JP2017116173A - Waste heat power generation system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance heat effective use in a waste heat power generation system which performs power generation by using waste heat of an incinerator.SOLUTION: A waste heat power generation system 1 is provided which includes: an incinerator 2; an exhaust gas line 5 in which an exhaust gas EG exhausted from the incinerator 2 circulates; a power generator 3 for generating power by using a heat medium oil HO as a heat source; a first heat exchanger 6 for exchanging heat between the exhaust gas EG and the heat medium oil HO supplied to the power generator 3; an air preheater 7 provided side by side with the first heat exchanger 6 in the exhaust gas line 5, and for exchanging heat between the exhaust gas EG and the air A1 supplied to the incinerator; a dust collecting device 14 for removing a solid component from the exhaust gas EG on which the heat exchange has been performed in the first heat exchanger 6 and the air preheater 7; and a second heat exchanger 8 provided on the upstream side of the dust collecting device 14 in the exhaust gas line 5, and for performing heat exchange between the exhaust gas EG on which the heat exchange has been performed in the first heat exchanger 6 and the air preheater 7 and the heat medium oil HO supplied to the first heat exchanger 6.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a waste heat power generation system that generates power using waste heat of an incinerator.

  In a sludge incineration plant that treats sludge such as sewage sludge, the waste heat of the incinerator is used to preheat the combustion air supplied to the incinerator or using steam generated in the boiler that recovers waste heat. Attempts have been made to improve the effective heat utilization rate of the entire plant by generating power (see, for example, Patent Document 1).

  In such a sludge incineration plant, it is common to provide a dust collecting device for collecting dust from exhaust gas discharged from an incinerator. In such a sludge incineration plant, the temperature of exhaust gas flowing into the dust collector is adjusted based on the heat-resistant temperature of the dust collector. Conventionally, the temperature of the exhaust gas introduced into the dust collector is adjusted by spraying water with an exhaust gas cooling tower to about 200 ° C., for example.

JP 2013-155974 A

  By the way, it is not preferable to adjust the temperature by spraying water on the exhaust gas because it results in the heat being discarded. It is also possible to control the temperature by mixing air or the like with the exhaust gas introduced into the dust collector. However, this method is also not preferable because, as with the exhaust gas cooling tower, heat is eventually discarded. In addition, a large volume of air is required, and it is necessary to increase the device capacity in order to cope with a large increase in the amount of gas.

  There is a method of controlling the temperature by installing a gas air preheater, but there is a problem that the heat transfer tube of the gas air preheater tends to be a low temperature corrosion zone.

  An object of the present invention is to provide a waste heat power generation system having a higher effective heat utilization rate in a waste heat power generation system that generates power using waste heat of an incinerator.

  According to the first aspect of the present invention, the waste heat power generation system includes an incinerator, an exhaust gas line through which exhaust gas discharged from the incinerator flows, a power generator that generates power using heat transfer oil as a heat source, and the exhaust gas. And a first heat exchanger that exchanges heat with the heat transfer oil supplied to the power generation device, and air that is provided in parallel with the first heat exchanger in the exhaust gas line and is supplied to the exhaust gas and the incinerator An air preheater that exchanges heat with each other, a dust collector that removes solid components from the exhaust gas heat-exchanged by the first heat exchanger and the air preheater, and an upstream of the dust collector in the exhaust gas line The second heat exchange that is provided on the side and exchanges heat between the exhaust gas heat-exchanged by the first heat exchanger and the air preheater and the heat transfer oil supplied to the first heat exchanger And a container.

  According to such a configuration, by reducing the temperature of the exhaust gas introduced into the dust collector using the second heat exchanger, for example, compared to reducing the temperature of the exhaust gas using an exhaust gas cooling tower. Thus, heat can be used more effectively.

  The waste heat power generation system may include a control device that adjusts the flow rate of the heat transfer oil that is heat-exchanged by the second heat exchanger based on the temperature of the exhaust gas discharged from the second heat exchanger.

  According to such a configuration, the temperature of the exhaust gas can be set to a temperature corresponding to the heat resistance temperature of the dust collector by adjusting the flow rate of the heat transfer oil and adjusting the temperature of the exhaust gas.

  In the waste heat power generation system, the heat medium oil circulation path through which the heat medium oil circulates, and the upstream side of the second heat exchanger and the downstream side of the second heat exchanger in the heat medium oil circulation path A bypass path that bypasses and connects the two heat exchangers, and the control device may adjust a flow rate of the heat transfer oil flowing through the bypass path.

  By adjusting the temperature of the exhaust gas flowing into the dust collector according to the flow rate of the heat transfer oil introduced into the second heat exchanger arranged upstream of the dust collector, the temperature of the exhaust gas is adjusted more quickly. be able to.

  In the waste heat power generation system, the flow rate of the heat transfer oil supplied to the power generation device may be adjusted based on the temperature of the heat transfer oil exchanged by the first heat exchanger.

  According to such a configuration, the temperature of the heat transfer oil can be adjusted to a temperature suitable for the power generator. Further, it is possible to cope with the temperature rise of the exhaust gas when the temperature (heat amount) of the exhaust gas discharged from the incinerator is significantly increased. Further, it is possible to cope with a temperature decrease of the exhaust gas when the temperature (heat amount) of the exhaust gas discharged from the incinerator is significantly reduced.

  The waste heat power generation system may include a white smoke preventer that heats the outside air with the exhaust gas that has been discharged from the second heat exchanger and passed through the dust collector, and that supplies the air to the chimney.

  According to such a configuration, for example, heat is recovered from the low temperature exhaust gas as compared with the case where the white smoke preventer is installed upstream of the second heat exchanger. The recovery rate can be improved.

  According to the present invention, by reducing the temperature of the exhaust gas introduced into the dust collector using the second heat exchanger, for example, compared to reducing the temperature of the exhaust gas using an exhaust gas cooling tower, Heat can be used more effectively.

It is a systematic diagram of the sludge incineration plant of the embodiment of the present invention. It is a flowchart explaining the 1st control method of the sludge incineration plant of embodiment of this invention. It is a flowchart explaining the 2nd control method of the sludge incineration plant of embodiment of this invention.

Hereinafter, the sludge incineration plant 1 which is the waste heat power generation system of embodiment of this invention is demonstrated in detail with reference to drawings.
As shown in FIG. 1, the sludge incineration plant 1 of this embodiment uses an incinerator 2 that incinerates sludge S such as sewage sludge, and waste heat (incineration heat) of exhaust gas EG discharged from the incinerator 2. A power generation device 3 for generating power and a control device 4 are provided. The sludge incineration plant 1 according to the present embodiment is a waste heat power generation system that incinerates sludge S and collects heat generated by the incineration to generate electric power. The power generation device 3 uses heat medium oil HO circulating in the plant as a heat medium.

  The sludge incineration plant 1 includes an exhaust gas line 5 into which the exhaust gas EG discharged from the incinerator 2 is introduced, a first heat exchanger 6 provided on the exhaust gas line 5, and a first heat exchanger 6 in the exhaust gas line 5. The air preheater 7 provided in parallel, the first heat exchanger 6 and the second heat exchanger 8 provided downstream of the air preheater 7, and the second heat exchanger 8 provided downstream. The exhaust gas treatment device 9 is provided.

  You may provide the sludge dryer which dries the dewatered sludge which is the sludge containing a water | moisture content in the upstream of the incinerator 2. FIG. The sludge dryer is a device that dries dehydrated sludge (dehydrated cake, for example, moisture content 72%) introduced through a volume reduction process of concentration / dehydration to produce dry sludge (for example, moisture content 50%).

  The first heat exchanger 6 and the second heat exchanger 8 are heat exchangers that perform heat exchange (heating) between the exhaust gas EG discharged from the incinerator 2 and the heat transfer oil HO supplied to the power generation device 3. The air preheater 7 is a heat exchanger that performs heat exchange (preheating) between the exhaust gas EG discharged from the incinerator 2 and the combustion air A1 supplied to the incinerator 2.

  The exhaust gas treatment device 9 is configured to bring a cleaning solution into contact with a dust collector 14 (bag filter) that removes solid components (ash and the like) from the exhaust gas EG and performs dust collection, a white smoke preventer 15, and the exhaust gas EG. It has a scrubber 16 (exhaust gas cleaning device) that detoxifies, and a chimney 17 that releases the treated exhaust gas EG to the atmosphere.

  The power generation apparatus 3 includes a power generation apparatus main body 11 and a heat medium oil circulation path 12 (indicated by a two-dot chain line) that is an annular heat source system that introduces the heat medium oil HO into the power generation apparatus main body 11. . The heat medium oil circulation path 12 is a path through which the heat medium oil HO is circulated between the power generation apparatus main body 11 and the first heat exchanger 6 and the second heat exchanger 8. In the heat medium oil circulation path 12, the heat medium oil HO flows in one direction.

The incinerator 2 is equipment that incinerates sludge S by stirring and mixing in a high-temperature fluidized bed. The incinerator 2 may be an incineration facility that incinerates waste and discharges high-temperature exhaust gas EG. As the incinerator 2, an incineration facility such as a bubble type fluidized furnace or a circulating fluidized furnace can be adopted.
Combustion air A1 (fluid air) is introduced into the incinerator 2 via a combustion air line 13 (indicated by a one-dot chain line). Exhaust gas EG is discharged from the incinerator 2 through the first exhaust gas line 5a. The temperature of the exhaust gas EG discharged from the incinerator 2 is, for example, 850 ° C.

The first exhaust gas line 5a branches to two second exhaust gas lines 5b (5b1, 5b2) provided in parallel on the downstream side. One second exhaust gas line 5 b 1 is connected to the first heat exchanger 6. The first heat exchanger 6 is provided on the heat medium oil circulation path 12 and on the second exhaust gas line 5b1. The first heat exchanger 6 functions as a heating device that recovers the heat of the high-temperature exhaust gas EG flowing through the second exhaust gas line 5b1 and heats the heat transfer medium oil HO.
The other second exhaust gas line 5 b 2 is connected to the air preheater 7. The air preheater 7 is a heat exchanger that recovers the heat of the high-temperature exhaust gas EG flowing through the second exhaust gas line 5b2 and heats (preheats) the combustion air A1 flowing through the combustion air line 13.
The first heat exchanger 6 and the air preheater 7 are provided in parallel in the exhaust gas line 5.

  The two second exhaust gas lines 5 b join at the downstream side of the first heat exchanger 6 and the air preheater 7. The two second exhaust gas lines 5b are connected to the third exhaust gas line 5c. The second heat exchanger 8 is provided on the downstream side of the first heat exchanger 6 and the air preheater 7, that is, on the third exhaust gas line 5c. The second heat exchanger 8 functions as a heating device that recovers the heat of the exhaust gas EG heat-exchanged by the first heat exchanger 6 and the air preheater 7 and heats the heat transfer medium oil HO.

Next, the exhaust gas treatment device 9 that removes soot, SO ₂ , HCl, and the like contained in the exhaust gas EG discharged from the incinerator 2 to obtain clean exhaust gas will be described.
The dust collector 14 provided on the downstream side of the second heat exchanger 8 is a device that filters and collects solid components such as dust and ash in the exhaust gas EG using a heat-resistant filter cloth or the like. That is, dust and the like are removed from the exhaust gas EG discharged from the second heat exchanger 8 and introduced into the dust collector 14 via the fourth exhaust gas line 5d.
In the dust collector 14, a heat resistant temperature is set with respect to the temperature of the introduced exhaust gas EG. The heat-resistant temperature of the dust collector 14 is 220 ° C., for example.

  The white smoke preventer 15 provided on the downstream side of the dust collector 14 in the exhaust gas line 5 is a device that prevents the exhaust gas EG from becoming white smoke. The white smoke preventer 15 exchanges heat between the air supply fan 19 that sucks and sends out the air A2, and the exhaust gas EG introduced from the dust collector 14 through the fifth exhaust gas line 5e and the air A2, thereby An air heater 20 that heats A2 to be mixed air A3 and a mixing air line 21 that guides the mixing air A3 to the chimney 17 are provided.

As the air heater 20 of the white smoke preventer 15, for example, a shell and tube heat exchanger can be adopted. The heat transfer tube of the air heater 20 is covered with, for example, a Teflon (registered trademark) corrosion-resistant material. In other words, a corrosion-resistant layer made of Teflon is formed on the exhaust gas contact surface of the air heater 20. That is, the air heater 20 of this embodiment has a low-temperature corrosion prevention type heat transfer tube.
Thereby, corrosion of the metal surface of the heat transfer tube is suppressed, and low temperature corrosion is prevented. The treatment for making the white smoke preventer 15 into a low temperature corrosion prevention type is not limited to the above-mentioned Teflon, and for example, a non-metallic material such as a resin can be adopted. It is also possible to form the heat transfer tube itself with a corrosion-resistant material such as ceramic.

The scrubber 16 is an exhaust gas cleaning device that makes the exhaust gas EG discharged from the white smoke preventer 15 and introduced through the sixth exhaust gas line 5f come into contact with a cleaning liquid such as water or an aqueous solution of caustic soda to render it harmless.
The exhaust gas EG in the exhaust gas line 5 is sucked by an induction blower (not shown) and discharged through the chimney 17.

  In the exhaust gas line 5, an exhaust gas temperature measuring device 18 that measures the temperature of the exhaust gas EG flowing through the fourth exhaust gas line 5 d is provided in the fourth exhaust gas line 5 d that connects the second heat exchanger 8 and the dust collector 14. ing. The exhaust gas temperature measuring device 18 measures the temperature of the exhaust gas EG flowing into the dust collector 14. The temperature of the exhaust gas EG measured by the exhaust gas temperature measuring device 18 is transmitted to the control device 4.

Next, details of the power generation device 3 of the present embodiment will be described.
The power generation device main body 11 uses the waste heat of the incinerator 2 as a heat source, heats and evaporates the organic working medium M, and generates power by rotating the steam turbine 23 with the steam. (Organic Rankine cycle waste heat power generation system) is adopted.

  The power generator main body 11 of the present embodiment includes an evaporator 22 that heats and evaporates the organic working medium M using the heat of the heat medium oil HO supplied to the power generator main body 11 via the heat medium oil circulation path 12. A steam turbine 23 rotated by the steam of the organic working medium M, a generator 24 directly connected to the steam turbine 23, and a condenser 25 for condensing the organic working medium M guided from the steam turbine 23. .

The heat transfer oil circulation path 12 is a path for recovering the heat of the exhaust gas EG flowing through the third exhaust gas line 5c and recovering the heat of the exhaust gas EG flowing through the second exhaust gas line 5b1.
The heat transfer oil circulation path 12 includes a first circulation path 12 a that connects the power generator main body 11 and the second heat exchanger 8, and a second circulation that connects the second heat exchanger 8 and the first heat exchanger 6. It has the path | route 12b and the 3rd circulation path | route 12c which connects the 1st heat exchanger 6 and the electric power generating apparatus main body 11. FIG.

The heat transfer oil HO obtained by heating the organic working medium M in the power generation apparatus main body 11 circulates in the order of the second heat exchanger 8 and the first heat exchanger 6. The first heat exchanger 6 is provided on the downstream side of the second heat exchanger 8 in the heat medium oil circulation path 12.
The heat transfer oil HO introduced into the second heat exchanger 8 through the first circulation path 12a is heated by the exhaust gas EG flowing through the third exhaust gas line 5c. The heat transfer oil HO introduced into the first heat exchanger 6 through the second circulation path 12b is heated by the exhaust gas EG flowing through the second exhaust gas line 5b1. The heat transfer oil HO heated in the second heat exchanger 8 and the first heat exchanger 6 is introduced into the evaporator 22 of the power generator main body 11 via the third circulation path 12c.

The first circulation path 12a that is upstream of the second heat exchanger 8 and the second circulation path 12b that is downstream of the second heat exchanger 8 bypass the second heat exchanger 8 by a bypass path 27b. Connected directly. That is, a part of the heat transfer oil HO flowing through the first circulation path 12 a is introduced into the bypass path 27 b without being introduced into the second heat exchanger 8.
A first flow rate adjusting valve 29 that adjusts the flow rate of the heat transfer oil HO is provided between the branch point 28 of the bypass route 27b provided in the first circulation route 12a and the second heat exchanger 8. The bypass passage 27b is provided with a second flow rate adjustment valve 30 that adjusts the flow rate of the heat transfer oil HO.

  A heat medium oil pump 31 that adjusts the flow rate of the heat medium oil HO flowing through the heat medium oil circulation path 12 is provided on the first circulation path 12 a and upstream of the branch point 28. The heat medium oil pump 31 is a pump for supplying the heat medium oil HO to the heat medium oil circulation path 12. The heat medium oil pump 31 controls the flow rate of the heat medium oil HO discharged by a discharge damper or an inverter.

The first flow rate adjustment valve 29, the second flow rate adjustment valve 30, and the heat transfer oil pump 31 are controlled by the control device 4.
Assuming that the flow rate of the heat transfer oil HO flowing through the main route 27a downstream from the branch point 28 of the first circulation route 12a is O1, and the flow rate of the heat transfer oil HO flowing through the bypass route 27b is O2, the control device 4 Usually, the first and second flow rate adjusting valves 29 and 30 are controlled so that O1: O2 = about 4: 1. That is, the control device 4 adjusts the first and second flow rates so that the flow rate of the heat transfer fluid HO flowing through the main flow 27a that is the main flow is sufficiently larger than the flow rate of the heat transfer fluid HO flowing through the bypass flow 27b. The valves 29 and 30 are controlled.

  In the heat medium oil circulation path 12, a heat medium oil that measures the temperature of the heat medium oil HO flowing through the third circulation path 12 c is connected to the third circulation path 12 c that connects the first heat exchanger 6 and the power generator main body 11. A temperature measuring device 32 is provided. The heat medium oil temperature measuring device 32 measures the temperature of the heat medium oil HO introduced into the power generator main body 11. The temperature of the heat transfer oil HO measured by the heat transfer oil temperature measuring device 32 is transmitted to the control device 4.

The control device 4 of the present embodiment has a function of adjusting the flow rate of the heat transfer oil HO introduced into the second heat exchanger 8 based on the temperature of the exhaust gas EG measured by the exhaust gas temperature measuring device 18.
The control device 4 flows through the main path 27a of the first circulation path 12a (downstream of the branch point 28) when the temperature of the exhaust gas EG becomes higher than a set first threshold (for example, 220 ° C.). The first and second flow rate adjusting valves 29 and 30 are controlled so that the flow rate of the heat transfer oil HO increases. Specifically, the control device 4 operates the second flow rate adjustment valve 30 so that the flow rate of the heat medium oil HO flowing through the bypass path 27b is small, and the flow rate of the heat medium oil HO flowing through the main path 27a is large. The first flow rate adjustment valve 29 is operated so that

  At this time, the flow rate of the heat medium oil HO in the entire heat medium oil circulation path 12 does not change. That is, the flow rate of the heat medium oil HO supplied to the second heat exchanger 8 can be increased without changing the flow rate of the heat medium oil HO flowing through the entire heat medium oil circulation path 12. Thereby, the amount of heat exchange by the second heat exchanger 8 increases, and the temperature of the exhaust gas EG decreases.

Further, the control device 4 has a function of adjusting the flow rate of the heat medium oil HO flowing through the entire heat medium oil circulation path 12 based on the temperature of the heat medium oil HO measured by the heat medium oil temperature measuring device 32. .
When the temperature of the heat medium oil HO becomes higher than a set second threshold (for example, 280 ° C.), the control device 4 determines the flow rate of the heat medium oil HO flowing through the entire heat medium oil circulation path 12. The heat transfer oil pump 31 is controlled so as to increase.
As the flow rate of the heat medium oil HO in the entire heat medium oil circulation path 12 increases, the temperature of the heat medium oil HO decreases.

Next, operation | movement of the sludge incineration plant 1 of this embodiment is demonstrated.
Sludge S is thrown into the incinerator 2 and incinerated. The exhaust gas EG (for example, 850 ° C.) generated with the incineration is used as a heating source of the heat transfer oil HO in the first heat exchanger 6. Further, the exhaust gas EG is used as a heating source of the combustion air A1 by the air preheater 7.
The temperature of the exhaust gas EG that has passed through the first heat exchanger 6 and the air preheater 7 decreases to, for example, 300 ° C. That is, the exhaust gas EG is rapidly cooled from 850 ° C. to 300 ° C.

Next, the exhaust gas EG is used as a heating medium heating source in the second heat exchanger 8. The temperature of the exhaust gas EG that has passed through the second heat exchanger 8 is reduced to 220 ° C. That is, the temperature of the exhaust gas EG is reduced to the heat resistant temperature of the dust collector 14 by heat exchange in the second heat exchanger 8. The exhaust gas EG that has passed through the second heat exchanger 8 is introduced into the dust collector 14.
The exhaust gas EG that has passed through the second heat exchanger 8 is introduced into the dust collector 14 and subjected to dust collection treatment.

  The exhaust gas EG discharged from the dust collector 14 exchanges heat with the air A2 supplied by the air supply fan 19 in the air heater 20 of the white smoke preventer 15 to increase the temperature of the air A2. The temperature of the air A2 rises to 150 ° C., for example. The mixing air A <b> 3 that has passed through the air heater 20 is introduced into the chimney 17 through the mixing air line 21.

  The exhaust gas EG that has passed through the white smoke preventer 15 is introduced into the scrubber 16 and rendered harmless. The temperature of the exhaust gas EG is reduced to, for example, 40 ° C. in the scrubber 16. The exhaust gas EG that has passed through the scrubber 16 is introduced into the chimney 17 and mixed with the high-temperature mixing air A3 introduced through the mixing air line 21. Generation of white smoke from the chimney 17 is prevented by mixing the exhaust gas EG and the mixing air A3 for preventing white smoke.

Next, operation | movement of the electric power generating apparatus 3 is demonstrated.
The heat medium oil HO circulating in the heat medium oil circulation path 12 is heated to, for example, 280 ° C. by exchanging heat with the exhaust gas EG in the second heat exchanger 8 and the first heat exchanger 6. The heated heating medium oil HO is used to heat the organic working medium M in the evaporator 22 of the power generation apparatus body 11. The organic working medium M becomes steam in the evaporator 22 and is introduced into the steam turbine 23 to drive the generator 24. The steam exiting the steam turbine 23 is cooled and condensed in the condenser 25. The condensed organic working medium M is returned to the evaporator 22.

  Next, the control method of the sludge incineration plant 1 of this embodiment is demonstrated. The control method of the sludge incineration plant 1 of the present embodiment includes the first control method for adjusting the temperature of the exhaust gas EG introduced into the dust collector 14 and the temperature of the heat transfer oil HO introduced into the power generator main body 11. A second control method to be adjusted.

The first control method is a control method for adjusting the temperature of the exhaust gas EG introduced into the dust collector 14 by controlling the flow rate of the heat transfer oil HO introduced into the second heat exchanger 8.
The first control method is introduced into the exhaust gas temperature determination step P11 for determining whether or not the temperature of the exhaust gas EG discharged from the second heat exchanger 8 is higher than the first threshold, and the second heat exchanger 8. A main path flow rate increasing step P12 for increasing the flow rate of the heat transfer oil HO flowing through the main path 27a of the first circulation path 12a when the temperature of the exhaust gas EG is higher than the first threshold value.

In the exhaust gas temperature determination step P11, the control device 4 refers to the temperature of the exhaust gas EG transmitted from the exhaust gas temperature measurement device 18. The control device 4 determines whether or not the temperature of the exhaust gas EG is higher than a first threshold value (for example, 220 ° C.). When the temperature of the exhaust gas EG is 220 ° C. or less, the control device 4 does not change the opening degree of the valves 29 and 30.
When the temperature of the exhaust gas EG is higher than 220 ° C., the control device 4 executes the main path flow rate increasing step P12. In the main path flow rate increasing step P12, the control device 4 adjusts the opening degree of the valves 29 and 30 to increase the flow rate of the heat transfer oil HO flowing through the main path 27a. Thereby, the amount of heat exchange between the exhaust gas EG and the heat transfer oil HO increases, and the temperature of the exhaust gas EG decreases.
On the other hand, when the temperature of the exhaust gas EG is low, the control device 4 adjusts the opening degree of the first and second flow rate adjusting valves 29 and 30 to control the flow rate of the heat transfer oil HO flowing through the main path 27a. You may carry out.

The second control method is a control method for adjusting the flow rate of the heat medium oil HO introduced into the power generator main body 11 by controlling the flow rate of the heat medium oil HO flowing through the entire heat medium oil circulation path 12.
The second control method includes a heat medium oil temperature determination step P21 for determining whether the temperature of the heat medium oil HO discharged from the first heat exchanger 6 is higher than the second threshold, and the temperature of the heat medium oil HO. Has a heat medium oil flow rate increasing step P22 that increases the flow rate of the heat medium oil HO flowing through the entire heat medium oil circulation path 12 when the value is larger than the second threshold value.

  In the heat medium oil temperature determination step P21, the control device 4 refers to the temperature of the heat medium oil HO transmitted from the heat medium oil temperature measurement device 32. The control device 4 determines whether or not the temperature of the heat transfer oil HO is higher than a second threshold value (for example, 280 ° C.). When the temperature of the heat medium oil HO is 280 ° C. or less, the control device 4 does not change the discharge flow rate of the heat medium oil pump 31.

When the temperature of the heat medium oil HO discharged | emitted from the 1st heat exchanger 6 is larger than 280 degreeC, the control apparatus 4 performs the heat medium oil flow volume increase process P22. In the heat medium oil flow rate increasing step P22, the control device 4 increases the flow rate of the heat medium oil HO flowing through the entire heat medium oil circulation path 12 by adjusting the discharge flow rate of the heat medium oil pump 31. Thereby, the temperature of the heat transfer oil HO introduced into the power generator main body 11 is lowered.
On the other hand, when the temperature of the heat medium oil HO is low, the control device 4 may adjust the discharge flow rate of the heat medium oil pump 31 to perform control to reduce the flow rate of the heat medium oil HO.

  According to the above embodiment, by reducing the temperature of the exhaust gas EG introduced into the dust collector 14 using the second heat exchanger 8, for example, using the exhaust gas cooling tower, the temperature of the exhaust gas is reduced. In comparison, heat can be used more effectively.

  Further, the temperature of the exhaust gas EG is adjusted by adjusting the flow rate of the heat transfer oil HO introduced into the second heat exchanger 8 based on the temperature of the exhaust gas EG measured by the exhaust gas temperature measuring device 18. It can be set to a temperature corresponding to the heat resistant temperature.

  Further, by adjusting the temperature of the exhaust gas EG flowing into the dust collector 14 by the flow rate of the heat transfer oil HO introduced into the second heat exchanger 8 arranged on the upstream side of the dust collector 14, it becomes more rapid. The temperature of the exhaust gas EG can be adjusted.

  Further, the temperature of the heat transfer oil HO is generated by adjusting the flow rate of the heat transfer oil HO supplied to the power generation device body 11 based on the temperature of the heat transfer oil HO exchanged by the first heat exchanger 6. It can be adjusted to a temperature suitable for the apparatus 3. Further, it is possible to cope with the temperature rise of the exhaust gas EG when the temperature (heat amount) of the exhaust gas EG discharged from the incinerator 2 is significantly increased. Further, it is possible to cope with a temperature decrease of the exhaust gas when the temperature (heat amount) of the exhaust gas discharged from the incinerator is significantly reduced.

  Moreover, by providing the white smoke preventer 15 that heats the outside air with the exhaust gas EG that has passed through the dust collector 14 and supplies it to the chimney 17, for example, white smoke prevention is provided upstream of the second heat exchanger 8. Since heat is recovered from the low-temperature exhaust gas EG as compared with the case where a vessel is installed, the heat recovery rate of the entire system can be improved.

  Further, since the white smoke preventer 15 is of a low temperature corrosion prevention type, even when the white smoke preventer 15 recovers the temperature of the exhaust gas EG having a temperature of 200 ° C. or less, for example, the sulfur (S) content of the sludge is reduced. In addition, low-temperature corrosion of metals derived from chlorine (Cl) can be prevented.

In addition, by using heat transfer oil HO as the heat medium used for heat recovery from exhaust gas EG, which is a waste heat source, the equipment and devices are simplified and miniaturized compared to using steam for heat recovery. Can be achieved.
Further, by adopting a binary waste heat power generation system as the power generation device 3, even when the plant scale is small (for example, a sludge treatment amount of 100 t / day), power generation can be performed efficiently.

The embodiment of the present invention has been described in detail above, but various modifications can be made without departing from the technical idea of the present invention.
For example, when the smoke discharged from the chimney 17 may be white smoke, the white smoke preventer 15 may be omitted.
Further, the control device 4 may execute the first control method and the second control method at the same time. By simultaneously controlling the exhaust gas temperature and the heating medium temperature, it becomes possible to speed up the responsiveness of each other by a synergistic effect, and as a result, the speed of convergence can be increased.

1 Sludge incineration plant (waste heat power generation system)
DESCRIPTION OF SYMBOLS 2 Incinerator 3 Electric power generation apparatus 4 Control apparatus 5 Exhaust gas line 6 1st heat exchanger 7 Air preheater 8 Second heat exchanger 9 Exhaust gas processing apparatus 11 Power generation apparatus main body 12 Heat transfer oil circulation path 12a First circulation path 12b Second Circulation path 12c Third circulation path 13 Combustion air line 14 Dust collector 15 White smoke prevention device 16 Scrubber 17 Chimney 18 Exhaust gas temperature measurement device 19 Air supply fan 20 Air heater 21 Mixing air line 22 Evaporator 23 Steam turbine 24 Power generation Machine 25 Condenser 27a Main path 27b Bypass path 28 Branch point 29 First flow rate adjustment valve 30 Second flow rate adjustment valve 31 Heat transfer oil pump 32 Heat transfer oil temperature measuring device A1 Combustion air A2 Air EG Exhaust gas HO Heat transfer oil M Organic Working medium S Sludge

Claims (5)

An incinerator,
An exhaust gas line through which the exhaust gas discharged from the incinerator flows;
A power generator that generates heat using heat transfer oil as a heat source;
A first heat exchanger that exchanges heat between the exhaust gas and the heat transfer oil supplied to the power generation device;
An air preheater provided in parallel with the first heat exchanger in the exhaust gas line to exchange heat between the exhaust gas and air supplied to the incinerator;
A dust collector for removing solid components from the exhaust gas heat-exchanged by the first heat exchanger and the air preheater;
In the exhaust gas line, provided on the upstream side of the dust collector, the exhaust gas heat-exchanged by the first heat exchanger and the air preheater, and the heat transfer oil supplied to the first heat exchanger; A second heat exchanger for exchanging heat between, and a waste heat power generation system.   The waste heat according to claim 1, further comprising a control device that adjusts a flow rate of the heat transfer oil that is heat-exchanged in the second heat exchanger based on a temperature of the exhaust gas discharged from the second heat exchanger. Power generation system. A heat medium oil circulation path through which the heat medium oil circulates;
A bypass path that bypasses the second heat exchanger and connects the upstream side of the second heat exchanger and the downstream side of the second heat exchanger in the heat medium oil circulation path;
The waste heat power generation system according to claim 2, wherein the control device adjusts a flow rate of the heat transfer oil flowing through the bypass path.   4. The flow rate of the heat transfer oil supplied to the power generation device is adjusted based on the temperature of the heat transfer oil exchanged by the first heat exchanger. 5. Waste heat power generation system.   5. The white smoke preventer according to claim 1, further comprising a white smoke preventer that heats outside air by the exhaust gas discharged from the second heat exchanger and passes through the dust collecting device and supplies the heated air to a chimney. The waste heat power generation system described.

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