the heat input amount adjusting mechanism 50 is operated to adjust the air supply amount to the compressor 40c to the target air amount, and the heat input amount adjusting mechanism. When the air supply amount cannot be adjusted to the target air amount by 50, the inverter 75 can be immediately controlled to increase the blowing amount by the forced draft blower 30.

It is needless to say that the forced air blower 30 may be configured to stop when the forced air blower 30 enters a preset low power state. Further, although the example in which the heat input amount adjusting mechanism 50 is operated when the forced draft fan 30 enters the preset low power state has been described, the heat input amount regulating mechanism 50 and the pressure release mechanism 55 may be operated regardless of the power supplied to the forced draft fan 30. It may be configured to operate.

When the waste heat recovery amount by the first heat exchanger 5 becomes excessive and the air supply amount to the compressor, that is, the suction air amount by the compressor exceeds the target air amount, the control unit 70 controls the heat input amount adjustment mechanism 50. The heat input amount of the combustion air supplied to the turbine 40t is adjusted. As a result, the air supply amount to the compressor 40c can be adjusted to the target air amount.

Further, when the rotation speed of the supercharger 40 or the rate of change of the rotation speed exceeds a predetermined upper limit allowable value, the control unit 70 activates the pressure release mechanism 55. When the opening/closing valve mechanism 57 provided in the bypass path 56 is opened, the air sent from the compressor 40c and guided to the first heat exchanger 5 flows to the sending port side of the turbine 40t without heat exchange, and the supercharging is performed. Since the high-temperature compressed air that serves as the rotational power source of the machine 40 is not supplied to the turbine 40t, the rotation speed of the supercharger 40 sharply decreases. It is preferable that the control unit 70 opens the on-off valve mechanism 57 and stops the forced draft fan 30.

In the above-described embodiment, the example in which the heat exchanger is configured by the heat exchanger that preheats the combustion air by the retained heat of the exhaust gas guided to the flue has been described. It may be a heat exchanger for preheating air. In the latter case, the heat exchanger is installed in the heat treatment furnace 2.

That is, the operation method of the waste treatment facility according to the present invention is performed by the heat treatment furnace 2 for incinerating waste such as sludge, the combustion heat of the heat treatment furnace 2 and/or the heat of the exhaust gas guided to the flue. To a turbine, a supercharger including a heat exchanger for preheating the working air, a turbine rotated by the combustion air preheated by the heat exchanger, and a compressor for supplying the combustion air to the heat exchanger by the rotation of the turbine, A method for operating a waste treatment facility, comprising: a heat input amount adjusting mechanism for adjusting the heat input amount of supplied combustion air; and a pressure releasing mechanism for rapidly reducing the driving force of a supercharger. It is configured to monitor the number of revolutions of the machine and, when the number of revolutions or the rate of change of the number of revolutions exceeds a predetermined upper limit allowable value, activate the pressure release mechanism to rapidly reduce the driving force of the supercharger. There is.

Hereinafter, another embodiment will be described.
As shown in FIG. 4, the pressure release mechanism 55 is provided in the bypass passage 56 and the bypass passage 56 that directly introduces the air guided from the first heat exchanger 5 to the introduction port of the turbine 40t to the delivery port side of the turbine 40t. It may be configured with the open/close valve mechanism 57.

The air guided from the first heat exchanger 5 to the introduction port of the turbine 40t is directly guided to the delivery port side of the turbine 40t via the bypass path 56, and the high-temperature compressed air that serves as the rotational power source of the supercharger 40 is the turbine. Since it is no longer supplied to 40t, the rotation speed of the supercharger 40 sharply decreases.

As shown in FIG. 5, the pressure release mechanism 55 includes a bypass passage 56 that guides the air guided from the forced air blower 30 to the introduction port of the compressor 40c directly to the delivery port side of the turbine 40t, and an opening/closing valve provided in the bypass passage 56. It may be configured with the mechanism 57.

The air guided to the introduction port of the compressor 40c is directly guided to the delivery port side of the turbine 40t via the bypass passage 56, and the high-temperature compressed air that serves as the rotational power source of the supercharger 40 is not supplied to the turbine 40t. The rotation speed of the supercharger 40 sharply decreases.

As shown in FIG. 6, the pressure release mechanism 55 discharges the air sent from the compressor 40c and guided to the first heat exchanger 5 to the outside of the system, and the open/close valve mechanism 57 provided in the open passage 56. It may be composed of and.

The air sent from the compressor 40c and guided to the first heat exchanger 5 is discharged to the outside of the system through the open path 56, and the high-temperature compressed air that serves as the rotational power source of the supercharger 40 is not supplied to the turbine 40t. The rotation speed of the supercharger 40 sharply decreases. As described above, in any case, it is preferable that the opening/closing valve mechanism 57 be a ball valve.

Hereinafter, an embodiment regarding the heat input amount adjusting mechanism 50 will be described. Although the pressure release mechanism 55 is not clearly shown in FIGS. 8 to 11, in another embodiment of the heat input amount adjustment mechanism 50 described below, the pressure release mechanism of any one of FIGS. The mechanism 55 is adopted.

As shown in FIG. 7, the heat input adjustment mechanism 50 includes a bypass passage 51 that directly guides a part of the air sent from the compressor 40c and guided to the first heat exchanger 5 to the introduction port side of the turbine 40t, and a bypass passage 51. It may be configured by a flow rate adjusting valve 52 as a flow rate adjusting mechanism provided in the.

As shown in FIG. 8, it is preferable to include the second heat exchanger 4 that adjusts the temperature of the preheated air sent from the turbine 40t when the heat input amount adjusting mechanism 50 operates.

Then, the bypass passage 61 is provided in the flow path that guides the preheated air sent from the turbine 40t to the second heat exchanger 4, and the bypass passage 61 is provided with the temperature adjusting mechanism 60 that is provided with the damper mechanism as the flow rate adjusting mechanism 62. It is preferable that the combustion air obtained by merging the air heated by the second heat exchanger 4 and the air passing through the bypass passage 61 is supplied to the fluidized bed incinerator 2.

In this case, a temperature sensor St is provided in the supply section of the combustion air to the fluidized bed incinerator 2, and the control section 70 controls the flow rate adjusting mechanism 62 so that the temperature detected by the temperature sensor St becomes the target temperature. It is preferable that it is configured as follows.

The heat input amount adjusting mechanism 50 operates, and the temperature of the preheated air sent from the turbine 40t and guided to the fluidized bed incinerator 2 as combustion air fluctuates, which hinders stable operation of the fluidized bed incinerator 2. Even if there is a possibility that the preheated air is supplied from the turbine 40t to the fluidized bed incinerator 2 by providing the second heat exchanger 4, the temperature of the preheated air can be adjusted to an appropriate temperature.

Furthermore, as shown in FIG. 9, in order to adjust the temperature of the combustion air supplied to the fluidized bed incinerator 2, the most downstream side along the flow direction of the exhaust gas flowing through the heat transfer pipe arranged in the second heat exchanger 4. Side and the air inflow portions 4a and 4b for supplying combustion air are provided at two locations on the upstream side of the downstream side and the flow path 71 that guides the air sent from the turbine 40t to the second heat exchanger 4. A damper mechanism may be provided as the flow rate adjusting mechanism 72 that adjusts the amount of air flowing in from the air inflow portion 4a and the air inflow portion 4b.

Also in this case, the temperature sensor St is provided in the supply unit of the combustion air to the fluidized bed incinerator 2, and the control unit 70 controls the flow rate adjusting mechanism 72 so that the temperature detected by the temperature sensor St becomes the target temperature. It may be configured to do so.

As shown in FIG. 10, the heat input amount adjusting mechanism 50 includes a bypass passage 51 that directly guides part of the preheated air that is sent from the first heat exchanger 5 and is guided to the introduction port of the turbine 40t to the delivery port side of the turbine 40t. Alternatively, the damper mechanism may be configured as the flow rate adjusting mechanism 52 provided in the bypass path 51.

It is needless to say that any flow rate adjusting mechanism is not limited to the example in which the damper mechanism is adopted, and a known flow rate adjusting mechanism such as a valve mechanism can be appropriately adopted.

The entire amount of air sent from the compressor 40c is guided to the first heat exchanger 5, and part of the air preheated by the first heat exchanger 5 is guided to the bypass passage 51 via the flow rate adjusting mechanism 52, and As a result of the residue being guided to the turbine 40t, the amount of heat input to the turbine 40t is adjusted. The preheated air sent from the turbine 40t and the preheated air guided to the bypass passage 51 are combined and supplied to the fluidized bed incinerator 2 as combustion air.

As shown in FIG. 11, the second heat exchanger 4 and the first heat exchanger 5 arranged in the flue 10 may be arranged in parallel along the flow direction of the exhaust gas.

In the above-described embodiment, the example in which the first heat exchanger 5 is arranged in the flue 10 and is configured to preheat the combustion air by the retained heat of the exhaust gas guided to the flue has been described. The exchanger 5 may be provided in the fluidized bed incinerator 2 and configured to preheat the combustion air by the heat of combustion in the furnace.

Although the above-mentioned embodiment explained the case where fluidized bed type incinerator 2 was adopted as a heat treatment furnace, the incinerator to which the present invention is applied is not limited to fluidized bed type incinerator 2 and fluidized bed type incinerator 2 is used. Similarly, it can be applied to other types of industrial furnaces such as a shaft furnace having a large ventilation pressure loss. For example, a coke bed is formed in the bottom part, and a heat treatment furnace or scrap is put into the coke bed to melt the sludge from above the shaft furnace where the tuyere for supplying combustion air is formed. The present invention can be applied to a cupola or the like.

The above-described embodiments are all examples of the present invention, and the present invention is not limited to the description, and the respective characteristic configurations may be appropriately opposed to each other, and the specific configurations of the respective portions may be the same as those of the present invention. It goes without saying that the design may be appropriately changed within the range where the action and effect are exhibited.

100: Waste treatment facility 2: Fluidized bed incinerator (heat treatment furnace)
3: Air supply mechanism 4: Second heat exchanger 5: First heat exchanger 10: Flue 30: Push blower 40: Supercharger 40c: Compressor 40t: Turbine 50: Heat input adjustment mechanism 51: Bypass path 52: Flow rate adjustment mechanism (needle valve)
55: Pressure release mechanism 56: Bypass path (open path)
57: Open valve mechanism (ball valve)
70: Control unit 75: Inverter

Claims (8)

A heat treatment furnace that incinerates waste such as sludge,
A heat exchanger for preheating combustion air by the heat of combustion in the heat treatment furnace and/or the heat of the exhaust gas introduced to the flue;
A supercharger including a turbine rotated by combustion air preheated in the heat exchanger, and a compressor that supplies combustion air to the heat exchanger by rotation of the turbine,
A waste treatment facility comprising:
A heat input amount adjusting mechanism for adjusting the heat input amount of the combustion air supplied to the turbine,
A pressure release mechanism for rapidly reducing the driving force of the supercharger,
While adjusting the heat input amount adjusting mechanism so that the amount of combustion air supplied to the compressor becomes a target air amount, the rotation speed of the supercharger is monitored and the rotation speed or the rate of change of the rotation speed is A waste treatment facility including a control unit that activates the pressure release mechanism when a predetermined upper limit is exceeded. The pressure release mechanism is configured by a bypass passage that guides air sent from the compressor and introduced into the heat exchanger directly to the delivery port side of the turbine, and an opening/closing valve mechanism provided in the bypass passage. Item 1. Waste treatment equipment according to item 1. The waste treatment facility according to claim 2, wherein a flow rate adjusting mechanism is provided in the bypass passage in parallel with the on-off valve mechanism, and the heat input adjusting mechanism is constituted by the bypass passage and the flow rate adjusting mechanism. The pressure release mechanism is configured by a bypass passage that guides the air guided from the heat exchanger to the introduction port of the turbine directly to the delivery port side of the turbine, and an opening/closing valve mechanism provided in the bypass passage. The waste treatment facility according to claim 1. A pressure blower for supplying combustion air to the compressor, wherein the pressure release mechanism directs the air guided from the pusher blower to the introduction port of the compressor to the delivery port side of the turbine; and the bypass passage. The waste treatment facility according to claim 1, wherein the waste treatment facility is provided with an on-off valve mechanism provided in the. 2. The pressure release mechanism according to claim 1, wherein the pressure release mechanism includes an open passage for discharging the air sent from the compressor and guided to the heat exchanger to the outside of the system, and an opening/closing valve mechanism provided in the open passage. Waste treatment equipment. The waste treatment facility according to any one of claims 1 to 6, wherein the on-off valve mechanism is composed of a ball valve. A heat treatment furnace that incinerates waste such as sludge,
A heat exchanger for preheating combustion air by the heat of combustion in the heat treatment furnace and/or the heat of the exhaust gas introduced to the flue;
A supercharger including a turbine rotated by combustion air preheated in the heat exchanger, and a compressor that supplies combustion air to the heat exchanger by rotation of the turbine,
A heat input amount adjusting mechanism for adjusting the heat input amount of the combustion air supplied to the turbine,
A pressure release mechanism for rapidly reducing the driving force of the supercharger,
A method of operating a waste treatment facility comprising:
The rotation speed of the supercharger is monitored, and when the rotation speed or the rate of change of the rotation speed exceeds a predetermined upper limit allowable value, the pressure release mechanism is operated to rapidly reduce the driving force of the supercharger. How to operate waste treatment equipment.

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