JP7246293B2 - Waste treatment equipment and its operation method - Google Patents

Description

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

Conventionally, as described in Patent Document 1, a waste treatment facility for incinerating waste such as sewage sludge, in which air necessary for incinerating the waste is supplied into the incinerator by a supercharger. It has been known. Such supercharged waste treatment equipment can supply air to the incinerator by using the heat of the exhaust gas generated when incinerating waste to drive the supercharger, so it is energy efficient. It is an excellent facility in

The waste treatment facility described in Patent Document 1 includes an incinerator for incinerating waste, a supercharger having a compressor and a turbine, and an oxygen-containing gas discharged from the compressor by exhaust gas discharged from the incinerator. a preheater, an oxygen-containing gas supply passage connecting the compressor, preheater, turbine and incinerator in this order, and a burner arranged in a portion of the oxygen-containing gas supply passage between the preheater and the turbine a blower that supplies the oxygen-containing gas to a portion between the preheater and the burner in the oxygen-containing gas supply channel, and the oxygen-containing gas is supplied from the blower downstream of the preheater in the oxygen-containing gas supply channel an exhaust passage branching from a portion of the oxygen-containing gas supply passage downstream of the preheater and upstream of the first flow regulating valve; and a second flow control valve disposed in the exhaust flow path.

The start-up operation of this conventional waste treatment facility is performed in the following procedure. That is, with the first flow control valve fully closed and the second flow control valve fully open, first, the blower and the burner are respectively driven. Next, after the temperature of the oxygen-containing gas on the outlet side of the preheater exceeds a predetermined reference temperature, the pressure on the upstream side of the first flow control valve becomes higher than the pressure on the downstream side of the first flow control valve. First, the opening of the second flow control valve is decreased, and then the opening of the first flow control valve is increased. After the second flow control valve is fully closed and the first flow control valve is fully open, the burner and the blower are stopped in order.

Japanese Patent No. 6363310

The present inventors have found that in the start-up operation of the waste treatment facility described in Patent Document 1, from the blower to the oxygen-containing gas supply flow path after the first flow control valve is fully opened until the burner is extinguished. We have newly found that it becomes difficult to supply the oxygen-containing gas, and the flow rate of the oxygen-containing gas may be insufficient.

That is, in order for the self-sustaining condition of the turbocharger to be established, it is necessary for the gas having sufficient thermal energy to flow into the turbine. A gas mixture comprising oxygen-containing gas and flue gas produced by the burner enters the turbine. After the burner is extinguished, the thermal energy corresponding to the combustion exhaust gas of the burner decreases among the thermal energy supplied to the turbine. Therefore, after the first flow control valve is fully opened, it is not sufficient that the thermal energy of the mixed gas flowing into the turbine reaches the thermal energy required to establish the self-sustaining condition. It is necessary to keep driving the burner and the blower until the heat energy required for establishment can be secured.

During this time, the temperature of the gas in the oxygen-containing gas supply channel rises, and the pressure in the channel also rises accordingly. For this reason, if the blower has low specifications, the pressure in the flow path will exceed the maximum discharge pressure of the blower, and the gas discharged from the blower will flow backward without being supplied to the flow path. .

The present invention has been made in view of the above problems, and its object is to stably supply air into the path without using a high-spec blower in the start-up operation of a waste treatment facility. It is to provide a treatment facility and its operating method.

A waste treatment facility according to one aspect of the present invention includes an incinerator for incinerating waste, an air introduction path for introducing combustion air to the incinerator, and a combustion air flowing in from the air introduction path, a preheater heated by exhaust gas discharged from the incinerator; a supercharger arranged in the air introduction path, the compressor compressing combustion air and discharging it to the preheater side; and the preheater a turbine for driving the compressor by being rotated by combustion air heated by a supercharger; a switching valve for switching between communication and blocking of combustion air; a burner disposed closer to the turbine than the switching valve in the high-pressure path; a blower that supplies combustion air to the high-pressure path; A pressure detection unit that detects the pressure in the high-pressure path, a blowout valve for discharging combustion air to the outside of the high-pressure path, and after opening the switching valve and before extinguishing the burner, and a control unit that controls the blow-off valve so that the pressure detected by the pressure detection unit becomes a target pressure that is equal to or lower than the maximum pressure of the blower.

According to the waste treatment facility, the pressure detected by the pressure detection unit after the switching valve is opened and before the burner extinguishes The blow-off valve is controlled so that the pressure) becomes a target pressure equal to or lower than the maximum pressure of the blower. For this reason, unlike conventional waste treatment equipment, which maintains the blow-off valve in a fully closed state from after the switching valve is fully opened until the burner is extinguished, the blower can be used without using a high-spec blower. It becomes possible to stably supply combustion air from the air introduction path. As a result, it is possible to suppress the shortage of the flow rate of the combustion air during the start-up operation of the waste treatment facility.

In the above-described waste treatment facility, the control unit does not execute control of the blow-off valve using the target pressure as an index before the switching valve is opened, and the high-pressure path is upstream of the switching valve. A first control may be executed to control the blow-off valve such that the pressure in the high-pressure path is higher than the pressure downstream of the switching valve. After the switching valve is opened, the control unit may switch from the first control to the second control for controlling the blow-off valve so that the pressure detected by the pressure detection unit becomes the target pressure. good.

According to this configuration, it is possible to prevent the combustion air from flowing back to the compressor side after the switching valve is opened. In addition, the control of the blow-off valve can be appropriately switched in accordance with the timing of opening the switching valve.

A method of operating a waste treatment facility according to another aspect of the present invention includes an incinerator for incinerating waste, an air introduction path for introducing combustion air to the incinerator, and combustion flowing in from the air introduction path. a preheater that heats the combustion air with the exhaust gas discharged from the incinerator; and a supercharger that is arranged in the air introduction path and compresses the combustion air and discharges it to the preheater side. , a turbine that is rotated by the combustion air heated by the preheater to drive the compressor; and a portion of the air introduction path between the compressor and the turbine. A switching valve arranged in a high-pressure path for switching between communication and blocking of combustion air, a burner arranged in the high-pressure path closer to the turbine than the switching valve, and supplying combustion air into the high-pressure path. A method of operating a waste treatment facility comprising a blower and a blow-off valve for discharging combustion air out of said high-pressure path. In this method, the pressure in the high-pressure path reaches a target pressure equal to or lower than the maximum pressure of the blower after the switching valve is opened and before the burner extinguishes during the start-up operation of the waste treatment facility. Operate the blow-off valve so that

In this method, the pressure in the high-pressure path between the compressor and the turbine in the air introduction path increases after the switching valve is opened during start-up operation of the waste treatment facility and before the burner extinguishes. Operate the blow-off valve so that the target pressure is less than the maximum pressure. For this reason, unlike the conventional method of maintaining the blow-off valve in a fully closed state from after the switching valve is fully opened until the burner is extinguished at the start-up operation of the waste treatment facility, a high-spec blower is used. Even without it, it is possible to stably supply combustion air from the blower into the air introduction path. As a result, it is possible to suppress the shortage of the flow rate of the combustion air during the start-up operation of the waste treatment facility.

As is clear from the above description, according to the present invention, a waste treatment facility capable of stably supplying air into the path without using a high-spec blower during start-up operation of the waste treatment facility and its A driving method can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows typically the structure of the waste disposal facility which concerns on one Embodiment of this invention. It is a flow chart for explaining a method of operating a waste disposal facility according to an embodiment of the present invention. 4 is a flow chart for explaining opening degree control of the blow-off valve in the above operation method. It is a time chart for demonstrating the operating method of the waste disposal facility which concerns on one Embodiment of this invention.

BEST MODE FOR CARRYING OUT THE INVENTION A waste treatment facility and a method for operating the same according to embodiments of the present invention will be described below in detail with reference to the drawings.

(waste treatment equipment)
First, the configuration of a waste disposal facility 1 according to one embodiment of the present invention will be described based on FIG. The waste disposal facility 1 according to this embodiment is a facility for incinerating waste such as sewage sludge. As shown in FIG. 1, the waste treatment facility 1 includes an incinerator 10, an air introduction path 20, a preheater 30, an exhaust gas path 40, a supercharger 50 including a compressor 51 and a turbine 52, a switching valve V1, burner 60, fan 70, first pressure detector 80, second pressure detector 85, first air discharge path 90, first air discharge valve V2, and second air discharge path 91 , a second blow-off valve V6, and a control unit 100. As shown in FIG. Each of these components will be described below.

The incinerator 10 is equipment for incinerating waste such as sewage sludge, and is, for example, a fluidized bed incinerator. An air inlet 11 for introducing combustion air A1 into the furnace is formed on the side of the incinerator 10, and an exhaust gas G1 generated during the incineration of waste is discharged to the outside of the furnace at the top of the incinerator 10. An exhaust gas outlet 12 is formed for discharge.

As shown in FIG. 1, a fluidized bed 110 is formed in the lower part of the incinerator 10 by being filled with a fluidizing medium such as sand, and the space above the fluidized bed 110 is a freeboard FB. It's becoming Combustion air A1 introduced into the furnace through the air inlet 11 is used for combustion of waste and fluidization of sand.

The air introduction path 20 is a path for introducing combustion air A1 to the incinerator 10 . The air introduction path 20 has first to fourth paths 21 to 24, and the combustion air A1 is introduced into the incinerator 10 through the first to fourth paths 21 to 24 in order. Each of the first to fourth paths 21 to 24 is composed of a pipe in which a flow path for the combustion air A1 is formed. The combustion air A1 in this embodiment is outdoor air (outside air), but indoor air may be used as the combustion air.

The first path 21 has an intake port (not shown) for combustion air A1 formed at its upstream end, and is connected to the intake port of the compressor 51 at its downstream end. In this embodiment, the intake port is open to the outside air. The second path 22 has an upstream end connected to the discharge port of the compressor 51 and a downstream end connected to the air inlet 31 of the preheater 30 . The third path 23 has an upstream end connected to the air outlet 32 of the preheater 30 and a downstream end connected to the inlet of the turbine 52 . The fourth path 24 has an upstream end connected to the outlet of the turbine 52 and a downstream end connected to the air inlet 11 of the incinerator 10 . As shown in FIG. 1 , a temperature detector 84 is installed near the air outlet 32 of the preheater 30 in the third path 23 . In addition, "upstream and downstream in the air introduction path 20" in this specification are based on the flow direction of the combustion air A1 toward the incinerator 10. As shown in FIG.

The preheater 30 is a heat exchanger arranged in the air introduction path 20 and the exhaust gas path 40, and converts the combustion air A1 flowing in from the air introduction path 20 (second path 22) into the exhaust gas discharged from the incinerator 10. Heat with G1. The preheater 30 is, for example, a shell-and-tube heat exchanger, and heats the combustion air A1 through heat exchange with the exhaust gas G1. Note that the preheater 30 is not limited to a shell-and-tube heat exchanger, and may be another type of heat exchanger.

The exhaust gas path 40 includes a first exhaust gas path 41 whose upstream end is connected to the exhaust gas outlet 12 of the incinerator 10 and whose downstream end is connected to the exhaust gas inlet 33 of the preheater 30, and whose upstream end is connected to the exhaust gas of the preheater 30. and a second exhaust gas path 42 connected to the outlet 34 . After being discharged from the incinerator 10 through the exhaust gas outlet 12 , the exhaust gas G<b>1 passes through the first exhaust gas path 41 and flows into the preheater 30 . The exhaust gas G1 flows out of the preheater 30 from the exhaust gas outlet 34 after the temperature of the exhaust gas G1 is lowered by heat exchange with the combustion air A1 in the preheater 30 . After that, the exhaust gas G1 passes through each facility (not shown) such as a boiler, a temperature reduction tower, a bag filter and a catalytic reaction tower in order, and is discharged from a chimney.

The supercharger 50 is arranged in the air introduction path 20, and has a configuration in which a compressor 51 and a turbine 52 are connected to each other by a rotating shaft 50A. As shown in FIG. 1 , the compressor 51 is arranged upstream of the preheater 30 in the air introduction path 20 . The turbine 52 is arranged downstream of the preheater 30 in the air introduction path 20 .

Compressor 51 is driven by a rotational force transmitted from turbine 52 via rotating shaft 50A. The compressor 51 compresses the combustion air A1 sucked from the first passage 21 to a predetermined pressure, and discharges the increased combustion air A1 to the preheater 30 side. The discharged combustion air A1 flows into the preheater 30 after passing through the second path 22 . The compressor 51 is, for example, a centrifugal compressor, and has an impeller that rotates about its axis and pressurizes the combustion air A1 by centrifugal force, and a casing that houses the impeller.

The turbine 52 is rotated by the combustion air A1 heated by the preheater 30 to drive the compressor 51 . Specifically, the turbine 52 has an impeller (not shown) that rotates about its axis in response to the flow of the combustion air A1, and the rotation of the impeller is transmitted to the compressor 51 via the rotation shaft 50A. be.

The switching valve V1 is a valve that switches between circulating and blocking the combustion air A1 in the air introduction path 20, and is arranged in the high pressure path 25 between the compressor 51 and the turbine 52 in the air introduction path 20. there is As shown in FIG. 1, in the present embodiment, the switching valve V1 is located downstream of the portion L1 of the third path 23 to which the first air discharge path 90 is connected and upstream of the burner 60. are placed. The switching valve V<b>1 is a flow control valve whose opening can be adjusted by the control unit 100 .

The burner 60 is arranged in a portion of the high-pressure path 25 closer to the turbine 52 (downstream side) than the switching valve V1. As shown in FIG. 1 , the burner 60 is connected to a blower 70 via a combustion air supply path 71 and to a fuel pump 73 via a fuel supply path 72 . The burner 60 burns fuel such as heavy oil supplied from the fuel pump 73 through the fuel supply path 72 with air supplied from the blower 70 through the combustion air supply path 71 . The fuel supply path 72 is provided with a fuel supply valve V4 for switching between flow and shutoff of fuel, and the combustion air supply path 71 is provided with a combustion air supply valve V5 for switching between flow and shutoff of air. .

The blower 70 supplies combustion air A1 into the high-pressure path 25, and is, for example, a blower. As shown in FIG. 1, the combustion air supply path 71 has an upstream end connected to the discharge port of the blower 70 and a downstream end connected to the air inlet of the burner 60. The air blowing path 74 branches from. The blowing path 74 is connected to a portion L2 downstream of the switching valve V1 and upstream of the burner 60 in the third path 23, and is provided with a blowing valve V3 for switching between air flow and shutoff. . As a result, part of the combustion air A1 discharged from the blower 70 is supplied to the burner 60 and the remaining part is supplied to the portion L2 of the third path 23 . The blower 70 is an auxiliary blower that is used when the air flow rate is insufficient during start-up operation of the waste treatment facility 1 or during steady operation.

The first pressure detector 80 is a sensor that detects the pressure inside the high-pressure path 25 . As shown in FIG. 1, in the present embodiment, the first pressure detection unit 80 is installed on the compressor 51 side (upstream side) of the part L3 of the second path 22 to which the second air discharge path 91 is connected. ing. The first pressure detection unit 80 detects pressure on the downstream side of the compressor 51 and transmits a signal corresponding to the detected pressure to the control unit 100 .

The second pressure detector 85 is a sensor that detects the pressure inside the high-pressure path 25 like the first pressure detector 80 . The second pressure detection unit 85 is installed at a portion of the third path 23 downstream of the switching valve V1 and upstream of the portion L2. The second pressure detection unit 85 detects pressure on the downstream side of the switching valve V1 and transmits a signal corresponding to the detected pressure to the control unit 100 .

The first air discharge path 90 is a path for discharging the combustion air A1 flowing inside the third path 23 to the outside of the third path 23 (into the outside air). As shown in FIG. 1, one end of the first air discharge path 90 is connected to a portion L1 of the third path 23 upstream of the switching valve V1 and downstream of the temperature detection section 84. The ends are open to the atmosphere.

The first blow-off valve V2 is a valve for discharging the combustion air A1 to the outside of the third path 23, and is installed in the first blow-off path 90. As shown in FIG. The first air release valve V2 is a flow control valve configured to be adjustable in opening by the control unit 100. Depending on the opening, air is discharged from the third path 23 to the outside air through the first air release path 90. The flow rate of combustion air A1 is adjusted.

The second air discharge path 91 is a path for discharging the combustion air A1 flowing inside the second path 22 to the outside of the second path 22 (into the outside air). As shown in FIG. 1, one end of the second air discharge path 91 is connected to a portion L3 of the second path 22 on the downstream side of the first pressure detection section 80, and the other end is open to the outside air. ing.

The second blow-off valve V6 is a valve for discharging the combustion air A1 to the outside of the second passage 22, and is installed in the second blow-off passage 91. As shown in FIG. The second air release valve V6 is a flow control valve configured to be adjustable in opening by the control unit 100, and depending on the opening, air is discharged from the second path 22 to the outside air via the second air release path 91. The flow rate of combustion air A1 is adjusted.

The control unit 100 is a computer that controls various operations of the waste treatment facility 1, and includes a reception unit 101, a determination unit 102, a valve control unit 103, a blower control unit 104, a burner control unit 105, and a pump control. A unit 106 and a storage unit 107 are included. The reception unit 101, the determination unit 102, the valve control unit 103, the blower control unit 104, the burner control unit 105, and the pump control unit 106 are functions executed by the central processing unit (CPU) of the computer. The storage unit 107 is configured by a storage device such as a memory.

The reception unit 101 receives detection signals transmitted from each of the first pressure detection unit 80 , the second pressure detection unit 85 and the temperature detection unit 84 . The determination unit 102 compares the pressure detected by the first pressure detection unit 80 and the pressure detected by the second pressure detection unit 85 to determine the magnitude relationship therebetween. A comparison is made with a target pressure that is equal to or lower than the maximum pressure (maximum discharge pressure) to determine the magnitude relationship. The target pressure is predetermined according to the specifications (maximum discharge pressure) of the blower 70 , and information (data) thereof is stored in the storage unit 107 .

The valve control section 103 controls the degree of opening of the first blow-off valve V2 based on the determination result of the determination section 102 . The blower control unit 104 switches ON/OFF of driving of the blower 70 . The burner control unit 105 switches between ignition and extinguishing of the burner 60 . The pump control unit 106 switches ON/OFF of driving of the fuel pump 73 .

The control unit 100 determines that the pressure detected by the first pressure detection unit 80 reaches the maximum pressure of the blower 70 after the switching valve V1 is opened and before the burner 60 is extinguished during the start-up operation of the waste treatment facility 1. The opening degree of the first blow-off valve V2 is controlled so that the target pressure is equal to or lower than the pressure. More specifically, the control unit 100 does not control the first blow-off valve V2 using the target pressure as an index before opening the switching valve V1 during the start-up operation of the waste treatment facility 1, A first control is executed to control the first blow-off valve V2 so that the pressure on the upstream side of the switching valve V1 in the high-pressure path 25 is higher than the pressure on the downstream side of the switching valve V1 in the high-pressure path 25. . After the switching valve V1 is opened during the start-up operation of the waste treatment facility 1, the control unit 100 controls the pressure detected by the first pressure detection unit 80 from the first control so that the pressure detected by the first pressure detection unit 80 becomes the target pressure. to the second control that controls the degree of opening of the first blow-off valve V2. Specific contents of this control will be described below.

(Method of operating waste treatment facility)
Next, the operation method of the waste treatment facility according to this embodiment will be described with reference to the flow charts of FIGS. 2 and 3 and the time chart of FIG. This operation method is an operation method when the waste treatment facility 1 is started up, and is executed by the control unit 100 in the following order. In FIG. 4, the horizontal axis indicates the passage of time during the start-up operation, and the vertical axis indicates the open/closed state of the switching valve V1 and the first blower valve V2, the blower (blower 70) on/off, and the burner 60 on/off. Off, the pressure detected by the first pressure detection unit 80, and the energy of the supercharger 50 are shown, respectively.

First, at the start-up of the waste treatment facility 1, the switching valve V1 is fully closed, the first blower valve V2 is fully open, and the blower 70 and the burner 60 are stopped. In this state, the controller 100 first drives the blower 70 and the burner 60 (ST10).

Specifically, the blower control unit 104 drives the blower 70 and the burner control unit 105 drives the burner 60 . Further, the valve control unit 103 opens the blower valve V3, the combustion air supply valve V5, and the fuel supply valve V4, and the pump control unit 106 drives the fuel pump 73.

As a result, part of the combustion air A1 from the blower 70 is supplied to the burner 60 via the combustion air supply path 71, and fuel such as heavy oil is supplied to the burner 60 via the fuel supply path 72. . Then, the fuel is combusted in the burner 60 to generate high-temperature flue gas. On the other hand, the rest of the combustion air A1 from the blower 70 flows into the portion L2 of the third passage 23 through the air blowing passage 74, is mixed with the combustion exhaust gas in the burner 60, and then flows into the turbine 52. After exiting the turbine 52 , the mixed gas is introduced into the incinerator 10 via the fourth path 24 .

The turbine 52 rotates in response to the mixed gas flow, thereby driving the compressor 51 . The compressor 51 sucks combustion air A1 (outside air) from the first path 21, compresses it to a predetermined pressure, and then discharges it. The combustion air A1 discharged from the compressor 51 passes through the second path 22 and the preheater 30 in order, flows out from the air outlet 32 into the third path 23, and then flows through the first air discharge path 90 into the outside air. is released to

In a state before the switching valve V1 is opened (hereinafter also referred to as a “pre-connection state”, between T0 and T1 in FIG. 4), the control unit 100 controls the pressure on the upstream side of the switching valve V1 in the high-pressure path 25. is greater than the pressure downstream of the switching valve V1 in the high-pressure path 25 (ST20). Specifically, in the pre-connection state, the first pressure detection unit 80 and the second pressure detection unit 85 detect the pressures before and after the switching valve V1 in the high-pressure path 25, respectively, and the determination unit 102 detects the difference between the two detected pressures. Compare sizes. When the pressure detected by the first pressure detection unit 80 is equal to or lower than the pressure detected by the second pressure detection unit 85, the valve control unit 103 reduces the degree of opening of the first blow-off valve V2. In this embodiment, as shown in FIG. 4, the valve control unit 103 gradually decreases the degree of opening of the first blow-off valve V2 with the lapse of time. The pressure in the area (the pressure detected by the first pressure detection unit 80, pressure P1 in FIG. 4) gradually rises over time. During this time, the control unit 100 does not control the first blow-off valve V2 using the target pressure that is equal to or lower than the maximum pressure of the blower 70 as an index. As an example, in the pre-connection state, the pressure detected by the second pressure detection unit 85 is 70 to 80 kPa, whereas the pressure detected by the first pressure detection unit 80 is 83 kPa. Gradually narrow the opening of the

Next, when the connection condition between the compressor 51 and the turbine 52 (that the pressure detected by the first pressure detection unit 80 is higher than the pressure detected by the second pressure detection unit 85) is satisfied (YES in ST30), the valve control unit 103 The switching valve V1 is switched from the closed state to the open state (ST40). After that, the control unit 100 determines that the pressure detected by the first pressure detection unit 80 is increased by the pressure detected by the first pressure detection unit 80 after the switching valve V1 is opened and before the burner 60 is extinguished (between T1 and T2 in FIG. 4). A second control (post-connection control) is executed to control the degree of opening of the first blow-off valve V2 so that the target pressure is equal to or lower than the maximum pressure of . That is, the control unit 100 switches the control mode of the first blow-off valve V2 from the first control to the second control when the switching valve V1 is switched from fully closed to fully open.

The target pressure in the present embodiment is a pressure lower than the maximum discharge pressure (eg, 150 kPa) of the blower 70 (eg, 145 kPa, which is 5 kPa less than the maximum discharge pressure), but is not limited thereto. The target pressure may be the same as the maximum pressure of blower 70 .

FIG. 3 is a flow chart showing the flow of the second control. As shown in FIG. 3 , first, the first pressure detection section 80 detects the pressure in the second path 22 (ST21), and the detection signal is transmitted to the reception section 101. As shown in FIG. Then, the determination section 102 determines whether or not the pressure detected by the first pressure detection section 80 is less than the target pressure (ST22). Then, when the pressure detected by the first pressure detection section 80 is less than the target pressure (YES in ST22), the valve control section 103 reduces the opening degree of the first blow-off valve V2 (ST23). On the other hand, when the pressure detected by the first pressure detection unit 80 is equal to or higher than the target pressure (NO in ST22), the process proceeds to step ST24 without decreasing the opening degree of the first blow-off valve V2.

In step ST24, the determination section 102 determines whether or not the pressure detected by the first pressure detection section 80 exceeds the target pressure. Then, when the detected pressure exceeds the target pressure (YES in ST24), the valve control section 103 increases the opening degree of the first blow-off valve V2 (ST25). As a result, the flow rate of the combustion air A1 discharged to the outside of the high-pressure passage 25 via the first air discharge passage 90 increases, and the pressure inside the high-pressure passage 25 decreases. On the other hand, when the pressure detected by the first pressure detection section 80 is the same as the target pressure, the opening degree of the first blow-off valve V2 is maintained, and the process returns to step ST21.

The opening degree control of the first blow-off valve V2 as described above (the post-connection control by ST21 to ST25 in FIG. 3) is repeatedly performed until the self-sustaining condition of the supercharger 50 is satisfied. Specifically, as shown in FIG. 4, when the energy of the supercharger 50 reaches energy E2 that is greater than the energy E1 required for the self-sustaining operation of the supercharger 50, the self-sustaining condition of the supercharger 50 is To establish. The difference between the energy E1 and the energy E2 is the thermal energy of the burner 60 during the post-connection control (the thermal energy of the flue gas generated while supplying the minimum flow rate of fuel to the burner 60). As a result, even after the burner 60 is extinguished, the energy E1 required for self-sustaining operation of the supercharger 50 is ensured.

In this way, the temperature in the high-pressure passage 25 rises until the energy of the supercharger 50 reaches the energy E2 (FIG. 4), and the pressure in the high-pressure passage 25 accordingly rises. If the blow-off valve V2 remains in the fully closed state, the pressure in the high-pressure path 25 may rise excessively. Therefore, in the present embodiment, as described above, by adjusting the degree of opening of the first blow-off valve V2 so that the pressure in the high-pressure path 25 does not rise excessively, the high pressure from the blower 70 is released even after the switching valve V1 is opened. Air can be sent into the path 25 stably.

When the self-sustaining condition of the supercharger 50 is established (YES in ST50), for example, when the temperature of the combustion air A1 flowing out of the preheater 30 reaches or exceeds a predetermined reference temperature, the burner control section 105 extinguishes the burner 60 and closes the valve. The controller 103 closes the first blower valve V2 (ST60), and then the fan controller 104 stops the fan 70 (ST70). As described above, the start-up operation of the waste disposal facility 1 is completed, and thereafter the steady operation of the waste disposal facility 1 is performed.

As described above, according to the waste treatment facility 1 according to the present embodiment, after the switching valve V1 is opened during the start-up operation and before the burner 60 extinguishes the burner 60, the first pressure detection unit 80 detects The degree of opening of the first blow-off valve V2 is controlled so that the pressure applied is the target pressure equal to or lower than the maximum pressure of the blower 70 . Therefore, unlike the case where the first blow-off valve V2 is maintained in the fully closed state from after the switching valve V1 is fully opened until the burner 60 is extinguished, air is introduced from the blower 70 without using a high-spec blower. It becomes possible to stably supply the combustion air A1 into the path 20 . As a result, the shortage of the flow rate of the combustion air A1 during the start-up operation of the waste disposal facility 1 can be suppressed.

(Other embodiments)
Other embodiments of the invention will now be described.

In the above embodiment, the case where the opening degree of the first blow-off valve V2 is controlled from after the switching valve V1 is opened until the burner 60 is extinguished has been described as an example. is not particularly limited as long as it is between the compressor 51 and the turbine 52 in the air introduction path 20 . For example, the degree of opening of the second blow-off valve V6 may be controlled according to the flowchart of FIG. 3 after the switching valve V1 is opened until the burner 60 is extinguished.

In the above embodiment, the case where the degree of opening of the first blow-off valve V2 is controlled based on the pressure detected by the first pressure detector 80 during the period from the opening of the switching valve V1 to the extinguishing of the burner 60 will be described as an example. However, the position where the pressure is detected during this period is not particularly limited as long as it is between the compressor 51 and the turbine 52 in the air introduction path 20 . For example, after the switching valve V1 is opened and before the burner 60 is extinguished, the opening degree of the first blow-off valve V2 (or the second blow-off valve V6) is controlled based on the pressure detected by the second pressure detector 85. You may

In the above embodiment, the case where the blower 70 supplies the combustion air A1 to the portion L2 downstream of the preheater 30 in the high pressure path 25 has been described as an example. Combustion air A<b>1 may be supplied from the blower 70 to a portion on the upstream side of the vessel 30 .

In the above embodiment, the case where the opening degree of the first blow-off valve V2 is controlled in both the pre-connection control and the post-connection control has been described as an example, but different blow-off valves may be used in both controls. For example, in the pre-connection control, the pressure on the upstream side of the switching valve V1 is controlled by the degree of opening of the first blow-off valve V2, and in the post-connection control, the pressure in the high-pressure path 25 is controlled by the degree of opening of the second blow-off valve V6. Pressure may be controlled.

In the above embodiment, the case where the control unit 100 automatically operates the first blow-off valve V2 in the post-connection control has been described, but the degree of opening of the first blow-off valve V2 may be manually adjusted.

In the above-described embodiment, the blower 70 is started during the start-up operation of the waste treatment facility 1, and the opening degree of the first blow-off valve V2 is controlled in order to stably supply air from the blower 70 into the high-pressure path 25. Although the case has been described, there are cases where the flow rate of the combustion air A1 is insufficient even during steady operation of the waste treatment facility 1, and the blower 70 needs to be started. In this case as well, the degree of opening of the first blow-off valve V2 may be controlled according to the flowchart of FIG.

In the above embodiment, the fluidized bed type incinerator is described as an example, but other types of incinerators such as a stoker type incinerator may be used. Moreover, the waste to be incinerated in the incinerator is not limited to sewage sludge, and may be, for example, municipal waste.

It should be understood that the embodiments disclosed this time are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the scope of the claims rather than the above description, and is intended to include all modifications within the scope and meaning equivalent to the scope of the claims.

1 Waste Treatment Facility 10 Incinerator 20 Air Introduction Path 25 High Pressure Path 30 Preheater 50 Turbocharger 51 Compressor 52 Turbine 60 Burner 70 Blower 80 First Pressure Detector 100 Control Part A1 Combustion Air G1 Exhaust Gas V1 Switching Valve V2 1 air release valve (air release valve)
V6 2nd air release valve (air release valve)

Claims (3)

an incinerator for incinerating waste;
an air introduction path for guiding combustion air to the incinerator;
a preheater that heats the combustion air flowing in from the air introduction path with the exhaust gas discharged from the incinerator;
A supercharger disposed in the air introduction path, wherein the compressor compresses combustion air and discharges it to the preheater, and the compressor is rotated by the combustion air heated by the preheater. a turbocharger to drive;
a switching valve disposed in a high-pressure path between the compressor and the turbine in the air introduction path and switching between communication and blocking of the combustion air;
a burner disposed closer to the turbine than the switching valve in the high-pressure path;
a blower that supplies combustion air into the high-pressure path;
a pressure detection unit that detects the pressure in the high-pressure path;
a blow-off valve for discharging combustion air out of the high-pressure path;
A control unit for controlling the blow-off valve so that the pressure detected by the pressure detection unit becomes a target pressure equal to or lower than the maximum pressure of the blower after the switching valve is opened and before the burner is extinguished. and a waste disposal facility. The control unit
Before the switching valve is opened, the control of the blow-off valve with the target pressure as an index is not executed, and the pressure on the upstream side of the switching valve in the high-pressure path is higher than the switching valve in the high-pressure path. Execute a first control that controls the blow-off valve so that the pressure on the downstream side is greater than the pressure on the downstream side,
2. The method according to claim 1, wherein after the switching valve is opened, the first control is switched to the second control for controlling the blow-off valve so that the pressure detected by the pressure detection unit becomes the target pressure. Waste disposal facility. An incinerator for incinerating waste, an air introduction path for introducing combustion air to the incinerator, and a preheater for heating the combustion air flowing in from the air introduction path with exhaust gas discharged from the incinerator. and a supercharger disposed in the air introduction path, which compresses combustion air and discharges it to the preheater side, and is rotated by the combustion air heated by the preheater. a turbocharger that drives a compressor; and a switching valve that is disposed in a high-pressure path between the compressor and the turbine in the air introduction path and switches between communication and shutoff of combustion air. a burner arranged on the turbine side of the switching valve in the high-pressure path; an air blower for supplying combustion air into the high-pressure path; A method of operating a waste treatment facility comprising:
After opening the switching valve and before extinguishing the burner during start-up operation of the waste treatment facility, the A method of operating a waste disposal facility by operating a blow-off valve.

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