JPH029999B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a marine propulsion plant that is particularly effective when applied to ships that require extremely large amounts of electric power, such as liquefied petroleum gas carriers and container ships.

As in the case of general ships, steam turbine generators have been adopted for these conventional ships as a system to effectively utilize the exhaust gas energy generated by the main engine. However, in the above-mentioned specific ships, even if the exhaust gas energy of the main engine is fully utilized to generate electricity, it may still not be possible to cover the maximum power load on board, and in that case, the fuel oil for the main engine may be It was necessary to make up for the power shortage by installing a separate generator that uses comparatively higher grade fuel oil and running it in parallel, or by installing a main shaft generator and running it in parallel. In the case where the main shaft generator and the steam turbine generator are operated in parallel, it is necessary to install an expensive thyristor converter or the like in order to enable the main shaft generator and the steam turbine generator to operate in parallel. In some cases, expensive power load reduction measures were taken, such as the adoption of absorption chillers, in order to reduce the onboard power load and increase the chances that the onboard power load could be covered by steam turbine generators alone. On the other hand, the exhaust gas energy and onboard power load change depending on the season, navigation conditions, cargo conditions, etc., so in some cases, the exhaust gas energy exceeds the required onboard power load, or a separate power load is required. When operating in parallel with a generator, the required onboard power may be lower than the total power obtained by adding the minimum power generated by that generator to the power generated by the steam turbine generator. Exhaust gas energy was being dumped into the atmosphere.

Figure 4 is shown in Japanese Utility Model Publication No. 44-15084, and is an example of a conventional system in which the load sharing between a main internal combustion engine and a steam turbine driven using its exhaust gas can be adjusted. , the exhaust gas from the main internal combustion engine 21 is led to the exhaust gas heater 22 through a conduit 29, the steam generated here is led to the steam turbine 23 through the pipe 30, and the output of the steam turbine 23 is transmitted to the gear transmission device 24. Then, a part of it is used to drive the generator 25, and the remaining part is used to drive the propulsion shaft 28 via the gear transmission 27, and the main internal combustion engine is included in the mechanism for driving the propulsion shaft 28. A shaft coupling 26 is provided which disengages when the speed fluctuation exceeds the allowable speed fluctuation range of the generator,
Further, the output from the main internal combustion engine 21 is transmitted to the generator 25 via the shaft coupling 26 when the amount of steam generated is small.

However, with the above-mentioned conventional device, it is impossible to obtain a large amount of inexpensive electric power by using the main internal combustion engine 21 as a power source for power generation, for example, when the ship is at anchor. Furthermore, if the main internal combustion engine 21 fails, only the steam turbine 23 can provide propulsion power, and the exhaust gas heater 22 cannot be expected to generate steam, and steam introduced from other steam generation sources can be used. This means that the steam turbine 23 must be driven just barely. Furthermore, if the failure of the main internal combustion engine 21 is a failure that makes it inoperable, such as a seizure accident, the situation becomes even more difficult.

An object of the present invention is to provide a marine propulsion plant that can achieve energy savings by fully utilizing the exhaust gas energy generated by the main engine when operating the main engine to propel the ship.

Another object of the present invention is to provide a plant that can be applied to ships that require an extremely large amount of electric power, can sufficiently satisfy the electric power demand, and can supply electric power at an extremely low cost. be.

Still another object of the present invention is to provide a plant that is equipped with a device that can be used as an alternative propulsion drive means other than the main engine even when the main engine fails, and that can easily activate the device. Our goal is to provide the following.

Next, the configuration of the plant of the present invention will be specifically explained below based on drawings showing one embodiment.

In FIG. 1, 1 is a main engine, 2 is a steam turbine, and 3 is a main engine 1 and a steam turbine 2.
A speed reduction device 4 connects the output shaft systems of the respective output shaft systems, and 4 is a propulsion device rotationally driven via the speed reduction device 3. Reference numeral 5 denotes a speed increasing device, which is interposed in the middle of an output shaft system that connects the main engine 1 and the speed reducing device 3, and a joint 9 and a clutch 10 are provided before and after the speed increasing device. Reference numeral 6 denotes a main shaft generator, and the main shaft generator 6 is configured to be able to operate as an electric motor by being supplied with power from another generator 7. Therefore, the joint 9 is "connected",
By disengaging the clutch 10, the power of the main engine 1 is transmitted only to the main shaft generator 6, and by disengaging both the joint 9 and the clutch 10, the power of the main engine 1 is transmitted to the main shaft generator 6 only. Power can be transmitted to both the drive of the main shaft generator 6 and the drive of the propulsion device 4, and by turning the joint 9 "disconnected" and the clutch 10 "connected", the main shaft generator 6 can be transferred to the electric motor. It is also possible to transmit the power to the propulsion unit 4 via the speed increasing device 5. Needless to say, in this state, the speed increasing device 5 functions as a speed reducing device. Further, as can be easily understood from the above explanation, the frequency of connection/disconnection operations at this location of the joint 9 is higher than that of the clutch 10.
The joint structure was only adopted because the frequency of the same operation at this point is far less in practice, and therefore there is no problem in using a clutch at this point instead of the joint 9.

Reference numeral 11 denotes a joint, which is provided in the middle of the output shaft system that connects the steam turbine 2 and the speed reduction device 3. Joint 11
It is of course possible to replace this with a clutch mechanism for the same reason as the joint 9. 8 is an exhaust gas boiler that uses the exhaust gas energy of the main engine 1, and 12 is a boiler that uses heat energy other than the exhaust gas energy of the main engine 1. Steam taken out from these boilers is taken out along the broken line in the figure. The steam is introduced into the steam turbine 2 via the steam control valve 13, or sent to a steam demand 15 for heating or miscellaneous purposes. 1
Reference numeral 4 denotes an inboard power load, which is supplied by the power generated by the main shaft generator 6 or generator 7.

The operation of the plant of the present invention configured as described above will be explained: (1) During normal voyage The joint 9, clutch 10, and joint 11 are all "contacted". As a result, the entire exhaust gas energy of the main engine 1 is effectively absorbed into the steam turbine 2 via the exhaust gas boiler 8 and utilized as driving power for the propulsion device 4. Further, the power generated by the main engine 1 is used not only as driving power for the propeller, but also is converted into electricity by the main shaft generator 6, and this electricity can cover the onboard power during the voyage.

(2) When berthing: Coupling 9 should be "engaged" and clutch 10 should be "disengaged". As a result, the power generated by the main engine 1 is input only to the main shaft generator 6, and it can be used as an independent generator while at berth.

(3) In the event of main engine failure (a) Joints 9 and 11 should be "disconnected" and clutch 10 should be "connected". In this state, the generator 7 is operated, and the generated power causes the main shaft generator 6 to function as an electric motor, and the propeller 4 is driven in accordance with the above-mentioned procedure for cruising.

(b) Set the clutch 10 to "disconnected" and the joint 11 to "connected". In this state, the exhaust gas boiler 8 is reheated (when the exhaust gas boiler 8 is a boiler that can be reheated), or the steam turbine 2 is driven by steam from a separately provided boiler 12, and the propulsion device 4 is driven. Drive rotation.

(c) Set the joint 9 to "disconnected" and set both the clutch 10 and the joint 11 to "connected". In this state, the power from the electric motor in (a) above and the power from the steam turbine 2 in (b) above are used together to increase the propulsion power.

In the above configuration, when switching the forward and backward rotation of the propeller 4, it is necessary to control the supplied steam by the steam control valve 13 when the steam turbine 2 is reversely operated. In this case, although the forward switching can be performed quickly, the decrease in main engine output cannot keep up with the decrease in propeller load, resulting in overspeed in many cases. If the steam supply source to the steam turbine 2 is an exhaust gas boiler using exhaust gas from the main engine as in the plant in question, the amount of steam supplied to the steam turbine 2 will increase rapidly due to the heat capacity of the exhaust gas boiler even if the hand engine output suddenly decreases. is not reduced, and therefore is more prone to overspeed than other plants that drive the propulsion unit only with the main engine. Therefore, in the case of a plant that uses a variable pitch propeller for its propulsion unit, the amount of steam supplied to the steam turbine must be adjusted so that forward and backward switching operations can be performed extremely easily and with a high degree of followability. It is necessary to equip a steam control valve that can control the

Figure 2 shows the characteristics of the steam control valve as a graph with respect to valve opening degree and time. In the figure, valve opening degree A indicates the forward movement degree A indicates the valve opening degree when moving forward, and B indicates the valve opening degree when moving backward. Indicates the valve opening degree. The two-dot chain line curve after the reverse command is issued indicates the steam control valve in a generally considered control method, that is, a method in which the steam control valve is controlled only by the steam pressure and steam temperature of the exhaust gas boiler and the permissible steam conditions of the steam turbine. The curve shows the change in valve opening when using the steam control valve according to the control method of the present invention, which will be described below. In the curve, the position of the inflection point P where the steam control valve changes from the minimum opening to the increased opening is determined by the steam pressure of the exhaust gas boiler, the steam temperature, the pitch angle of the variable pitch propeller, and the main shaft rotation speed. Further, the valve opening degrees A and B are determined by the steam pressure and steam temperature of the exhaust gas boiler and the allowable steam conditions of the steam turbine. Therefore, as shown in Fig. 3, the steam pressure of the exhaust gas boiler, the steam temperature, the pitch angle of the variable pitch propeller,
If the numerical values of the rotation speed and the main shaft rotation speed are input to the controller as signals, and a reverse command signal is input to the controller to control the steam control valve, the valve opening shown in the curve in Figure 2 can be obtained. In other words, the valve opening is rapidly decreased at the same time as the reverse command is issued, and the valve opening is rapidly increased from point P when the propeller pitch passes through neutral and advances to the astern region. This allows the steam control of this type of steam turbine to efficiently follow the switching operation of the variable pitch propeller. Note that in this case, some of the signals input to the controller may be omitted depending on the case.

Since the marine propulsion plant according to the present invention is configured as described above, when the main engine is operated to make the ship sail, the exhaust gas energy generated by the main engine is fully utilized, thereby realizing energy saving. be able to.

Furthermore, in the plant of the present invention, all output of the steam turbine is used to drive the propulsion shaft, and all power for driving the generator is supplied from the main engine, and the main engine and the generator are connected to the propulsion shaft. It is constructed so that it can be easily disconnected from the system and used as an independent diesel generator. In other words, the steam turbine and generator are connected separately to the propulsion shaft system,
Further, the generator is connected to be driven by the main engine. Therefore, in the present invention, when the ship is at anchor, the main engine and generator can be separated from the propulsion shaft system and used as an independent diesel generator. Since diesel generators have better thermal efficiency than turbine generators, they consume less fuel per unit of power generation, and can therefore supply a large amount of inexpensive electricity. On the other hand, the conventional device shown in FIG. 4 cannot be used as a diesel generator, so it does not have the same effect as the present invention.

Furthermore, in the plant of the present invention, when the main engine fails, the main engine can be easily separated from the propulsion shaft system, and the ship can be navigated using only the steam turbine. By disconnecting the joint 9 and connecting the generator to the propulsion shaft system (connecting the clutch 10), the generator can be operated as an electric motor, so the ship can be sailed with the combined output of both the steam turbine and the electric motor. It can be run.

In the conventional device shown in FIG. 4, when the steam turbine output is larger than the generator driving power, the difference is transmitted to the propulsion shaft via the shaft coupling 26, and the steam turbine output is smaller than the generator driving power. At that time, power is transmitted from the main engine to the generator via the shaft coupling 26 by the difference. This means that the power transmitted via the shaft coupling 26 and gear transmission 27 is
Naturally, in certain cases it will be large, in other cases it will be small, and in extreme cases it will be zero. In general, it is said that in a gear transmission device, a hammering phenomenon occurs when the transmitted torque is smaller than the fluctuating torque, and in a transmission device where the transmitted torque can become small, some kind of countermeasure is often required to deal with this. On the other hand, in the present invention, the steam turbine transmits all its output to the propulsion shaft system, and the generator takes all its necessary power from the main engine, so the transmitted torque in both transmission devices will not be very small. do not have. That is, the device of the present invention has an excellent effect in that it does not require the measures required in the conventional device.

[Brief explanation of drawings]

Figure 1 is a layout diagram of the plant of the present invention, Figure 2 is a characteristic curve diagram for explaining the function of the steam control valve, Figure 3 is its block diagram, and Figure 4 is a layout diagram of the conventional equipment. . 1... Main engine, 2... Steam turbine, 3... Reduction device, 4... Propulsion device, 5... Speed increase device, 6...
Main shaft generator, 7... Generator, 8... Exhaust gas boiler, 9, 11... Coupling, 10... Clutch, 12
...Boiler, 13...Steam control valve.

Claims (1)

[Claims] 1 A main engine and a steam turbine driven by steam supplied from an exhaust gas boiler that utilizes the exhaust gas energy of the main engine are installed together, and each output shaft system is connected to a common reduction gear to drive the propulsion device. In a marine propulsion plant, a joint 9 provided on the main engine side and a clutch 10 provided on the reduction device side are provided in the middle of the output shaft system connecting the main engine and the reduction device, and a speed increasing Interpose a device,
A main shaft generator is connected to the speed increasing shaft of the speed increasing device, and another power supply source for operating the main shaft generator as an electric motor is connected to the main shaft generator, and the steam turbine and the speed reducing device are connected to each other. A marine propulsion plant characterized in that a joint 11 is provided in the middle of an output shaft system that connects.