JP5232766B2 - Ship engine control system - Google Patents

Description

  The present invention relates to an engine control system for a ship provided with an exhaust heat recovery facility that generates electric power using exhaust heat of an internal combustion engine directly connected to a propeller.

Generally, a ship uses a propeller driven by an internal combustion engine, which is the main engine, to obtain propulsive power. In order to effectively use the exhaust heat of the main engine, the ship generates power using the exhaust heat and uses the generated power to Covered the load power.
For example, in Patent Document 1 (Japanese Patent Laid-Open No. 2007-1339), in a waste heat recovery facility for a ship having a combined propulsion system of a main engine and electric propulsion, high pressure steam and low pressure steam are generated by exhaust heat of the main engine. A configuration is disclosed in which high-pressure steam and low-pressure steam are divided and introduced into a turbine that generates electric power for electric propulsion of a ship.

  FIG. 6 is an example of a conventional ship engine control system. The main equipment 61 and the exhaust heat recovery equipment 71 are mounted on the ship. In the main equipment 61, the intake air compressed on the compression side of the turbocharger 64 is cooled by the intake air cooler 65 and supplied to the main equipment 62, and the propeller 63 is driven by the main equipment 62. The exhaust gas discharged from the main machine 62 is introduced to the turbine side of the turbocharger 64. In the exhaust heat recovery equipment 71, the exhaust gas discharged from the main engine 62 passes through the turbocharger 64 and is then introduced into the exhaust gas economizer 72, and the exhaust gas economizer 72 generates steam by exhaust heat of the exhaust gas. The generated steam is introduced into the steam turbine 73 and drives a generator 74 connected to the steam turbine 73 to generate power. The generated power is used, for example, in ship power use facilities such as a refrigerator in a cargo compartment and an air conditioning facility in a residential area. The steam discharged from the steam turbine 73 is condensed by the condenser 73 and then returned to the exhaust gas economizer 72.

  The exhaust gas flow rate introduced into the exhaust gas economizer 72 is provided on the exhaust gas flow rate adjusting valve 81 provided on the line that sends the exhaust gas from the turbocharger 64 to the exhaust gas economizer 72 and on the line that bypasses the exhaust gas economizer 72 and discharges the exhaust gas. The bypass amount adjustment valve 82 is adjusted. Further, a steam flow rate adjusting valve 83 for controlling the flow rate of steam introduced into the steam turbine 73 is provided on a line for sending steam from the exhaust gas economizer 72 to the steam turbine 73, and the steam flow rate adjusting valve 83 is opened by the governor 84. Be controlled.

The ship engine control system controls each of the main engine control device 66 that controls the fuel injection amount control of the main engine 62, the exhaust gas flow rate adjustment valve 81, the bypass amount adjustment valve 82, the governor 84, etc. of the exhaust heat recovery equipment 71. And a PMS (Power Management System) 76. Conventionally, the main machine control device 66 and the PMS 76 are controlled independently of each other.
As shown in FIG. 7, the main engine control device 66 detects the propeller rotational speed with a sensor, calculates a propeller rotational speed command value that is a target value that allows the ship to achieve a desired ship speed, and transmits the propeller rotational speed command. The control deviation is obtained by subtracting the detected value of the propeller rotation number from the value, and the PID control calculation is performed by the controller based on the control deviation, and the fuel injection amount is derived to control the fuel injection device of the main engine.

JP 2007-1339 A Japanese Patent Laying-Open No. 2005-042600

  In the above-described system, since a large internal combustion engine is generally used in a ship, the amount of heat of exhaust gas discharged from the internal combustion engine is large. Therefore, in order to further improve the power generation efficiency, it is preferable to provide a gas turbine having a higher power generation efficiency than the steam turbine in addition to the steam turbine conventionally used as a driving means for the generator. However, waste heat recovery equipment with steam turbines and gas turbines has been used for land power generation facilities, etc., but simply using this waste heat recovery equipment for ships can cause fluctuations in ship load power. The speed and acceleration of the ship may become unstable due to the response delay of the control system.

  Therefore, in view of the problems of the prior art, the present invention provides a ship engine control system that has high exhaust heat recovery efficiency and can stably control the speed and acceleration of the ship even when the load power on the ship fluctuates. The purpose is to do.

  Therefore, in the engine control system for a ship according to the present invention, the compression side of the supercharger is disposed in the intake system of the internal combustion engine that drives the propeller, and a part of the exhaust gas discharged from the internal combustion engine is disposed on the turbine side of the supercharger. An internal combustion engine facility to be introduced into the steam generator, steam generated by steam generating means using exhaust gas that has passed through the turbine side of the turbocharger, and a generator connected to the steam turbine by introducing the steam into the steam turbine In a ship engine control system equipped with a driving exhaust heat recovery facility, the exhaust heat recovery facility is connected to the steam turbine via a shaft and is introduced with another exhaust gas discharged from the internal combustion engine. And a basic fuel of the internal combustion engine based on a deviation between a propeller rotational speed command value that is a target value of the rotational speed of the propeller and a detected value of the propeller rotational speed detected from the propeller A feedback control unit for deriving an injection amount, a power generation amount command value for the gas turbine, a correction value calculation unit for deriving a correction value for the fuel injection amount of the internal combustion engine from the load of the internal combustion engine, and the basic fuel injection An internal combustion engine control means having a feedforward control unit for deriving an actual fuel injection amount by adding the correction value to the amount is provided.

According to the present invention, by providing a gas turbine that is connected to a steam turbine via a shaft and into which other exhaust gas discharged from an internal combustion engine is introduced, the exhaust heat recovery efficiency is higher than when power is generated by the steam turbine alone. Can be improved.
However, if the exhaust gas from the internal combustion engine is sent to the gas turbine separately from the exhaust gas introduced into the turbocharger, the flow rate of the exhaust gas sent to the turbine side of the turbocharger fluctuates due to sudden load fluctuations of the generator. The scavenging air pressure of the internal combustion engine may fluctuate. As a result, an appropriate fuel injection amount cannot be ensured with respect to the scavenging pressure of the internal combustion engine, the engine output becomes unstable, and the speed and acceleration of the ship may fluctuate in an unstable manner.

On the other hand, in the present invention, the internal combustion engine control means has a power generation amount command value of the gas turbine for a basic fuel injection amount that is derived based on a deviation between the propeller rotation speed command value and the propeller rotation speed detection value. The correction value derived based on the load of the internal combustion engine is added to derive the fuel injection amount that is actually controlled, so even if there is a sudden load fluctuation in the generator, Therefore, it is possible to secure an appropriate fuel injection amount and to prevent the engine output from fluctuating in an unstable manner. Therefore, it is possible to stably control the speed and acceleration of the ship.
The propeller rotation speed detection value may be detected by a sensor installed on the propeller, or may be calculated from the rotation speed of the internal combustion engine.

  The exhaust heat recovery facility is provided on a line for sending other exhaust gas discharged from the internal combustion engine to the gas turbine, and an exhaust gas flow rate adjustment valve for adjusting an exhaust gas flow rate introduced into the gas turbine; It is preferable to include a bypass line for branching other exhaust gas discharged from the internal combustion engine and sending the branched exhaust gas to the steam generation means, and a bypass amount adjusting valve provided on the bypass line.

  In this way, the exhaust heat recovery facility includes the exhaust gas flow rate adjustment valve and the bypass amount adjustment valve, so that the flow rate (extraction amount) of other exhaust gas sent to the exhaust heat recovery facility side can be adjusted to be constant, As a result, the scavenging pressure of the internal combustion engine can be kept constant. However, although the scavenging air pressure may fluctuate when the control is switched due to a delay in the response of the valve, the engine output is stabilized by performing the feedforward control for adding the correction value to the basic fuel injection amount as described above. It is possible.

The correction value calculation unit is preset with a map representing a correlation between the power generation amount command value of the gas turbine, the load of the internal combustion engine, and the correction value of the fuel injection amount. It is preferable to derive the correction value.
As described above, the correction value can be easily derived by using the map representing the correlation between the power generation amount command value of the gas turbine, the load of the internal combustion engine, and the correction value of the fuel injection amount. Note that the correlation between the power generation amount command value of the gas turbine, the load of the internal combustion engine, and the correction value of the fuel injection amount may be obtained experimentally or by simulation.

Furthermore, a relational expression between the power generation amount command value of the gas turbine, the load of the internal combustion engine, and the correction value of the fuel injection amount is set in advance in the correction value calculation unit, and based on the relational expression, It is preferable to derive a correction value.
Thus, by using the relational expression of the power generation amount command value of the gas turbine, the load of the internal combustion engine, and the correction value of the fuel injection amount, the data amount set in advance in the internal combustion engine control means can be reduced. .

As described above, according to the present invention, a gas turbine connected to a steam turbine via a shaft and into which other exhaust gas discharged from the internal combustion engine is introduced, compared with a case where power is generated only by the steam turbine. This makes it possible to improve the exhaust heat recovery efficiency.
Further, the internal combustion engine control means determines whether the power generation amount command value of the gas turbine and the load of the internal combustion engine are relative to the basic fuel injection amount derived based on the deviation between the propeller rotational speed command value and the propeller rotational speed detection value. Since the actual fuel injection amount is derived by adding the correction values derived based on this, the amount of exhaust gas sent to the turbine side of the turbocharger fluctuates due to a sudden load fluctuation of the generator, and the internal combustion engine is swept away. Even when the air pressure fluctuates, it is possible to secure an appropriate fuel injection amount with respect to the scavenging air pressure, and to prevent the engine output from fluctuating in an unstable manner. Therefore, it is possible to stably control the speed and acceleration of the ship.

1 is an overall configuration diagram including main machine equipment and exhaust heat recovery equipment according to an embodiment of the present invention. 1 is a configuration diagram of an engine control system according to an embodiment of the present invention. It is a block diagram explaining the arithmetic processing of a main machine control apparatus. It is a flowchart which shows the arithmetic processing of a main machine control apparatus. FIG. 7 is a block diagram for explaining arithmetic processing of the main engine control device in the modification of FIG. 3. It is a whole block diagram including the conventional main machine equipment and waste heat recovery equipment. It is a block diagram explaining the arithmetic processing of the conventional main machine control apparatus.

  Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. However, the dimensions, materials, shapes, relative arrangements, and the like of the components described in this embodiment are not intended to limit the scope of the present invention unless otherwise specified, but are merely illustrative examples. Not too much.

FIG. 1 is an overall configuration diagram including a main machine facility 1 and an exhaust heat recovery facility 10 according to an embodiment of the present invention.
The main machine facility 1 mainly cools the main machine 2 which is an internal combustion engine, a propeller 3 connected to the main machine 2, a turbocharger (supercharger) 5 disposed in the intake system of the main machine 2, and the main machine 2. A main cooler 8 that cools the intake air, and an intake air cooler 9 that cools the intake air.

  The main engine 2 rotationally drives the propeller 3 connected via the propeller shaft to obtain the main propulsive force of the ship. A reduction gear may be interposed between the main machine 2 and the propeller 3. The main engine 2 includes a fuel injection valve that injects fuel into the cylinder and a fuel injection pump that supplies fuel to the fuel injection valve (not shown), and is based on the fuel injection amount controlled by the fuel injection pump. The output is determined.

The turbocharger 5 has a configuration in which a compressor 6 disposed in an intake line 31 of the main engine 2 and a turbine 7 disposed in an exhaust line (first exhaust gas line) 32 are connected via a shaft. The turbine 7 is rotated by the energy of the exhaust gas, and the intake air is compressed by the compressor 6 by this rotational force and is supplied to the main engine 2.
The main unit cooler 8 cools the main unit 2 by flowing cooling water through the jacket of the main unit 2.
The intake air cooler 9 cools the intake air supplied from the compressor 6 to the main engine 2 using the cooling water discharged from the main engine cooler 8.

  The exhaust heat recovery equipment 10 mainly includes an exhaust gas economizer 11 that generates steam from the exhaust gas of the main engine 2, a steam drum 12 provided in the exhaust gas economizer 11, and a steam turbine 15 that is driven by the steam generated by the exhaust gas economizer 11. And a generator 16 driven by the steam turbine 15 and a power turbine 21 driven by the exhaust gas of the main engine 2.

The exhaust gas economizer 11 is introduced with exhaust gas that has passed through the turbine 7, exhaust gas that has passed through the power turbine 21, and the like, and heats water with these exhaust gases to generate steam. The generated steam is separated into steam and water by the steam drum 12, a part of the steam is sent to the inboard steam utilization facility 48, and the water is returned to the exhaust gas economizer 11. The other steam is returned to the exhaust gas economizer 11 and superheated to generate superheated steam.
The steam turbine 15 receives the superheated steam generated by the exhaust gas economizer 11 and is rotationally driven by this steam.

The generator 16 is connected to the steam turbine 15 via a shaft and is driven by the steam turbine 15 to generate power. A speed reducer 17 is interposed between the generator 16 and the steam turbine 15. The electric power generated by the generator 16 is sent to the inboard power utilization facility 49. Examples of the onboard power utilization facility 49 include a refrigerator in a cargo compartment, an air conditioning facility in a residential area, and the like.
The power turbine 21 is a large gas turbine that is driven by exhaust gas, and is connected to the steam turbine 15 via a shaft and drives the generator 16 together with the steam turbine 15. A reduction gear 22 and a clutch 23 are interposed between the power turbine 21 and the steam turbine 15. The power distribution between the steam turbine 15 and the power turbine 21 may be determined according to the engine load of the main engine 2.

In the exhaust heat recovery facility 10 described above, a part of the exhaust gas discharged from the main engine 2 is introduced into the turbine 7 through the first exhaust gas line 32 and then introduced into the exhaust gas economizer 11 through the exhaust gas line 36. The
Other exhaust gas discharged from the main engine 2 is introduced into the power turbine 21 through the second exhaust gas line 33 and then introduced into the exhaust gas economizer 11 through the exhaust gas line 36. Note that most of the exhaust gas discharged from the main engine 2 is discharged to the first exhaust gas line 32.

An exhaust gas line 36 directed to the exhaust gas economizer 11 is branched in the middle, and a bypass line 37 that bypasses the exhaust gas economizer 11 is provided.
The exhaust gas passing through the exhaust gas line 36 is adjusted in the exhaust gas flow rate adjusting valve 44 to the exhaust gas economizer 11, and the exhaust gas flow rate adjusted by the bypass amount adjusting valve 45 passes through the bypass line 37, and the exhaust gas economizer 11. It is discharged by detouring. The amount of exhaust gas bypass is set based on the capacity of the exhaust gas economizer 11, the amount of steam generated by the exhaust gas economizer 11, and the like.

A part of the steam generated by the exhaust gas economizer 11 is sent to the ship steam utilization facility 48 via the steam drum 12. The other steam is returned to the exhaust gas economizer 11 via the steam drum 12 and is heated by the exhaust gas economizer 11 to generate superheated steam. This superheated steam is sent to the steam turbine 15.
The steam flow rate introduced into the steam turbine 15 is adjusted by a steam flow rate adjustment valve 46 controlled by a governor 47.
The steam discharged from the steam turbine 15 is condensed by the condenser 18 and stored in the drain tank 19. The exhaust gas economizer passes through the main cooler 8 and the intake air cooler 9 together with the water collected from the in-steam steam utilization facility 48. 11 is returned.

The second exhaust gas line 33 is branched in the middle, and a bypass line 35 that bypasses the power turbine 21 and is connected to the exhaust gas economizer 11 is provided.
The second exhaust gas line 33 upstream from the branch point of the bypass line 35 is provided with a shutoff valve 41 that can shut off the exhaust gas supply to the power turbine 21 side. An exhaust gas flow rate adjustment valve 42 that adjusts the exhaust gas flow rate introduced into the power turbine 21 is provided in the second exhaust gas line 33 downstream of the branch point. The bypass line 35 is provided with a bypass amount adjusting valve 43 that adjusts the bypass amount of the exhaust gas.

  As described above, the exhaust heat recovery facility 10 includes the exhaust gas flow rate adjustment valve 42 and the bypass amount adjustment valve 43, so that the flow rate (extraction amount) of other exhaust gas sent to the exhaust heat recovery facility 10 side becomes constant. Thus, the scavenging air pressure of the main engine 2 can be kept constant. However, although the scavenging pressure may fluctuate when the control is switched due to a delay in the response of the valve, the engine output is stabilized by performing feedforward control that adds a correction value to the basic fuel injection amount as described later. It is possible.

Next, an engine control system including a main engine control device 50 that controls the main machine equipment 1 and a PMS (power management system) 55 that controls the exhaust heat recovery equipment 10 will be described with reference to FIG. In FIG. 2, a broken line shows a control line.
The PMS 55 controls the governor 47 based on the ST power generation amount command value and the generator rotational speed, adjusts the flow rate of steam introduced into the steam turbine 15, and power turbine power generation amount command value (hereinafter referred to as PT power generation amount command value). And the exhaust gas flow rate adjustment valve 42 is controlled based on the generator rotational speed to adjust the exhaust gas flow rate introduced into the power turbine 21. The power generation ratio between the power turbine 21 and the steam turbine 15 is set in advance according to the load of the generator 16 and the engine load state, and the ST power generation amount command value and the PT power generation amount command value are set based on this power generation ratio. It has come to be. Further, when the power generation demand of the generator 16 becomes zero, or when the power generation by the exhaust gas is reduced and only the steam turbine 15 generates power, the exhaust gas introduced into the power turbine 21 is controlled by closing the shut-off valve 41. Cut off.

  The main engine control device 50 is a device that controls an object to be controlled by the main machine facility 1 and mainly controls the fuel injection pump to adjust the fuel injection amount injected into the cylinder of the main engine 2. The main engine control device 50 includes a feedback control unit 51, a correction value calculation unit 52, and a feedforward control unit 53.

With reference to FIG. 3 and FIG. 4, arithmetic processing of the main engine control device 50 will be described below. FIG. 3 is a block diagram for explaining the arithmetic processing of the main machine control device 50, and FIG. 4 is a flowchart showing the arithmetic processing of the main machine control device.
The main engine control device 50 detects the propeller rotation speed by a sensor disposed on the propeller 3 (S1), and calculates a propeller rotation speed command value that is a target value of the rotation speed of the propeller 3 (S2). Then, the feedback control unit 51 subtracts the propeller rotational speed detection value from the propeller rotational speed command value to obtain the control deviation (S3), and the controller 51a performs PID control calculation based on the control deviation, and the basics of the main engine 2 are calculated. A fuel injection amount is derived (S4). The propeller rotation speed detection value may be detected by a sensor installed on the propeller, or may be calculated from the rotation speed of the internal combustion engine.

On the other hand, the PT power generation command value is acquired from the PMS 55 (S5), the engine load of the main engine 2 is calculated (S6), and the correction value calculation unit 52 calculates the fuel injection amount from the PT power generation command value and the engine load. A correction value is derived (S7). As shown in FIG. 3, a map that represents an optimal correlation between the PT power generation amount command value, the engine load, and the fuel injection amount correction value is set in advance. It is preferable to derive a correction value for the fuel injection amount from the value and the engine load. The correlation between the power generation amount command value of the power turbine 21, the engine load of the main engine 2 and the fuel injection amount correction value may be obtained experimentally or by simulation.
Further, the feedforward control unit 53 adds the correction value derived by the correction value calculation unit 52 to the basic fuel injection amount derived by the feedback control unit 51 to derive the actually controlled fuel injection amount ( S8). Then, the fuel injection pump of the main engine 2 is controlled based on the derived fuel injection amount.

According to the present embodiment, the power turbine 21 is connected to the steam turbine 15 via the shaft and into which other exhaust gas discharged from the main engine 2 is introduced. It becomes possible to improve exhaust heat recovery efficiency.
In addition, the main engine control device 50 determines the power generation amount command value of the gas turbine and the load of the internal combustion engine with respect to the basic fuel injection amount derived based on the deviation between the propeller rotation speed command value and the propeller rotation speed detection value. Since the actual fuel injection amount is derived by adding the correction values derived on the basis of this, the amount of exhaust gas sent to the turbine 7 of the turbocharger 5 fluctuates due to a sudden load fluctuation of the generator 16, and the main engine 2 Even when the scavenging air pressure fluctuates, it is possible to secure an appropriate fuel injection amount with respect to the scavenging air pressure, and to prevent the engine output from fluctuating in an unstable manner. Therefore, it is possible to stably control the speed and acceleration of the ship.
Furthermore, the correction value can be easily derived by using a map representing the correlation between the power generation amount command value of the power turbine 21 and the correction value of the engine load of the main engine 2 and the fuel injection amount.

FIG. 5 is a block diagram for explaining arithmetic processing of the main engine control device 50, which is a modification of FIG.
In the modification of FIG. 5, when the correction value calculation unit 52 derives the fuel injection amount correction value from the engine load of the main engine 2 and the PT power generation amount command value, instead of the map, the PT power generation amount command value and the main unit are calculated. The fuel injection amount correction value is derived based on the relational expression showing the optimum correlation between the engine load of 2 and the fuel injection amount correction value.

As this relational expression, for example, the following expression is used.
Q = E (L + K _P × P)
Where Q: fuel injection amount correction value, L: main engine load, P: PT power generation command value, K _P : coefficient or table function, E (L): thermodynamic function (pressure, engine shape) Efficiency, etc. are parameters).
Thus, by using the relational expression of the power generation amount command value of the power turbine 21, the engine load of the main engine 2, and the fuel injection amount correction value, the data amount preset in the main engine control device 50 can be reduced. it can.
In the above-described embodiment, an example in which the main machine control device 50 and the PMS 55 are separately provided is shown. However, as long as the functions included in each device are provided, the division form is not limited, and The same control device may be used.

1 Main equipment 2 Main equipment (internal combustion engine)
3 Propeller 5 Turbocharger (supercharger)
11 Exhaust gas economizer 15 Steam turbine 16 Generator 21 Power turbine (gas turbine)
32 First exhaust gas line 33 Second exhaust gas line 35 Bypass line 41 Shutoff valve 42 Exhaust gas flow rate adjustment valve 43 Bypass amount adjustment valve 46 Steam flow rate adjustment valve 47 Governor 50 Main engine control device 51 Feedback control unit 52 Correction value calculation unit 53 Feed Forward control unit 55 PMS

Claims (4)

An internal combustion engine facility in which a compression side of a supercharger is arranged in an intake system of an internal combustion engine that drives a propeller, and a part of the exhaust gas discharged from the internal combustion engine is introduced to a turbine side of the supercharger; Of a ship equipped with exhaust heat recovery equipment that generates steam by means of steam generation means using the exhaust gas that has passed through the turbine side of the machine, drives the generator connected to the steam turbine by introducing the steam into the steam turbine In the engine control system,
The exhaust heat recovery facility includes a gas turbine connected to the steam turbine via a shaft and into which other exhaust gas discharged from the internal combustion engine is introduced,
A feedback control unit for deriving a basic fuel injection amount of the internal combustion engine based on a deviation between a propeller rotational speed command value that is a target value of the rotational speed of the propeller and a detected propeller rotational speed detected from the propeller;
A correction value calculation unit for deriving a correction value of the fuel injection amount of the internal combustion engine from the power generation amount command value of the gas turbine and the load of the internal combustion engine;
An internal combustion engine control system comprising an internal combustion engine control means having a feedforward control unit for deriving an actual fuel injection amount by adding the correction value to the basic fuel injection amount.   The exhaust heat recovery facility is provided on a line for sending other exhaust gas discharged from the internal combustion engine to the gas turbine, and adjusts an exhaust gas flow rate control valve that adjusts an exhaust gas flow rate introduced into the gas turbine; and the internal combustion engine 2. A bypass line for branching another exhaust gas discharged from the pipe and sending the branched exhaust gas to the steam generating means; and a bypass amount adjusting valve provided on the bypass line. The described engine control system for ships.   In the correction value calculation unit, a map representing a correlation between a power generation amount command value of the gas turbine, a load of the internal combustion engine, and a correction value of the fuel injection amount is set in advance, and the map is based on the map. The ship engine control system according to claim 1, wherein a correction value is derived.   In the correction value calculation unit, a relational expression of a power generation amount command value of the gas turbine, a load of the internal combustion engine, and a correction value of the fuel injection amount is set in advance, and the correction value is based on the relational expression. The ship engine control system according to claim 1, wherein the ship engine control system is derived.

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