JP7533842B2 - Waste heat power generation method - Google Patents

Description

The present invention relates to a method for generating electricity using waste heat.

The exhaust gas from incinerators such as sewage sludge incinerators is high-temperature exhaust gas at around 800 to 850°C. For this reason, for example, a method of generating electricity using exhaust heat has been proposed in which this high-temperature exhaust gas is introduced into a boiler to generate steam, which is then used to rotate a generator using a steam turbine.

However, waste heat power generation as described above may not produce enough power to justify the capital investment, and there is a demand for systems that can achieve a higher energy recovery rate.

For this reason, in a typical incineration plant, for example, the high-temperature exhaust gas discharged from the incinerator is passed through a heat exchanger such as a white smoke prevention air preheater to recover part of the exhaust heat, and then the dust is separated and removed in a dust collector. The exhaust gas is then passed through a flue gas treatment tower where it is washed with water to remove components such as _NOx and _SOx in the exhaust gas.

In the waste heat treatment tower described above, exhaust gas at about 200 to 400°C is cooled to about 30°C, while smoke washing wastewater at about 50 to 75°C is discharged. Although this smoke washing wastewater is relatively cold, it contains a lot of thermal energy (for example, more than 50% of the heat contained in the exhaust gas) due to the large specific heat of water. For this reason, in recent years, waste heat power generation has been carried out using the heat contained in the smoke washing wastewater (see Patent Documents 1 and 2).

JP 2010-174845 A JP 2013-213658 A

However, in the above-mentioned waste heat power generation, it is sometimes impossible to fully utilize the heat contained in the smoke washing wastewater. Therefore, in the field of waste heat power generation that utilizes the heat contained in exhaust gas, there is a demand for more effective use of the heat contained in the smoke washing wastewater.

Therefore, the present invention aims to provide a method for generating electricity using exhaust heat that effectively utilizes the heat contained in smoke washing wastewater.

The waste heat power generation method of the present invention for achieving the above object involves branching a fluid from which the heat retained in the smoke scrubbing wastewater discharged from a flue gas scrubber has been recovered into a first fluid and a second fluid, supplying each of the branched first fluid and second fluid to a heat pump, and supplying the second fluid, which has been heated by the heat retained in the first fluid, to a waste heat power generation system.

The waste heat power generation method of the present invention makes it possible to effectively utilize the heat contained in the smoke washing wastewater.

FIG. 1 is a diagram illustrating a schematic configuration example of a sludge incineration system 100 in a first comparative example. FIG. 2 is a diagram illustrating a schematic configuration example of the flue gas treatment tower 3 in the first comparative example. FIG. 3 is a diagram illustrating a schematic configuration example of a sludge incineration system 200 according to the first embodiment. FIG. 4 is a diagram illustrating functional blocks of the heat pump 7 in the first embodiment. FIG. 5 is a diagram illustrating functional blocks of the heat pump 7 in the first embodiment. FIG. 6 is a diagram illustrating a comparison between the sludge incineration system 100 in the first comparative example and the sludge incineration system 200 in the first embodiment. FIG. 7 is a diagram illustrating a schematic configuration example of a sludge incineration system 300 in a second comparative example. FIG. 8 is a diagram illustrating a schematic configuration example of a sludge incineration system 400 according to the second embodiment. FIG. 9 is a diagram illustrating a comparison between a sludge incineration system 300 in the second comparative example and a sludge incineration system 400 in the second embodiment.

Below, an embodiment of the present invention will be described with reference to the drawings. However, such an embodiment does not limit the technical scope of the present invention.

[Sludge incineration system 100 in the first comparative example]
First, a sludge incineration system 100 in a first comparative example will be described. Fig. 1 is a diagram illustrating a schematic configuration example of the sludge incineration system 100 in the first comparative example. Fig. 2 is a diagram illustrating a schematic configuration example of the flue gas treatment tower 3 in the first comparative example.

As shown in FIG. 1, the sludge incineration system 100 includes, for example, a white smoke prevention air preheater 1, a dust collector 2, a flue gas treatment tower 3, a chimney 4, and an exhaust heat power generation system 10.

The white smoke prevention air preheater 1 is a heat exchanger for exhaust gas, and uses the heat contained in high-temperature exhaust gas (approximately 800-850°C) output from an incinerator (not shown) for incinerating sewage sludge, for example, to heat the air and generate white smoke prevention air A. The white smoke prevention air A is heated air used to prevent the water vapor in the exhaust gas released from the chimney 4 from appearing as white smoke. The temperature of the white smoke prevention air A is, for example, approximately 400°C. The temperature of the exhaust gas that has passed through the white smoke prevention air preheater 1 is, for example, approximately 200-400°C.

The dust collector 2 is disposed downstream of the white smoke prevention air preheater 1 and removes impurities from the exhaust gas output from the white smoke prevention air preheater 1. The dust collector 2 is, for example, a ceramic dust collector with excellent heat resistance, and collects impurities directly from the exhaust gas that has passed through the white smoke prevention air preheater 1. The temperature of the exhaust gas G1 that has passed through the dust collector 2 is, for example, about 200 to 400°C.

Next, the flue gas treatment tower 3 will be described with reference to Fig. 2. The flue gas treatment tower 3 introduces flue gas G1 from the bottom of the tower and brings it into contact with water sprayed from a spray nozzle 3a at the top, thereby removing components such as _NOx and _SOx in the flue gas G1 by incorporating them into smoke washing water W. After being used for water washing of the flue gas G1, the smoke washing water W accumulates in the bottom of the tower. Thereafter, the smoke washing water W is sent to the spray nozzle 3a as smoke washing cooling water W1 by, for example, a circulation pump P1.

For example, a smoke washing heat exchanger 23 is disposed downstream of the circulating pump P1. The smoke washing heat exchanger 23 recovers heat from the smoke washing water W sent to the smoke washing heat exchanger 23. The thermal energy recovered by the smoke washing heat exchanger 23 is then supplied to the exhaust heat power generation system 10 (see FIG. 1) via the circulating water L1, for example, by the circulating pump P3 (see FIG. 1). Note that, in the following description, the fluid supplied to the exhaust heat power generation system 10 is water (water vapor) such as the circulating water L1, but other types of fluids (gas or liquid) may be supplied to the exhaust heat power generation system 10.

Furthermore, a chimney 4 is disposed on the top of the flue gas treatment tower 3. The exhaust gas G2 cleaned in the flue gas treatment tower 3 is subjected to white smoke prevention treatment in the chimney 4, and then released from the chimney 4 into the atmosphere.

In addition, treated water W2 is supplied to the upper part of the flue gas treatment tower 3 and in front of the chimney 4, and the treated water W2 is brought into sufficient contact with the flue gas G2 to wash the flue gas G2 with water. The low-temperature wastewater W3 generated by the water washing of the flue gas G2 is then mixed with the smoke washing water W, for example.

Returning to the explanation of FIG. 1, the exhaust heat power generation system 10 has a function of recovering thermal energy of the smoke washing water W in the flue gas treatment tower 3 and converting it into other energy, and has, for example, an evaporator 11, a steam turbine 12, a generator 13, a regenerator 14, a condenser 15, and a circulation pump P2. The evaporator 11, the steam turbine 12, the regenerator 14, the condenser 15, and the circulation pump P2 form a thermal cycle such as a Rankine cycle or a Kalina cycle in which the working medium L is circulated. The working medium is also called a working fluid, and is, for example, a low-boiling-point medium such as a fluorocarbon having a lower boiling point than water, a fluorocarbon substitute, ammonia, or a mixture of ammonia and water.

The circulation pump P2 circulates the working medium L through a cycle consisting of the evaporator 11, the steam turbine 12, the regenerator 14, the condenser 15, the regenerator 14 and the evaporator 11.

The evaporator 11 evaporates the working medium L by using the heat contained in the circulating water L1 (thermal energy recovered from the smoke washing water W in the smoke washing heat exchanger 23). The temperature of the circulating water L1 sent to the evaporator 11 is, for example, about 72°C. The temperature of the circulating water L1 sent from the evaporator 11 to the smoke washing heat exchanger 23 is, for example, about 66°C.

The steam turbine 12 rotates by the steam of the working medium L generated by the evaporator 11. The generator 13 connected to the rotating shaft of the steam turbine 12 generates electricity by the rotation of the steam turbine 12.

The condenser 15 condenses the working medium L steam output from the steam turbine 12 using cooling water W4 sent by a circulation pump (not shown). The condenser 15 then supplies the condensed working medium L to the evaporator 11 via the regenerator 14 using the circulation pump P2. The temperature of the cooling water W4 is, for example, about 20°C. Specifically, in this case, the regenerator 14 cools the working medium L steam output from the steam turbine 12 by performing heat exchange between the working medium L steam output from the steam turbine 12 and the working medium L condensed by the condenser 15, and then supplies it to the condenser 15. The condenser 15 condenses the working medium L steam supplied from the regenerator 14 using cooling water W4 sent by a circulation pump (not shown), for example. In this case, the cooling water W4 is heated by the heat of condensation.

[Sludge incineration system 200 in the first embodiment]
Next, the sludge incineration system 200 in the first embodiment will be described. Figure 3 is a diagram illustrating a schematic configuration example of the sludge incineration system 200 in the first embodiment. Also, Figures 4 and 5 are diagrams illustrating the functional blocks of the heat pump 7 in the first embodiment. Note that, below, differences from the sludge incineration system 100 described in Figure 1 will be described. Also, the arrangement positions and numbers of the pipes and circulation pumps shown in Figures 3 to 5 are examples, and are not limited to these.

As shown in FIG. 3, the sludge incineration system 200 has, for example, a branching device 6 and a heat pump 7 between the flue gas treatment tower 3 (smoke washing heat exchanger 23) and the exhaust heat power generation system 10 (evaporator 11).

The branching device 6 is disposed in front of the heat pump 7 and branches, for example, the circulating water L1 circulated by the circulation pump P4 into circulating water L11 (hereinafter also referred to as the first fluid L11) and circulating water L12 (hereinafter also referred to as the second fluid L12). The branching device 6 may be, for example, a ball valve or a gate valve provided in the pipe through which the circulating water L1 flows.

The sludge incineration system 200 may have, for example, flow control valves (not shown) in each pipe through which the circulating water L11 and the circulating water L12 flow, instead of the branching device 6. The sludge incineration system 200 may adjust the flow rates of the circulating water L11 and the circulating water L12 by controlling each flow control valve.

The heat pump 7 is a heating type absorption heat pump, and is a device that heats the circulating water L12 by using the heat contained in the circulating water L11.

Specifically, as shown in Figures 4 and 5, the heat pump 7 has, for example, an evaporator 7a, an absorber 7b, a regenerator 7c, a condenser 7d, a circulation pump P6, and a circulation pump P7. The operation of the heat pump 7 will be described below.

[Operation of heat pump 7 in the first embodiment]
Fig. 4 is a diagram illustrating the flows of the refrigerant liquid L21 and the absorbing liquid L31 in the heat pump 7. Fig. 5 is a diagram illustrating the flows of the circulating water L11 and the circulating water L12 in the heat pump 7.

First, we will explain the operation of the heat pump 7 associated with the circulation of the refrigerant liquid L21 and the absorption liquid L31.

As shown in Figures 4 and 5, the evaporator 7a evaporates the refrigerant liquid L21 using the heat contained in the circulating water L11. The evaporator 7a then supplies the vapor of the refrigerant liquid L21 (hereinafter also referred to as vapor L22) generated by evaporating the refrigerant liquid L21 to the absorber 7b.

As shown in FIG. 4, the absorber 7b generates a dilute solution, absorbing liquid L32 (hereinafter also referred to as a second absorbing liquid L32), by absorbing the steam L22 generated in the evaporator 7a into a concentrated solution, absorbing liquid L31 (hereinafter also referred to as a first absorbing liquid L31), generated in the regenerator 7c. The absorbing liquid L31 and the absorbing liquid L32 are, for example, lithium bromide, which has a lower boiling point than water. The absorber 7b then supplies the generated absorbing liquid L32 to the regenerator 7c.

As shown in FIG. 4, the regenerator 7c heats the absorbing liquid L32 produced in the absorber 7b to evaporate the refrigerant liquid L21 contained in the absorbing liquid L32, producing steam L22 and absorbing liquid L31. The regenerator 7c then supplies the produced steam L22 to the condenser 7d. The regenerator 7c also supplies the produced absorbing liquid L31 to the absorber 7b, for example, by a circulation pump P7.

As shown in Figures 4 and 5, the condenser 7d generates refrigerant liquid L21 by liquefying the steam L22 generated in the regenerator 7c using cooling water W5 sent by a circulation pump (not shown). The condenser 7d then supplies the generated refrigerant liquid L21 to the evaporator 7a using, for example, a circulation pump P6. The temperature of the cooling water W5 sent to the condenser 7d is, for example, about 22°C, and the temperature of the cooling water W5 after it has been heated by the heat of condensation is, for example, about 33°C.

Next, we will explain the operation of the heat pump 7 associated with the circulation of the circulating water L11.

As shown in Figures 4 and 5, the evaporator 7a receives the circulating water L11 and then evaporates the refrigerant liquid L21 using the heat contained in the circulating water L11. The evaporator 7a then supplies the circulating water L11 used to evaporate the refrigerant liquid L21 to the regenerator 7c. The temperature of the circulating water L11 sent to the evaporator 7a is, for example, about 74°C.

As shown in Figures 4 and 5, the regenerator 7c receives circulating water L11 from the evaporator 7a, and then heats the absorbing liquid L32 with the heat contained in the circulating water L11. The regenerator 7c then supplies the circulating water L11 used to heat the absorbing liquid L32 to the smoke washing heat exchanger 23. In this case, the circulating water L11 may be, for example, merged with the circulating water L12 before being supplied to the smoke washing heat exchanger 23. The temperature of the circulating water L11 supplied from the regenerator 7c to the smoke washing heat exchanger 23 is, for example, about 68°C.

Next, we will explain the operation of the heat pump 7 associated with the circulation of the circulating water L12.

As shown in Figures 4 and 5, when the absorber 7b receives the circulating water L12, it heats the circulating water L12 by the heat of absorption generated when the steam L22 is absorbed by the absorbing liquid L31. The absorber 7b then supplies the heated circulating water L12 to the evaporator 11 (exhaust heat power generation system 10). The temperature of the circulating water L12 sent from the absorber 7b to the evaporator 11 is, for example, about 120°C. The circulating water L12 is sent from the evaporator 11 to the smoke washing heat exchanger 23, and the temperature of the circulating water L12 is, for example, about 51°C.

As described above, in the sludge incineration system 200 of this embodiment, the circulating water L11 and the circulating water L12 branched off from the circulating water L1 are each supplied to the heat pump 7, and the circulating water L12 heated by the heat pump 7 due to the heat contained in the circulating water L11 is supplied to the exhaust heat power generation system 10.

This allows the exhaust heat power generation system 10 to efficiently utilize the heat contained in the smoke washing wastewater W, thereby increasing the amount of power generated by the exhaust heat power generation system 10.

In addition, in the sludge incineration system 200 of this embodiment, by using a heating absorption heat pump as the heat pump 7, it is possible to reduce the power consumption associated with the operation of the heat pump 7.

[Comparison between the first comparative example and the first embodiment]
Fig. 6 is a diagram for explaining a comparison between the sludge incineration system 100 in the first comparative example and the sludge incineration system 200 in the first embodiment. Specifically, Fig. 6 is a diagram for explaining a comparison between the sludge incineration system 100 (sludge incineration system without the heat pump 7) described in Fig. 1 and Fig. 2 and the sludge incineration system 200 (sludge incineration system with the heat pump 7) described in Fig. 3 to Fig. 5.

Specifically, the example shown in Figure 6 shows that the thermal energy (heat content of the smoke washing wastewater) supplied to the exhaust heat power generation system 10 is "1277 kW" when the heat pump 7 is not provided, whereas it is "1346 kW" when the heat pump 7 is provided.

The example shown in FIG. 6 also shows that the temperature (inlet temperature) of the circulating water sent to the exhaust heat power generation system 10 and the temperature (outlet temperature) of the circulating water sent from the exhaust heat power generation system 10 are "72°C" and "66°C" when there is no heat pump 7, whereas they are "120°C" and "51°C" when there is a heat pump 7.

In addition, in the example shown in Figure 6, the amount of power generated by the exhaust heat power generation system 10 is "68 kW" when the heat pump 7 is not included, and "77 kW" when the heat pump 7 is included.

Furthermore, the example shown in Figure 6 shows that the increase in power generation in the exhaust heat power generation system 10, i.e., the amount of power obtained by subtracting the amount of power consumption associated with the operation of the heat pump 7 from the increase in power generation due to the use of the heat pump 7, is "4.3 kW."

In this way, the example shown in Figure 6 shows that by using a heat pump 7 to generate waste heat energy, it is possible to recover the heat contained in the smoke washing wastewater W more efficiently than when the heat pump 7 is not used, and furthermore, it is possible to increase the amount of power generated in the waste heat power generation system 10.

[Sludge incineration system 300 in the second comparative example]
Next, a sludge incineration system 300 in a second comparative example will be described. Fig. 7 is a diagram illustrating a schematic configuration example of the sludge incineration system 300 in the second comparative example. The following describes the differences from the sludge incineration system 100 described in Fig. 1.

As shown in FIG. 7, the sludge incineration system 300 has a hot water generator 21 between the white smoke prevention air preheater 1 and the chimney 4, for example.

The hot water generator 21 is a heat exchanger that recovers heat from the white smoke prevention air A. The thermal energy recovered by the hot water generator 21 is then supplied to the evaporator 11 (exhaust heat power generation system 10) by, for example, a circulation pump P8. Specifically, the circulation pump P8 supplies the circulating water L4, which has been heated by the hot water generator 21, to the evaporator 11. The temperature of the circulating water L4 sent to the evaporator 11 is, for example, about 143°C. The temperature of the circulating water L4 sent from the evaporator 11 to the hot water generator 21 is, for example, about 108°C.

As shown in FIG. 7, the exhaust heat power generation system 10 has a preheater 16 in addition to the configuration described in FIG. 1.

The preheater 16 is disposed before the evaporator 11, and superheats the working medium L by using the heat contained in the circulating water L1 circulated by the circulation pump P3 (thermal energy recovered in the smoke washing heat exchanger 23). The temperature of the circulating water L1 sent to the preheater 16 is, for example, about 72°C. The temperature of the circulating water L1 sent from the preheater 16 to the smoke washing heat exchanger 23 is, for example, about 62°C.

The evaporator 11 evaporates the working medium L superheated by the preheater 16, for example, by using the heat (thermal energy recovered in the hot water generator 22) contained in the circulating water L4 circulated by the circulation pump P8. The temperature of the circulating water L4 sent from the hot water generator 21 to the evaporator 11 is, for example, about 143°C. The temperature of the circulating water L4 sent from the evaporator 11 to the hot water generator 21 is, for example, about 108°C.

[Sludge incineration system 400 in the second embodiment]
Next, a sludge incineration system 400 in a second embodiment will be described. Figure 8 is a diagram for explaining a schematic configuration example of the sludge incineration system 400 in the second embodiment. Note that the following will explain the differences from the sludge incineration system 200 explained in Figure 3 and the sludge incineration system 300 explained in Figure 7. Also, the arrangement positions and numbers of the pipes and circulation pumps shown in Figure 8 are merely examples, and are not limited thereto.

As shown in FIG. 8, the sludge incineration system 400 has a branching device 6 and a heat pump 7 between the smoke washing heat exchanger 23 and the exhaust heat power generation system 10 (evaporator 11 and preheater 16). As shown in FIG. 8, the sludge incineration system 400 also has a hot water generator 22 between the hot water generator 21 and the exhaust heat power generation system 10 (evaporator 11 and preheater 16).

The heat pump 7 has, for example, an evaporator 7a, an absorber 7b, a regenerator 7c, a condenser 7d, a circulation pump P6, and a circulation pump P7. Below, with reference to Figures 4 and 5, we will explain the operation of the heat pump 7 in the second embodiment that differs from the operation of the heat pump 7 in the first embodiment.

[Operation of heat pump 7 in the second embodiment]
4 and 5, when the absorber 7b is supplied with the circulating water L12, the absorber 7b heats the circulating water L12 by the heat of absorption generated when the steam L22 is absorbed in the absorbing liquid L31. The absorber 7b then supplies the heated circulating water L12 to the hot water generator 22. The temperature of the circulating water L12 sent from the absorber 7b to the hot water generator 22 is, for example, about 120° C. The operation of the hot water generator 22 will be described below.

[Operation of Hot Water Generator 22]
The hot water generator 22 is a heat exchanger, and recovers heat from the circulating water L12 supplied from the absorber 7b. Specifically, the hot water generator 22 exchanges heat between the circulating water L12 supplied from the absorber 7b and the circulating water L4 supplied from the evaporator 11. The circulating water L12 cooled by the hot water generator 22 is supplied to the preheater 16 (exhaust heat power generation system 10) by, for example, a circulation pump P9. The temperature of the circulating water L12 sent to the preheater 16 is, for example, about 110°C. The temperature of the circulating water L12 sent from the preheater 16 to the smoke washing heat exchanger 23 is, for example, about 60°C.

The circulating water L4 heated by the hot water generator 22 is supplied to the hot water generator 21 by, for example, a circulation pump P8. The temperature of the circulating water L4 sent from the hot water generator 21 to the evaporator 11 is, for example, about 143°C, and the temperature of the circulating water L4 sent from the evaporator 11 to the hot water generator 22 is, for example, about 108°C. The temperature of the circulating water L4 sent from the hot water generator 22 to the hot water generator 21 (the circulating water L4 preheated in the hot water generator 22) is, for example, about 111°C.

In other words, in the sludge incineration system 400 of this embodiment, the thermal energy recovered by the hot water generator 22 is also supplied to the exhaust heat power generation system 10.

This allows the exhaust heat power generation system 10 to more efficiently utilize the heat contained in the smoke washing wastewater W, making it possible to further increase the amount of power generated in the exhaust heat power generation system 10.

In addition, in the sludge incineration system 400 of this embodiment, the circulating water L12 heated by the absorber 7b is supplied to the hot water generator 22 to perform heat exchange, making it possible to adjust the thermal energy supplied to each of the evaporator 11 and the preheater 16.

[Comparison between the second comparative example and the second embodiment]
Fig. 9 is a diagram for explaining a comparison between the sludge incineration system 300 in the second comparative example and the sludge incineration system 400 in the second embodiment. Specifically, Fig. 9 is a diagram for explaining a comparison between the sludge incineration system 300 described in Fig. 7 (a sludge incineration system without a heat pump 7) and the sludge incineration system 400 described in Fig. 8 (a sludge incineration system with a heat pump 7).

Specifically, the example shown in Figure 9 shows that, of the thermal energy supplied to the exhaust heat power generation system 10, the thermal energy (heat amount contained in the high-temperature water) recovered by the hot water generators 21 and 22 is "2689 kW" when the heat pump 7 is not provided, whereas it is "2883 kW" when the heat pump 7 is provided.

The example shown in FIG. 9 also shows that, of the thermal energy supplied to the exhaust heat power generation system 10, the thermal energy held in the smoke washing wastewater W (heat amount held in the smoke washing wastewater) is 457 kW when the heat pump 7 is not provided, whereas it is 698 kW when the heat pump 7 is provided.

The example shown in FIG. 9 also shows that the temperature (inlet temperature) of the circulating water sent to the exhaust heat power generation system 10 and the temperature (outlet temperature) of the circulating water sent from the exhaust heat power generation system 10 are "72°C" and "62°C" when there is no heat pump 7, whereas they are "120°C" and "60°C" when there is a heat pump 7.

In addition, in the example shown in Figure 9, the amount of power generated by the exhaust heat power generation system 10 is 348 kW when the heat pump 7 is not included, whereas it is 396 kW when the heat pump 7 is included.

Furthermore, the example shown in Figure 9 shows that the increase in power generation in the exhaust heat power generation system 10, i.e., the amount of power obtained by subtracting the amount of power consumption associated with the operation of the heat pump 7 from the increase in power generation due to the use of the heat pump 7, is "43.3 kW."

In this way, the example shown in Figure 9 shows that by using a heat pump 7 to generate waste heat electricity, it is possible to recover the heat contained in the smoke washing wastewater W more efficiently than when a heat pump 7 is not used, and furthermore, it is possible to increase the power generation efficiency in the waste heat power generation system 10.

1: White smoke prevention air preheater 2: Dust collector 3: Flue gas treatment tower 4: Chimney 6: Brancher 7: Heat pump 7a: Evaporator 7b: Absorber 7c: Regenerator 7d: Condenser 10: Exhaust heat power generation system 11: Evaporator 12: Steam turbine 13: Generator 14: Regenerator 15: Condenser 16: Preheater 21: Hot water generator 22: Hot water generator 23: Smoke washing heat exchanger 100: Sludge incineration system 200: Sludge incineration system 300: Sludge incineration system 400: Sludge incineration system

Claims (4)

A fluid from which heat has been recovered from the flue gas scrubbing wastewater discharged from the flue gas scrubbing tower is divided into a first fluid and a second fluid;
Supplying each of the branched first fluid and the branched second fluid to a heat pump;
The heat pump supplies the second fluid, the temperature of which has been increased by the heat retained in the first fluid, to a heat exchanger;
supplying a third fluid whose temperature has been increased by the heat of the second fluid in the heat exchanger to a waste heat power generation system ;
The heat pump comprises:
an evaporator for evaporating a refrigerant liquid;
an absorber for generating a second absorbing liquid by absorbing the vapor of the refrigerant liquid evaporated in the evaporator into a first absorbing liquid;
a regenerator for evaporating the refrigerant liquid contained in the second absorption liquid by heating the second absorption liquid produced in the absorber to produce vapor of the refrigerant liquid;
a condenser that liquefies the vapor of the refrigerant liquid generated in the regenerator and supplies the liquefied vapor to the evaporator,
In the step of supplying the first fluid to the heat pump,
supplying the first fluid to the evaporator, and evaporating the refrigerant liquid in the evaporator by using heat retained in the first fluid;
supplying the first fluid from the evaporator to the regenerator, and heating the second absorbing liquid in the regenerator using heat retained by the first fluid;
In the step of supplying the second fluid to the heat pump,
The second fluid is supplied to the absorber, and the second fluid is heated by absorption heat generated when the vapor of the refrigerant liquid is absorbed into the first absorption liquid in the absorber.
A waste heat power generation method comprising: A fluid from which heat has been recovered from the flue gas scrubbing wastewater discharged from the flue gas scrubbing tower is divided into a first fluid and a second fluid;
Supplying each of the branched first fluid and the branched second fluid to a heat pump;
The heat pump supplies the second fluid, the temperature of which has been increased by the heat retained in the first fluid, to a heat exchanger;
supplying a third fluid whose temperature has been increased by the heat exchanger due to the heat retained by the second fluid and the second fluid whose temperature has been increased by the heat exchanger to a waste heat power generation system ;
The heat pump comprises:
an evaporator for evaporating a refrigerant liquid;
an absorber for generating a second absorbing liquid by absorbing the vapor of the refrigerant liquid evaporated in the evaporator into a first absorbing liquid;
a regenerator for evaporating the refrigerant liquid contained in the second absorption liquid by heating the second absorption liquid produced in the absorber to produce vapor of the refrigerant liquid;
a condenser that liquefies the vapor of the refrigerant liquid generated in the regenerator and supplies the liquefied vapor to the evaporator,
In the step of supplying the first fluid to the heat pump,
supplying the first fluid to the evaporator, and evaporating the refrigerant liquid in the evaporator by using heat retained in the first fluid;
supplying the first fluid from the evaporator to the regenerator, and heating the second absorbing liquid in the regenerator using heat retained by the first fluid;
In the step of supplying the second fluid to the heat pump,
The second fluid is supplied to the absorber, and the second fluid is heated by absorption heat generated when the vapor of the refrigerant liquid is absorbed into the first absorption liquid in the absorber.
A waste heat power generation method comprising: In claim 1 or 2 ,
In the step of supplying the second fluid to the exhaust heat power generation system, the second fluid whose temperature has been increased by the absorber is supplied to the exhaust heat power generation system.
A waste heat power generation method comprising: In claim 1 or 2, further comprising:
a temperature of a working fluid in the exhaust heat power generation system is increased by the heat retained in the second fluid;
A waste heat power generation method comprising:

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