KR101660655B1 - Internal combustion engine system, ship provided with same, and method for operating internal combustion engine system - Google Patents

Abstract

There is provided an internal combustion engine system capable of stably operating a steam turbine and a steam turbine generator while avoiding sudden fluctuations in the amount of steam generated in an exhaust gas boiler when performing a power generation stop operation or a power generation start operation of a supercharger which performs power generation. The water supply control valve 27 is controlled in the opening direction when the water level in the water separator 12 is lower than the allowable water level range and is controlled in the closing direction when the water level in the water separator 12 is higher than the allowable water level range, Is controlled so as to supplement the amount of power generated by the steam turbine generator 40 as the amount of power generated by the generator 3c of the turbocharger 3 increases or decreases. When the supercharger generator stop operation for stopping the power generation by the generator 3c of the supercharger 3 and / or the supercharger power generation start operation for starting the power generation by the generator 3c of the supercharger 3 are performed, 12) is increased.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine system and a method of operating the internal combustion engine system,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an internal combustion engine system having an internal combustion engine such as a ship diesel engine, a ship having the internal combustion engine, and a method of operating the internal combustion engine system.

For example, in a low-speed two-cycle diesel engine (internal combustion engine) used as a ship main engine, a supercharger is provided to improve performance. As such a supercharger, there is known a hybrid supercharger equipped with a generator (see Patent Document 1 below) and a VTI (Variable Turbine Inlet) supercharger having a variable turbine nozzle passage area of the exhaust gas (see Patent Document 2).

Patent Document 1: Japanese Patent Publication No. 4648347 Patent Document 2: JP-A-2010-216468

The hybrid supercharger as shown in Patent Document 1 is capable of generating power when the load of the diesel engine as a cycle becomes about 50% or more. This is because the efficiency of the supercharger does not rise at a low load at which the diesel engine load becomes less than about 50%, and there is no room for development. Therefore, in the hybrid supercharger, power generation is stopped at a predetermined diesel engine load (for example, 50% load) at the time of load drop, and power generation is started at the time of load increase.

When a diesel engine provided with a hybrid supercharger is combined with an exhaust gas economizer that recovers heat from the exhaust gas of a diesel engine and the steam turbine is driven by the steam obtained from the exhaust gas boiler to generate electricity using the steam turbine generator, The following problems may occur.

That is, when the power generation stopping operation of the hybrid supercharger is performed when the load of the diesel engine is lowered, not only the power generation amount is reduced but also the temperature of the exhaust gas discharged from the diesel engine is lowered. When the power generation amount decreases, the steam inlet control valve of the steam turbine is controlled in the opening direction so as to increase the generation amount of the steam turbine generator, in order to supplement it. Further, when the exhaust gas temperature drops, the pressure in the water separator provided in the exhaust gas boiler decreases, so that the steam inlet control valve is controlled in the opening direction to further obtain the steam. When the steam inlet control valve is opened, the steam in the water separator is forcibly generated, the water level in the water separator is lowered, and the water supply control valve is controlled in the opening direction to maintain the water level within the allowable water level. However, since new low-temperature water is supplied, the temperature in the water separator drops and the pressure in the water separator further decreases.

In this manner, when the power generation stopping operation of the hybrid supercharger is performed, not only the power generation amount is reduced but also the exhaust gas temperature is lowered, so that the opening operation of the steam inlet control valve and the opening operation of the water supply control valve are overlapped, And the amount of steam generated in the exhaust gas boiler is greatly reduced, which may make it difficult to operate a stable steam turbine and steam turbine generator. In addition, if the amount of steam generated in the exhaust gas boiler is greatly reduced, the necessary steam can not be supplied, and in the worst case, the viscosity of the heavy fuel oil and the lubricating oil of high viscosity can not be controlled and viscosity control can not be performed. There is a possibility.

Further, when the power generation start operation of the hybrid supercharger is performed when the load of the diesel engine is increased, not only the power generation amount but also the temperature of the exhaust gas discharged from the diesel engine increases. In order to compensate for this increase in power generation, the steam inlet control valve is controlled (tightened) in the closing direction to reduce the power generation of the steam turbine generator. Further, when the temperature of the exhaust gas rises, the pressure in the water separator provided in the exhaust gas boiler rises, so that the steam inlet control valve is further controlled in the closing direction. When the steam inlet control valve is controlled in the closing direction, the water level in the water separator rises, and the water supply control valve is controlled (tightened) in the closing direction to keep the water level within the allowable water level range, thereby reducing water supply. However, since the new low-temperature water is not appropriately supplied, the temperature in the water separator rises and the pressure in the water separator further rises.

In this way, when the power generation start operation of the hybrid supercharger is performed, not only the power generation amount increases but also the exhaust gas temperature rises, so that the closing operation of the steam inlet control valve and the closing operation of the water supply control valve are overlapped, The amount of steam generated in the exhaust gas boiler increases sharply, and there is a possibility that the operation of the stable steam turbine and steam turbine generator becomes difficult.

As described above, when a diesel engine provided with a hybrid supercharger is combined with an exhaust gas boiler that recovers heat from exhaust gas from a diesel engine, and the steam turbine is driven by the steam obtained from the exhaust gas boiler to generate electricity with the steam turbine generator , The amount of steam generated in the exhaust gas boiler fluctuates greatly during the power generation stop operation or the power generation start operation of the hybrid supercharger, making it difficult to operate the stable steam turbine and steam turbine generator. In the power generation stop operation, There is a problem in that even stable operation of the diesel engine, which is a cycle, becomes difficult.

On the other hand, the VTI supercharger as shown in Patent Document 2 can be operated with a reduced turbine nozzle passage area only at a periodic load of about 65% or less. This is because, at a periodic load of about 65% or more, the sweeping pressure becomes too high and exceeds the permissible range of the combustion pressure in the cylinder of the diesel engine. Therefore, the VTI supercharger alone can not contribute to the reduction of the fuel consumption of the diesel engine in the entire unloading operation.

Therefore, it is conceivable to suppress the fuel consumption amount in the entire propulsion plant in the unloading operation by combining the VTI supercharger with the hybrid supercharger which operates in the high unloading operation, which is about 50% load or more of the diesel engine.

Here, the fuel consumption reduction in the entire propulsion plant means that the fuel consumption of the power generation engine is reduced by effectively utilizing the exhaust gas energy from the diesel engine, and the entire propulsion plant including the engine for cycle and power generation Which means that the fuel consumption is reduced.

However, when the turbine nozzle area reducing operation for reducing the passage area of the turbine nozzle is performed, the exhaust temperature drops and the same operation as the power generation stop operation of the hybrid supercharger, that is, the opening operation of the steam inlet control valve and the opening operation of the water supply control valve The pressure in the water separator is suddenly increased, and the amount of steam generated in the exhaust gas boiler is greatly reduced. Further, when the turbine nozzle area increasing operation for increasing the turbine nozzle passage area is performed, the exhaust temperature rises and the same operation as that of the power generation start operation of the hybrid supercharger, that is, the closing operation of the steam inlet control valve and the closing operation of the water supply control valve So that the pressure in the water separator sharply increases and the amount of steam generated in the exhaust gas boiler greatly increases. As described above, in the case of a supercharger further equipped with a turbine nozzle passage area varying mechanism together with the power generation mechanism, the problem associated with stopping and starting the power generator of the supercharger is further promoted. Particularly, this is remarkable in the case where the supercharger power generation stop operation and the turbine nozzle area reduction operation are performed at the same time, and the supercharger power generation start operation and the turbine nozzle area increase operation are performed at the same time.

Therefore, even when the VTI supercharger is combined with the hybrid supercharger, the amount of steam generated in the exhaust gas boiler greatly fluctuates, which makes it difficult to operate the steam turbine and the steam turbine in a stable manner.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a steam turbine and a steam turbine generator capable of stably preventing steam fluctuations in the amount of steam generated in an exhaust gas boiler when performing a power generation stop operation or a power generation start operation of a supercharger performing power generation. And an operation method of a ship and an internal combustion engine system having the internal combustion engine system.

Further, the present invention is characterized in that, when a supercharger that performs power generation and has a variable turbine nozzle passage area performs a power generation stop operation or a power generation start operation and performs a turbine nozzle area reduction operation or a turbine nozzle area increase operation, Which is capable of stably operating the steam turbine and the steam turbine generator by avoiding sudden fluctuations in the amount of steam generated in the steam turbine and the steam turbine generator, and a method of operating a ship and an internal combustion engine system having the steam turbine and steam turbine generator.

In order to solve the above problems, an internal combustion engine system of the present invention, a ship having the same, and a method of operating the internal combustion engine system employ the following means.

That is, the internal combustion engine system of the present invention comprises an internal combustion engine, a turbine portion driven by the exhaust gas from the internal combustion engine, a compressor portion driven by the turbine portion for feeding air to the internal combustion engine, An exhaust gas boiler provided with a water separator for recovering heat from the exhaust gas from the internal combustion engine and having a power generating section to generate power with a rotational force; a water supply control valve for controlling the amount of water supplied to the exhaust gas boiler; , A steam turbine driven by steam obtained from the exhaust gas boiler, a steam inlet control valve for controlling the amount of steam introduced into the steam turbine, and a steam turbine generator for generating steam by the steam turbine, Is controlled in the opening direction when the water level in the water separator is lower than the allowable water level range, And the steam inlet control valve is controlled to supplement the amount of power generated by the steam turbine generator as the power generation amount of the supercharger increases or decreases as the power generation amount increases or decreases A supercharger power generation stopping operation for stopping the power generation by the power generation unit of the supercharger and / or a supercharger power generation start operation for starting power generation by the power generation unit of the supercharger, Is enlarged.

The water level of the water separator is increased when the supercharger power generation stop operation is performed and the water supply control valve is opened to increase the water supply amount when the water level in the water separator is within the allowable water level range that has been enlarged. As a result, even if the water level drops, the water supply amount is not increased. Therefore, the decrease in the pressure in the water separator can be suppressed, the steam amount generated in the exhaust gas boiler can be prevented from dropping rapidly, and stable operation of the steam turbine and steam turbine generator can be ensured. can do.

Further, when the supercharger power generation start operation is performed, the allowable water level range of the water separator is enlarged. In the case where the water level in the water separator is within the allowable water level range expanded even when the water level in the water separator rises, it is prohibited to tighten the water control valve to reduce the water supply amount . As a result, even when the water level rises, the water supply amount is not reduced, so that the surge of the pressure in the water separator can be suppressed and the steep increase in the amount of steam generated in the exhaust gas boiler can be avoided and the operation of the stable steam turbine and steam turbine generator can be ensured .

However, the allowable water level range of the water separator is extended from, for example, ± 50 mm to ± several hundreds of millimeters (for example, ± 150 mm).

Typically, the power generator and the steam turbine of the supercharger are connected to a power generator (not shown) that manages the power generation of the other generator (for example, a diesel engine generator) or the secondary battery so as to satisfy the demanded power The power generation operation is controlled by a system (PMS; Power Management System).

Further, in the internal combustion engine system of the present invention, the supercharger has a turbine nozzle passage area varying mechanism for varying a turbine nozzle passage area of the exhaust gas supplied to the turbine section.

When the turbine nozzle area reducing operation for reducing the passage area of the turbine nozzle is performed, the exhaust temperature drops and the same phenomenon as the operation for stopping the generator is generated. Further, when the turbine nozzle area increasing operation for increasing the turbine nozzle passing area is performed, the exhaust temperature rises and the same operation as that of the operation of starting the turbocharger power generation occurs. As described above, in the case of a supercharger equipped with a mechanism for varying the turbine nozzle passage area, the problems associated with stopping and starting the power generator of the supercharger are further promoted. Particularly, this is remarkable in the case where the supercharger power generation stop operation and the turbine nozzle area reduction operation are performed at the same time, and the supercharger power generation start operation and the turbine nozzle area increase operation are performed at the same time. In the present invention, since the above-described internal combustion engine system is used, stable operation of the steam turbine and the steam turbine generator can be assured even in a supercharger equipped with a mechanism for varying the passage area of the turbine nozzle.

Further, the ship of the present invention is characterized by including the internal combustion engine system described in any one of the above.

By providing any one of the above internal combustion engine systems, it is possible to provide a ship having an internal combustion engine system capable of stable operation of a steam turbine and a steam turbine generator.

A method of operating an internal combustion engine system according to the present invention includes an internal combustion engine, a turbine portion driven by exhaust gas from the internal combustion engine, a compressor portion driven by the turbine portion and feeding air to the internal combustion engine, An exhaust gas boiler provided with a water separator for recovering heat from the exhaust gas from the internal combustion engine and a water separator; a water supply control valve for controlling the water supply amount to the exhaust gas boiler; A steam inlet control valve for controlling the amount of steam introduced into the steam turbine, and an operation of the internal combustion engine system including the steam turbine generator that is generated by the steam turbine As a method, it is preferable that the water supply control valve be arranged such that the water level in the water separator is within the allowable water level range And controlling the steam inlet control valve in a closing direction when the steam turbine generator output is lower than the permissible water level range, and controlling the steam inlet control valve in accordance with an increase or decrease in the amount of power generated by the power generator of the supercharger, A supercharging power generation stop operation for stopping the power generation by the power generation unit of the supercharger and / or a supercharger power generation start operation for starting power generation by the power generation unit of the supercharger are performed And a step of expanding the allowable water level range of the water separator.

The allowable water level range of the water separator is expanded when the supercharger power generation stop operation or supercharger power generation start operation and / or the turbine nozzle passage area increase operation or the turbine nozzle passage area decrease operation is performed. Therefore, It is possible to avoid the sudden fluctuation of the amount of steam generated in the exhaust gas boiler, and it is possible to secure the operation of the steam turbine and the steam turbine generator stably. In addition, during the power generation stop operation, it is possible to avoid a drastic decrease in the amount of steam generated in the exhaust gas boiler, thereby ensuring stable operation of the internal combustion engine.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic block diagram showing the overall configuration of an internal combustion engine system according to an embodiment of the present invention. FIG.
2 is a longitudinal sectional view showing the turbocharger of FIG.
3 is a graph showing the behavior of the supercharger at the time of switching between the power generating function and the VTI function.
4 is a table summarizing the operation of each device in the internal combustion engine system according to the first embodiment of the present invention.
5 is a table summarizing the operation of each device of the internal combustion engine system according to the reference embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[First Embodiment]

Hereinafter, a first embodiment of the present invention will be described with reference to Figs. 1 to 3. Fig.

Fig. 1 shows a marine diesel engine system (internal combustion engine system) 1 used for a ship. As shown in the drawing, the marine diesel engine system 1 includes, for example, a cycle (internal combustion engine) 2 of a low-speed two-cycle diesel engine, a turbocharger 3 for supplying compressed air to the cycle 2, And an exhaust gas economizer (exhaust gas boiler) 4 for recovering heat from the exhaust gas from the cycle 2.

A screw propeller (not shown) is directly or indirectly mounted to a crankshaft (not shown) constituting the cycle 2 through a propeller shaft (not shown). In the cycle 2, a cylinder portion 6 made of a cylinder liner (not shown), a cylinder cover (not shown), and the like is provided. In each cylinder portion 6, a piston (Not shown).

An exhaust port (not shown) of each cylinder portion 6 is connected to the exhaust manifold 7. [ The exhaust manifold 7 is connected to the inlet side of the turbine section 3a of the turbocharger 3 through the exhaust pipe L1.

The exhaust manifold 7 is provided with an exhaust bypass valve 11 and the exhaust bypass valve 11 is opened so that a part of the exhaust gas from the exhaust manifold 7 Is bypassed to the exhaust gas economizer (4) side without being supplied to the supercharger (3). The exhaust bypass valve 11 is controlled by a control unit (not shown).

The air supply port (not shown) of each cylinder portion 6 is connected to an air supply manifold (air storage portion) 8 and the air supply manifold 8 is connected to the supercharger 3 And the compressor section 3b. The class supply line L2 is provided with a cycle feed heater 17 and an air cooler 13 so as to perform heat exchange with air compressed by the compressor unit 3b. The cyclic feed heater 17 is provided on the upstream side of the compressed air flow of the air cooler 13 so that the feed water derived from the feed pump 18 to be described later is heated by the compressed air. The feed water heated by the cycle feed heater 17 is sent to the water separator 12 of the auxiliary boiler 14 and the low pressure water separator 21 provided in the low pressure steam system 19. [ The air cooler 13 further cools the compressed air whose temperature has been lowered by the period feed water heater 17 by cooling water not shown.

The air supply manifold 8 is provided with a scavenging bypass valve 9 to open the scavenging bypass valve 9 so that the air in the air supply manifold 8 So that it can be discharged. The scavenge bypass valve 9 is controlled by a control unit (not shown).

1 and 2, the turbocharger 3 includes a turbine portion 3a driven by an exhaust gas (combustion gas) derived from the cycle 2 through an exhaust pipe L1, And a compressor unit 3b which is driven by the compressor 3a and feeds outside air (air) to the cycle 2 as a main component.

The turbocharger 3 is provided with a generator 3c that generates power by receiving the rotational force of the turbine portion 3a. The generator 3c is controlled by a control signal from a PMS (Power Converting Old Gateway System) 28 provided in an MSB (period-by-period? D ??) 26. That is, a control signal is exchanged between the PMS 28 and the inverter 30 of the generator 3c. A converter 32 is provided between the inverter 30 and the generator 3c to exchange control signals with the inverter 30. The AC power generated in the generator 3c is orthogonally converted to a desired frequency in the inverter 30 after being converted into a teaching wave by the converter 32 and sent to the inboard bus 33 through the contactor 35. [

The PMS 28 controls generation electric power in accordance with the on-board demand electric power, and also controls the diesel engine 37 for power generation, for example, four strokes for driving the diesel engine generator DG. The generated power of the diesel engine generator (DG) is output to the intraboard line bus (33). In FIG. 1, three sets of the power generation diesel engine 37 and the diesel engine generator DG are shown, but one set, two sets, or four sets or more may be used. Further, the PMS 28 may control the secondary battery such as a lithium secondary battery.

The supercharger 3 is provided with a turbine nozzle passage area varying mechanism 3g for varying the turbine nozzle passage area of the exhaust gas supplied from the exhaust pipe L1 to the turbine section 3a. Specifically, the turbine nozzle passage area varying mechanism 3g includes a partition 3f (see FIG. 2) for dividing the turbine nozzle into an inner periphery side and an outer periphery side, a branching portion 3f for branching a part of the exhaust gas derived from the exhaust pipe L1 A pipe 3d and an on-off valve 3e for opening and closing the branch pipe 3d. As shown in Fig. 2, the exhaust gas flowing through the branch pipe 3d flows on the inner peripheral side of the partition 3f of the turbine nozzle. However, the on-off valve 3e is controlled by a control unit (not shown).

When the opening / closing valve 3e is closed, the exhaust gas flows only on the outer peripheral side of the partition 3f of the turbine nozzle without flowing through the branch pipe 3d, and the VTI function is turned on by narrowing the passage area of the turbine nozzle. On the other hand, when the open / close valve 3e is opened, the exhaust gas flows through the branch pipe 3d and also flows to the inner circumferential side of the partition 3f of the turbine nozzle, and the VTI function is turned off by enlarging the passage area of the turbine nozzle.

1, the exhaust gas economizer 4 includes a high-pressure heat exchanger 10a, a medium-pressure heat exchanger 10b, and a low-pressure heat exchanger 10b in this order from the upstream side of the exhaust gas flow, And a heat exchanger 10c. Each of the heat exchangers 10a, 10b and 10c is provided with a plurality of heat transfer tubes for heating the water flowing in the heat transfer tubes by the high temperature exhaust gas flowing in the flue of the exhaust gas economizer 4. [

Steam separated from the water separator (12) of the auxiliary boiler (14) is introduced into the high-pressure heat exchanger (10a). The super heated steam heated by the high pressure heat exchanger 10a and having an increased superheat degree is introduced into the steam turbine 23 through the steam inlet control valve 22. [ However, a part of the steam separated in the water separator 12 is led to the in-vessel viewing auxiliary device 20. The main purpose of the steam in the inboard boat 20 is to heat the heavy fuel oil and the lubricating oil used as the fuel in the cycle 2.

A part of the superheated steam heated in the high-pressure heat exchanger 10a is led to the in-vessel boiler 20 through the high-pressure steam bypass valve 29. [ Distribution of the steam supplied to each in-cabin view 20 is performed by controlling the flow control valves 31a and 31b. The surplus steam which is not induced in each in-cabin view 20 is led to the condenser 34. [

The water separated from the water separator 12 of the auxiliary boiler 14 is introduced into the intermediate-pressure heat exchanger 10b through the water feed pump 25a. The steam heated by the medium pressure heat exchanger (10b) and evaporated is led to the water separator (12).

In the water separator 12, water and steam are separately contained in the upper and lower portions. Water heated by the cyclic feed heater 17 is supplied to the water separator 12 as described above. The amount of water supplied to the water separator (12) is controlled by the water supply control valve (27). The opening degree of the water supply control valve 27 is controlled by a control unit (not shown) such that the water level in the water separator 12 is maintained within the allowable water level range. The water level in the water separator 12 is measured by a water level meter (not shown), and the measured value is transmitted to a control unit (not shown).

A safety valve 24 is provided on the upper part of the water separator 12 so that when the pressure in the water separator 12 becomes a predetermined value or more, the safety valve is opened to discharge the internal steam to the outside.

The low-pressure heat exchanger 10c is provided in the low-pressure steam system 19 and heats the water derived from the low-pressure water separator 21 through the water feed pump 25b to evaporate. The vapor evaporated in the low pressure heat exchanger 10c is sent to the low pressure water separator 21. The steam separated in the low pressure water separator 21 is led to the middle stage of the steam turbine 23 and the remainder is led to the inboard view 20.

The steam after being used in each in-cabin view 20 is led to the drain cooler 15 and the drain water condensed by the drain cooler 15 is stored in the drain reservoir 16. Condensate water from the ground condenser 36, which will be described later, is also introduced into the drain reservoir 16. The drain water stored in the drain reservoir 16 is led to the above-described cyclic water heater 17 by the water feed pump 18.

A steam turbine generator 40 is connected to the steam turbine 23 through a speed reducer 38. The power generation output of the steam turbine generator 40 is guided to the inboard ship bus 33 through a power line (not shown).

The high-pressure steam flow rate supplied to the steam turbine 23 is regulated by the steam inlet control valve 22. The opening degree of the steam inlet control valve 22 is controlled by a signal from the governor 44 to which the turbine control panel 43 is commanded. The turbine control panel 43 is controlled by the PMS 28. Therefore, the steam inlet control valve 22 is controlled so that the steam turbine generator 40 outputs the power generation amount determined by the PMS 28, whose opening degree is controlled.

The steam that has been finished in the steam turbine 23 is led to the condenser 34 and condensed and the condensed water (plural condensed water) is led to the grand condenser 36 by the plural pumps 42.

The internal combustion engine system of the above configuration operates as follows. Hereinafter, it is divided into "normal operation", "switching at the time of cyclic load increase", and "switching at the time of cyclic load reduction". Here, the normal operation state means a state other than the timing of switching the power generating function and the VTI function in the state of power generation in the turbocharger 3, and the pressure in the water separator 12 does not fluctuate rapidly, 23 can be continuously operated.

[During normal operation]

The drain water stored in the drain reservoir 16 is led to the cyclic feedwater heater 17 by the feed pump 18 and heated to be fed to the water separator 12 and the low pressure steam system 19 of the auxiliary boiler 14, The low pressure water separator 21 of FIG.

The water led to the water separator 12 is led to the intermediate pressure heat exchanger 10b by the water feed pump 25a to be steam and returned to the water separator 12. The steam separated by the water separator 12 is led to the high-pressure heat exchanger 10a, and becomes a high-temperature superheated steam. The superheated steam generated in the high-pressure heat exchanger 10a is led to the steam turbine 23 after the flow rate is adjusted in the steam inlet control valve 22.

On the other hand, the water led to the low-pressure water separator 21 is led to the low-pressure heat exchanger 10c by the water feed pump 25b to be steam and returned to the low-pressure water separator 21. The low pressure steam separated in the low pressure water separator (21) is led to the middle end of the steam turbine (23).

The rotational output of the steam turbine 23 driven by the induced steam is transmitted to the steam turbine generator 40 through the speed reducer 38, and power generation is performed. The amount of power generated by the steam turbine generator 40 is managed by the PMS 28. The PMS 28 acquires the power generation amount of the generator 3c of the supercharger 3, the power generation amount of the other generator (the diesel engine generator DG) and the charge and discharge state of the secondary battery BT on-line, And sends a power generation command to each device so that the sum of electric power satisfies the on-board demand electric power. For the amount of power generated by the steam turbine generator 40, an instruction is sent to the turbine control panel 43 to control the opening of the steam inlet control valve 22 through the governor 44. Concretely, the steam inlet control valve 22 is controlled so as to supplement the amount of power generated by the steam turbine generator 40 as the amount of power generated by the generator 3c of the turbocharger 3 increases or decreases. That is, when the power generation amount of the generator 3c of the supercharger 3 is reduced, the opening degree of the steam inlet control valve 22 is controlled in the opening direction so that the amount of power generated by the steam turbine generator 40 is increased, The opening degree of the steam inlet control valve 22 is controlled in the closing direction so that the amount of power generated by the steam turbine generator 40 is reduced when the power generation amount of the generator 3c of the steam generator 3c increases.

The power generation amount of the generator 3c of the supercharger 3 is increased or decreased in accordance with the load of the period 2. As shown in the graph of the "hybrid supercharger generation power" in Fig. 3, The power generation amount increases when the periodic load increases, and the power generation amount decreases when the periodic load decreases.

The water level in the water separator (12) of the auxiliary boiler (14) is adjusted by the water supply control valve (27). During normal operation, when the water level in the water separator 12 is lower than the desired value, it is controlled in the opening direction, and when the water level is higher than the desired value, it is controlled in the closing direction. That is, at the time of normal operation, the water level control is performed by setting the allowable water level range (tolerance) to ± 50 mm. This allowable water level range is set according to the plant, but it is desirable to narrow the allowable water level range as much as possible since it aims at stable operation of the steam turbine and steam turbine generator in normal operation.

[When switching cycle load is increased]

Next, a description will be given of a case where the power generation function of the supercharger and the VTI function are switched when the cycle load is increased.

As shown in Fig. 3, when the cycle load is increased (at the time of increasing speed), the power generation function is switched from the non-power generation operation to the power generation operation at a predetermined load (65% in Fig. 3). This can be seen from the fact that the solid line in the graph of the "hybrid supercharger generated power" in Fig. 3 is rising at a load of 65%. On the other hand, the VTI function is switched from ON to OFF at a predetermined load (65% in FIG. 3). This can be seen from the fact that the thin solid line in the graph of the "periodic urging pressure" of FIG. 3 drops from a higher pressure than the one dotted line to 65% of the load. Then, as can be seen from the graph of the "periodic exhaust gas temperature" in the figure, the exhaust gas temperature rises sharply.

In this manner, when the VTI function is switched from ON to OFF while switching from the non-generating operation to the generating operation at the time of increasing the period load, not only the power generation amount of the generator 3c of the supercharger 3 is increased, The temperature of the exhaust gas discharged from the combustion chamber increases. The steam inlet control valve 22 is controlled so as to reduce the amount of power generated by the steam turbine generator 40 as the amount of power generated by the generator 3c of the turbocharger 3 increases as the power generation amount of the generator 3c of the supercharger 3 increases (Tightened) in the closing direction. Further, when the temperature of the exhaust gas rises, the pressure in the water separator 12 rises, so that the steam pressure supplied to the steam turbine rises further, so that the steam inlet control valve 22 is further controlled in the closing direction. When the steam inlet control valve 22 is controlled in the closing direction, the water level in the water separator 12 rises and the water supply control valve 27 is controlled in the closing direction to maintain the water level within the allowable water level range used during normal operation Tightened) to reduce the water supply. However, since new water having a low temperature is not properly supplied, the temperature in the water separator 12 rises and the pressure in the water separator 12 further rises.

When the power generation start operation of the supercharger 3 is performed in this way, not only the power generation amount of the generator 3c of the turbocharger 3 is increased but also the exhaust gas temperature is raised. Therefore, the closing operation of the steam inlet control valve 22 The closing operation of the water supply control valve 27 is overlapped and the pressure in the water separator 12 rises sharply and the amount of steam generated in the exhaust gas economizer 4 greatly increases and the operation of the stable steam turbine and steam turbine generator becomes difficult There is a concern.

Therefore, in the present embodiment, when the power generation start operation of the turbocharger 3 is performed, the allowable water level range of the water separator 12 is set to be larger than that during normal operation (+/- 50 mm in the present embodiment) , It is prohibited to reduce the water supply amount by tightening the water supply control valve 27 when the water level in the water separator 12 rises within the allowable water level range larger than that during normal operation. Thus, since the water supply amount is not reduced even when the water level rises above the allowable water level range in the normal operation, the surge of the pressure in the water separator 12 can be suppressed, and the rapid increase of the steam amount generated in the exhaust gas economizer 4 can be suppressed So as to ensure the operation of the stable steam turbine and steam turbine generator.

[When switching cycle load is reduced]

Conversely to the above-mentioned periodic load rise, when the periodic load is reduced (deceleration), the power generation operation is switched from the power generation operation to the non-generation operation with a predetermined load (65% in FIG. 3). On the other hand, the VTI function is switched from OFF to ON at a predetermined load (65% in FIG. 3). In this case, as can be seen from the graph of "periodically scavenging pressure" in Fig. 3, the scavenging pressure sharply increases. Then, as can be seen from the "periodic exhaust gas temperature" in Fig. 3, the exhaust gas temperature drops sharply.

When the VTI function is switched from the OFF state to the ON state while switching from the power generation operation to the non-generation operation at the periodic load reduction, power generation by the generator 3c of the supercharger 3 is stopped, The temperature of the exhaust gas discharged from the combustion chamber is lowered. The steam inlet control valve 22 of the steam turbine 23 is opened in the opening direction so as to increase the generation amount of the steam turbine generator 40 in order to supplement the power generation by the generator 3c of the turbocharger 3 Respectively. Further, when the exhaust gas temperature drops, the pressure in the water separator 12 is lowered, so that the steam pressure supplied to the steam turbine further decreases, so that the steam inlet control valve 22 is controlled in the opening direction to further obtain the steam. When the steam inlet control valve 22 is opened, the steam in the water separator 12 is forcibly generated and the water level in the water separator 12 is lowered. In order to maintain the water level in the water level separator 12, So that the water supply is increased. However, since new low-temperature water is supplied, the temperature in the water separator 12 drops and the pressure in the water separator 12 further decreases.

When the power generation stopping operation of the turbocharger 3 is performed in this way, not only the power generation is stopped but also the exhaust gas temperature is lowered. Therefore, the opening operation of the steam inlet control valve 22 and the opening operation of the water supply control valve 27 The pressure in the water separator 12 is reduced, and the amount of steam generated in the exhaust gas economizer 4 is greatly reduced, which may make it difficult to operate the steam turbine and the steam turbine in a stable manner. Further, when the amount of steam generated in the exhaust gas economizer 4 decreases, necessary steam can not be supplied, and in the worst case, the heavy oil fuel and the lubricating oil having high viscosity can not be heated and viscosity control can not be performed. There is a possibility that even stable driving may be difficult.

Therefore, in this embodiment, when the power generation stop operation of the turbocharger 3 is performed, the allowable water level range of the water separator 12 is set to be larger than that during normal operation (+/- 50 mm in the present embodiment) , It is prohibited to increase the water supply amount by opening the water supply control valve 27 when the water level in the water separator 12 is lower than the permissible water level range which is larger than the normal water level. As a result, even if the water level falls below the allowable water level range in the normal operation, the water supply amount is not increased, so that the decrease in the pressure in the water separator 12 can be suppressed and the amount of steam generated in the exhaust gas economizer 4 can be reduced , Thereby ensuring the stable operation of the steam turbine and steam turbine generator, and hence the cycle (2).

Fig. 4 shows the operation of each device during normal operation and switching described above.

As shown in the figure, the allowable water level range of the water separator 12 is set to ± 50 mm at the time of normal operation and to ± 150 mm at the time of the change.

The timing of switching of the water level range of the water separator 12 is performed at the time of switching the power generating function and VTI function of the turbocharger 3, and this can be obtained by various methods. For example, the time rate of change of the pressure in the water separator 12, the time rate of change of the water level, and the time rate of change of the inlet temperature or the outlet temperature or the average temperature of the exhaust gas economizer 4 or a combination thereof And the control unit predicts the increase or decrease in the amount of steam generation. The switching of the power generating function of the turbocharger 3 can be judged by receiving the control output of the inverter 30 and the switching of the VTI function is performed by the operation of the opening and closing valve 3e of the turbocharger 3 It may be judged on the basis of these switching timings. Further, in the case where the generation function and the timing of switching the VTI function are fixed in advance at a predetermined cycle load, it can be easily predicted by grasping the cycle load increasing rate by the control unit.

As the timing for returning to the allowable water level range in the normal operation after increasing the allowable water level range, for example, the time rate of change of the pressure in the water separator 12, the rate of change of the water level, It is possible to determine whether the control unit predicts the increase or decrease in the amount of steam generation by using any one of the inlet temperature or the outlet temperature of the economizer 4 or the rate of change of the average temperature.

It is also possible to make the return timing that the periodic load changes by a predetermined amount from the periodic load (65%) at the time of switching. Alternatively, the return timing may be set to a return timing after elapse of a predetermined time from the switching time, or may be set to a return timing when the time variation amount of the water level measured by the water level meter is equal to or less than a predetermined value.

Although the above-described embodiments have been described on the premise that the supercharger 3 is provided with the power generating function and the VTI function, in the case of the so-called hybrid supercharger having only the power generating function without the VTI function, Can be applied. This is because the exhaust gas temperature fluctuates abruptly when the power generation function is switched and the generation command value of the steam turbine generator 40 fluctuates rapidly even when the VTI function is not provided.

[Reference Embodiment]

Next, a reference embodiment will be described. The basic configuration is the same as that of the first embodiment described with reference to Figs. 1 to 3, and a description thereof will be omitted. In the first embodiment, abrupt pressure fluctuation in the water separator 12 is avoided by changing the allowable water level range of the water separator 12 when the power generation function of the turbocharger 3 and the VTI function are switched. However, Is different in that the secondary battery BT is used without changing the allowable water level range.

Therefore, this embodiment can be applied to the case where the PMS 28 manages the secondary battery.

The normal operation is the same as that of the first embodiment, and a description thereof will be omitted.

When the power generation start operation of the supercharger 3 is performed at the rising of the cycle load, the charging request command by the secondary battery is issued to the PMS 28 from the control unit not shown. Upon receiving the charging request command, the PMS 28 sends a charging command to the secondary battery. The secondary battery is charged so as to absorb an increase in the power generation amount of the generator 3c of the supercharger 3. In this way, the PMS 28 can adjust the total power from each generator to the on-board demand power.

As a result, tightening of the steam inlet control valve 22 to absorb the increase in the power generation amount of the generator 3c of the turbocharger 3 is avoided, so that the surge of the pressure in the water separator 12 can be suppressed, The steep increase in the amount of steam generated in the economizer 4 can be avoided, and stable operation of the steam turbine and the steam turbine generator can be ensured.

Further, when the power generation stop operation of the supercharger 3 is performed at the time of reducing the cycle load, the discharge request command by the secondary battery is issued to the PMS 28 from the control unit (not shown). When the PMS 28 receives a discharge request command, it sends a discharge command to the secondary battery. The secondary battery discharges to compensate for a decrease in the amount of electricity generated by the generator 3c of the supercharger 3. In this way, the PMS 28 can adjust the total power from each generator to the on-board demand power.

This prevents the steam inlet control valve 22 from being opened in order to compensate for the decrease in the power generation amount in the ship due to the power generation stoppage of the generator 3c of the turbocharger 3, It is possible to avoid a rapid decrease in the amount of steam generated in the exhaust gas economizer 4, thereby ensuring stable operation of the steam turbine and the steam turbine generator.

5, the operations of the respective devices at the time of the normal operation and the switching described above are summarized.

As shown in the figure, during the normal operation, the PMS 28 does not request an operation for the secondary battery, and requests charging or discharging at the time of switching.

Although the above-described embodiments have been described on the premise that the supercharger 3 is provided with the power generating function and the VTI function, in the case of the so-called hybrid supercharger having only the power generating function without the VTI function, Can be applied. This is because the event that the exhaust gas temperature fluctuates suddenly at the time of switching the power generation function and the power generation command value to the steam turbine generator 40 fluctuates suddenly occurs even if the VTI function is not provided.

1 Marine diesel engine system (internal combustion engine system)
2 cycles (internal combustion engine)
3 supercharger
3a turbine section
3b compressor section
3c generator
3d branch tube (Variable mechanism of turbine nozzle passage area)
3e opening / closing valve (variable turbine nozzle passage area)
3f Bulkhead (variable turbine nozzle passage area)
4 Exhaust gas economizer (exhaust gas boiler)
12 water separator
22 Steam inlet control valve
23 Steam turbines
28 PMS (Power Management System)
40 Steam turbine generator

Claims (4)

An internal combustion engine,
A supercharger having a turbine portion driven by exhaust gas from the internal combustion engine, a compressor portion driven by the turbine portion to pressurize and feed air to the internal combustion engine, and a power generating portion generating power by the rotation of the turbine portion,
An exhaust gas boiler provided with a water separator for recovering heat from the exhaust gas from the internal combustion engine,
A water supply control valve for controlling the water supply amount to be supplied to the exhaust gas boiler so as to be controlled in the opening direction when the water level in the water separator is lower than the allowable water level range and to be controlled in the closing direction if the water level exceeds the allowable water level range,
A steam turbine driven by the steam obtained from the exhaust gas boiler;
A steam turbine generator that is generated by the steam turbine,
A steam inlet control valve for controlling the amount of steam introduced into the steam turbine so as to supplement the amount of power generated by the steam turbine generator in accordance with an increase or decrease in the amount of power generated by the power generator of the supercharger;
Wherein the internal combustion engine system comprises:
Wherein when at least one of the supercharger generation stop operation for stopping the power generation by the power generation portion of the supercharger and the supercharger power generation start operation for starting the power generation by the power generation portion of the supercharger is performed, Internal combustion engine system. The method according to claim 1,
Wherein the supercharger includes a turbine nozzle passage area varying mechanism for varying a turbine nozzle passage area of the exhaust gas supplied to the turbine section. A ship equipped with the internal combustion engine system according to claim 1 or 2. A step of driving the internal combustion engine;
A step of driving the turbine section by the exhaust gas from the internal combustion engine and driving the compressor section by driving the turbine section to pressurize the internal combustion engine,
A step of obtaining a rotational force of the turbine section to perform power generation in the turbocharger,
Supplying water to an exhaust gas boiler provided with a water separator and performing heat exchange with exhaust gas from the internal combustion engine to generate steam,
A step of driving the steam turbine by the steam generated by the heat exchange and performing power generation
The method comprising the steps of:
A step of starting the water supply when the water level in the water separator is lower than the allowable water level range and stopping the water supply when the water level exceeds the allowable water level range;
Controlling the amount of power generated by the steam turbine as the amount of power generated by the supercharger increases or decreases;
A step of expanding the allowable water level range of the water separator when at least one of the supercharger generation stop operation for stopping the power generation by the supercharger and the supercharger power generation start operation for starting the power generation by the supercharger is performed
And a control unit for controlling the operation of the internal combustion engine.

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