JP2012149541A - Exhaust heat recovery power generating apparatus and marine vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an exhaust heat recovery power generating apparatus and a marine vessel for efficiently recovering heat of a heat source and improving thermal efficiency of the entire system.SOLUTION: The exhaust heat recovery power generating apparatus 1 includes: a first evaporator 12 evaporating a first organic fluid with heat obtained from the first heat source; a first turbine 13 driven by the first organic fluid evaporated by the first evaporator 12; a first power generator 14 generating electricity by the rotational output of the first turbine 13; a first condenser 15 condensing the first organic fluid that has passed the first turbine 13; a second evaporator 22 evaporating a second organic fluid with heat obtained from a second heat source that is controlled to a temperature lower than that of the first heat source; a second turbine 23 driven by the second organic fluid evaporated by the second evaporator 22; a second power generator 24 generating electricity by the rotational output of the second turbine 23; and a second condenser 25 condensing the second organic fluid that has passed the second turbine 23.

Description

  The present invention relates to an exhaust heat recovery power generation apparatus and a ship.

  There has been proposed a technique for generating power by collecting exhaust heat such as geothermal heat and exhaust gas from an internal combustion engine using the Rankine cycle. For example, there is an exhaust heat recovery power generator that generates power by an organic Rankine Cycle using exhaust heat from a diesel generator as a heat source and an organic fluid as a heat medium.

  Patent Document 1 discloses a technique for generating electricity using an organic Rankine cycle (ORC) in a ship. Patent Document 2 discloses a technology for improving energy utilization efficiency by storing exhaust heat in a ship and generating electric power using the stored thermal energy.

Special table 2008-522081 gazette JP 2010-116847 A

  The evaporation temperature of the organic fluid in the organic Rankine cycle (ORC) is determined by the pressure of a circulation pump provided in the organic fluid path, and the temperature increases as the pressure increases. And since the pressure in a turbine inlet_port | entrance becomes high pressure and a pressure drop becomes large, turbine output becomes large and heat recovery efficiency improves.

  By the way, the Rankine cycle is represented by a cycle diagram as shown in FIG. 6, for example. FIG. 6 is a graph showing the relationship between the temperature T [° C.] and the work L [kW]. FIG. 6 also shows changes in the temperature and work of the heat source that supplies heat to the Rankine cycle. The change of the heat source is represented by the line H on FIG.

  Here, in the organic Rankine cycle represented by the cycle diagram as shown in FIG. 6, when the pressure is set high for the purpose of increasing the turbine output, the temperature becomes high. As a result, when the temperature of the organic fluid in the Rankine cycle is higher than the heat source at the heat source inlet, a crossover as shown in FIG. 7 occurs, and the organic fluid cannot recover heat from the heat source.

  Therefore, in order to avoid crossover with the pressure set high, the flow rate of the organic fluid in the Rankine cycle must be reduced, and the heat must be recovered only in the region where the temperature of the heat source does not drop so much. As a result, the Rankine cycle is represented by a cycle diagram as shown in FIG. 8, and unused heat is generated on the low temperature side of the heat source. At this time, since the organic fluid of the Rankine cycle has not completely recovered the heat of the heat source, the heat utilization efficiency is lowered.

  Further, when there are a plurality of exhaust heat sources such as a diesel engine, for example, the heat radiation line on the heat source side may be a polygonal line as shown in FIG. Generally, compared to high-temperature heat sources such as exhaust gas and turbocharged compressed air, low-temperature heat sources such as engine jacket cooling water have a relatively small heat capacity and a small temperature drop per unit heat dissipation. The profile is such that the inclination of the low temperature heat source is smaller than that of the high temperature heat source.

  Even in this case, in order to avoid crossover with the pressure set high, the flow rate of the organic fluid in the Rankine cycle must be reduced, and the heat must be recovered only in the region where the temperature of the heat source does not drop so much. . As a result, the Rankine cycle is represented by a cycle diagram as shown in FIG. 10, and unused heat is generated on the low temperature side of the heat source. At this time, the Rankine cycle is subject to restrictions on the high-temperature heat source side having a smaller heat capacity, and the low-temperature heat source cannot be effectively used.

  The present invention has been made in view of such circumstances, and provides an exhaust heat recovery power generator and a ship that can efficiently recover the heat of a heat source and improve the thermal efficiency of the entire system. With the goal.

In order to solve the above-described problems, the exhaust heat recovery power generator and the ship of the present invention employ the following means.
That is, the exhaust heat recovery power generation apparatus according to the present invention includes a first evaporator that evaporates a liquefied first organic fluid by heat obtained from a first heat source, and a first evaporator that is evaporated by the first evaporator. Than the first turbine driven by the organic fluid, the first generator that generates electric power by the rotational output of the first turbine, the first condenser that condenses the first organic fluid that has passed through the first turbine, and the first heat source A second evaporator that evaporates the second organic fluid that is liquefied by heat obtained from the second heat source that is set to a low temperature, and a second turbine that is driven by the second organic fluid that is evaporated by the second evaporator And a second generator that generates electric power by the rotational output of the second turbine, and a second condenser that condenses the second organic fluid that has passed through the second turbine.

  According to the present invention, the liquefied first organic fluid is evaporated by the heat obtained from the first heat source in the first evaporator, and the evaporated first organic fluid drives the first turbine. Then, the first generator generates electricity by the rotational output of the first turbine. The first organic fluid that has passed through the first turbine is condensed by the first condenser. The liquefied second organic fluid is evaporated by the heat obtained from the second heat source in the second evaporator, and the evaporated second organic fluid drives the second turbine. Then, the second generator generates electricity by the rotational output of the second turbine. The second organic fluid that has passed through the second turbine is condensed by the second condenser.

  Therefore, the present invention has a first evaporator, a first turbine, and a first condenser, and has a Rankine cycle through which the first organic fluid flows, a second evaporator, a second turbine, and a second condenser. Thus, a Rankine cycle in which the second fluid flows is configured. Here, the second organic fluid is evaporated in the second evaporator by heat obtained from the second heat source having a temperature lower than that of the first heat source. That is, the first heat source and the second heat source are at different temperatures, and by using two Rankine cycles that recover heat from the heat sources having different temperatures to generate power by generating turbine output, it is possible to effectively use heat. .

  The exhaust heat recovery power generator according to the present invention includes a first evaporator that evaporates a liquefied first organic fluid by heat obtained from a first heat source, and a first evaporator that is evaporated by the first evaporator. A first turbine driven by an organic fluid; a second evaporator that evaporates a liquefied second organic fluid by heat obtained from a second heat source that is lower in temperature than the first heat source; A second turbine that shares a shaft and is driven by a second organic fluid evaporated by a second evaporator, a generator that generates electric power by using the rotational output of the first turbine and the rotational output of the second turbine, and the first turbine And a condenser for condensing the second organic fluid that has passed through the second turbine and the second organic fluid that has passed through the second turbine.

  According to the present invention, the liquefied first organic fluid is evaporated by the heat obtained from the first heat source in the first evaporator, and the evaporated first organic fluid drives the first turbine. The liquefied second organic fluid is evaporated by the heat obtained from the second heat source in the second evaporator, and the evaporated second organic fluid drives the second turbine. The first turbine and the second turbine share a shaft, and the generator generates electricity by the rotational output of the first turbine and the rotational output of the second turbine. The first organic fluid that has passed through the first turbine and the second organic fluid that has passed through the second turbine are condensed by a condenser.

  Therefore, in this invention, it has a 1st evaporator, a 1st turbine, and a condenser, has a Rankine cycle through which a 1st organic fluid flows, a 2nd evaporator, a 2nd turbine, and a condenser, A Rankine cycle through which an organic fluid flows is formed. Here, the second organic fluid is evaporated in the second evaporator by heat obtained from the second heat source having a temperature lower than that of the first heat source. That is, the first heat source and the second heat source are at different temperatures, and by using two Rankine cycles that recover heat from the heat sources having different temperatures to generate power by generating turbine output, it is possible to effectively use heat. .

  Further, in the present invention, since the first turbine and the second turbine share a shaft and power is generated by one generator, compared to the case where a generator is provided for each of the two turbines, the exhaust is reduced. The entire heat recovery power generator can be made compact.

  Further, the exhaust heat recovery power generation device according to the present invention includes a first evaporator that evaporates the liquefied first organic fluid by heat obtained from the first heat source, and a second temperature that is lower than the first heat source. A second evaporator that evaporates the liquefied second organic fluid by heat obtained from the heat source, a first organic fluid that is evaporated by the first evaporator, and a second evaporator that is evaporated by the second evaporator. A turbine driven by the organic fluid, a generator that generates electric power by the rotational output of the turbine, and a condenser that condenses the first organic fluid and the second organic fluid that have passed through the turbine.

  According to the present invention, the liquefied first organic fluid is evaporated by the heat obtained from the first heat source in the first evaporator, and the liquefied second organic fluid is the second evaporator in the second evaporator. Evaporate with heat from two heat sources. Then, the evaporated first organic fluid and the evaporated second organic fluid drive the turbine, and the generator generates electricity by the rotational output of the turbine. The first organic fluid and the second organic fluid that have passed through the turbine are condensed by a condenser.

  Therefore, in this invention, it has a 1st evaporator, a turbine, and a condenser, has a Rankine cycle through which a 1st organic fluid flows, has a 2nd evaporator, a turbine, and a condenser, and a 2nd organic fluid flows. A Rankine cycle is constructed. Here, the second organic fluid is evaporated in the second evaporator by heat obtained from the second heat source having a temperature lower than that of the first heat source. That is, the first heat source and the second heat source are at different temperatures, and by using two Rankine cycles that recover heat from the heat sources having different temperatures to generate power by generating turbine output, it is possible to effectively use heat. .

  In the present invention, since the first organic fluid and the second organic fluid drive one turbine and the power is generated by one generator, a case where two turbines are provided or a plurality of turbines Compared to the case where a generator is provided for each, the overall exhaust heat recovery power generator can be made more compact.

  In the above invention, the first heat medium is used as a first heat source in the first evaporator to exchange heat with the first organic fluid, and the second heat medium is used as a second heat source in the second evaporator. A second heat medium path different from the first heat medium path that exchanges heat with two organic fluids may be provided.

  According to the present invention, the first organic fluid exchanges heat with the first heat medium flowing through the first heat medium path in the first evaporator, and the second organic fluid is second in the second evaporator. Heat exchange with the second heat medium flowing through the heat medium path. Here, the first heat medium path and the second heat medium path are different. Therefore, the first heat medium flowing through the first heat medium path and the second heat medium flowing through the second heat medium path can recover heat from different places, for example, different devices, and the heat can be effectively used by a plurality of devices. Can be used.

  In the above invention, the heat medium that exchanges heat with the first organic fluid in the first evaporator as the first heat source and heat exchanges with the first organic fluid in the first evaporator serves as the second heat source. A heat medium path for exchanging heat with the second organic fluid in the evaporator may be provided.

  According to the present invention, the first organic fluid exchanges heat with the heat medium flowing through the heat medium path in the first evaporator, and the second organic fluid heats with the first organic fluid in the second evaporator. Heat is exchanged with the heat medium flowing through the exchanged heat medium path. Here, the heat medium path passing through the first evaporator and the second evaporator is common. Accordingly, since the first evaporator uses the high temperature side of the heat medium and the second evaporator uses the low temperature side of the heat medium, the heat recovered by the heat medium is effectively used without wasting it. be able to.

  In the above invention, the first heat medium recovers heat with an air cooler that cools compressed air discharged from a supercharger of the internal combustion engine and / or exhaust gas heat exchanger that exchanges heat with the exhaust gas of the internal combustion engine. And heat exchange with the first organic fluid in the first evaporator.

  According to the present invention, in the air cooler, the compressed air discharged from the supercharger of the internal combustion engine is cooled by exchanging heat with the first heat medium, and the first heat medium recovers heat and rises in temperature. . Further, the exhaust gas of the internal combustion engine is cooled by exchanging heat with the first heat medium in the exhaust gas heat exchanger, and the temperature of the first heat medium is recovered by heat recovery. In addition, the heat recovery in the air cooler and the heat recovery in the exhaust gas heat exchanger may both be performed, or one of them may be performed. Then, in the first evaporator, the first heat medium is cooled by exchanging heat with the first organic fluid, and the first organic fluid is recovered by heat to rise in temperature and evaporate.

  In the above invention, the second heat medium may recover heat with an exhaust heat recovery device that exchanges heat with engine cooling water that cools the internal combustion engine body, and may exchange heat with the second organic fluid with a second evaporator. .

  According to the present invention, in the exhaust heat recovery device, the engine cooling water that cools the internal combustion engine body is cooled by exchanging heat with the second heat medium, and the second heat medium recovers the heat and rises in temperature. Then, in the second evaporator, the second heat medium is cooled by exchanging heat with the second organic fluid, and the second organic fluid recovers the heat and rises in temperature to evaporate.

  The ship which concerns on this invention is equipped with the exhaust-heat recovery electric power generation apparatus of the said either structure.

  According to the present invention, when the ship is equipped with the exhaust heat recovery power generation device, the first heat source and the second heat source are at different temperatures, and the turbine output is obtained using two Rankine cycles for recovering heat from the heat sources having different temperatures. In order to generate electricity, the heat in the ship can be effectively used.

  The heat of the heat source can be efficiently recovered to improve the thermal efficiency of the entire system.

It is a cycle diagram in the Rankine cycle of the exhaust heat recovery power generator of the present invention. 1 is a schematic diagram showing an exhaust heat recovery power generator according to a first embodiment of the present invention. It is the schematic which shows the waste heat recovery electric power generating apparatus which concerns on 2nd Embodiment of this invention. It is the schematic which shows the waste heat recovery electric power generating apparatus which concerns on 3rd Embodiment of this invention. It is the schematic which shows the exhaust heat recovery system in the ship which has the exhaust heat recovery power generation device and exhaust heat recovery power generation device which concern on 4th Embodiment of this invention. It is a cycle diagram in the conventional Rankine cycle. It is a cycle diagram when the organic fluid becomes higher temperature than the heat source in the evaporator of Rankine cycle. FIG. 7 is a cycle diagram in the Rankine cycle when the conventional Rankine cycle shown in FIG. 6 is changed. It is a cycle diagram in Rankine cycle which showed together a heat dissipation line in case there are a plurality of exhaust heat sources. FIG. 10 is a cycle diagram in the Rankine cycle when the conventional Rankine cycle shown in FIG. 9 is changed.

Embodiments according to the present invention will be described below with reference to the drawings.
The exhaust heat recovery power generation apparatus of the present invention is designed to effectively use heat by combining a plurality of cycles having different pressures. The Rankine cycle of the present invention is represented by a cycle diagram as shown in FIG. FIG. 1 is a graph showing the relationship between temperature T [° C.] and work [kW], and represents a cycle diagram in the Rankine cycle of the exhaust heat recovery power generator of the present invention. That is, on the high temperature side of the heat source, heat recovery is performed with a high pressure cycle, and on the low temperature side of the heat source, heat recovery is performed with a low pressure cycle. In FIG. 1, the high pressure cycle and the low pressure cycle show a case where heat is recovered from the same heat source, and the temperature regions where the high pressure cycle and the low pressure cycle recover heat do not overlap.

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to FIG. FIG. 2 is a schematic view showing the exhaust heat recovery power generator 1 according to the first embodiment of the present invention.

  The exhaust heat recovery power generation apparatus 1 has two organic fluid paths of a high pressure cycle 2 and a low pressure cycle 3. The high-pressure cycle 2 includes a circulation pump 11, a first evaporator 12, a turbine 13, and a condenser 15. The low pressure cycle 3 includes a circulation pump 21, a second evaporator 22, a turbine 23, and a condenser 25. Generators 14 and 24 are connected to the turbines 13 and 23, respectively.

  As the organic fluid flowing through the organic fluid path of the high-pressure cycle 2 and the low-pressure cycle 3, low-molecular hydrocarbons such as isopentane, butane, and propane, R134a and R245fa used as refrigerants, and the like can be used. The organic fluid path is a closed circuit, and in the case of the high pressure cycle 2, the organic fluid is circulated by the circulation pump 11. The organic fluid passes through the first evaporator 12, the turbine 13, and the condenser 15 and circulates while repeating the phase change.

  The first evaporator 12 heats the liquid organic fluid sent from the circulation pump 11 by the heat recovered by the heat medium flowing through the heat source, and changes the organic fluid into a gas phase.

  The turbine 13 is rotationally driven by a heat drop (enthalpy drop) of the organic fluid evaporated by the first evaporator 12. The rotational power of the turbine 13 is transmitted to the generator 14, and electric power is obtained by the generator 14. The electric power obtained by the generator 14 is supplied to the inboard system via a power line (not shown).

  The condenser 15 cools the vapor-phase organic fluid with seawater to condense. The condensed and liquefied organic fluid is sent to the first evaporator 12 by the circulation pump 11.

  Thus, the organic fluid path of the high pressure cycle 2 constitutes an organic Rankine cycle by the pump 11, the first evaporator 12, the turbine 13 and the condenser 15.

  On the other hand, in the organic fluid path of the low pressure cycle 3, the organic fluid is circulated by the circulation pump 21. The organic fluid passes through the second evaporator 22, the turbine 23, and the condenser 25 and circulates while repeating the phase change.

  Here, the 2nd evaporator 22, the turbine 23, the generator 24, and the condenser 25 have the structure and effect | action similar to the 1st evaporator 12, the turbine 13, the generator 14, and the condenser 15, respectively. However, in the case of the low pressure cycle 3, the second evaporator 22 is at a lower temperature than the first evaporator 12 of the high pressure cycle 2. The organic fluid evaporated by the second evaporator 22 has a lower pressure than the organic fluid evaporated by the first evaporator 12.

  The organic fluid flowing through the high-pressure cycle 2 and the organic fluid flowing through the low-pressure cycle 3 may be the same medium or different media having different vapor pressures.

  The heat flow path that flows through the first evaporator 12 in the high-pressure cycle 2 and the second evaporator 22 in the low-pressure cycle 3 is such that the first evaporator 12 and the second evaporator 22 are connected by a heat flow path as shown in FIG. , It is common. The heat medium passes through the first evaporator 12, heats the organic fluid in the high-pressure cycle 2, drops in temperature, and then flows to the second evaporator 22. Then, the heat medium passes through the second evaporator 22 and heats the organic fluid in the low pressure cycle 3.

  The heat flow path flowing through the first evaporator 12 of the high pressure cycle 2 and the heat flow path flowing through the second evaporator 22 of the low pressure cycle 3 may be different flow paths unlike FIG. That is, the first evaporator 12 only needs to have a higher temperature than the second evaporator 22, and the heat flow of the heat flow path that flows through the first evaporator 12 in the high pressure cycle 2 and the heat flow that flows through the second evaporator 22 in the low pressure cycle 3. The heat source of the path may be different.

Next, the operation of the exhaust heat recovery power generator 1 having the above configuration will be described with reference to FIG.
The heat medium guided from the heat source exchanges heat with the organic fluid flowing through the high-pressure cycle 2 in the first evaporator 12. As a result, the heat of the heat medium is recovered in the organic fluid of the high pressure cycle 2. The organic fluid is heated and evaporated by the heat of the heat medium in the first evaporator 12.

  The evaporated and evaporated organic fluid is guided to the turbine 13, and the turbine 13 is driven to rotate by the heat difference. Rotational output of the turbine 13 is obtained and power generation is performed by the generator 14. The organic fluid (gas phase) that has finished its work in the turbine 13 is led to the condenser 15 and cooled by cooling water such as seawater to be condensed and liquefied.

  The heat medium guided from the heat source is subjected to heat exchange in the first evaporator 12, and then the heat medium having a temperature lower than that of the heat medium in the first vapor 12 is converted into a low-pressure cycle in the second evaporator 22. Heat exchange is performed with the organic fluid flowing through 3. As a result, the heat of the heat medium is recovered in the organic fluid of the low pressure cycle 3. The organic fluid is heated and evaporated by the heat of the heat medium in the second evaporator 22.

  The evaporated and evaporated organic fluid is guided to the turbine 23, and the turbine 23 is rotationally driven by the heat drop. Power is generated by the generator 24 by obtaining the rotational output of the turbine 23. The organic fluid (gas phase) that has finished its work in the turbine 23 is led to the condenser 25 and cooled by cooling water such as seawater to be condensed and liquefied.

  From the above, the exhaust heat recovery power generator 1 of the present invention generates power with the generator 14 and the generator 24. At this time, the Rankine cycle of the present invention is represented by a cycle diagram as shown in FIG. That is, heat recovery is performed in the high pressure cycle 2 on the high temperature side of the heat source, and heat recovery is performed in the low pressure cycle 3 on the low temperature side of the heat source. The present invention uses two Rankine cycles having a plurality of evaporation temperatures while recovering heat from two heat sources having different temperatures. Therefore, heat can be recovered not only from the high temperature side of the heat source but also from the low temperature side, and according to the present invention, effective use of heat can be achieved.

[Second Embodiment]
Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 3 is a schematic view showing an exhaust heat recovery power generator 4 according to the second embodiment of the present invention.
Although 1st Embodiment demonstrated the case where the two turbines 13 and 23 were connected with the generators 14 and 24, respectively, this invention is not limited to this example. In the exhaust heat recovery power generator 4 of the second embodiment, the turbines 13 and 23 share a shaft as shown in FIG. 3, and one generator 34 is connected to the turbines 13 and 23. Although not shown, the turbines 13 and 23 also share a turbine casing.

  The exhaust heat recovery power generator 4 has two organic fluid paths, a high pressure cycle 5 and a low pressure cycle 6. The high pressure cycle 5 includes a circulation pump 11, a first evaporator 12, a turbine 13, and a condenser 35. The low pressure cycle 6 includes a circulation pump 21, a second evaporator 22, a turbine 23, and a condenser 35. The high pressure cycle 5 and the low pressure cycle 6 have the same organic fluid.

  In the case of the high-pressure cycle 5, the organic fluid is circulated by the circulation pump 11, and in the case of the low-pressure cycle 6, the organic fluid is circulated by the circulation pump 21. In the exhaust heat recovery power generator 4 shown in FIG. 3, the condenser 35 is common in the high-pressure cycle 5 and the low-pressure cycle 6, and the organic fluid paths merge after the turbines 13 and 23 and before the condenser 35. The organic fluid path branches off after the condenser 35 and before the circulation pumps 11 and 21.

  In the exhaust heat recovery power generation device 4 shown in FIG. 3, the flow rates of the two organic fluid paths are adjusted by the two circulation pumps 11 and 21, but the present invention is not limited to this example. For example, one circulation pump common to the high pressure cycle 5 and the low pressure cycle 6 may be provided, and the difference in the flow rate of the organic fluid between the high pressure cycle 5 and the low pressure cycle may be adjusted by providing a flow rate adjusting valve in the path. .

  The rotational power of the turbine 13 and the rotational power of the turbine 23 are transmitted to the generator 34, and electric power is obtained by the generator 34.

  As described above, the exhaust heat recovery power generation apparatus 4 of the present invention generates power with the generator 34. By using two Rankine cycles having a plurality of evaporation temperatures while recovering heat from two heat sources having different temperatures, respectively. Effective use of heat can be achieved. Further, the exhaust heat recovery power generator 4 uses the same organic fluid flowing through the high-pressure cycle 5 and the low-pressure cycle 6, and shares the shafts of the turbines 13 and 23 and the turbine casing, so that two cycles and two turbines are separated. Compared with the case where it is provided in, the exhaust heat recovery power generation device 4 as a whole can be made compact.

[Third Embodiment]
Next, a third embodiment of the present invention will be described with reference to FIG.
In the exhaust heat recovery power generator 7 of the third embodiment, one turbine 33 is provided, and one generator 34 is connected to the turbine 33.

  The exhaust heat recovery power generation device 7 has two organic fluid paths of a high pressure cycle 5 and a low pressure cycle 6 as in the second embodiment. The high-pressure cycle 5 includes a circulation pump 11, a first evaporator 12, a turbine 33, and a condenser 35. The low pressure cycle 6 includes a circulation pump 21, a second evaporator 22, a turbine 33, and a condenser 35. The high pressure cycle 5 and the low pressure cycle 6 have the same organic fluid.

  The turbine 33 is introduced with an organic fluid evaporated in the first evaporator 12 of the high-pressure cycle 5 from an inlet provided at an end. Further, in the turbine 33, an organic fluid evaporated by the second evaporator 22 of the low pressure cycle 6 is introduced into an intermediate stage of the turbine 33 from an inlet provided in an intermediate portion. The turbine 33 is rotationally driven by a heat drop (enthalpy drop) of the organic fluid evaporated by the first evaporator 12 and the second evaporator 22.

  The rotational power of the turbine 33 is transmitted to the generator 34, and electric power is obtained by the generator 34. As described above, the exhaust heat recovery power generation device 7 of the present invention generates power with the generator 34. By using two Rankine cycles having a plurality of evaporation temperatures while recovering heat from two heat sources having different temperatures, respectively. Effective use of heat can be achieved. Further, the exhaust heat recovery power generation device 7 is provided with only the turbine 33, and the exhaust heat recovery power generation device 7 as a whole can be made more compact than the case where two turbines are provided.

[Fourth Embodiment]
Next, a fourth embodiment of the present invention will be described with reference to FIG.
Hereinafter, a configuration in which the exhaust heat recovery power generation device 8 of the present invention is installed as an exhaust heat recovery of a main engine for propulsion of a ship (diesel engine 40; internal combustion engine) will be described with reference to the drawings. In FIG. 5, the area surrounded by the broken line is the exhaust heat recovery power generator 8 of the present invention.

  The exhaust heat recovery power generation device 8 has two organic fluid paths of a high pressure cycle 9 and a low pressure cycle 10. The high-pressure cycle 9 includes a circulation pump 31, a flow rate adjustment valve 26, a first evaporator 12, a turbine 33, and a condenser 35. The low pressure cycle 10 includes a circulation pump 31, flow rate adjusting valves 26 and 27, a second evaporator 22, a turbine 33, and a condenser 35. The turbine 33 is connected to a generator 34 via a speed reducer 36.

  The organic fluid path is a closed circuit. The high-pressure cycle 9 and the low-pressure cycle 10 are provided with a common circulation pump 31, and the organic fluid is circulated by the circulation pump 31. The pressure and flow rate of the high pressure cycle 9 are adjusted by the flow rate adjustment valve 26, and the pressure and flow rate of the low pressure cycle 10 are adjusted by the flow rate adjustment valves 26 and 27.

  As the organic fluid flowing through the organic fluid path of the high-pressure cycle 9 and the low-pressure cycle 10, low molecular hydrocarbons such as isopentane, butane, and propane, R134a and R245fa used as refrigerants, and the like can be used. The organic fluid passes through the circulation pump 31, the first evaporator 12, the turbine 33, and the condenser 35 in the high-pressure cycle 9 and circulates while repeating the phase change. In the low-pressure cycle 10, the organic fluid is circulated. And it circulates through the 2nd evaporator 22, the turbine 33, and the condenser 35, repeating a phase change.

  The first evaporator 12 is a liquid phase organic material sent from the circulation pump 31 by the heat recovered by the heat medium water flowing through the flow path 56 by the first air cooler 46 or the exhaust gas economizer (exhaust gas heat exchanger) 55. The fluid is heated to change the organic fluid into the gas phase. The first air cooler 46 cools the compressed air discharged from the turbocharger (supercharger) 42 of the diesel engine 40 by exchanging heat with the heat transfer water. Further, the exhaust gas economizer 55 cools the exhaust gas discharged from the diesel engine 40 by exchanging heat with the heat transfer water.

  The second evaporator 22 heats the liquid organic fluid sent from the circulation pump 31 by the heat collected by the jacket cooling water (heat medium) flowing through the jacket cooling water circulation passage 52 in the cylinder jacket of the diesel engine 40. Then, the organic fluid is changed to the gas phase. The cylinder jacket is provided in the diesel engine 40 and cools the cylinder block and the like of the diesel engine 40 by exchanging heat with the jacket cooling water.

  The turbine 33 is introduced with the organic fluid evaporated in the first evaporator 12 of the high-pressure cycle 9 and the organic fluid evaporated in the second evaporator 22 of the low-pressure cycle 10. The turbine 33 is rotationally driven by a heat drop (enthalpy drop) of the organic fluid evaporated by the first evaporator 12 and the second evaporator 22.

  The rotational power of the turbine 33 is transmitted to the generator 34, and electric power is obtained by the generator 34. The electric power obtained by the generator 34 is supplied to the inboard system via a power line (not shown). The organic fluid that has passed through the turbine 33 is cooled by seawater in the condenser 35 to be condensed and liquefied. The condensed and liquefied organic fluid is sent to the first evaporator 12 and the second evaporator 22 by the circulation pump 31.

Next, the circulation channel 52 will be described.
Jacket cooling water flowing in the cylinder jacket of the diesel engine 40 is circulated in the circulation passage 52 by the jacket cooling water pump 51. The circulation channel 52 is formed such that jacket cooling water flows in the order of the cylinder jacket, the second evaporator 22, the temperature adjusting three-way valve 54, and the jacket cooling water pump 51.

  The jacket cooling water inlet temperature of the second evaporator 22 is about 85 ° C. and the jacket cooling water outlet temperature is about 69 ° C., for example. In the second evaporator 22, the organic fluid is evaporated by the jacket cooling water.

  The temperature adjusting three-way valve 54 operates so that jacket cooling water flowing into the cylinder jacket reaches a desired inlet temperature. Specifically, when the inlet temperature at which the jacket cooling water flows into the cylinder jacket is higher than a set value, the operation is performed so that a large amount of fresh water led from a central cooler (not shown) flows to the circulation passage 52.

  In the circulation channel 52, a branch channel that branches to the central cooler is provided on the upstream side of the temperature adjusting three-way valve 54. The jacket cooling water flowing in the circulation flow path 52 from the branch flow path is discharged to the central cooler side, so that the mass balance of the circulation flow rate flowing in the circulation flow path 52 is maintained.

Next, the exhaust heat recovery path 56 will be described.
The exhaust heat recovery path 56 is a closed circuit, and is provided with an exhaust heat recovery pump 60 for circulating the heat transfer water. The heat transfer water is circulated by the exhaust heat recovery pump 60 so as to exchange heat with the first air cooler 46, the exhaust gas economizer 55, and the first evaporator 12. The heat transfer water cooled by the first evaporator 12 is collected in the atmospheric pressure drain tank 58 via the pressure reducing valve 66. The flow rate of the heat transfer water sent from the exhaust heat recovery pump 60 to the first evaporator 12 is adjusted by a water supply control valve 61 provided in the exhaust heat recovery path 56.

  The heat medium water inlet temperature of the first evaporator 12 is, for example, about 196 ° C., and the heat medium water outlet temperature is, for example, about 70 ° C. In the first evaporator 12, the organic fluid is evaporated by the heat transfer water.

  The second air cooler 47 is installed on the downstream side of the first air cooler 46 with respect to the flow of compressed air discharged from the turbocharger 42. Therefore, the temperature of the first air cooler 46 is set to be higher than that of the second air cooler 47. The fresh water flowing in the second air cooler 47 is guided to the second air cooler 47 after being cooled by a central cooler (not shown). As a result, the compressed air discharged from the turbocharger 42 is cooled by the first air cooler 46 and the second air cooler 47 and supplied to the diesel engine 40.

  A composite boiler is provided on the high temperature side (exhaust gas flow upstream side) of the exhaust gas economizer 55. The composite boiler includes a steam drum 64, a circulation pump 65, and an evaporator 44. The water in the steam drum 64 is sent to the evaporator 44 where it is evaporated by exchanging heat with the exhaust gas.

  The vapor evaporated in the evaporator 44 is guided to the vapor drum 64. The steam staying above the steam drum 64 is guided to the auxiliary device, and then collected in the atmospheric pressure drain tank 58. The water level in the steam drum 64 is adjusted by the steam drum level control valve 62, and water is supplied from the atmospheric pressure drain tank 58 to the steam drum 64 by the boiler feed pump 63.

Next, the operation of the exhaust heat recovery power generator 8 configured as described above will be described with reference to FIG.
The jacket cooling water led to the cylinder jacket of the diesel engine 40 by the jacket cooling water pump 51 cools the cylinder block and the like by the cylinder jacket. As a result, the jacket cooling water is heated and then guided to the second evaporator 22. In the second evaporator 22, heat exchange is performed between the organic fluid flowing through the low pressure cycle 10 and the jacket cooling water, and the sensible heat of the jacket cooling water is recovered into the organic fluid of the low pressure cycle 10. The temperature of the organic fluid after heat recovery from the jacket cooling water is, for example, about 65 ° C. The organic fluid is heated and evaporated by the sensible heat of the heat transfer water in the second evaporator 22. The organic fluid that has evaporated to high enthalpy is guided to the turbine 33, and the turbine 33 is driven to rotate by the heat drop. Rotational output of the turbine 33 is obtained, and power generation is performed by the generator 34.

  The air compressed by the turbocharger 42 of the diesel engine 40 is cooled by the first air cooler 46 and the second air cooler 47. At this time, the heat transfer water in the exhaust heat recovery path 56 flowing in the first air cooler 46 is heated by the compressed air, so that the heat transfer water recovers heat from the compressed air. The heat transfer water temperature after heat recovery by the first air cooler 46 is, for example, about 142 ° C.

  The exhaust gas discharged from the diesel engine 40 is cooled by the evaporator 44 and the exhaust gas economizer 55 of the composite boiler. At this time, the heat transfer water in the exhaust heat recovery path 56 flowing through the exhaust gas economizer 55 is heated by the exhaust gas, so that the heat transfer water recovers heat from the exhaust gas. The temperature of the heat transfer water after heat recovery by the exhaust gas economizer 55 is, for example, about 196 ° C.

  The heat transfer water that has recovered the exhaust heat by the first air cooler 46 and the exhaust gas economizer 55 and has reached a high temperature is guided to the first evaporator 12 and exchanges heat with the organic fluid circulating in the high-pressure cycle 9. The organic fluid is heated and evaporated by the sensible heat of the heat transfer water in the first evaporator 12. The temperature of the organic fluid after heat recovery from the heat transfer water is about 126 ° C., for example.

  The organic fluid that has evaporated to high enthalpy is guided to the turbine 33, and the turbine 33 is driven to rotate by the heat drop. Rotational output of the turbine 33 is obtained, and power generation is performed by the generator 34. The organic fluid (gas phase) that has finished work in the turbine 33 is led to the condenser 35 and is cooled by cooling water such as seawater to be condensed and liquefied.

As described above, according to the present embodiment, the following operational effects are obtained.
As the heat source of the organic Rankine cycle, the high-pressure cycle 9 uses heat recovered by the first air cooler 46 and the exhaust gas economizer 55, and the low-pressure cycle 10 recovers heat using jacket cooling water (engine cooling water). It was decided to use heat.

  Thus, instead of using the exhaust gas of the diesel engine 40 having a high temperature level such as about 250 ° C., the first air cooler 46 (for example, about 70 ° C.) whose temperature level is lower than the exhaust gas and has not been effectively used, An exhaust gas economizer 55 (eg, about 207 ° C.) and jacket cooling water (eg, about 85 ° C.) can be used.

  And although the waste heat recovery power generation device 8 of the present invention generates power by the generator 34, by using two Rankine cycles having a plurality of evaporation temperatures while recovering heat from two heat sources having different temperatures, Effective use of heat can be achieved.

  In the fourth embodiment of the present invention, the jacket cooling water having a low temperature but always having a high flow rate is used as the heat source of the low-pressure cycle 10, so that the recovered heat of the jacket cooling water can be effectively used, and the temperature is high. By using the first air cooler 46 and the exhaust gas economizer 55 having a small flow rate as the heat source of the high-pressure cycle 9, the recovered heat of the first air cooler 46 and the exhaust gas economizer 55 can be used effectively.

  In addition, the jacket cooling water has a small change in the amount of heat compared to the heat of the exhaust gas, regardless of the operating condition of the ship. Therefore, even when the heat quantity of the exhaust gas is reduced and the heat recovery on the high pressure cycle 9 side is reduced, the heat recovery on the low pressure cycle 10 side can be continued, and the exhaust heat recovery power generation device 8 of the present invention generates power by exhaust heat recovery. It can be carried out.

  The fourth embodiment of the present invention focuses on jacket cooling water and heat sources having different temperatures and flow rates, such as the first air cooler 46 and the exhaust gas economizer 55. Conventionally, in the high-pressure Rankine cycle, the flow rate of the organic fluid has to be reduced, and where the unused heat is generated on the low-temperature side of the heat source, combined with the low-pressure Rankine cycle, it can be used from the temperature range that was previously unused. Heat recovery is possible. In the present invention, by paying attention to the heat sources having different properties as described above, the exhaust heat recovery power generator 8 combining two Rankine cycles with different temperatures at which the organic fluid recovers heat can be realized.

  In the fourth embodiment, the heat transfer water is used for both heat recovery in the first air cooler 46 and heat recovery in the exhaust gas economizer 55, but the present invention is not limited to this example. For example, heat recovery of the heat transfer medium water may be performed on either side. In the above description, two Rankine cycles with different heat recovery temperatures are combined, but the present invention is not limited to this example. If the temperature at which the organic fluid recovers heat is different, three or more Rankine cycles may be combined.

1, 4, 7, 8 Waste heat recovery power generator 2, 5, 9 High pressure cycle 3, 6, 10 Low pressure cycle 11, 21, 31 Circulation pump 12 First evaporator 13 Turbine (first turbine)
14 Generator (1st generator)
15 Condenser (first condenser)
22 Second evaporator 23 Turbine (second turbine)
24 Generator (second generator)
25 Condenser (second condenser)
26, 27 Flow control valve 33 Turbine 34 Generator 35 Condenser 40 Diesel engine 42 Turbocharger 46 First air cooler 51 Jacket cooling water pump 55 Exhaust gas economizer 60 Exhaust heat recovery pump

Claims (8)

A first evaporator that evaporates a liquefied first organic fluid by heat obtained from a first heat source;
A first turbine driven by the first organic fluid evaporated by the first evaporator;
A first generator for generating electricity by the rotational output of the first turbine;
A first condenser for condensing the first organic fluid that has passed through the first turbine;
A second evaporator that evaporates a liquefied second organic fluid by heat obtained from a second heat source having a temperature lower than that of the first heat source;
A second turbine driven by the second organic fluid evaporated by the second evaporator;
A second generator for generating electric power by the rotational output of the second turbine;
A second condenser for condensing the second organic fluid that has passed through the second turbine;
An exhaust heat recovery power generator. A first evaporator that evaporates a liquefied first organic fluid by heat obtained from a first heat source;
A first turbine driven by the first organic fluid evaporated by the first evaporator;
A second evaporator that evaporates a liquefied second organic fluid by heat obtained from a second heat source having a temperature lower than that of the first heat source;
A second turbine that is shared by the first turbine and driven by the second organic fluid evaporated by the second evaporator;
A generator for generating electric power by the rotational output of the first turbine and the rotational output of the second turbine;
A condenser that condenses the first organic fluid that has passed through the first turbine and the second organic fluid that has passed through the second turbine;
An exhaust heat recovery power generator. A first evaporator that evaporates a liquefied first organic fluid by heat obtained from a first heat source;
A second evaporator that evaporates a liquefied second organic fluid by heat obtained from a second heat source having a temperature lower than that of the first heat source;
A turbine driven by the first organic fluid evaporated by the first evaporator and the second organic fluid evaporated by the second evaporator;
A generator for generating electricity by the rotational output of the turbine;
A condenser for condensing the first organic fluid and the second organic fluid that have passed through the turbine;
An exhaust heat recovery power generator. A first heat medium path through which the first heat medium exchanges heat with the first organic fluid in the first evaporator as the first heat source;
A second heat medium path different from the first heat medium path, in which the second heat medium exchanges heat with the second organic fluid in the second evaporator as the second heat source;
The exhaust heat recovery power generator according to any one of claims 1 to 3.   The heat medium that exchanges heat with the first organic fluid in the first evaporator as the first heat source and exchanges heat with the first organic fluid in the first evaporator is the second heat source. The exhaust heat recovery power generator according to any one of claims 1 to 3, further comprising a heat medium path that exchanges heat with the second organic fluid in the second evaporator.   The first heat medium recovers heat with an air cooler that cools compressed air discharged from a supercharger of the internal combustion engine and / or an exhaust gas heat exchanger that exchanges heat with the exhaust gas of the internal combustion engine The exhaust heat recovery power generator according to claim 4, wherein heat recovery is performed and heat exchange is performed with the first organic fluid in the first evaporator.   The second heat medium recovers heat with an exhaust heat recovery device that exchanges heat with engine coolant that cools the internal combustion engine body, and exchanges heat with the second organic fluid with the second evaporator. 6. The exhaust heat recovery power generator according to 6. A ship provided with the exhaust heat recovery power generator according to any one of claims 1 to 7.

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