JPWO2012147246A1 - Marine power generation system - Google Patents

Abstract

  The marine power generation system (100) is driven by a waste heat recovery system (3) that generates steam using the exhaust heat of the supercharged main engine (1), and steam generated in the waste heat recovery system (3). A steam turbo generator (4), temperature detection means (61) for detecting the temperature of the supply or exhaust of the main machine (1), and load detection means for detecting the load of the main machine (1) ( 62), flow rate adjusting means (47) for adjusting the flow rate of the exhaust gas flowing through the bypass passage (46) and the flow rate of the exhaust gas sent to the supercharger (2), and the steam turbo according to the temperature and load And a control means (50) for controlling the flow rate adjusting means (47) so that the generator (4) can generate electric power that is greater than or equal to the power required for inboard use.

Description

  The present invention relates to a marine power generation system in which a generator is driven by a steam turbine, and more particularly to a marine power generation system provided with a waste heat recovery system that generates steam using exhaust heat of a main engine with a supercharger.

  Large ships are equipped with a power generation system that generates the power required during operation. In recent years, in order to meet the demand for energy saving, a waste heat recovery system that recovers waste heat around the main engine and generates steam is added to the ship power generation system, and the steam turbine is driven by the steam generated in the waste heat recovery system. The generator may be driven based on the output of the driving turbine (see, for example, Patent Document 1).

JP 2011-27053 A

  The amount of heat recovered by the waste heat recovery system varies depending on the load on the main engine. That is, the electric power that can be generated by the generator changes according to the load of the main engine. Conventionally, there are generally two approaches as to what specifications to design the waste heat recovery system and the generator in relation to the load of the main engine and the electric power for ship use.

  The first is to design the waste heat recovery system and the generator so that the generator can generate enough power to cover the onboard power demand even when the main engine is operating in a low load range. In this case, if the main engine is operated at the normal output, the generator generates surplus power. In ships used for long-term voyages, the main engine is operated at normal power for most of the period, so unnecessary fuel consumption increases, and the overall size of the system becomes large in relation to the power required for inboard ships. .

  The second is to design the waste heat recovery system and the generator so that the generator generates enough power to cover the power for shipboard when the main engine is operated at normal output. In this case, if the main engine is operated at a partial load, the generator cannot generate enough power to cover the power for shipboard demand. For this reason, it is necessary to increase the amount of steam generated with the combustion of fossil fuels, such as driving up the auxiliary boiler. Thus, even with the second approach, it is difficult to obtain a sufficient energy saving effect by adding the waste heat recovery system to the power generation system.

  In view of this, the present invention aims to make the power generation system for a ship with a waste heat recovery system as wide as possible so that the on-board demand power can be generated without excess or deficiency, thereby minimizing the deterioration of the fuel consumption rate. It is aimed.

  The inventors have found that the amount of heat recovered by the waste heat recovery system changes according to the load of the main engine, and the amount of heat recovered by the waste heat recovery system changes according to the temperature of the supply air or exhaust of the main machine, and the temperature and load. The knowledge that the amount of heat recovered by the waste heat recovery system changes according to the flow rate of the exhaust gas sent to the supercharger even under the same conditions. Therefore, by adjusting the flow rate of the exhaust gas sent to the turbocharger according to the temperature and load, the amount of heat that can be recovered by the waste heat recovery system is kept substantially constant regardless of changes in temperature and load. The idea was that the power generated by the machine could be kept almost constant. The present inventors have invented the following marine power generation system based on such knowledge and ideas.

  That is, a marine power generation system according to the present invention includes a waste heat recovery system that generates steam using exhaust heat of a supercharged main engine, and a generator that is driven by the steam generated in the waste heat recovery system. A temperature detection means for detecting the temperature of the supply or exhaust of the main machine, a load detection means for detecting a load of the main machine, an exhaust passage through which exhaust from the main machine flows, and a connection to the exhaust passage A bypass passage through which the exhaust gas bypasses the supercharger, a flow rate adjusting means for adjusting a flow rate of the exhaust gas flowing through the bypass passage and a flow rate of the exhaust gas sent to the supercharger, and the temperature detection Control means for controlling the flow rate adjusting means so that the generator generates electric power that is equal to or greater than the power for on-board demand according to the temperature detected by the means and the load detected by the load detecting means.

  According to the said structure, according to temperature and load, the flow volume of the exhaust_gas | exhaustion sent to a supercharger and the flow volume of the exhaust gas which bypasses a supercharger are adjusted. And a waste heat recovery system can receive supply of exhaust heat required in order that a generator may generate electric power more than power for inboard use. As described above, according to the present invention, even if the temperature of the supply or exhaust of the main engine changes or the load of the main engine changes, the generator can stably generate electric power that is greater than the power for shipboard use. Will be able to. Therefore, even if the temperature and load change, the situation where surplus power is generated or the auxiliary boiler is operated is reduced, and the deterioration of the fuel consumption rate can be suitably suppressed.

  The temperature detection means includes a temperature of supply air supplied to the supercharger, a temperature of supply air supplied from the supercharger to the main unit, a temperature of exhaust gas supplied from the main unit to the supercharger, Or you may detect the temperature of the exhaust_gas | exhaustion in the inlet_port | entrance of the said waste heat recovery system. According to the said structure, the flow volume adjustment control according to temperature and by extension, stabilization control of generateable electric power can be performed suitably.

  Further, the load detecting means includes a rotation speed of a shaft power system including an output shaft of the main machine and a rotation shaft rotating with the output shaft, a rotation speed of the supercharger, a fuel injection amount to the main machine, or the main machine The flow rate of the exhaust from may be detected. According to the said structure, the flow volume adjustment control according to load and by extension, stabilization control of generateable electric power can be performed suitably.

  The flow rate adjusting means includes an exhaust bypass valve provided on the bypass passage with a variable opening degree, and the control means is configured to allow the generator to generate electric power that is greater than or equal to the power required for inboard ships according to temperature and load. You may control the opening degree of the said exhaust bypass valve so that it may generate | occur | produce. According to the said structure, stabilization control of the electric power which can be generated according to temperature and load can be performed suitably only by controlling the opening degree of an exhaust gas bypass valve.

  Relationship between the temperature and load of the control means and the opening degree of the exhaust bypass valve that can supply the exhaust heat necessary for the generator to generate electric power that is greater than the power required for inboard ships to the waste heat recovery system You may have the memory | storage part which memorize | stored the control rule which prescribed | regulated previously. According to the said structure, the stabilization control of the electric power which can be generated according to temperature and load can be performed suitably.

  In the control rule, a relationship between a load in a load range lower than a normal load and an opening degree of the exhaust bypass valve may be defined. According to the said structure, even if the main machine is drive | operated by partial load, a generator can generate | occur | produce the electric power more than the power for ship use. It is possible to reduce the situation where the auxiliary boiler has to be relegated and improve the fuel consumption rate.

  The control means may increase the opening of the exhaust bypass valve as the temperature is lower. According to the above configuration, even when the amount of exhaust heat supplied to the waste heat recovery system becomes smaller due to a decrease in temperature, the flow rate of exhaust gas that bypasses the turbocharger increases, thereby reducing the amount of exhaust heat due to temperature decrease. Is compensated. Therefore, even if the temperature is lowered, the power that can be generated by the generator is stabilized with power that is equal to or greater than the power for shipboard use.

  The control means may increase the opening of the exhaust bypass valve as the load is lower. According to the above configuration, even when the amount of exhaust heat supplied to the waste heat recovery system becomes smaller due to a decrease in load, the flow rate of exhaust gas that bypasses the turbocharger increases, thereby reducing the amount of exhaust heat due to the decrease in load. Is compensated. Therefore, even if the load is reduced, the power that can be generated by the generator is stabilized with power that is equal to or greater than the power for shipboard use.

  The supercharger-equipped main machine is composed of a first main machine and a second main machine, and the flow rate adjusting means is provided in correspondence with the first main machine and the second main machine, respectively. The flow rate adjusting means is configured, and the control means obtains the electric power that can be generated by using the exhaust heat of the first main engine by half of the electric power for inboard use, and uses the exhaust heat of the second main engine. The first flow rate adjusting means and the second flow rate adjusting means may be controlled such that the generated power that can be generated is half of the power for on-board demand. According to the said structure, a marine power generation system can be mounted in what is called a 2 machine 2 axis type ship, and the deterioration of the fuel consumption rate of the said ship can be suppressed favorably.

  The control means is capable of generating using the exhaust heat of the second main machine when the generated power obtained using the exhaust heat of the first main machine is less than half of the power for on-board demand. The second flow rate adjusting means may be controlled so that the electric power is corrected to increase from half the value of the on-board demand electric power. According to the above configuration, even if the power that can be generated in the main engine falls below a target value (for example, half of the power for onboard demand), the value that can be generated on the other main engine (for example, power for inboard shipping). Half of the power), thereby making up for the shortage of the one possible power generation. For this reason, since it is possible to cover the electric power for inboard use as much as possible by the power generation of the generator, it is possible to favorably suppress the deterioration of the fuel consumption rate.

  According to the present invention, in a marine power generation system to which a waste heat recovery system is added, the situation where the onboard demand power can be generated without excess or deficiency is made as wide as possible, thereby suppressing the deterioration of the fuel consumption rate to the minimum necessary. Can do. The above object, other objects, features, and advantages of the present invention will become apparent from the following detailed description of the preferred embodiments with reference to the accompanying drawings.

1 is a conceptual diagram illustrating an overall configuration of a marine power generation system according to a first embodiment of the present invention. It is a conceptual diagram which shows the structure of the supercharger periphery of the marine power generation system shown in FIG. 1, and the structure of a control system. It is a graph which shows typically an example of the control map memorized by the control map storage part shown in FIG. It is a flowchart which shows an example of the processing content of the control performed by the controller shown in FIG. It is a conceptual diagram which shows the whole structure of the ship electric power generation system which concerns on 2nd Embodiment of this invention. It is a conceptual diagram which shows the structure of the supercharger periphery of the marine power generation system shown in FIG. 5, and the structure of a control system. It is a graph which shows typically an example of the control map memorized by the control map storage part shown in FIG. It is a flowchart which shows an example of the processing content of the control performed by the controller shown in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The same or corresponding elements are denoted by the same reference numerals throughout all the drawings, and the detailed description thereof is omitted. FIG. 1 is a conceptual diagram showing the overall configuration of a marine power generation system 100 according to an embodiment of the present invention. A marine power generation system 100 shown in FIG. 1 is mounted on a marine vessel having a marine diesel engine as a main engine 1. The main machine 1 is provided with a supercharger 2 driven by exhaust.

  The marine power generation system 100 includes a waste heat recovery system 3 and a steam turbo generator 4. The waste heat recovery system 3 recovers the waste heat of the main machine 1 and generates steam. This waste heat mainly includes the exhaust heat of the main machine 1, and also includes the heat of supply or scavenging of the main machine 1. The steam turbo generator 4 includes a steam turbine 5 driven by steam generated in the waste heat recovery system 3 and a generator 6 driven by the steam turbine 5 to generate AC power.

  The waste heat recovery system 3 mainly includes an exhaust gas economizer 10, a condenser 21, a feed water system 22, a feed water heater 23 a and 23 b, a high pressure drum (high pressure steam separator) 24, and an intermediate pressure drum (medium pressure steam separator) 25. , Low pressure drum (low pressure steam separator) 26, high pressure circulating water system 27, steam system 28, medium pressure circulating water system 29, medium pressure mixed water system 30, low pressure circulating water system 31, low pressure evaporator 32 and low pressure mixed gas system 33 is provided.

  The exhaust gas economizer 10 is interposed between the supercharger 2 and the exhaust outlet, and constitutes a part of the exhaust system of the main engine 1. The exhaust system includes a bypass pipe 7 that bypasses the exhaust gas economizer 10. The inlet part of the exhaust gas economizer 10 and the inlet part of the bypass pipe 7 are opened and closed by the first damper 8 and the second damper 9, respectively. By controlling the operation of the first damper 8 and the second damper 9, the flow rate and heat quantity of the exhaust gas supplied to the exhaust gas economizer 10 can be adjusted.

  The exhaust gas economizer 10 includes an inlet pipe 11, a high-pressure evaporator 12, an intermediate pipe 13, an intermediate-pressure evaporator 14, and an outlet pipe 15 in order from the upstream side. The inlet pipe 11 guides the exhaust to the high pressure evaporator 12. The intermediate pipe 13 guides the exhaust gas after heat exchange in the high-pressure evaporator 12 to the intermediate-pressure evaporator 14. The outlet pipe 15 guides the exhaust gas after the heat exchange in the intermediate pressure evaporator 14 to the exhaust outlet.

  The condenser 21 is connected to the steam outlet 5a of the steam turbine 5, and condenses the steam flowing out from the steam outlet 5a. The water supply system 22 connects the condenser 21 to each drum 24-26, and sends the condensate produced | generated by the condenser 21 to each drum 24-26 as water supply. The water supply system 22 has a line 21a extending from the condenser 21 and lines 22b, 22c, and 22d branched from the line 22a. The lines 22b, 22c, and 22d are connected to the high-pressure drum 24, the intermediate-pressure drum 25, and the low-pressure drum 26, respectively. The 1st feed water heater 23a and the 2nd feed water heater 23b are provided in line 22a and line 22b, respectively. The first feed water heater 23a exchanges heat between the feed water sent to each of the drums 24 to 26 and the scavenging of the main machine 1, thereby heating the feed water and cooling the scavenging. The second feed water heater 23b exchanges heat between the feed water sent to the high-pressure drum 24 and the feed air of the main machine 1, thereby heating the feed water and cooling the feed air. Each of the drums 24 to 26 stores feed water as circulating water and stores steam obtained from the circulating water.

  The high-pressure circulating water system 27 includes a line 27 a that connects the high-pressure drum 24 to the high-pressure evaporator 12 and a line 27 b that connects the high-pressure evaporator 12 to the high-pressure drum 24. The steam system 28 connects the high-pressure drum 24 to the steam inlet 5 b of the steam turbine 5. When the pump on the line 27a is operated, the circulating water in the high-pressure drum 24 is sent to the high-pressure evaporator 12 along the line 27a, and the sent circulating water is steamed by heat exchange with the exhaust gas in the high-pressure evaporator 12. It becomes. The circulating water is returned to the high-pressure drum 24 through the line 27 b in a gas-liquid mixed state, and the returned circulating water is separated into vapor and liquid in the high-pressure drum 24. The steam in the high-pressure drum 24 is supplied to the steam inlet 5b through the steam system 28. The intermediate pressure circulating water system 29 includes a line 29 a that connects the intermediate pressure drum 25 to the intermediate pressure evaporator 14, and a line 29 b that connects the intermediate pressure evaporator 14 to the intermediate pressure drum 25. The intermediate pressure mixture system 30 connects the intermediate pressure drum 25 to the intermediate pressure mixture inlet 5 c of the steam turbine 5. When the pump on the line 29a operates, the circulating water in the intermediate pressure drum 25 is sent to the intermediate pressure evaporator 14 via the line 29a, and the sent circulating water exchanges heat with the exhaust gas in the intermediate pressure evaporator 14. It becomes steam. The circulating water is returned to the intermediate pressure drum 25 through the line 29b in a gas-liquid mixed state, and the returned circulating water is separated into vapor and liquid in the intermediate pressure drum 25. The steam in the intermediate pressure drum 25 is supplied to the intermediate pressure mixture inlet 5 c via the intermediate pressure mixture system 30. The low-pressure circulating water system 31 includes a line 31 a that connects the low-pressure drum 26 to the low-pressure evaporator 32, and a line 31 b that connects the low-pressure evaporator 32 to the low-pressure drum 26. The low-pressure mixture system 33 connects the low-pressure drum 26 to the low-pressure mixture inlet 5 d of the steam turbine 5. When the pump on the line 31a operates, the circulating water in the low pressure drum 26 is sent to the low pressure evaporator 32 via the line 31a. In the present embodiment, an air cooler for cooling the supply air is applied to the low-pressure evaporator 32, and the circulating water that is sent becomes steam by heat exchange with the supply air in the low-pressure evaporator 32. The circulating water is returned to the low-pressure drum 26 through the line 31 b in a gas-liquid mixed state, and the returned circulating water is separated into steam and liquid in the low-pressure drum 26. The steam in the low-pressure drum 26 is supplied to the low-pressure mixture inlet 5d through the low-pressure mixture system 33.

  The steam turbine 5 is a multistage steam turbine having a plurality of moving blades. The steam turbine 5 rotates a moving blade by steam and mixed gas supplied to the steam inlet 5b, the medium pressure mixed gas inlet 5c, and the low pressure mixed gas inlet 5d, thereby generating a rotation output on the output shaft. The generator 6 generates AC power according to the output of the steam turbine 5, that is, the flow rate and pressure of the steam and mixed gas supplied to the steam turbine 5.

  The steam system 28 includes an upstream line 28a on the high pressure drum 24 side and a downstream line 28b on the steam turbine 5 side. A superheater 35 is interposed between the upstream line 28a and the downstream line 28b. The steam system 28 further includes a bypass line 28c that bypasses the superheater 35 and connects the upstream line 28a and the downstream line 28b. The waste heat recovery system 3 includes a valve unit 34 that controls whether or not the steam from the high-pressure drum 24 passes through the superheater 35 before being sent to the steam inlet 5b. The valve unit 34 includes a first opening / closing valve 34a that allows or blocks the flow of steam through the bypass line 28c, a second opening / closing valve 34b that allows or blocks the flow of steam through the superheater 35, and an overheating. And a relief valve 34c for partially escaping the steam flowing through the vessel 35. The superheater 35 is provided in the inlet pipe 11 of the exhaust gas economizer 10. When the steam passes through the superheater 35, the steam can be superheated by heat exchange with the exhaust, and thereby the output of the steam turbine 5 can be increased. Further, the low-pressure mixed system 32 includes an inlet valve 36. In accordance with the opening degree of the inlet valve 36, the flow rate of the air-fuel mixture supplied to the low-pressure air-fuel mixture inlet 5d is adjusted. When the inlet valve 36 operates to increase the flow rate of the air-fuel mixture supplied to the low-pressure air-fuel mixture inlet 5d, the output of the steam turbine 5 can be increased.

  The high-pressure drum 24 includes an auxiliary boiler 24a. The auxiliary boiler 24 a can heat the circulating water in the high-pressure drum 24 with heat generated by the combustion of fossil fuel, and thereby generate steam in the high-pressure drum 24. The output of the steam turbine 5 can also be increased by the reheating of the auxiliary boiler 24a. The intermediate pressure drum 25 and the low pressure drum 25 are provided with heaters 25a and 26a, respectively. Each heater 25a, 26a receives the supply of steam from the high-pressure drum 24 via the steam system 28 (see the US mark in FIG. 1), and thereby can heat the circulating water in the drums 25, 26.

  In the following description, the output of the steam turbine 5 generated by the steam generated based only on the recovered waste heat without depending on the reheating of the auxiliary boiler 24a is referred to as “the output of the steam turbine 5 by the waste heat”. The electric power that can be generated by the steam turbo generator 4 when the generator 6 is driven based on the output of the steam turbine 5 due to the waste heat is referred to as “power that can be generated by the steam turbo generator 4 due to waste heat”. There is a case.

  The marine power generation system 1 includes a controller 50. The controller 50 controls the operation of the valve unit 34, the inlet valve 36, the first damper 8, the second damper 9, and the like, and controls the power that can be generated by the steam turbo generator 4 due to waste heat according to the operating state. In particular, the controller 50 according to the present embodiment controls the operation of the exhaust bypass valve 48 provided on the bypass passage 46 that bypasses the supercharger 2 and flows exhaust. The controller 50 controls the flow rate of the exhaust gas sent to the supercharger 2 and the flow rate of the exhaust gas bypassing the supercharger 2 through the control of the exhaust gas bypass valve 48 according to the operating state, and is supplied to the exhaust gas economizer 10. Adjust exhaust temperature and heat. Thereby, even if a change occurs in the operation state, the electric power that can be generated by the steam turbo generator 4 due to waste heat is stably maintained at the in-board demand electric power or a higher value. “In-vessel power demand” as used herein refers to the amount of power required during the navigation of the ship, and the power required temporarily during the navigation of the ship (so-called continuous power). It is the amount of electric power obtained by adding the amount. Note that the temporarily required power amount is generated when starting a compressor of a refrigeration apparatus mounted on a ship.

  FIG. 2 is a conceptual diagram showing the configuration around the supercharger and the configuration of the control system of the marine power generation system 100 shown in FIG. As shown in FIG. 2, an air supply passage 41 and an exhaust passage 42 are connected to the main engine 1. The air supply passage 41 is a passage for sending the air supplied from the intake port and supercharged by the supercharger 2 to a combustion chamber (not shown) of the main engine 1. The exhaust passage 42 is a passage through which exhaust from a combustion chamber (not shown) of the main engine 1 flows. The supercharger 2 includes a turbine 43 provided on the exhaust passage 42, a compressor 44 provided on the air supply passage 41, and a rotor 45 that connects the turbine 43 and the compressor 44 to rotate integrally. ing.

  The bypass passage 46 described above is connected to the exhaust passage 42 so as to bypass the supercharger 2. That is, the upstream end portion of the bypass passage 46 is connected to the upstream side of the turbine 43 in the exhaust passage 42. The downstream end of the bypass passage 46 is connected to the downstream side of the turbine 43 in the exhaust passage 42 and upstream of the branch point between the passage toward the exhaust gas economizer 10 and the passage toward the bypass pipe 7. . For this reason, in the bypass passage 46, the exhaust flows around the supercharger 2, and the exhaust can be supplied to the exhaust gas economizer 10.

  The bypass passage 46 is provided with a flow rate adjusting means 47 for adjusting the flow rate of the exhaust gas flowing through the bypass passage 46 and the flow rate of the exhaust gas sent to the supercharger 2. In other words, the flow rate adjusting means 47 adjusts the ratio of the flow rate of the exhaust gas flowing through the bypass passage 46 to the total flow rate of the exhaust gas from the main engine 1. Hereinafter, this ratio will be referred to as “supercharger bypass rate”.

  The flow rate adjusting means 47 includes an exhaust bypass valve 48 provided on the bypass passage 46 so as to have a variable opening, and an orifice 49 provided on the bypass passage 46. When the opening degree of the exhaust bypass valve 48 increases, the supercharger bypass rate increases. That is, by adjusting the opening degree of the exhaust bypass valve 48, the flow rate of the exhaust gas flowing through the bypass passage 46 is adjusted, and the flow rate of the exhaust gas sent to the supercharger 2 is passively adjusted. The orifice 49 is a factor that restricts the supercharger bypass rate from exceeding a certain value, and functions as a limiter for the supercharger bypass rate. Thereby, exhaust can be appropriately sent to the supercharger 2, and the output of the main engine 1 can be prevented from undesirably decreasing. In FIG. 2, the orifice 49 is disposed on the downstream side of the exhaust bypass valve 48, but may be disposed on the upstream side of the exhaust bypass valve 48.

  The controller 50 is a microcomputer mainly composed of a CPU, a ROM, a RAM, and an input / output interface. The input side of the controller 50 is connected to a temperature sensor 61 and a supercharger rotation speed sensor 62. The temperature sensor 61 detects the temperature of the supply air flowing toward the supercharger 2 along the supply passage 41. The supercharger rotational speed sensor 62 detects the rotational speed of the supercharger 2. As described above, the output side of the controller 50 is connected to the exhaust bypass valve 48, the first damper 8, the second damper 9, and the auxiliary boiler 24a. The ROM of the controller 50 stores a control program. The CPU of the controller 50 executes a control program stored in advance in the ROM, and the exhaust bypass valve 48, the first damper 8, the second damper 9, and the auxiliary depending on the temperature of the supply air of the main machine 1 and the load of the main machine 1. The boiler 24a is operated, thereby controlling the supercharger bypass rate and the electric power generated by the steam turbo generator 4.

  The controller 50 includes a temperature measurement unit 51, a load measurement unit 52, a control map storage unit 53, a bypass rate calculation unit 54, a bypass valve control unit 55, a damper control unit 56, and an auxiliary boiler as functional units that execute such control. A control unit 57 is provided.

  The temperature measuring unit 51 measures the temperature of the supply air of the main machine 1 according to the input from the temperature sensor 61. The load measuring unit 52 measures the load of the main engine 1 according to the input from the supercharger rotation speed sensor 62. The load measurement value measured by the load measurement unit 52 is, for example, a percentage with the rated load being 100%. The control map storage unit 53 is necessary so that the supply air temperature of the main engine 1 and the load of the main engine, and the electric power that can be generated by the steam turbo generator 4 due to waste heat become a target generated electric power that is a value that is equal to or greater than the electric power for shipboard demand The control map 65 (refer FIG. 3) which prescribed | regulated the corresponding relationship between the supercharger bypass rate made into it is memorize | stored. The bypass rate calculation unit 54 calculates the calculated value of the supercharger bypass rate according to the temperature of the supply air of the main unit 1 measured by the temperature measurement unit 51 and the load of the main unit 1 measured by the load measurement unit 52. To derive. The bypass valve control unit 55 controls the exhaust bypass valve 48 according to the calculated value of the supercharger bypass rate. The damper control unit 56 controls the first damper 8 and the second damper 9 according to the calculated value of the turbocharger bypass rate. The auxiliary boiler control unit 57 controls the auxiliary boiler 24a according to the calculated value of the supercharger bypass rate.

  FIG. 3 is a graph schematically showing an example of the control map 65 stored in the control map storage unit shown in FIG. The lower side of FIG. 3 is a graph schematically showing the control map 65. The upper side of FIG. 3 is a graph for explaining how the control map 65 is derived. Each graph is represented in a two-dimensional orthogonal coordinate system, and the horizontal axis of each graph is a percentage of the main engine load with the rated load being 100%. The vertical axis of the control map 65 is the turbocharger bypass rate as shown on the right side of FIG. The vertical axis of the explanatory graph is the electric power that can be generated by the steam turbo generator 4 as shown on the left side of FIG. The thin line represents the case where the supply air temperature T is T1, the broken line represents the case where the supply air temperature T is T2, and the thick line represents the case where the supply air temperature T is T3. T1, T2 And T3 satisfy the relationship: T1 <T2 <T3. Note that T1 may be, for example, 25 degrees Celsius based on the international standard. The line through which the diamond-shaped plot (♦) passes is when the turbocharger bypass rate is 0%, and the line through which the round plot (●) passes is when the turbocharger bypass rate is the maximum value. Each represents. As described above, the maximum value is mechanically determined according to the specification of the orifice 49. The line through which the square plot (■) passes, the line through which the triangular plot (▲) passes, and the line through which the cross plot (x) passes are between the supercharger bypass rate of 0% and the maximum value The case of taking the value of is shown respectively.

  With reference to the explanatory graph shown on the upper side of FIG. 3, the change in the electric power that can be generated by the steam turbo generator 4 according to the change in the operation state will be described. As can be seen by referring to any one of the plurality of lines constituting the explanatory graph, the higher the load, the more the electric power that can be generated by the steam turbo generator 4 under the same temperature and the same turbocharger bypass rate conditions. Get higher. This is because the higher the load on the main engine 1, the higher the flow rate of the exhaust gas, and the corresponding amount of heat that can be recovered by the waste heat recovery system 3. As can be seen by comparing the lines constituting the explanatory graph, the tendency of the change in the power that can be generated by the steam turbo generator 4 according to the change in the load is less dependent on the temperature and the turbocharger bypass rate. It is almost the same regardless of temperature and turbocharger bypass rate.

  As can be seen by comparing lines through which the same shape plot passes among the plurality of lines constituting the explanatory graph, under the same load and the same turbocharger bypass rate conditions, the higher the temperature of the supply air, the higher the steam turbo. The electric power that can be generated by the generator 4 increases. This is probably because the temperature and amount of heat of the exhaust gas supplied to the exhaust gas economizer 10 depend on the temperature of the supply air. As can be seen by comparing lines of the same line type among a plurality of lines constituting the explanatory graph, the higher the turbocharger bypass rate, the more the turbo turbo generator 4 can be generated under the same temperature and the same load condition. The power becomes high. It is considered that the heat loss of the exhaust gas until it is supplied to the exhaust gas economizer 10 is smaller when the turbocharger 2 is bypassed than when the turbocharger 2 is routed.

  Conventionally, in general, in a marine power generation system to which a waste heat recovery system is added, the rated output of the steam turbo generator 4 is set to a value higher than the electric power for ship use. When the main engine 1 is operated at a normal output (80 to 90% load) and the temperature of the supply air is a predetermined temperature (for example, 25 degrees Celsius according to the international standard), the steam turbo due to waste heat is used. The specifications of the waste heat recovery system 3 and the steam turbo-generator 4 are designed so that the electric power that can be generated by the generator 4 can cover the power required for shipboard. Conventionally, if the main engine 1 is operated at less than the normal output, the power that can be generated by the steam turbo generator 4 due to waste heat cannot cover the power for onboard demand, and the auxiliary boiler 24a needs to be replenished immediately. Yes. Further, when the main engine 1 is operated at a normal output, the steam turbo generator 4 generates surplus power if the temperature of the supply air becomes higher than the predetermined temperature. In this way, when the operating state changes, the power that can be generated by the steam turbo generator 4 due to waste heat changes, and the power for shipboard demand tends to be excessive or insufficient.

  On the other hand, according to the present embodiment, not only the load but also the temperature and the turbocharger bypass rate are based on the knowledge that the power that can be generated by the steam turbo generator 4 due to waste heat is a factor that affects the temperature. And a correspondence relationship showing how the supercharger bypass rate changes when the load changes and the power that can be generated by the steam turbo-generator 4 due to waste heat becomes the target generated power that is greater than or equal to the power demanded in the ship. The control map 65 that defines the derived correspondence relationship is stored in the control map storage unit 53 in advance.

  An example of the procedure for deriving this correspondence will be described along with what this correspondence is. First, the diagram shown on the upper side of FIG. 3 is obtained. That is, the temperature and the turbocharger bypass rate are fixed, and the power that can be generated by the steam turbo generator 4 due to waste heat with respect to the load is analyzed. This analysis is performed multiple times with different values of temperature and turbocharger bypass rate. The analysis may be based on data calculated by numerical simulation, or may be based on data acquired from an actual machine. As a result of the analysis, in the two-dimensional orthogonal coordinate system in which the horizontal axis represents the load and the vertical axis represents the power that can be generated by the steam turbogenerator 4 due to waste heat, a plurality of rising lines can be obtained (FIG. 3). See above). Of course, the trend and position of the obtained line vary depending on the specifications of the main engine 1, the supercharger 2, the waste heat recovery system 3, and the steam turbo generator 4.

  Then, for each of the obtained lines, a load value for obtaining the target generated power is derived. Then, the supercharger bypass rate is plotted against the derived load value in a two-dimensional orthogonal coordinate system with the horizontal axis representing the load and the vertical axis representing the supercharger bypass rate (see the lower side of FIG. 3). And the correspondence of the supercharger bypass rate with respect to load is derived | led-out using the plot under the same temperature conditions. This correspondence can be expressed by approximating a straight line with a downward slope. That is, when the turbocharger bypass rate changes approximately linearly according to the load change under the condition where the temperature is fixed, the power that can be generated by the steam turbo generator 4 is maintained at the target generated power. When different temperature conditions are compared, the slopes of the approximate lines are substantially the same (see the lower side of FIG. 3). That is, the correspondence relationship between the load and the supercharger bypass rate under another temperature condition can be derived by simply translating the approximate straight line under a certain temperature condition in the horizontal axis direction. Therefore, if approximate straight lines are derived under some temperature conditions, the supercharger bypass rate necessary for maintaining the power that can be generated by the steam turbo-generator 4 due to waste heat at the target generated power is determined by the load and temperature. Equation (1) can be derived according to the following.

Y = aX + f (T) (1)
Here, a is the slope of the approximate line, T is the temperature, X is the load, and Y is the turbocharger bypass rate. f (T) is a correction term of the approximate line, and takes into account the parallel movement amount of the approximate line in the horizontal axis direction according to the temperature, taking the inclination a into consideration. If the load X and the temperature T are determined according to the above formula (1), the supercharger bypass rate Y necessary for maintaining the power that can be generated by the steam turbo generator 4 due to waste heat at the target generated power is derived. Can do. Since the slope a is a negative value, the supercharger bypass rate Y increases as the load decreases. Further, the lower the temperature T, the larger the supercharger bypass rate Y. However, the supercharger bypass rate Y cannot take a value less than zero, and cannot take a value larger than the maximum value MAX defined by the orifice 49. Therefore, the controller 50 controls the exhaust bypass valve 48, the dampers 8, 9 and the auxiliary boiler 24a as follows according to the calculated value of the supercharger bypass rate Y.

  FIG. 4 is a flowchart showing an example of the processing contents of the control executed by the controller 50 shown in FIG. The process shown in FIG. 4 is repeatedly executed at a predetermined cycle during navigation. As shown in FIG. 4, first, the temperature measurement unit 51 measures the temperature T in response to an input from the temperature sensor 61 (step S1). Next, the load measuring unit 52 measures the load of the main machine 1 in accordance with the input from the supercharger rotation speed sensor 62 (step S2). Next, the bypass rate calculation unit 54 refers to the control map 65 stored in the control map storage unit 53 according to the temperature measured by the temperature measurement unit 51 and the load measured by the load measurement unit 52. Then, the supercharger bypass rate Y necessary for the electric power that can be generated by the steam turbo generator 4 due to waste heat to be the target generated electric power is calculated (step S3). Next, the bypass rate calculation unit 54 determines whether or not the calculated value of the turbocharger bypass rate is greater than the maximum value MAX defined by the orifice and is less than zero (step S4). , S5).

  If the calculated value is greater than or equal to zero and less than or equal to the maximum value MAX (S4: NO, S5: NO), the bypass valve control unit 55 opens the exhaust bypass valve 48 according to the calculated value of the turbocharger bypass rate. And the opening degree of the exhaust bypass valve 48 is controlled so as to be the calculated value (step S6).

  Thus, according to the marine power generation system 100 according to the present embodiment, the calculated value of the turbocharger bypass rate Y calculated according to the equation (1) is not less than zero and satisfies the maximum value MAX or less. Can maintain the power that can be generated by the steam turbo-generator 4 due to waste heat at the target generated power. In an operating state that satisfies this condition, the electric power that can be generated by the steam turbo generator 4 does not become excessively larger than the electric power for on-board demand, so that it is possible to suppress unnecessary deterioration of the fuel consumption rate. In this embodiment, the load on the main engine 1 when the turbocharger bypass rate Y takes the maximum value MAX is the load at the normal output under any of the three conditions where the temperature T is T1, T2 or T3. It is less than XN (see FIG. 3). In this way, the operating range in which the power that can be generated by the steam turbo-generator 4 can cover the power for on-board demand can be expanded to a lower load side than the regular output XN without refueling the auxiliary boiler 24a. The deterioration of the consumption rate can be suppressed satisfactorily.

  If the calculated value Y is less than zero (S5: YES), the bypass valve control unit 55 fully closes the opening degree of the exhaust bypass valve 48 (step S7). Thereby, the supercharger bypass rate becomes zero. However, if it remains as it is, the power that can be generated by the steam turbo generator 4 due to waste heat exceeds the power for on-board demand. Therefore, the damper control unit 57 controls the dampers 8 and 9 according to the deviation between the calculated value Y and zero (step S8). For example, as the deviation is larger, the first damper 8 and the second damper 9 are controlled such that the opening degree of the second damper 9 becomes larger and / or the opening degree of the first damper 8 becomes smaller. Thereby, it is possible to avoid the steam turbo generator 4 from generating surplus power. In FIG. 3, examples of operation regions where the calculated value Y is less than zero are represented by P1 and P2. P1 represents a load range where the calculated value of the turbocharger bypass rate Y is less than zero when the temperature is T3, and P2 is a calculation of the turbocharger bypass rate Y when the temperature is T2. Represents the range of loads where the value is less than zero.

  If the calculated value Y is larger than the maximum value MAX (S4: YES), the bypass valve control unit 55 controls the opening degree of the exhaust bypass valve 48 to be fully opened (step S9). Thereby, the supercharger bypass rate becomes the maximum value MAX defined by the orifice 49. However, in this state, the power that can be generated by the steam turbo generator 4 due to waste heat cannot cover the power for on-board demand. Therefore, the auxiliary boiler control unit 46 replenishes the auxiliary boiler 24a in order to compensate for the shortage of electric power (step S10). The amount of heat generated by the auxiliary boiler 24a may be determined according to the deviation between the calculated value and the maximum value. By doing in this way, when the auxiliary boiler 24a is retreated, it is possible to suppress as much as possible the generation of surplus power exceeding the power for on-board demand, and wasteful fuel consumption can be suppressed satisfactorily. In FIG. 3, an example of the operation region where the calculated value Y is larger than the maximum value MAX is represented by Q1 and Q2. Q1 represents a load range in which the calculated value of the turbocharger bypass rate Y is greater than the maximum value MAX when the temperature is T1, and Q2 is the turbocharger bypass rate when the temperature is T2. This represents a load range in which the calculated value of Y is greater than the maximum value MAX.

  As described above, according to the present embodiment, it is possible to expand the operating range in which the power that can be generated by the steam turbo generator due to waste heat is maintained at a value that is greater than or equal to the power for shipboard use, and the deterioration of the fuel consumption rate is improved. Can be suppressed.

  The graph representing the control map 65 shown on the lower side of FIG. 3 can be created based on the graph shown on the upper side of FIG. 3. The trend and position of the graph on the upper side of FIG. Depending on the specifications of the waste heat recovery system 3 and the steam turbo generator 4. In other words, if the specifications of the main engine 1 and the supercharger 2 are determined, the waste heat recovery system 3 and the steam turbo generator are set so that the graph shown in the lower part of FIG. 4 specifications can be adjusted. That is, based on the optimized control map 65 based on the design concept that makes optimization of the control map 65 shown at the bottom of FIG. 3 primary, the waste heat recovery system 3 and the steam turbo generator 4 It becomes possible to design the specifications in reverse calculation. Thus, the control map 65 is also very useful as a tool for supporting the design of the waste heat recovery system 3 and the steam turbo generator 4.

  The temperature of the supply air largely depends on the use situation of the ship. Therefore, in a ship that is expected to have many opportunities to navigate in the high latitude band, a graph shown in the lower part of FIG. 3 so that the steam turbo generator 4 can cover the power for on-board demand even when the temperature of the supply air is low. Is preferably shifted to the left. Conversely, in a ship that is expected to have many opportunities to navigate in the low-latitude zone, there are few opportunities for the temperature of the supply air to decrease, so the graph shown in the lower part of FIG. 3 can be shifted to the right. In this way, it is possible to design the specifications of the waste heat recovery system 3 and the steam turbo generator 4 in reverse calculation after determining the specifications of the control map 65 on the lower side of FIG. Therefore, the specification of the marine power generation system 100 can be easily and optimally designed according to the usage situation assumed for the ship to be mounted.

  As described above, the operation range in which the steam turbo generator 4 covers the power for inboard ships can be expanded to the low load side, and the specifications of the main engine 1 and the supercharger 2 and the optimum control map 65 are eliminated. In light of the fact that the specifications of the heat recovery system 3 and the steam turbo-generator 4 can be optimally calculated in reverse calculation, it has been difficult to install a marine power generation system with a waste heat recovery system. Such a ship power generation system can be easily applied to a relatively small ship. Thereby, energy saving in the marine industry can be widely promoted.

  FIG. 5 is a conceptual diagram showing an overall configuration of a marine power generation system 200 according to the second embodiment of the present invention. This embodiment is suitably applied to a ship equipped with a so-called two-machine two-axis propulsion system. Hereinafter, the ordinal number “first” may be added to the name of the component corresponding to one main machine 1A, and “A” may be added to the reference number of the component. In some cases, an ordinal number “second” is added to the name of the component corresponding to the other main engine 1B, and “B” is added to the reference number of the component.

  As shown in FIG. 5, the power generation system 200 according to the present embodiment is mounted on a ship including two main engines 1 </ b> A and 1 </ b> B, and includes a waste heat recovery system 203 and a steam turbo generator 204. The steam turbo generator 204 is substantially the same as that of the first embodiment, and one steam turbine 205 driven by the steam generated in the waste heat recovery system 203, and the steam turbine 205 driven by the steam turbine 205 is AC. And one generator 206 that generates electric power. Two main engines 1A and 1B are provided with superchargers 2A and 2B and an exhaust system, respectively. Each exhaust system includes exhaust gas economizers 10A and 10B, bypass pipes 7A and 7B, exhaust passages 42A and 42B, and bypass passages 46A and 46B in the same manner as the exhaust system of the first embodiment. Each exhaust gas economizer 10A, 10B has an inlet pipe 11A, 11B, a high pressure evaporator 12A, 12B, an intermediate pipe 13A, 13B, an intermediate pressure evaporator 14A, 14B, and an outlet pipe 15A, 15B, as in the first embodiment. I have.

  The waste heat recovery system 203 includes exhaust gas economizers 10A and 10B, a high pressure drum (high pressure steam separator) 224, an intermediate pressure drum 225, a high pressure circulating water system 227, a steam system 228, an intermediate pressure circulating water system 229, and an intermediate pressure mixed gas system. 230 is provided. Although not shown in FIG. 5 for convenience of explanation, the waste heat recovery system 203 is similar to the first embodiment in that the condenser, the feed water system, the feed water heater, the low pressure drum, the low pressure circulating water system, and the low pressure mixing system. It has a qi system. The high-pressure drum 224 is substantially the same as that of the first embodiment, and includes an auxiliary boiler 224a. The intermediate pressure drum 225 is substantially the same as that of the first embodiment.

  The high-pressure circulating water system 227 includes a line 227a that connects the high-pressure drum 224 to the first high-pressure evaporator 12A of the first exhaust gas economizer 10A, a line 227b that connects the first high-pressure evaporator 12A to the high-pressure drum 224, and a line 227a. It has a line 227c that branches and connects to the second high-pressure evaporator 12B of the second exhaust gas economizer 10B, and a line 227d that connects the second high-pressure evaporator 12B to the high-pressure drum 224. As described above, the high-pressure circulating water system 227 of the high-pressure drum 224 connects the first high-pressure evaporator 12A and the second high-pressure evaporator 12B to the high-pressure drum 224 in parallel.

  The steam system 228 includes a line 228 a extending from the high-pressure drum 224, a line 228 b branched from the line 228 a, and a line 228 c formed by a combination of the lines 228 a and 228 b, and the line 228 c is connected to the steam inlet of the steam turbine 205. Has been. A first superheater 35A and a second superheater 35B are connected to the lines 228a and 228b, respectively.

  When the pump on the line 227a is operated, a part of the circulating water in the high-pressure drum 224 is sent to the first high-pressure evaporator 12A via the line 227a, and the sent circulating water is sent in the first high-pressure evaporator 12A. It becomes steam by heat exchange with exhaust gas. The circulating water is returned to the high-pressure drum 224 through the line 227b in a gas-liquid mixed state. In addition, a part of the circulating water in the high-pressure drum 224 is sent to the second high-pressure evaporator 12B via the line 227c, and the sent circulating water is vaporized by heat exchange with the exhaust gas in the second high-pressure evaporator 12B. It becomes. The circulating water is returned to the high-pressure drum 224 via the line 227d in a gas-liquid mixed state. A part of the steam in the high-pressure drum 224 is supplied to the steam inlet of the steam turbine 205 via the line 228a and the line 228c. A part of the steam in the high-pressure drum 224 is supplied to the steam inlet of the steam turbine 205 via the line 228b and the line 228c.

  The intermediate pressure circulating water system 229 includes a line 229a that connects the intermediate pressure drum 225 to the first intermediate pressure evaporator 14A of the first exhaust gas economizer 10A, and a line 229b that connects the first low pressure evaporator 14A to the intermediate pressure drum 225. , A line 229c branched from the line 229a and connected to the second intermediate pressure evaporator 14B of the second exhaust gas economizer 10B, and a line 229d connecting the second intermediate pressure evaporator 14B to the intermediate pressure drum 225. . Thus, the intermediate pressure circulating water system 229 connects the first intermediate pressure evaporator 14A and the second intermediate pressure evaporator 14B to the intermediate pressure drum 225 in parallel. When the pump on the line 229a operates, the circulating water in the intermediate pressure drum 225 becomes steam in the first intermediate pressure evaporator 14A or the second intermediate pressure evaporator 14B in the same manner as the high pressure circulating water system 227, and the circulating water Returns to the intermediate pressure drum 225 in a gas-liquid mixed state. The medium pressure mixed system 230 is substantially the same as that of the first embodiment. The steam in the intermediate pressure drum 225 is supplied to the intermediate pressure mixture inlet of the steam turbine 205 through the intermediate pressure mixture system 230.

  Thus, in the present embodiment, the exhaust heat from the two main engines 1A and 1B is individually recovered by the two exhaust gas economizers 10A and 10B. Two exhaust gas economizers 10A and 10B are connected in parallel to a single high-pressure drum 224 via a high-pressure circulating water system 227, and are connected in parallel to a single medium-pressure drum 225 via an intermediate-pressure circulating water system 229. ing. With this configuration, the configuration of the waste heat recovery system 203 can be made compact as compared with the case where the set of the high-pressure drum 224 and the intermediate-pressure drum 225 is individually provided in the two exhaust gas economizers 10A and 10b. Although not shown in the figure, the low-pressure circulating water system also has two low-pressure evaporators individually provided in the main machines 1A and 1B connected in parallel to the low-pressure drum, and has the same effect.

  FIG. 6 is a conceptual diagram showing the configuration around the superchargers 2A and 2B and the configuration of the control system of the marine power generation system 200 shown in FIG. As shown in FIG. 6, air supply passages 41A and 41B and exhaust passages 42A and 42B are connected to the two main engines 1A and 1B, respectively. Each of the superchargers 2A and 2B includes turbines 43A and 43B provided on the exhaust passages 42A and 42B, compressors 44A and 44B provided on the supply passages 41A and 41B, turbines 43A and 43B, and compressors 44A, And rotors 45A and 45B that connect 44B and rotate integrally. Bypass passages 46A and 46B are connected to the exhaust passages 42A and 42B, respectively. The bypass passages 46A and 46B are provided with flow rate adjusting means 47A and 47B, and each of the flow rate adjusting means 47A and 47B includes exhaust bypass valves 48A and 48B and orifices 49A and 49B.

  The input side of the controller 250 is connected to the first temperature sensor 61A, the second temperature sensor 61B, the first supercharger rotation speed sensor 62A, and the second supercharger rotation speed sensor 62B. The first temperature sensor 61A detects the temperature of air supply toward the first supercharger 2A, and the second temperature sensor 61B detects the temperature of air supply toward the second supercharger 2B. The first supercharger rotational speed sensor 62A detects the rotational speed of the first supercharger 2A, and the second supercharger rotational speed sensor 62B detects the rotational speed of the second supercharger 2B. The output side of the controller 250 is connected to the first exhaust bypass valve 48A, the second exhaust bypass valve 48B, the auxiliary boiler 224a (see FIG. 5), and the like. The output side of the controller 250 includes a damper 8A corresponding to the first exhaust gas economizer 10A, a damper 9A corresponding to the first bypass pipe 7A, a damper 8B corresponding to the second exhaust gas economizer 10B, and a damper 9B corresponding to the second bypass pipe 7B. Also connected to.

  The controller 250 controls the first exhaust bypass valve 48A and the second exhaust bypass valve 48B according to the temperature of the supply air of each main machine 1A, 1B and the load of each main machine 1A, 1B, and thereby the supercharger bypass rate. And the electric power generated by the steam turbo generator 204 is controlled. As a functional unit that executes such control, the controller 250 is a temperature measuring unit 251, a load measuring unit 252, a control map storage unit 253, a bypass rate calculating unit 254, and a bypass valve control unit, as in the first embodiment. 255, a damper control unit 256, and an auxiliary boiler control unit 257.

  FIG. 7 is a graph schematically showing an example of the control map 265 stored in the control map storage unit 253 shown in FIG. The bypass rate calculation unit 254 refers to the control map 265 shown in FIG. 7 and determines the turbocharger bypass rate for each of the two main engines 1A and 1B (for each of the two exhaust bypass valves 48A and 48B) according to the temperature and load. Is calculated. By referring to the control map 265, the controller 250 can generate electric power that can be generated by waste heat from the first main machine 1A (hereinafter referred to as first electric power that can be generated) corresponding to half of the electric power for ship use, and the second main machine 1B. The opening degree of the exhaust bypass valves 48A and 48B is controlled so that the electric power that can be generated by the waste heat from the engine (hereinafter, the second electric power that can be generated) corresponds to half of the electric power for shipboard. That is, in the present embodiment, the opening degrees of the two exhaust bypass valves 48A and 48B are independently controlled while using the common control map 265, whereby the electric power that can be generated by the waste heat of the main engines 1A and 1B. Is divided into half of the onboard demand electric power Wd, and the electric power that can be generated by the waste heat of the two aircraft as a whole is used as the onboard demand electric power Wd.

  FIG. 8 is a flowchart showing the control contents executed by the controller 250 shown in FIG. The process shown in FIG. 8 is repeatedly executed at a predetermined cycle during navigation. As shown in FIG. 8, first, the temperature measurement unit 251 measures the supply air temperature T1 corresponding to the first supercharger 2A in response to the input from the first temperature sensor 61A, and the second temperature sensor 61B In response to the input, the supply air temperature T2 corresponding to the second supercharger 2B is measured (step S101). Next, the load measuring unit 252 measures the load X1 of the first main engine 1A according to the input from the first supercharger rotation speed sensor 62A, and according to the input from the second supercharger rotation speed sensor 62B. The load X2 of the second main machine 1B is measured (step S102).

  Next, the bypass rate calculation unit 254 refers to the control map 265, and refers to the control map 265. The first required power W1 is set to be equal to or more than half of the onboard demand power Wd according to the supply air temperature T1 and the load X1. One turbocharger bypass rate Y1 is calculated (step S103). Further, the bypass rate calculation unit 254 refers to the control map 256, and the second necessary power for making the second generateable power W2 more than half of the onboard demand power Wd according to the supply air temperature T2 and the load X2. A supercharger bypass rate Y2 is calculated (step S103).

  Next, the bypass rate calculation unit 254 determines whether or not the sum of the first generateable power W1 and the second generateable power W2 has reached the shipboard demand power Wd (step S104). If it has reached (S104: YES), auxiliary machinery such as the auxiliary boiler 224a and the diesel generator is stopped, and the first supercharger bypass rate Y1 and the second supercharger bypass rate Y2 are the values obtained in step S103, respectively. Thus, the first exhaust bypass valve 48A and the second exhaust bypass valve 48B are each driven (step S105). Thereby, the electric power which can be generated by the waste heat from the two main engines 1A and 1B can cover the electric power for onboard use.

  If not reached (S104: NO), it is determined whether or not the first possible power W1 is less than half of the onboard demand power Wd and the second possible power W2 is less than half of the onboard demand power Wd. (Step S106). If only one of them is less than half (S106: YES), it is determined whether it is the first generateable power W1 or the second generateable power W2 (step S107).

  Note that, when the first possible power W1 is less than half of the onboard demand power Wd, the first supercharger bypass rate Y1 has reached the maximum value MAX defined by the orifice 49A, This means that the first generateable power W1 cannot cover half of the onboard demand power Wd. Therefore, when the first possible electric power W1 cannot cover half of the onboard demand electric power Wd, there is already no room for increasing the opening of the first exhaust bypass valve 48A. The same can be said for the second possible electric power W2.

  If the first generateable power W1 is less than half of the onboard demand power Wd and the second generateable power W2 is less than half of the onboard demand power Wd (S106: YES), the two main engines 1A and 1B as a whole Since the electric power that can be generated due to the waste heat cannot cover the power Wd for shipboard, the auxiliary machine is driven to compensate for the shortage (step S108).

  If the first generateable power W1 is less than half of the onboard demand power Wd and the second generateable power W2 reaches half of the onboard demand power Wd (S106: NO, S107: YES), the second The supercharger bypass rate Y2 is increased from the value obtained in step S103 (step S109). As a result, the second generateable power W2 increases from a half value of the onboard demand power Wd, thereby making up for the shortage of the first generateable power W1. Next, it is determined whether or not the sum of the first generateable power W1 and the second generateable power W2 after the increase correction has reached the shipboard demand power Wd (step S110). If it has reached, the process proceeds to step S105, and the steam turbo generator is driven with the auxiliary machine stopped. If not, it is determined whether or not the second supercharger bypass rate Y2 has reached the maximum value MAX (that is, whether or not there is still room for increasing the second possible electric power W2) (step). S111). If the maximum value MAX has not been reached (S111: NO), the process returns to step S109, the second supercharger bypass rate Y2 is further increased, and the process is repeated. If the maximum value MAX has been reached (S111: YES), the process proceeds to step S108, and the accessory is driven to compensate for the shortage.

  If the second generateable power W1 is less than half of the onboard demand power Wd while the first generateable power W2 reaches half of the onboard demand power Wd (S106: NO, S107: NO), the same as described above. This process is performed by switching the first supercharger bypass rate and the second supercharger bypass rate (steps S112 to S114). That is, the shortage of the second generateable power W2 is compensated as much as possible by increasing correction of the first generateable power W1 (enlargement correction of the first supercharger bypass rate Y1). If the sum of the first possible power W1 and the second possible power W2 is less than the ship demand power Wd even when the first possible power W1 is corrected to increase to the maximum (S114: NO), The shortage is made up by driving the auxiliary equipment.

  As described above, according to the present embodiment, even if the power that can be generated by waste heat from one main machine is lower than the target value (half of the power for inboard use), the power that can be generated by waste heat from the other main machine. Can be increased from the target value (half of the onboard power demand), thereby making up for the shortage of the one possible power generation. For this reason, since the steam turbo generator 204 can cover the power for on-board demand with the auxiliary machine stopped as much as possible, the deterioration of the fuel consumption rate can be satisfactorily suppressed.

  From the foregoing description, many modifications and other embodiments of the present invention are obvious to one skilled in the art. Accordingly, the foregoing description is to be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the preferred mode of carrying out the invention. The details of the structure and / or function can be substantially changed without departing from the spirit of the invention. For example, the temperature sensor is not limited to the one that detects the temperature of the supply air supplied to the supercharger 2, but the temperature of the supply air supplied from the supercharger 2 to the main unit 1, Or the temperature of the exhaust gas at the inlet of the waste heat recovery system 3 (inlet of the exhaust gas economizer 10) may be detected. The load of the main machine 1 is not limited to that measured based on the rotation speed of the supercharger, but the rotation speed of the shaft power system including the output shaft of the main machine 1 and the rotation shaft rotating with the output shaft, It may be measured based on the fuel injection amount and the flow rate of exhaust from the main engine 1.

  The control map 65 may be in any form as long as it is a control rule that defines the correspondence relationship between the turbocharger bypass rate with respect to temperature and load, as shown in FIG. It is not limited to an arithmetic expression representing a graph, but may be a form such as a lookup table.

  In the marine power generation system to which the waste heat recovery system is added, the present invention can make the situation where the onboard demand power can be generated without excess or deficiency as much as possible, thereby suppressing the deterioration of the fuel consumption rate to the minimum necessary. And can be widely used for ships equipped with a supercharged main engine.

DESCRIPTION OF SYMBOLS 100 Marine power generation system 1 Main engine 2 Supercharger 3 Waste heat recovery system 4 Steam turbo generator 41 Supply passage 46 Bypass passage 47 Flow rate adjusting means 48 Exhaust bypass valve 50 Controller 51 Temperature measurement section 52 Load measurement section 53 Control map storage section 61 Temperature sensor 62 Turbocharger speed sensor 65 Control map

The condenser 21 is connected to the steam outlet 5a of the steam turbine 5, and condenses the steam flowing out from the steam outlet 5a. The water supply system 22 connects the condenser 21 to each drum 24-26, and sends the condensate produced | generated by the condenser 21 to each drum 24-26 as water supply. The water supply system 22 has a line 22a extending from the condenser 21 and lines 22b, 22c, and 22d branched from the line 22a. The lines 22b, 22c, and 22d are connected to the high-pressure drum 24, the intermediate-pressure drum 25, and the low-pressure drum 26, respectively. The 1st feed water heater 23a and the 2nd feed water heater 23b are provided in line 22a and line 22b, respectively. The first feed water heater 23a exchanges heat between the feed water sent to each of the drums 24 to 26 and the scavenging of the main machine 1, thereby heating the feed water and cooling the scavenging. The second feed water heater 23b exchanges heat between the feed water sent to the high-pressure drum 24 and the feed air of the main machine 1, thereby heating the feed water and cooling the feed air. Each of the drums 24 to 26 stores feed water as circulating water and stores steam obtained from the circulating water.

The steam system 28 includes an upstream line 28a on the high pressure drum 24 side and a downstream line 28b on the steam turbine 5 side. A superheater 35 is interposed between the upstream line 28a and the downstream line 28b. The steam system 28 further includes a bypass line 28c that bypasses the superheater 35 and connects the upstream line 28a and the downstream line 28b. The waste heat recovery system 3 includes a valve unit 34 that controls whether or not the steam from the high-pressure drum 24 passes through the superheater 35 before being sent to the steam inlet 5b. The valve unit 34 includes a first opening / closing valve 34a that allows or blocks the flow of steam through the bypass line 28c, a second opening / closing valve 34b that allows or blocks the flow of steam through the superheater 35, and an overheating. And a relief valve 34c for partially escaping the steam flowing through the vessel 35. The superheater 35 is provided in the inlet pipe 11 of the exhaust gas economizer 10. When the steam passes through the superheater 35, the steam can be superheated by heat exchange with the exhaust, and thereby the output of the steam turbine 5 can be increased. Further, the low pressure mixed system 33 includes an inlet valve 36. In accordance with the opening degree of the inlet valve 36, the flow rate of the air-fuel mixture supplied to the low-pressure air-fuel mixture inlet 5d is adjusted. When the inlet valve 36 operates to increase the flow rate of the air-fuel mixture supplied to the low-pressure air-fuel mixture inlet 5d, the output of the steam turbine 5 can be increased.

Claims (10)

A waste heat recovery system that generates steam using the exhaust heat of the main engine with a turbocharger;
A generator driven by steam generated in the waste heat recovery system;
Temperature detection means for detecting the temperature of the supply or exhaust of the main engine;
Load detecting means for detecting the load of the main machine;
An exhaust passage through which exhaust from the main engine flows;
A bypass passage connected to the exhaust passage and through which the exhaust gas bypasses the supercharger;
Flow rate adjusting means for adjusting the flow rate of the exhaust gas flowing through the bypass passage and the flow rate of the exhaust gas sent to the supercharger;
Control means for controlling the flow rate adjusting means so that the generator can generate electric power that is equal to or greater than the power required for inboard use according to the temperature detected by the temperature detecting means and the load detected by the load detecting means. And a marine power generation system.   The temperature detection means includes a temperature of supply air supplied to the supercharger, a temperature of supply air supplied from the supercharger to the main unit, a temperature of exhaust gas supplied from the main unit to the supercharger, The marine power generation system according to claim 1, wherein the temperature of the exhaust gas at the inlet of the waste heat recovery system is detected.   The load detection means includes a rotation speed of a shaft power system including an output shaft of the main machine and a rotation shaft that rotates with the output shaft, a rotation speed of the supercharger, a fuel injection amount to the main machine, or from the main machine. The marine power generation system according to claim 1, wherein the flow rate of exhaust gas is detected. The flow rate adjusting means has an exhaust bypass valve provided on the bypass passage with a variable opening.
2. The marine power generation system according to claim 1, wherein the control means controls the opening degree of the exhaust bypass valve so that the generator can generate electric power that is greater than or equal to electric power for ship use according to temperature and load.   Relationship between the temperature and load of the control means and the opening degree of the exhaust bypass valve that can supply the exhaust heat necessary for the generator to generate electric power that is greater than the power required for inboard ships to the waste heat recovery system The marine power generation system according to claim 4, further comprising a storage unit that preliminarily stores a control rule that defines   The marine power generation system according to claim 5, wherein the control rule defines a relationship between a load in a load region lower than a normal output and an opening degree of the exhaust bypass valve.   The marine power generation system according to claim 4, wherein the control means increases the opening of the exhaust bypass valve as the temperature is lower.   The marine power generation system according to claim 4, wherein the control means increases the opening of the exhaust bypass valve as the load is lower. The supercharger-equipped main machine is composed of a first main machine and a second main machine, and the flow rate adjusting means is provided corresponding to each of the first main machine and the second main machine. It consists of flow rate adjustment means,
The control means is configured such that the electric power that can be generated using the exhaust heat of the first main engine is half of the electric power for onboard use, and the electric power that can be obtained using the exhaust heat of the second main apparatus is 2. The marine power generation system according to claim 1, wherein the first flow rate adjusting unit and the second flow rate adjusting unit are controlled so as to be half of electric power for demand.   The control means is capable of generating using the exhaust heat of the second main machine when the generated power obtained using the exhaust heat of the first main machine is less than half of the power for on-board demand. 10. The marine power generation system according to claim 9, wherein the second flow rate adjusting unit is controlled so that electric power is corrected to increase from a value half of the electric power for inboard use.

Images