KR20130100175A - Marine power generation system - Google Patents

Abstract

The marine power generation system 100 has a storage battery 5 electrically connected to the generator 4, and the power generation system 100 by waste heat when the load of the main engine is in a high load region and the engine room temperature is a reference temperature. The generators generated by the waste heat are capable of generating power that is larger than the continuous power required continuously in the ship (WC) and smaller than the total demand power (WT) added temporarily and additionally necessary power components (WA) to the continuous power (WC). When the power that can be generated in (4) exceeds the power demand in the ship, the storage battery 5 is charged with surplus power generated by the generator 4, and the power that can be generated by the generator 4 due to the waste heat is generated in the ship. When the demand is less than the demand, the battery 5 is discharged to help drive the generator 4.

Description

Marine Power Generation System {MARINE POWER GENERATION SYSTEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine power generation system which drives a steam turbine with steam generated from waste heat of a main engine device and generates power in accordance with the output of the steam turbine.

Large vessels are equipped with a power generation system for generating electric power required during operation. Recently, in order to meet energy saving demands, a waste heat recovery system for recovering waste heat around the main engine to generate steam is added to a marine power generation system, a steam turbine is driven by steam generated in a waste heat recovery system, And the generator can be driven according to the output of the steam turbine (see, for example, Patent Documents 1 to 3).

Japanese Patent Laid-Open No. 2010-116847 Japanese Patent Laid-Open No. 5-65804 Japanese Patent Laid-Open No. 8-93410

However, when the main engine is operated at a low load, the amount of exhaust gas and the amount of waste heat around the main engine decrease, so that the amount of steam flowing into the steam turbine is reduced. In addition, when the main engine is a diesel engine, soot contained in the exhaust gas may be attached to the exhaust gas economizer, and the operation of removing soot to maintain the heat recovery efficiency of the waste heat recovery system (soot blow) It is necessary to perform a soot blow every suitable period. When such a soot blow is performed using the steam produced by the waste heat recovery system, the amount of steam flowing into the steam turbine is reduced. When the amount of steam decreases in this way, the output of the steam turbine is reduced, so there is a fear that the power generation amount of the generator may not be able to meet the power demand in the ship.

In addition, the power demand in the ship may be temporarily greater than the power used continuously. For example, when operating an intermittent auxiliary device such as a compressor of a refrigeration apparatus mounted on a ship, the power demand in the ship is a value obtained by adding the power required for the operation to continuous power.

In the conventional marine power generation system, when the amount of steam decreases or when the power demand of the vessel temporarily becomes larger than the continuous power, the power generation amount of the generator is increased by operating the auxiliary boiler to increase the amount of steam supplied to the steam turbine. Other generators such as diesel generators are operated to cope. In general, since the operation of the auxiliary boiler and the diesel generator requires fossil fuel, it leads to an increase in running cost and it is difficult to realize a high energy saving.

On the contrary, when the power demand of the generator is to be supplied to the power demand of the ship without operating the auxiliary boiler and the diesel generator, the value obtained by adding the power required for the generator temporarily to the continuous power when the main engine is at low load It is considered to design the system so that it is possible. In this case, however, it is necessary to ensure that the steam turbine generates a large output even when the main engine is at a low load, resulting in an enlargement of the configuration of the waste heat recovery system. This makes it difficult to arrange the marine power generation system in a limited space within the ship. In addition, when the main engine becomes a high load, the amount of power generation of the generator exceeds the power demand in the ship, generating surplus power that is not effectively utilized.

Accordingly, an object of the present invention is to provide a power generation system for ships that can meet the demand for electricity in ships while controlling the fossil fuel as much as possible, and also to effectively utilize it when surplus power is generated in the generator. do.

A marine power generation system according to the present invention includes a waste heat recovery system for recovering waste heat of a main engine to generate steam, a steam turbine driven by steam generated by the waste heat recovery system, and a steam turbine driven by the output of the steam turbine And a generator electrically connected to the generator, wherein the generator generates power that can be generated by the waste heat when the load of the main engine is in a high load region is larger than the continuous power required continuously in the ship, And a power component that is temporarily and additionally required to the continuous power is smaller than a total demand power added to the continuous power. When the generated power of the generator due to the waste heat exceeds the power demand in the ship, Is charged with surplus electric power generated by the generator The electric power is generated discharge or to fall below the power demand in the vessel is configured to aid the operation of the generator.

According to the above configuration, when the power that can be generated by the generator by waste heat can sufficiently satisfy the power demand in the ship, it is possible to charge the storage battery with the surplus power generated by the generator. In this manner, the surplus power can be effectively utilized even when the generator generates surplus power for the demand for power in the ship. In addition, even when the power that can be generated by the generator due to the waste heat cannot meet the power demand in the ship, the battery can be discharged to assist in driving the generator. Accordingly, the amount of power generated by the generator can be increased, thereby reducing the case of operating the auxiliary boiler or the diesel generator. Accordingly, even if the power generated in the generator due to the waste heat fluctuates depending on the load fluctuation of the main engine or the like, and the power demand in the ship fluctuates, this can be easily coped with. Further, the power generation power of the generator due to the waste heat when the load of the main engine is in the high load region is set to be larger than the continuous power and smaller than the total demand power. For this reason, the opportunity to charge and the discharge to generate | occur | produce while sailing of a main engine generate | occur | produce mutually without bias, and it can make it possible to balance charge and discharge of a charger.

And control means for controlling charging and discharging of the storage battery, wherein the control means is generated by the generator when a predetermined charging condition for generating power of the generator by waste heat exceeds the power demand in the ship is established. The battery is charged with surplus power, and the battery is discharged to assist the driving of the generator when a predetermined discharge condition in which the power generated by the waste heat generated by the waste heat is less than the power demand in the ship is satisfied. It may be configured to.

According to the above configuration, the charging operation and the discharging operation of the storage battery can be appropriately switched according to the situation.

Further comprising auxiliary device start detection means for detecting starting of the auxiliary device in the ship, wherein the charging condition includes a condition that the start of the auxiliary device is not detected by the auxiliary device start detection means, and the discharge condition is The auxiliary device start detection means may include the condition that the start of the auxiliary device is detected.

According to the above configuration, when the power demand in the ship increases temporarily and additionally with the start of the auxiliary equipment, the battery can be discharged correspondingly to assist the driving of the generator, and the opportunity to operate the auxiliary boiler or the diesel generator. Can be reduced.

An exhaust gas reducer through which the waste heat of the main engine flows, a blower for injecting steam generated in the waste heat recovery system into the exhaust gas reducer, and whether the blower is in operation And a blow detection means for detecting a value, wherein the charging condition includes a condition that the stop of the blower is detected by the blow detection means, wherein the discharge condition indicates that the operation of the blower is detected by the blow detection means. Conditions may be included.

According to the above configuration, since all the steam generated by the waste heat recovery cannot be used to drive the steam turbine by injecting steam into the exhaust gas saver, even when the power generated by the waste heat is reduced, the battery can be coped with. Discharging can help drive the generator. This reduces the chance of running an auxiliary boiler or diesel generator.

The steam system which sends steam to the steam inlet of the said steam turbine, and the governor which adjusts the flow volume of the steam sent to the said steam inlet by changing the lift amount by installing the variable lift amount by the said steam system. And a lift amount detecting means for detecting a lift amount of the governor valve, wherein the filling condition includes a condition that the lift amount detected by the lift amount detecting means is less than a first lift threshold. The discharge condition may include a condition that the lift amount detected by the lift amount detecting means is equal to or larger than a second lift threshold value larger than the first lift threshold value.

According to the above configuration, when the lift amount of the Governor valve is increased, the flow rate of the steam supplied to the steam inlet is increased to generate a large output of the steam turbine, and vice versa as the lift amount of the Governor valve becomes smaller. In this way, the magnitude of possible power generation of the generator by waste heat can be determined according to the lift amount, and accordingly, it can be appropriately determined whether the storage battery should be charged or discharged.

A water separator which constitutes the waste heat recovery system, collects the generated steam, and pressure detecting means for detecting the internal pressure of the water separator, wherein the charging condition is detected by the pressure detecting means. The pressure may include a condition that the internal pressure is equal to or greater than the first pressure threshold, and the discharge condition may include a condition that the internal pressure detected by the pressure detection means is less than the second pressure threshold smaller than the first pressure threshold.

According to the above configuration, when the pressure of the steam is high, the steam turbine can generate a large output, and when the pressure is low, the reverse is true. In this way, the magnitude of the power that can be generated by the waste heat can be determined according to the pressure of the steam, and accordingly, it can be appropriately determined whether the storage battery should be charged or discharged.

According to the present invention, when the fossil fuel can be used, it is possible to meet the demand for power in ships while keeping control of the fluctuations, and to increase the size of the waste heat recovery system, while generating surplus power in the generator. It is possible to provide a power generation system for ships that can effectively utilize this.

The above objects, other objects, features and advantages of the present invention will become apparent from the following detailed description of preferred embodiments with reference to the accompanying drawings.

1 is a conceptual diagram showing the overall configuration of a ship power generation system according to an embodiment of the present invention.
Fig. 2 is a graph showing the relationship between the engine load and the generator-generable power due to the waste heat.
FIG. 3 is a graph showing the correlation between the possible power of the generator due to the waste heat and the internal pressure of the high-pressure drum, the correlation between the possible power of the generator due to the waste heat and the lift amount of the Governor valve, And a concept diagram of charge / discharge control.
4 is a flowchart showing a procedure of charge / discharge control executed by a main controller.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In addition, the same code | symbol is attached | subjected and the overlapping description is abbreviate | omitted to the element which is the same or it corresponds through all the drawings.

1 is a conceptual diagram showing the overall configuration of a marine power generation system 100 according to an embodiment of the present invention. The ship power generation system 100 shown in FIG. 1 is mounted on the ship provided with the ship diesel engine 1 (henceforth simply "engine") as a main engine.

The ship power generation system 100 includes a waste heat recovery system 2 for recovering waste heat and generating steam around the engine 1, a steam turbine 3 driven by steam generated in the waste heat recovery system 2, and And a generator 4 driven in accordance with the output of the steam turbine 3, and a storage battery 5 electrically connected to the generator 4.

The waste heat recovery system 2 mainly includes an exhaust gas reducer 10, a condenser 21, a water supply system 22, a water supply heater 23, a high pressure drum (high pressure water separator) 24, and a medium pressure drum. (Medium pressure water separator) (25), low pressure drum (low pressure water separator) (26), high pressure circulating water system (27), steam system (28), medium pressure circulating water system (29), medium pressure mixing system ( 30), the low pressure circulation water system 31, the low pressure evaporator 32, and the low pressure mixing system 33 are provided. The waste heat recovered by the waste heat recovery system 2 is used to heat exhaust gas to be discharged by the exhaust system of the engine 1, heat of the cooling water of the engine 1, .

The exhaust system of the engine 1 includes an exhaust pipe 1a for guiding exhaust gas to exhaust outlets such as a chimney. The exhaust gas saver 10 is interposed between the exhaust pipe 1a and the exhaust outlet, and constitutes a part of the exhaust system. A bypass pipe 8 bypassing the exhaust gas reducer 10 is connected to the exhaust pipe 1a, and an inlet portion of the exhaust gas reducer 10 and an inlet portion of the bypass tube 8 are dampers. It is opened and closed by each of the dampers 9a and dampers 9b. When the flow rate or the heat amount of the exhaust gas necessary for generating the steam for driving the steam turbine 3 such as when the load of the engine 1 exceeds a predetermined value is sufficiently secured, The damper 9a is opened and the damper 9b on the side of the bypass pipe 8 is closed. If the flow rate or heat amount of the exhaust gas is not sufficient, the damper 9a is closed and the damper 9b is opened. In the following description, the damper 9a is opened and the damper 9b is closed unless otherwise described.

The exhaust gas saver 10 includes an inlet tube 11, a high pressure evaporator 12, an intermediate tube 13, a medium pressure evaporator 14, and an outlet tube 15 on the upstream side. The inlet pipe (11) is connected to the exhaust pipe (1a) to lead the exhaust gas from the engine (1) to the high pressure evaporator (12). The intermediate pipe 13 guides the exhaust gas after the heat exchange in the high pressure evaporator 12 to the medium pressure evaporator 14. The outlet pipe 15 guides the exhaust gas after the heat exchange in the medium pressure evaporator 14 to the exhaust outlet.

In the course of the exhaust gas flowing through the exhaust gas reducer 10, since the soot in the exhaust gas can be attached to the high pressure evaporator 12 and the medium pressure evaporator 14, the exhaust gas saver 10 is sooted. A first soot blower 16 and a second soot blower 17 are provided for blowing off. Each soot blower 16, 17 is connected to at least one of the high pressure drum 24, the medium pressure drum 25 and the low pressure drum 26 via a blow system (not shown), and vaporizes in at least one corresponding drum. Get supplied. The first soot blower 16 has a plurality of ejection openings for ejecting the supplied steam toward the high-pressure evaporator 12, and blows soot attached to the high-pressure evaporator 12 by jetting the steam by the ejection openings You can knock. The second soot blower 17 also has a plurality of injection holes for injecting the supplied steam toward the medium pressure evaporator 14.

The condenser 21 is connected to the steam outlet 3a of the steam turbine 3 to condense the steam flowing out of the steam outlet 3a. The water supply system 22 connects the condenser 21 to each of the drums 24 to 26, and sends the plurality generated in the condenser 21 to each of the drums 24 to 26 as water supply. The water supply system 22 has a line 22a extending from the condenser 21 and two lines 22b and 22c branching from the line 22a and the line 22b being again bifurcated And is connected to the high-pressure drum 24 and the intermediate-pressure drum 25 in a branched state, and the line 22c is connected to the low-pressure drum 26. [ The water supply heater 23 is provided on the line 22b. The water feed heater 23 causes heat exchange between the feed water sent to the high pressure drum 24 and the intermediate pressure drum 25 and the sweep of the engine 1 (supercharger outlet blower air) Cool the corresponding scum while heating.

The high pressure drum 24, the intermediate pressure drum 25 and the low pressure drum 26 store the water supply from the water supply system 22 as circulation water and store the steam obtained from the circulation water. The high pressure drum 24 is provided with a first pressure sensor 41 that detects the internal pressure of the high pressure drum 24 (pressure of steam collected in the high pressure drum 24). The same 2nd pressure sensor 42 and the 3rd pressure sensor 43 are provided also in the medium pressure drum 25 and the low pressure drum 26, respectively.

The high pressure circulating water system 27 has a line 27a connecting the high pressure drum 24 to the high pressure evaporator 12 and a line 27b connecting the high pressure evaporator 12 to the high pressure drum 24. . The steam system 28 connects the high pressure water separator 24 to the steam inlet 3b of the steam turbine 3. When the pump 27P on the line 27a is operated, the circulating water in the high pressure drum 24 is sent into the high pressure evaporator 12 through the line 27a, and the circulated water is sent to the exhaust gas in the high pressure evaporator 12. It becomes steam by heat exchange. The circulating water is returned into the high pressure drum 24 through the line 27b in a mixed state of gas and liquid, 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 3b of the steam turbine 3 through the steam system 28.

The medium pressure circulation water system 29 has a line 29a connecting the medium pressure drum 25 to the medium pressure evaporator 14, and a line 29b connecting the medium pressure evaporator 14 to the medium pressure drum 25. . The intermediate-pressure dynamo system 30 connects the intermediate-pressure drum 25 to the intermediate-pressure dew condenser inlet 3c of the steam turbine 3. When the pump 29P on the line 29a is operated, the circulating water in the medium pressure drum 25 is sent into the medium pressure evaporator 14 through the line 29a, and the circulated water is sent to the exhaust gas in the medium pressure evaporator 14. It becomes steam by heat exchange. The circulating water is returned into the intermediate pressure drum 25 through the line 29b in a mixed state of gas and liquid and the returned circulating water is separated into vapor and liquid in the intermediate pressure drum 25. [ Steam in the medium pressure drum 25 is supplied to the medium pressure mixing inlet 3c of the steam turbine 3 via the medium pressure mixing system 30.

The low pressure circulating water system 31 has a line 31a connecting the low pressure drum 26 to the low pressure evaporator 32 and a line 31b connecting the low pressure evaporator 32 to the low pressure drum 26. . The low pressure mixing system 33 connects the low pressure drum 26 to the low pressure mixing inlet 3d of the steam turbine 3. When the pump 31P on the line 31a is operated, the circulating water in the low pressure drum 26 is sent into the low pressure evaporator 32 through the line 31a. In the present embodiment, an air cooler for cooling the air supply is applied to the low-pressure evaporator 32, and the circulating water sent is steamed by heat exchange with the air supply in the low-pressure evaporator 32. [ The circulating water is returned to the low pressure drum 26 through the line 31b in a mixed state of gas and liquid, and the returned circulating water is separated into vapor and liquid in the low pressure drum 26. The steam in the low pressure drum 26 is supplied to the low pressure mixed gas inlet 3d of the steam turbine 3 through the low pressure mixed gas system 33.

The steam turbine 3 is a multistage turbine having a plurality of blades. The steam turbine 3 rotates the blade by the steam supplied to the steam inlet 3b, the medium pressure mixed gas supplied to the medium pressure mixing inlet 3c, and the low pressure mixing supplied to the low pressure mixing inlet 3d. Rotational output occurs on the output shaft 3e.

The steam system 28 includes an upstream line 28a on the drum side and a downstream line 28b on the turbine side. The superheater 35 is interposed between the upstream line 28a and the downstream line 28b. The steam system 28 bypasses the superheater and connects the upstream line 28a and the downstream line 28b with a bypass line 28c and when steam from the high pressure drum 24 is sent to the steam inlet 3b. It is provided with the valve unit 34 which controls whether or not via the superheater 35 until now. The valve unit 34 includes a first on-off valve 34a for allowing or preventing the flow of steam through the bypass line 28c, and a second on-off valve for allowing or preventing the flow of steam through the superheater 35. 34b and relief valve 34c which partially discharges the steam flowing through the superheater. The superheater 35 is provided in the inlet pipe 11 of the exhaust gas saver 10. When the steam passes through the superheater 35, the steam can be heated and boosted by heat exchange with the exhaust gas, so that the output of the steam turbine 3 can be increased.

Moreover, the steam system 28 is equipped with the governor valve 36 as an inlet valve and an regulating valve in the downstream side (namely, the steam inlet 3b side) of the valve unit 34. As shown in FIG. The Governor valve 36 is provided with a valve rod (not shown) whose lift amount is variable, and can adjust the flow rate of the steam supplied to the steam inlet 3b in accordance with the lift amount of the valve rod. The intermediate-pressure dynamo system 30 and the low-pressure homogenizer system 33 also have inlet valves 37 and 38 for adjusting the flow rates of the mixed gas supplied to the intermediate-pressure dynamo-inlet 3c and the low- have. When the governor valve 36 and the inlet valves 37 and 38 are operated to increase the flow rate of the steam, the output of the steam turbine 3 can be increased. The governor valve 36 is provided with a lift amount sensor 44 for detecting the lift amount.

The high pressure drum 24 is provided with the auxiliary boiler 24a. The auxiliary boiler 24a heats the circulating water in the high pressure drum 24 with the heat generated by the combustion of the fossil fuel, thereby generating steam in the high pressure drum 24. The output of the steam turbine 3 can be increased by reheating the auxiliary boiler 24a. Hereinafter, the output of the steam turbine 3 which generate | occur | produced with steam produced | generated based only on the waste heat which was recovered not depending on reheating of the auxiliary boiler 24a is called "output of the steam turbine 3 by waste heat." The power that can be generated by the generator 4 when the generator 4 is driven in accordance with the output of the steam turbine 3 by the waste heat will be referred to as "the power that can be generated by the generator 4 by waste heat". In addition, the medium pressure drum 25 and the low pressure drum 25 are provided with the heaters 25a and 26a, respectively. Each heater 25a, 26a receives steam from the high pressure drum 24 via the steam system 28 (refer to * of FIG. 1), and accordingly heats the circulating water in the drum 25, 26, and a drum ( It is possible to generate steam in 25, 26).

The generator 4 generates electric power in accordance with the output of the steam turbine 3, that is, the pressure and flow rate of the steam and the mixed air supplied from the waste heat recovery system 2 to the steam turbine 3. When the pressure and flow rate of the steam tend to decrease due to the low engine load, or when a part of the steam generated in the waste heat recovery system 2 is used in the first soot blower 16 or the second soot blower 17, waste heat. Output of the steam turbine 3 is relatively small, so that the power generated by the waste heat can be less than the power demand in the ship. On the other hand, when the pressure and the flow rate of the steam are sufficiently large, or when the first soot blower 16 and the second soot blower 17 are stopped, the power that can be generated by the waste heat is higher than the power demand . ≪ / RTI >

The storage battery 5 is electrically connected to the generator 4 via a sub controller 7 described later. For this reason, when the generator 4 can generate electric power exceeding the electric power demand in a ship, it is possible to charge the storage battery 5 with surplus electric power. In addition, when the generator 4 can generate power only below the electric power demand, the storage battery 5 can be discharged to help drive the generator 4. The storage battery 5 is appropriately selected from various kinds of storage batteries such as nickel-hydrogen storage batteries, nickel-iron storage batteries, nickel-cadmium storage batteries, nickel-zinc storage batteries, lead storage batteries, and lithium ion secondary batteries.

Nickel-hydrogen batteries have a small voltage change due to SOC change in the middle of state of charge (SOC) compared to other types, and are very easy to handle due to normal temperature operation, and use an aqueous electrolyte solution. As a result, it is possible to eliminate the risk of fire, and lead-free (lead free), mercury-free, cadmium-free, which is advantageous in terms of environment-friendly.

Moreover, it is preferable to employ | adopt the structure which makes internal resistance small for a nickel hydrogen storage battery. Accordingly, it is possible to suppress the temperature rise due to high current charge and discharge by improving the cooling performance, to enable charge and discharge at high efficiency and high speed, and to improve cycle durability to repeat the fast charge and discharge. Long term use is also possible. Moreover, it is preferable to employ | adopt the non-welding structure which does not weld a battery material and an electrode to a nickel hydrogen storage battery. Accordingly, the recycling performance can be improved, so that assembly and disassembly can be easily performed. By adopting such a structure, it can be suitably used as a storage battery that can withstand long-term navigation by interacting with the characteristics of nickel-hydrogen storage battery.

The input side of the main controller 6 is, in addition to the above-described first pressure sensor 41, second pressure sensor 42, third pressure sensor 43 and lift amount sensor 44, blow switch 45 and auxiliary. It is connected to the appliance start switch 46. The blow switch 45 detects whether the first soot blower 16 and / or the second soot blower 17 are in operation or whether the first soot blower 16 and the second soot blower 17 are stationary. . The auxiliary device start switch 46 detects whether an intermittent mechanism such as a compressor of the refrigerating device is starting. The sub controller 7 is connected to the output side of the main controller 6. The sub-controller 7 controls the AC / DC conversion of the alternating current from the generator 4 at the time of charge / discharge control of the storage battery 5 at the time of charging and discharging the battery 5 according to the instruction from the main controller 6. DC / AC conversion control of the discharge direct current, the frequency control of the alternating current generated by the DC / AC conversion, and the synchronous control of the generated alternating current and alternating current generated by the generator 4 are performed.

2 is a graph showing the relationship between the engine load and the power that can be generated by the generator 4 by waste heat. The horizontal axis represents the engine load as a percentage of 100% of the total load, and the vertical axis represents the possible power generation of the generator 4 by waste heat as a percentage of 100% of the total demand power in the ship. The line WT represents the total demand power in the ship, and the line WC represents the ratio of continuous power to the total demand power (WT). These are drawn parallel to the horizontal axis. That is, the total demand power (WT) and the continuous power (WC) are values determined without depending on the engine load.

Continuous power WC is always required power during normal sailing of a ship. On the other hand, during voyage, a power demand different from continuous power WC may arise temporarily, such as when starting the compressor of a refrigerator. The total demand power WT is a value obtained by adding the power WA temporarily and additionally required to the continuous power WC. In this embodiment, the continuous power WC is about 83% of the total demand power WT (WC ≒ WT × 0.83, WA ≒ WT × 0.17). In other words, the total demand power (WT) is obtained by adding the additional power (WA) of about 20% of the continuous power (WC) to the continuous power (WC) (WA (WC × 0.20, WT ≒ WC × 1.20). ). A line, B line, and C line show an example of characteristic diagrams of the steam turbine 3 and the generator 4 when the engine room temperature is 35 degrees Celsius, 25 degrees Celsius, and 10 degrees Celsius, respectively. . It can be seen from the lines A to C that the higher the engine load and the higher the engine room temperature, the higher the power that can be generated by waste heat.

In the conventional system, for example, point D is a design point of the steam turbine 3 and the generator 4. That is, in the conventional system, when the engine room temperature is 25 degrees Celsius and the engine load is in a high load region (for example, 90% load) near the whole load, . Then, when the engine load is less than the design point (for example, less than 90% load), the power demand in the vessel can not be covered by the generator 4 at the time of starting the intermittent auxiliary equipment or performing the soot blow , The reheating of the auxiliary boiler 24a and the operation of the diesel generator are required. On the contrary, when the engine load is full load, the generator 4 generates electric power exceeding the total demand power WT, and the surplus power at that time is not effectively utilized and is discarded.

On the other hand, the ship power generation system 100 according to the present embodiment, as described above, has a storage battery 5 electrically connected to the generator (4). For this reason, when the engine load is high and the electric power which the generator 4 can generate | occur | produce by waste heat can fully satisfy the electric power demand in a ship, the storage battery 5 is charged with the surplus electric power which the generator 4 produced | generated. can do. On the contrary, when the power that can be generated by the generator 4 due to the waste heat cannot meet the power demand in the ship, the storage battery 5 can be discharged to help drive the generator 4. As a result, the fossil fuel required for reheating the auxiliary boiler 24a or operating the diesel generator can be saved, and the cost and energy can be saved.

In this way, since the power demand in the ship can be satisfied not only by the electric energy obtained from the waste heat but also by the electric energy generated by the generator 4 based on the electric power stored in the storage battery 5, the steam turbine 3 and The design point of the generator 4 can be made lower than before. For example, as shown in Fig. 2, it becomes possible to change the design point from point D to point E. That is, the system design can be changed so as to reduce the possible power generation of the generator 4 due to the waste heat under the same conditions as the engine room temperature and the engine load.

In this case, the drop width of the design point can correspond to the electric power that can be generated by discharging the storage battery 5 to help drive the generator 4. At this time, the engine load is in the range of 80% load to 95% load, and the power generated by the generator 4 by waste heat when the engine room temperature is 20 to 40 degrees is larger than the continuous power (WC) and the total demand power. It may be set smaller than (WT). For example, as shown in FIG. 2, when the design point falls to 10% of the total demand power (WT), and the engine load is in a high load region near the full load (for example, 90% load). It is preferable that the power which can generate | occur | produce by the waste heat of is set to the value exceeding continuous power WC. In this way, it is possible to balance the charging opportunity and the discharge opportunity without biasing any one of the charging and discharging.

As described above, when the engine room temperature and the engine load are the same, and the power consumption of the generator 4 due to the waste heat is to be reduced, the exhaust gas saver 10 can be reduced in size to reduce the amount of heat recovery from the exhaust gas. Or miniaturization of the steam turbine 3 may be attempted. For this reason, the waste heat recovery system 2 and the steam turbine 3 can be downsized, and the whole ship power generation system 100 can be downsized and the cost can be reduced. Therefore, due to the size and cost, it is possible to mount such a power generation system even in a small ship that cannot previously be equipped with a power generation system with a waste heat recovery system.

Hereinafter, the charge and discharge control performed in the ship power generation system 100 according to the present embodiment will be described. FIG. 3 shows the correlation between the generated power due to waste heat and the internal pressure of the high pressure drum 24 (that is, the steam pressure in the high pressure drum 24), the possible power due to the waste heat and the lift of the governor valve 36. It is a figure which shows together the correlation with quantity, the correlation between the electric power which can generate | occur | produce by waste heat, a planned point, and the conceptual diagram of charge / discharge control. In addition, a "planning point" is a point where the electric power demand in a ship balances with the electric power which can generate | occur | produce the generator 4 by waste heat.

As shown in Fig. 3, when the internal pressure P of the high-pressure drum 24 is in the commercial pressure region, it is assumed that the generator 4 generates a power that can be represented by a planned point. In addition, the commercial pressure is a pressure when the power demand in the ship is balanced with the power generated by the waste heat without reheating the auxiliary boiler during the normal voyage.

On the other hand, as the internal pressure P of the high-pressure drum 24 increases, the power that can be generated by the generator 4 by waste heat increases. Thus, if the internal pressure P of the high pressure drum 24 exceeds the commercial pressure PN, the power generated by the generator 4 due to the waste heat creates an excess for the power demand in the ship. On the contrary, when the internal pressure P of the high pressure drum 24 is less than the commercial pressure PN, the electric power which the generator 4 can generate | occur | produce by waste heat is insufficient in the electric power demand in a ship.

In addition, when the lift amount L of the governor valve 36 is a predetermined value LN and the internal pressure P is in the commercial pressure region, the generator 4 generates a power that can be generated as indicated by the planned point. Shall be. On the other hand, as the lift amount L increases, the power that can be generated by the generator 4 due to the waste heat decreases. Therefore, when the lift amount L is less than the predetermined value LN, the power that can be generated by the generator 4 due to the waste heat creates an excess for the power demand in the ship. On the contrary, if the lift amount L exceeds the predetermined value LN, the generator 4 generated power due to the waste heat is insufficient for the power demand in the ship.

Here, in the conventional power generation system, when the internal pressure P deviates from the commercial pressure range toward a lower value or the lift amount of the governor valve exceeds a predetermined value, the power generated in the generator 4 due to the waste heat is generated in the ship. As the power demand could not be met, the reheating of the auxiliary boiler and the operation of the diesel generator were performed automatically.

In the main controller 6 according to the present embodiment, during discharge, the internal pressure P of the high-pressure drum 24 detected by the first pressure sensor 41 is higher than or near the upper limit of the commercial pressure region. When the value becomes equal to or greater than the first pressure threshold P1, the first controller 7 is commanded to charge the storage battery 5. The main controller 6 determines that the lift amount L of the governor valve 36 detected by the lift amount sensor 44 is equal to the first lift threshold value L1 which is a value lower than the predetermined value LN, , The secondary controller 7 is instructed to charge the storage battery 5.

In addition, the main controller 6, during charging, the internal pressure P of the high-pressure drum 24 detected by the first pressure sensor 41 is a lower limit value of the commercial pressure region or a value near the limit value. When the pressure falls below the pressure threshold P2, the sub controller 7 is instructed to discharge the storage battery 5. In addition, the main controller 6, during charging, the second lift threshold value L2 at which the lift amount L of the governor valve 36 detected by the lift amount sensor 44 is higher than the predetermined value LN. If abnormal, the sub controller 7 is instructed to discharge the storage battery 5.

Thus, the threshold values P1 and L1 at the time of transition from discharge to charge and the threshold values P2 and L2 at the time of transition from charge to discharge have hysteresis. For this reason, when the internal pressure P of the high pressure drum 24 and the lift amount L of the governor valve 36 are controlled so that it may become near a planned point, it is preferable that transition of charge / discharge frequently occurs. It can be suppressed. More specifically, the high pressure drum 24 has a slow time constant that changes due to heat accumulation of the retained water. Therefore, by setting the internal pressure P of the high-pressure drum 24 as hysteresis as a detecting element, it is possible to satisfactorily suppress repetition of charging and discharging in accordance with the time constant.

Further, after the transition from charging to discharging, the internal pressure P is lower than the third pressure threshold P3, which is a value lower than the second pressure threshold P2, or the lift amount L is higher than the second lift threshold L2. If the value is equal to or greater than the third lift threshold value L3, the power demand in the ship cannot be satisfied even with the help of the storage battery 5, and the auxiliary boiler 24a may be reheated. Further, the fourth lift threshold L4 having the internal pressure P lower than the fourth pressure threshold P4 having a value lower than the third pressure threshold P3 or the lift amount L having a value higher than the third lift threshold L3. In this case, even if the reheating of the storage battery 5 and the auxiliary boiler 24a is assisted, it is assumed that the power demand in the ship cannot be satisfied, and the diesel generator may be driven. In this manner, after the assistance of the storage battery 5 is given the highest priority, the use of the fossil fuel can be greatly suppressed by providing the backup function for reheating the auxiliary boiler 24a and driving the diesel generator. It is possible to provide a power generation system that can meet the demand for power in ships even in the extreme shortage of power generated by waste heat. When the internal pressure P exceeds the first pressure threshold value P1 or the lift amount L is less than the first lift threshold value L1 in the case of providing such a backup function, It is preferable to determine whether or not the auxiliary boiler 24a is automatically extinguished or to stop the diesel generator. In addition, the diesel generator may be stopped manually without depending on the electronic control. The backup stop condition may be a condition that the internal pressure P is equal to or greater than the first pressure threshold P1 or the lift amount L is less than the first lift threshold L1, and the internal pressure P is the first pressure threshold P1. The condition may be higher than the fifth pressure threshold P5 which is a higher value or the lift amount L is lower than the fifth lift threshold L5 which is a value lower than the first lift threshold L1.

4 is a flowchart showing a procedure of charge / discharge control performed by the main controller 6. The main controller 6 determines whether the storage battery is being discharged or being charged (step S1). If discharging is in progress (Sl: YES), it is judged whether there is an increase in the electric power demand in the ship or a soot blowing operation (step S2). In addition, the main controller 6 can determine whether the electric power demand in a ship is increasing according to the input from the auxiliary equipment start-up detection means 45. FIG. When the start of the auxiliary device is detected by the auxiliary device start detection means 46, since the power demand in the ship exceeds the continuous power, it can be determined that the power demand in the ship is increasing at this time. In addition, the main controller 6 can determine whether the soot blow is performed according to the input from the blow switch 45. FIG. If there is an increase in the power demand in the ship or the execution of a soot blow (S2: YES), the main controller 6 assumes that the discharge conditions are established, and instructs the secondary controller 7 to discharge the storage battery 5. (Step S5). Accordingly, even if there is a possibility that the generated power of the generator 4 due to the waste heat may not be able to meet the power demand in the ship, the battery 5 is continuously discharged to help the generator 4 to drive the generator 4. Can increase the amount of power generated.

The main controller 6 determines whether or not the lift amount L of the Governor valve 36 is less than the first lift threshold value L1 (S2: NO) (Step S3). If the lift amount L is equal to or greater than the first lift threshold L1 (S3: NO), the main controller 6 determines whether or not the internal pressure P of the high pressure drum 24 is equal to or greater than the first pressure threshold P1. It judges (step S4). When the internal pressure P of the high-pressure drum 24 is less than the first pressure threshold P1 (S4: No), the main controller 6 assumes that discharge conditions are established, and the secondary controller 7 stores the storage battery ( A command is given to discharge 5) (step S5). Accordingly, the generator 4 is driven by continuously discharging the storage battery 5 even if there is a possibility that the power generated by the waste heat may not be able to meet the power demand in the ship due to low engine load. By increasing the power generation amount of the generator (4) can be increased.

If the lift amount L is less than the first lift threshold L1 or the internal pressure P of the high-pressure drum 24 is equal to or greater than the first pressure threshold P1 (S3: yes or S4: yes) during discharge, the main controller In (6), it is assumed that the charging condition is satisfied, and a command is given to charge the storage battery 5 to the secondary controller 7 (step S6). Accordingly, the steam generated by the waste heat recovery can be sufficiently utilized for driving the steam turbine 3 without the intermittent starting of the equipment, the power demand of the ship being near the continuous power WC, or the soot blow being not performed. In addition, when the power generated in the generator 4 due to the waste heat exceeds the power demand in the ship due to the high engine load and the engine room temperature, the surplus power can be charged in the storage battery 5 and the surplus power. Can be used effectively.

If the storage battery 5 is being charged (S1: No), it is judged whether there is an increase in power demand in the ship or implementation of soot blow as described above (step S22). The main controller 6 determines that the discharge condition is satisfied and instructs the secondary controller 7 to discharge the battery 5 if there is an increase in the electric power demand in the ship or a soot blow is performed (S22: YES) (Step S26).

During charging, if there is no increase in power demand in the ship and no soot blow is performed (S22: NO), the main controller 6 determines whether the lift amount L is equal to or larger than the second lift threshold L2 ( Step S23). If the lift amount L is less than the second lift threshold value L2 (S23: NO), the main controller 6 determines whether the internal pressure P of the high-pressure drum 24 is less than the second pressure threshold value P2 (Step S24). If the internal pressure P of the high-pressure drum 24 is equal to or greater than the second pressure threshold P2 (S24: No), the main controller 6 assumes that the charging conditions are satisfied, and the secondary controller 7 stores the storage battery ( A command is given to charge 5) (step S25).

During discharge, if the lift amount L is greater than or equal to the second lift threshold L2 or if the internal pressure P of the high pressure drum 24 is less than the second pressure threshold P2 (S23: yes or S24: yes), The controller 6 assumes that the discharge condition is satisfied, and gives a command to discharge the storage battery 5 to the secondary controller 7 (step S26).

As a result, even during charging, when there is a possibility that the generated power of the generator 4 due to the waste heat cannot satisfy the electric power demand in the ship, the generator 4 is assisted to drive the generator 4 by discharging the battery 5. The power generation amount of (4) can be increased. In addition, when the electric power which can generate | occur | produce the generator 4 by waste heat exceeds the electric power demand in a ship, the surplus electric power can continue to be charged to the storage battery 5, and an excess electric power can be utilized effectively.

From the above description, many modifications and other embodiments of the invention will be apparent to those skilled in the art. The foregoing description, therefore, is to be construed as illustrative only and is provided for the purpose of teaching those skilled in the art the best embodiment for carrying out the invention. And the details of its structure and / or function can be substantially altered without departing from the spirit of the invention. For example, in the charging condition or the discharge condition, detection results of the second pressure sensor and the third pressure sensor may be considered in the same manner as the first pressure sensor.

When the fossil fuel can be used as much as possible, the present invention can cope with fluctuating power demand in the ship, can suppress the enlargement of the waste heat recovery system, and can effectively do this when the generator can generate surplus power. With the effect of providing a ship power generation system that can be utilized, it is possible to mount such a system until now due to its size and cost, as well as a ship that has been equipped with a ship power generation system with a waste heat recovery system. It is also widely applicable to small ships that did not exist.

100: marine power generation system
1: marine diesel engine
2: waste heat recovery system
3: Steam turbine
4: generator
5: storage battery
6: main controller
7: secondary controller
10: exhaust gas saver
16, 17: suit blower
24: High pressure drum
25: medium pressure drum
26: low pressure drum
28: steam system
30: medium pressure mixing system
33: low pressure mixing system
36: governor valve
37, 38: inlet valve
41: first pressure sensor
42: second pressure sensor
43: third pressure sensor
44: lift amount sensor
45: blow switch
46: auxiliary start switch
P1: first pressure threshold
P2: second pressure threshold
L1: first lift threshold
L2: second lift threshold

Claims (6)

A waste heat recovery system for recovering waste heat of the main engine to generate steam,
A steam turbine driven by steam generated by the waste heat recovery system;
A generator driven and generated according to the output of the steam turbine,
A storage battery electrically connected to the generator,
The generator is characterized in that power generated by waste heat when the load of the main engine is in a high load region is greater than the continuous power continuously required in the ship, and a power component temporarily and additionally added to the continuous power is added. Less than total demand power,
The storage battery is charged with surplus power generated by the generator when the power that can be generated by the generator by waste heat exceeds the power demand in the ship, and the power that can be generated by the generator by waste heat is less than the power demand in the ship. When discharged to the power generation system for a ship, characterized in that to help drive the generator. The method of claim 1,
And control means for controlling charging and discharging of the storage battery,
The control means charges the storage battery with surplus power generated by the generator when a predetermined charging condition in which possible generation power of the generator by waste heat exceeds the power demand in the ship is established, And generating control to help drive the generator by discharging the storage battery when a predetermined discharge condition in which the generated power is less than the electric power demand in the ship is established. The method of claim 1,
Further comprising auxiliary device start detection means for detecting starting of the auxiliary device in the ship,
The charging condition includes a condition that the start of the auxiliary device is not detected by the auxiliary device start detection means, and the discharge condition includes a condition that the start of the auxiliary device is detected by the auxiliary device start detection means. Marine power generation system, characterized in that. The method of claim 2,
An exhaust gas reducer constituting the waste heat recovery system and flowing through the exhaust gas of the main engine;
A blower for injecting steam generated in the waste heat recovery system into the exhaust gas saver;
Further comprising a blow detecting means for detecting whether or not the blower is operating,
The charging condition includes a condition that the stop of the blower is detected by the blow detection means, and the discharge condition includes a condition that the operation of the blower is detected by the blow detection means. . The method of claim 2,
A steam system sending steam to a steam inlet of the steam turbine,
A governor valve installed in the steam system so as to change the lift amount to adjust a flow rate of steam sent to the steam inlet by changing the lift amount;
And a lift amount detecting means for detecting a lift amount of the governor valve,
The charging condition includes a condition that the lift amount detected by the lift amount detecting means is less than a first lift threshold, and the discharge condition is a second lift amount detected by the lift amount detecting means is greater than the first lift threshold. A power generation system for ships comprising the condition of a lift threshold value or more. The method of claim 2,
A water separator for constituting the waste heat recovery system and collecting the generated steam,
It is further provided with a pressure detecting means for detecting the internal pressure of the water separator,
The charging condition includes a condition that the internal pressure detected by the pressure detecting means is equal to or greater than a first pressure threshold, and the discharge condition includes a second pressure threshold whose internal pressure detected by the pressure detecting means is smaller than the first pressure threshold. Ship power generation system comprising a condition of less than.

Images