KR101464908B1 - Marine power generation system - Google Patents

Abstract

The marine power generation system 100 includes a battery 5 electrically connected to the generator 4 and is connected to the generator 4 by the waste heat when the load of the main engine is in a high load region and the engine room temperature is the reference temperature. The generated power is smaller than the total demand power WT that is larger than the continuous power WC continuously required in the ship and the power component WA temporarily and additionally required for the continuous power WC is smaller than the total demand power WT added by the waste heat, When the generated power of the generator 4 exceeds the power demand in the ship, the accumulator 5 is charged with the surplus power generated by the generator 4, and the generated power of the generator 4 by the waste heat becomes the power When the demand is lowered, the battery 5 is discharged to assist the generator 4 in driving.

Description

{MARINE POWER GENERATION SYSTEM}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a marine power generation system for driving a steam turbine with steam generated from waste heat of a main engine device and generating power according to an output of the steam turbine.

Large vessels are equipped with a power generation system that generates the necessary power 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 Application Laid-Open No. 2010-116847 Japanese Patent Application Laid-Open No. 5-65804 Japanese Patent Application Laid-Open No. 8-93410

However, when the main engine is operating at a low load, the amount of steam flowing into the steam turbine is reduced because the amount of exhaust gas and the amount of waste heat around the main engine become small. When the main engine is a diesel engine, the soot contained in the exhaust gas may be adhered to the exhaust gas economizer. In order to maintain the heat recovery efficiency of the waste heat recovery system, ) (soot blow) must be performed at appropriate intervals. When such a soot blow is performed using the steam generated in the waste heat recovery system, the amount of steam flowing into the steam turbine is reduced. If the amount of steam is reduced as described above, the output of the steam turbine becomes small, and there is a possibility that the power generation demand of the generator may not be able to be met.

In addition, the power demand in the vessel may temporarily become larger than the power used continuously. For example, when an intermittent auxiliary device such as a compressor of a refrigerating device mounted on a ship is operated, the power demand in the ship is a value obtained by adding the power required for the operation to the continuous power.

In the conventional marine power generation system, in a situation where the steam amount is small or the power demand of the ship is temporarily higher than the continuous power, by increasing the amount of steam supplied to the steam turbine by operating the auxiliary boiler, Diesel generators, and other generators. 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 also to a high degree of 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. However, in this case, even if the main engine is at a low load, it is necessary to ensure that the steam turbine generates a large output, leading to an increase in 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. Further, when the main engine is loaded at a high load, the power generation amount of the generator exceeds the power demand in the ship, and surplus power that is not utilized effectively occurs.

Therefore, it is an object of the present invention to provide a marine power generation system that can utilize fossil fuels as much as possible while meeting the power demand in a variable vessel, and can utilize it effectively 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 generated power of the generator due to the waste heat can sufficiently meet the power demand in the ship, the accumulator can be charged with the surplus power generated by the generator. Thus, even when the generator generates surplus power with respect to the power demand in the ship, the surplus power can be utilized effectively. In addition, even when the possible power of the generator due to the waste heat can not meet the power demand in the ship, the battery can be discharged to assist the generator. As a result, the power generation amount of the generator can be increased, and the case of operating the auxiliary boiler or the diesel generator can be reduced. This makes it possible to easily cope with fluctuations in the power that can be generated by the waste heat due to the load fluctuation of the main engine or even when the power demand in the ship fluctuates. 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. Therefore, the chance of charging and the opportunity of discharging occur during the voyage of the main engine without offsetting each other, so that the charging and discharging of the charger can be performed in a balanced manner.

And control means for controlling the charging and discharging of the battery, wherein the control means controls the charging and discharging of the battery when the generated power of the generator due to the waste heat satisfies a predetermined charging condition exceeding the power demand in the vessel A control is performed such that the battery is charged with surplus power and the battery is discharged to assist driving of the generator when a predetermined discharge condition is satisfied in which the power of the generator due to the waste heat is lower than the power demand in the ship .

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

Further comprising an auxiliary device starting detecting means for detecting the starting of the auxiliary device in the vessel, wherein the charging condition includes a condition that the starting of the auxiliary device is not detected by the auxiliary device starting detecting means, A condition that the start of the auxiliary device is detected by the auxiliary device startup detecting means.

According to the above configuration, when the power demand in the ship increases temporarily in accordance with the start of the auxiliary device, the electric power of the battery can be discharged in response to the increase in the electric power demand in the ship, thereby assisting the driving of the generator, .

A blower that constitutes the waste heat recovery system and injects steam generated in the waste heat recovery system in the exhaust gas saver, and a blower Wherein the blowing condition includes a condition that the blowing of the blower is detected by the blowing detection unit, and the discharge condition is that the operation of the blower is detected by the blowing detection unit Conditions may be included.

According to the above configuration, even if all of the steam generated by the waste heat recovery can not be used to drive the steam turbine due to the injection of the steam into the exhaust gas reduction device, the generated power of the generator due to waste heat is reduced, The discharge can help drive the generator. This reduces the chance of operating auxiliary boilers or diesel generators.

A steam line for supplying steam to the steam inlet of the steam turbine and a regulator for adjusting a flow rate of steam supplied to the steam inlet by varying a lift amount of the steam line, A governor valve and a lift amount detecting means for detecting a lift amount of the Governor valve, wherein the charging condition includes a condition that the lift amount detected by the lift amount detecting means is less than a first lift threshold value And the discharge condition may include a condition that the lift amount detected by the lift amount detecting means is not less 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 manner, the magnitude of the generated power of the generator due to the waste heat is determined according to the lift amount, and accordingly it is possible to appropriately determine whether the battery should be charged or discharged.

Further comprising: a brackish water separator constituting the waste heat recovery system for collecting 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 And the condition that the internal pressure is equal to or higher than the first pressure threshold may include a condition that the internal pressure detected by the pressure detecting means is less than a second pressure threshold value that is smaller than the first pressure threshold value.

According to the above arrangement, when the pressure of the steam increases, the steam turbine can generate a large output, and vice versa when the pressure is lowered. In this manner, the magnitude of the power that can be generated by the waste heat is determined according to the pressure of the steam, and accordingly it is possible to appropriately determine whether the battery should be charged or discharged.

According to the present invention, the use of fossil fuels can be controlled as much as possible while meeting the power demand in a variable vessel, and it is possible to suppress the enlargement of the waste heat recovery system. On the other hand, when surplus power can be generated in the generator It is possible to provide a marine power generation system capable of effectively utilizing this.

The above and 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 marine 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 the sequence of charge / discharge control executed by the main controller.

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 the drawings, and redundant explanations are omitted.

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 marine power generation system 100 shown in Fig. 1 is mounted on a ship provided with a marine diesel engine 1 (hereinafter simply referred to as " engine ") as a main engine.

The marine power generation system 100 includes a waste heat recovery system 2 for recovering waste heat around the engine 1 to generate steam, a steam turbine 3 driven by steam generated in the waste heat recovery system 2, 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 heater 23, a high pressure drum (high pressure brackish water separator) 24, (Intermediate pressure water separator) 25, a low pressure drum (low pressure water separator) 26, a high pressure circulating water system 27, a steam system 28, a medium pressure circulating water system 29, 30, a low-pressure circulating water system 31, a low-pressure evaporator 32, and a low-pressure refrigeration system 33. 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 has an exhaust pipe 1a for introducing the exhaust gas to an exhaust outlet such as a chimney. The exhaust gas reducer 10 is interposed between the exhaust pipe 1a and the exhaust outlet, and constitutes a part of the exhaust system. A bypass tube 8 bypassing the exhaust gas reducer 10 is connected to the exhaust pipe 1a and the inlet of the exhaust gas reducer 10 and the inlet of the bypass pipe 8 are connected to a damper and is opened and closed by a damper 9a and a damper 9b, respectively. 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 amount of exhaust gas is insufficient, 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 reducer 10 includes an inlet pipe 11, a high-pressure evaporator 12, an intermediate pipe 13, a middle-pressure evaporator 14, and an outlet pipe 15 in this order from 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) leads the exhaust gas after heat exchange in the high pressure evaporator (12) to the intermediate pressure evaporator (14). The outlet pipe (15) directs the exhaust gas after heat exchange in the intermediate-pressure evaporator (14) to the exhaust outlet.

Since the soot in the exhaust gas can be attached to the high-pressure evaporator 12 and the intermediate-pressure evaporator 14 in the course of the exhaust gas flowing through the exhaust gas reducer 10, the exhaust gas reducer 10 can remove soot A first soot blower 16 and a second soot blower 17 for blowing and dropping. Each soot blower 16 and 17 is connected to at least one of the high pressure drum 24, the intermediate pressure drum 25 and the low pressure drum 26 through a blow system (not shown) . 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 ejection openings for ejecting the supplied steam toward the intermediate-pressure evaporator 14.

The condenser 21 is connected to the steam outlet 3a of the steam turbine 3 to condense the steam flowing out from 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 of 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 feed water 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 for detecting the internal pressure of the high pressure drum 24 (the pressure of the steam collected in the high pressure drum 24). The second pressure sensor 42 and the third pressure sensor 43 are also provided to the intermediate 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 line 28 connects the high pressure drum 24 to the steam inlet 3b of the steam turbine 3. When the pump 27P on the line 27a operates, the circulating water in the high-pressure drum 24 is sent through the line 27a into 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 intermediate pressure circulating water system 29 has a line 29a connecting the intermediate pressure drum 25 to the intermediate pressure evaporator 14 and a line 29b connecting the intermediate pressure evaporator 14 to the intermediate 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 operates, the circulating water in the intermediate pressure drum 25 is sent into the intermediate-pressure evaporator 14 through the line 29a, 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. [ The steam in the intermediate pressure drum 25 is supplied to the intermediate pressure inlet 3c of the steam turbine 3 through the intermediate-pressure dynamo 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 dynamo system 33 connects the low pressure drum 26 to the low pressure dew condensation inlet 3d of the steam turbine 3. When the pump 31P on the line 31a operates, the circulating water in the low pressure drum 26 is sent through the line 31a into the low pressure evaporator 32. [ 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 chrome inlet 3d of the steam turbine 3 through the low-pressure chrome system 33.

The steam turbine (3) is a multi-stage turbine having a plurality of blades. The steam turbine 3 rotates the blades by the steam supplied to the steam inlet 3b, the intermediate pressure steam supplied to the intermediate pressure steam inlet 3c and the low pressure steam supplied to the low pressure steam inlet 3d, And a rotation output is generated in the output shaft 3e.

The steam system 28 has an upstream line 28a on the drum side and a downstream line 28b on the turbine side. A superheater 35 is interposed between the upstream line 28a and the downstream line 28b. The steam system 28 includes a bypass line 28c that bypasses the superheater and couples the upstream line 28a and the downstream line 28b to each other when the steam from the high pressure drum 24 is sent to the steam inlet 3b And a valve unit 34 for controlling whether to pass the superheater 35 or not. The valve unit 34 includes a first opening and closing valve 34a for allowing or blocking the passage of steam through the bypass line 28c and a second opening and closing valve 34a for allowing or blocking passage of the steam through the superheater 35. [ And a relief valve 34c for partially discharging the steam passing through the superheater. The superheater 35 is installed in the inlet pipe 11 of the exhaust gas reducer 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.

The steam system 28 is provided with an inlet valve and a Governor valve 36 as an additive valve on the downstream side of the valve unit 34 (i.e., on the side of the steam inlet 3b). 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. The output of the steam turbine 3 can be increased when the Governor valve 36 and the inlet valves 37 and 38 operate to increase the flow rate of the steam. 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 an auxiliary boiler 24a. The auxiliary boiler 24a can heat 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 generated by the steam generated based only on the recovered waste heat, without depending on the reheating of the auxiliary boiler 24a, will be referred to as "the output of the steam turbine 3 by the waste heat" The possible power of the generator 4 when the generator 4 is driven in accordance with the output of the steam turbine 3 due to the waste heat will be referred to as " possible power of the generator 4 due to waste heat " The intermediate pressure drum 25 and the low pressure drum 26 are provided with heaters 25a and 26a, respectively. Each of the heaters 25a and 26a receives steam from the high pressure drum 24 through the steam system 28 (see FIG. 1), thereby heating the circulating water in the drums 25 and 26, 25, 26).

The generator 4 generates electric power in accordance with the pressure or flow rate of the steam and the hydrogen supplied to the steam turbine 3 from the output of the steam turbine 3, that is, the waste heat recovery system 2. When the steam pressure and the flow rate are likely to be small because the engine load is low or when 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, The output of the steam turbine 3 by the steam turbine 3 becomes relatively small, so that the power that can be generated by the waste heat can be lower 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 battery 5 is electrically connected to the generator 4 through a sub-controller 7 described later. Therefore, when the generator 4 can generate electric power exceeding the electric power demand in the ship, it is possible to charge the storage battery 5 with surplus electric power. In addition, when the generator 4 can generate only power lower than the power demand, the battery 5 can be discharged to help the generator 4. The storage battery 5 is suitably selected among various kinds of storage batteries such as a nickel-hydrogen storage battery, a nickel / iron storage battery, a nickel / cadmium storage battery, a nickel / zinc storage battery, a lead storage battery, and a lithium ion secondary battery.

The nickel-metal hydride battery is relatively easy to handle due to the small voltage change due to SOC change in the middle of the state of charge (SOC) compared with other kinds of batteries, It can eliminate the risk of fire, and is lead-free, mercury-free, and non-cadmium, which is advantageous in terms of environmental friendliness.

It is preferable to employ a structure for reducing the internal resistance in the nickel-metal hydride battery. As a result, it is possible to improve the cooling performance, suppress the temperature rise due to high current charging and discharging, enable charging and discharging at high efficiency and high speed, improve the cycle durability, Can be used for a long time. It is also preferable to adopt a non-bonded structure in which the battery material and the electrode are not welded to the nickel-hydrogen storage battery. As a result, the recycling performance is improved, and assembly and disassembly can be facilitated. By adopting such a structure, it can be suitably used as a battery which can interact with the characteristics of a nickel-metal hydride battery and endure long-term voyage.

In addition to the first pressure sensor 41, the second pressure sensor 42, the third pressure sensor 43 and the lift amount sensor 44, the input side of the main controller 6 is connected to the blow switch 45 and the auxiliary And is connected to the device start switch 46. The blow switch 45 detects whether the first soap blower 16 and / or the second soap blower 17 are operating, or whether the first soap blower 16 and the second soap blower 17 are stopped . The auxiliary device start switch 46 detects whether or not an intermittent mechanism such as a compressor of the refrigerating apparatus is starting. A sub-controller 7 is connected to the output side of the main controller 6. [ The sub controller 7 controls the charging and discharging of the battery 5 according to a command from the main controller 6 and the AC / DC conversion control of the alternating current from the generator 4 at the time of charging, , DC / AC conversion control of the discharge DC from the DC / AC conversion, frequency control of the AC generated by the DC / AC conversion, synchronous control of the generated AC and the AC generated by the generator 4, and the like.

Fig. 2 is a graph showing the relationship between the engine load and the possible power of the generator 4 due to the waste heat. The abscissa represents the engine load as a percentage of 100% of the total load, and the ordinate represents the possible power of the generator 4 due to the waste heat as a percentage of the total demand power of the ship as 100%. The line WT represents the total demand power in the ship and the line WC represents the ratio of the continuous power to the total demand power (WT). These are drawn parallel to the transverse 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 the power always required during normal voyage of the ship. On the other hand, during voyage, a demand for electric power different from the continuous power (WC) may be generated temporarily, for example, when the compressor of the refrigeration apparatus is started. The total demand power WT is a value obtained by adding the power WA temporarily and additionally required to the continuous power WC. In the present embodiment, the continuous power WC is about 83% of the total demand power WT (WC? WT x 0.83, WA? WT x 0.17). In other words, the total demand power WT becomes a value obtained by adding an additional power WA of about 20% of the continuous power WC to the continuous power WC (WA? WC x 0.20, WT? WC x 1.20 ). Line A, line B and line C show an example of a characteristic diagram 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 the 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. Conversely, when the engine load is the full load, the generator 4 generates electric power exceeding the total demand electric power WT, and surplus electric power at that time is not effectively utilized and is discarded.

On the other hand, the marine power generation system 100 according to the present embodiment includes the storage battery 5 electrically connected to the generator 4, as described above. Therefore, when the engine load is high and the generated power of the generator 4 due to waste heat can sufficiently meet the power demand in the ship, the storage battery 5 is charged with the surplus power generated by the generator 4 can do. Conversely, when the generated power of the generator 4 due to the waste heat can not meet the power demand in the ship, the battery 5 can be discharged to help the generator 4. Accordingly, it is possible to save the fossil fuel required for reheating the auxiliary boiler 24a and for operating the diesel generator, and it is possible to reduce the cost and the energy saving.

In this way, since the electric power demand in the ship can be covered not only by the electric energy obtained from the waste heat but also by the electric energy generated by the generator 4 on the basis of the electric power stored in the battery 5, The design point of the generator 4 can be made lower than in the past. 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 power of the generator 4 due to the waste heat under the condition that the engine room temperature and the engine load are the same.

In this case, the drop width of the design point can correspond to the electric power that can be generated by discharging the battery 5 and helping the generator 4 to be driven. At this time, when the engine load is within a range from 80% load to 95% load and the generator 4 generates electric power that is generated by the waste heat when the engine room temperature is 20 to 40 degrees is greater than the continuous power WC, (WT). For example, as shown in Fig. 2, when the drop width of the design point is 10% of the total demand power WT and the engine load is in a high load region (for example, 90% load) near the entire load Is preferably set to a value exceeding the continuous power (WC). By setting in this way, it is possible to balance the charging opportunity and the discharging opportunity without bias to either the charging or the discharging.

In this way, under the condition that the engine room temperature and the engine load are the same, when it is intended to reduce the power that can be generated by the waste heat of the generator 4 from the conventional one, the exhaust gas reducer 10 is miniaturized to reduce the amount of heat recovery from the exhaust gas , Or attempt to miniaturize the steam turbine 3 or to do so. Therefore, it is possible to reduce the size of the waste heat recovery system 2 and the steam turbine 3, and it is possible to reduce the overall size and cost of the marine power generation system 100. Therefore, it is possible to mount such a power generation system in a small ship which can not mount a power generation system with a heat recovery system in the past due to its size and cost, and thus it is possible to widely promote energy saving in the ship industry.

Hereinafter, charge / discharge control performed in the marine power generation system 100 according to the present embodiment will be described. 3 is a graph showing the relationship between the power that can be generated by waste heat and the internal pressure of the high-pressure drum 24 (i.e., the steam pressure in the high-pressure drum 24), the power that can be generated by the waste heat, The degree of correlation with the charge amount, the degree of correlation between the possible power due to the waste heat and the planned point, and the concept of charge / discharge control. The " planned point " is a point where the power demand in the ship is balanced with the possible power of the generator 4 due to the waste heat.

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

On the other hand, the higher the internal pressure P of the high-pressure drum 24, the higher the power that can be generated by the generator 4 due to the waste heat. Therefore, if the internal pressure P of the high-pressure drum 24 exceeds the commercial pressure PN, the generated power of the generator 4 by the waste heat produces an excess for the power demand in the ship. Conversely, if the internal pressure P of the high-pressure drum 24 is lower than the normal pressure PN, the generated power of the generator 4 due to the waste heat is insufficient for the power demand in the ship.

Further, when the lift amount L of the Governor valve 36 is the predetermined value LN and the internal pressure P is in the normal pressure region, the generator 4 generates the generated power indicated by the planned point . On the other hand, as the lift amount L is larger, the power that can be generated by the generator 4 due to the waste heat decreases. Therefore, if the lift amount L is less than the predetermined value LN, the generated power of the generator 4 by the waste heat produces an excess to 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 to a lower value in the normal pressure range or the lift amount of the Governor valve exceeds a predetermined value, the generator 4 generates power The reheating of the auxiliary boiler or the operation of the diesel generator was automatically carried out assuming that the electric power demand could not be covered.

The main controller 6 according to the present embodiment is designed such that the internal pressure P of the high-pressure drum 24 detected by the first pressure sensor 41 during discharge is higher than the upper limit of the commercial pressure range, The controller 5 instructs the secondary controller 7 to charge the storage battery 5 first. 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.

The main controller 6 determines whether or not the internal pressure P of the high-pressure drum 24 detected by the first pressure sensor 41 is lower than the lower limit value of the normal- When the pressure falls below the second pressure threshold value (P2), the secondary controller (7) is instructed to discharge the battery (5). The main controller 6 determines whether or not the lift amount L of the governor valve 36 detected by the lift amount sensor 44 is equal to the second lift threshold value L2 that is higher than the predetermined value LN, If the abnormality occurs, the secondary controller 7 instructs the battery 5 to discharge.

As described above, the threshold values (P1, L1) at the time of transition from discharging to charging and the threshold values (P2, L2) at the time of transition from charging to discharging have hysteresis. Therefore, it is preferable that the transition of the charge / discharge frequently occurs when the internal pressure P of the high-pressure drum 24 and the lift amount L of the governor valve 36 are controlled to be close to the planned point . More specifically, the high-pressure drum 24 has a slow time constant that changes due to heat accumulation of its 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.

When the internal pressure P is lower than the third pressure threshold value P3 which is lower than the second pressure threshold value P2 or the lift amount L is higher than the second lift threshold value L2 It may be possible to reheat the auxiliary boiler 24a in such a manner that the electric power demand in the vessel can not be supplied even with the help of the battery 5 and the auxiliary boiler 24a can be reheated. When the inner pressure P is lower than the fourth pressure threshold value P4 which is lower than the third pressure threshold value P3 or the fourth lift threshold value L4 whose lift amount L is higher than the third lift threshold value L3, The diesel generator may be driven so that the power demand in the vessel can not be supplied even if the reheating of the battery 5 and the auxiliary boiler 24a is assisted. As described above, after the assistance of the accumulator 5 is given top priority and the reheating of the auxiliary boiler 24a and the driving of the diesel generator are provided as a backup function, the frequency of use of the fossil fuel is greatly suppressed It is possible to provide a power generation system that can meet the power demand in the ship even when the power that can be generated by the waste heat is extremely insufficient. 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. Further, the stop of the diesel generator may be manually performed without being subjected to 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 value P1 or the lift amount L is less than the first lift threshold value L1 and the internal pressure P is equal to or greater than the first pressure threshold value P1, Or may be a condition that the lift amount L is equal to or larger than the fifth pressure threshold value P5 which is a higher value or less than the fifth lift threshold value L5 which is lower than the first lift threshold value L1.

Fig. 4 is a flowchart showing the sequence of charge / discharge control performed by the main controller 6. Fig. The main controller 6 determines whether the battery is being discharged or 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). Further, the main controller 6 can determine whether or not the power demand in the vessel is increasing, in accordance with the input from the auxiliary device start switch 46. When the starting of the auxiliary device is detected by the auxiliary device start switch 46, the electric power demand in the vessel exceeds the continuous electric power, so that it can be judged that the electric power demand in the vessel is increasing at this time. Further, the main controller 6 can judge whether or not soot blowing is performed according to the input from the blow switch 45. [ The main controller 6 determines that the discharge condition is satisfied and instructs the sub controller 7 to discharge the battery 5 when there is an increase in the electric power demand in the ship or the execution of soot blowing (S2: YES) (Step S5). Thus, even if there is a concern that the generated power of the generator 4 due to the waste heat can not cover the power demand in the ship, the generator 4 is driven to assist the generator 4 as the battery 5 continues to discharge, Can be increased.

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). The main controller 6 determines whether or not the internal pressure P of the high-pressure drum 24 is equal to or higher than the first pressure threshold value P1 (S3: NO), if the lift amount L is not less than the first lift- (Step S4). If the internal pressure P of the high-pressure drum 24 is less than the first pressure threshold P1 (S4: NO), the main controller 6 determines that the discharge condition is satisfied, 5) (step S5). Thus, even if there is a concern that the generated power of the generator 4 due to the waste heat can not cover the power demand in the ship due to low engine load or the like, the generator 5 can be driven 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 higher than the first pressure threshold P1 during the discharge (S3: YES or S4: YES) The controller 6 determines that the charging condition is established and instructs the secondary controller 7 to charge the storage battery 5 (step S6). Thereby, it is possible to sufficiently utilize the steam generated by the waste heat recovery without driving the intermittent equipment, the power demand of the ship near the continuous power (WC), or the soot blowing is not carried out and the steam turbine 3 Or the generator 4 due to the waste heat exceeds the power demand in the ship due to reasons such as high engine load and engine room temperature, the surplus power can be charged in the storage battery 5, Can be effectively utilized.

If the battery 5 is being charged (S1: NO), it is determined whether there is an increase in power demand or a soot blow in the ship as in the above case (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).

The main controller 6 determines whether or not the lift amount L is equal to or greater than the second lift threshold value L2 (step S22: NO) 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 more than the second pressure threshold value P2 (S24: NO), the main controller 6 determines that the charging condition is satisfied, 5) (step S25).

If the lift amount L is equal to or larger than the second lift threshold value L2 or the internal pressure P of the high-pressure drum 24 is less than the second pressure threshold value P2 (S23: YES or S24: YES) The controller 6 determines that the discharge condition is satisfied and issues a command to the secondary controller 7 to discharge the battery 5 (step S26).

Accordingly, even when the charging is being performed, when there is a concern that the generated power of the generator 4 due to the waste heat can not cover the power demand in the ship, the generator 5 can be driven by the discharge of the battery 5, It is possible to increase the amount of power generated by the battery 4. Further, when the generated power of the generator 4 due to the waste heat exceeds the power demand in the ship, the surplus power can be continuously charged to the storage battery 5, and the surplus 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. Accordingly, the above description is to be construed as illustrative only and is for the purpose of teaching those skilled in the art the best mode of 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, the detection results of the second pressure sensor and the third pressure sensor may be considered in the charging condition or the discharging condition in the same manner as the first pressure sensor.

SUMMARY OF THE INVENTION [0008] The present invention is directed to a fuel cell system capable of coping with power demand in a variable vessel while restraining the use of fossil fuels as much as possible and restraining the enlargement of the waste heat recovery system, In addition to the vessels that have been equipped with a marine power generation system that has the effect of providing a marine power generation system that can be utilized and which has been equipped with a waste heat recovery system from the past, It can be widely applied to a small-sized ship which was not available.

100: Marine power generation system
1: Marine diesel engine
2: Waste Heat Recovery System
3: Steam turbine
4: generator
5: Battery
6: Main controller
7: Subcontroller
10: Exhaust gas saving
16, 17: soot blower
24: High pressure drum
25: Heavy duty drum
26: Low pressure drum
28: Steam system
30: Medium pressure system
33: Low-pressure system
36: Governor valve
37, 38: inlet valve
41: first pressure sensor
42: Second pressure sensor
43: Third pressure sensor
44: Lift 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-driven steam turbine generated by the waste heat recovery system,
A generator driven by the output of the steam turbine to generate electricity;
And a battery electrically connected to the generator,
Wherein the generator is capable of generating power that can be generated by the waste heat when the load of the main engine is in a high load region where the load of the main engine is in the range of 80% load to 95% load is larger than the continuous power continuously required in the ship, And the additional required power component is configured to be smaller than the added total demand power,
The battery is charged with surplus power generated by the generator when the possible power of the generator due to the waste heat exceeds the power demand in the ship and the generated power of the generator by the waste heat is lower than the power demand in the ship The generator is discharged in order to facilitate the driving of the generator. The method according to claim 1,
And control means for controlling charge and discharge of the battery,
Wherein the control means charges the storage battery with surplus electric power generated by the generator when a predetermined charging condition indicating that the possible electric power of the generator due to the waste heat exceeds the electric power demand in the ship is satisfied, Wherein the controller is configured to perform control for discharging the battery and assisting driving of the generator when a predetermined discharge condition indicating that the generator's possible electric power is lower than the electric power demand in the ship is established. 3. The method of claim 2,
Further comprising an auxiliary device starting detecting means for detecting the starting of the auxiliary equipment in the ship,
Wherein the charging condition includes a condition that the starting of the auxiliary device is not detected by the auxiliary device startup detecting means and the discharge condition includes a condition that the starting of the auxiliary device is detected by the auxiliary device startup detecting means Wherein said power generation system comprises: 3. The method of claim 2,
A waste heat recovery system constituting the waste heat recovery system, comprising an exhaust gas reducer through which the exhaust gas of the main engine flows,
A blower for injecting the steam generated in the waste heat recovery system into the exhaust gas reducer,
Further comprising a blow detecting means for detecting whether or not the blower is operating,
Wherein said charging condition includes a condition that the blowing of said blower is detected by said blowing detecting means and said discharging condition includes a condition that the operation of said blower is detected by said blowing detecting means . 3. The method of claim 2,
A steam system for sending steam to the steam inlet of the steam turbine,
A governor valve for adjusting the flow rate of the steam sent to the steam inlet by changing the lift amount of the valve,
Further comprising a lift amount detecting means for detecting a lift amount of the Governor valve,
Wherein the charging condition includes a condition that the lift amount detected by the lift amount detecting means is less than a first lift threshold value set for the lift amount, and the discharge condition is a condition in which the lift amount detected by the lift amount detecting means And a second lift threshold value that is greater than a lift threshold value and is equal to or greater than a second lift threshold value set for the lift amount. 3. The method of claim 2,
A water separator for constituting the waste heat recovery system and collecting the generated steam,
Further comprising pressure detecting means for detecting the internal pressure of the water separator,
Wherein said charging condition includes a condition that an internal pressure detected by said pressure detecting means is equal to or greater than a first pressure threshold value determined with respect to an internal pressure, and wherein said discharge condition is such that an internal pressure detected by said pressure detecting means is higher than said first pressure threshold value And a condition that the second pressure threshold value is smaller than a second pressure threshold value determined with respect to the internal pressure.

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