RU2521172C2 - Marine propulsive arrangement with power accumulator - Google Patents

Abstract

FIELD: engines and pumps.

SUBSTANCE: invention relates to electrical drives designed to transfer power from primary thermal engine to propulsors. Proposed complex comprises thermal engine, first shaft, variator and second shaft whereat screw propeller is fitted. Said variator incorporates first unipolar generator and second unipolar generator, not engaged mechanically, and third unipolar machine fitted on hollow shaft rung in bearings or magnetic suspensions coaxially with first or second shaft. Power accumulation flywheel is fitted on the same shaft. RPM transducers are fitted on all shafts. Said transducers are connected with control system whereto excitation windings of unipolar machines are connected as well as thermal engine rpm control unit. Subject to control signals this machine runs in engine or generator mode while flywheel accumulates or outputs the accumulated power.

EFFECT: higher efficiency, decreased overall dimensions and weight, higher reliability.

3 cl, 2 dwg

Description

The invention relates to the field of shipbuilding, and specifically to electric drive devices for transmitting energy from a primary heat engine to propulsion.

Known rowing electrical installation [RF patent No. 2392180, publ. 06/20/2010], consisting of a propeller motor connected to the propeller through a gearbox and disconnect couplings. A rowing electric motor is connected to a source of electricity through a static frequency converter. The structure also has a propeller speed controller, which is connected to the control system, the outputs of the latter are connected to the control inputs of the frequency converter and disconnect couplings.

The disadvantages of this installation include:

- significant weight and dimensions;

- increased levels of electromagnetic interference and harmonic components in the current consumed from the ship network with non-linear pulse-width conversion of electricity;

- reduced reliability and increased losses, due to the fact that energy is transferred from the heat engine to the propeller through the conversion path - an electric generator, a static frequency converter, designed for the full power of the installation, gearbox, disconnect couplings and the propeller motor;

- an additional power reserve is required in ice swimming conditions to overcome the effects of ice on the propeller, which, in turn, increases the mass and dimensions of the installation, as well as energy loss.

Known propulsion systems, in particular for wheeled vehicles in which energy storage devices are used. One of these settings is presented in the description of the patent for the invention Device for recovering braking energy of a machine [RF patent No. 2438884 from publ. 01/10/2012]. The installation contains a flywheel, shafts, a traction motor, reversible electric machines, a control device, an electric battery and electric circuits connecting them, as well as a transmission and differential. The shaft of one reversible electric machine is connected to the sun gear of the differential. The shaft of another reversible electric machine is connected to the differential carrier and transmission, which is connected to the shaft of the traction motor. The flywheel is connected to the differential ring gear.

The disadvantages of this device include the complexity of the design: the transfer of energy to the working body, in this case, to the wheels of the vehicle, is carried out from the heat engine to the flywheel and from the flywheel through a multi-link planetary gear train and two reversible electric machines. This reduces reliability, increases energy losses, mass, dimensions, cost of the device and is limited in application in shipbuilding by the lack of power of a possible implementation.

Known ship propulsion system of the type "rotary column" [RF patent No. 2119875, publ. 10.10.1998], which, despite the fact that it does not have an energy storage, is adopted as a prototype, because is a ship. The installation comprises a rotational rotational motor enclosed in a streamlined casing and two propellers rotating in opposite directions, namely a counter-propeller mounted on the rotor shaft of the biotational engine, and a propeller mounted on the hollow shaft of the rotating stator, the coaxial rotor shaft.

The casing is mounted to rotate in a horizontal plane. It is obvious to a specialist, although this is not explicitly stated in the description that the propulsion motor of the installation is connected to a static frequency converter, which, in turn, is connected to the power system and to the electric generator driven by the rotation of the heat engine.

The disadvantages of the prototype, as described above analogue include:

- increased weight and dimensions;

- increased levels of electromagnetic interference and harmonic components in the current consumed from the ship network with non-linear pulse-width conversion of electricity;

- reduced reliability and increased losses, due to the fact that energy is transferred from the heat engine to the propeller through the conversion path - an electric generator, a static frequency converter, designed for the full power of the installation, and a propeller motor;

- an additional power reserve is required in ice swimming conditions to overcome the effects of ice on the propeller, which, in turn, increases the mass and dimensions of the installation, as well as energy loss.

The problem solved by the invention is the expansion of the arsenal of means and the creation of a new, reliable ship propulsion and propulsion system with improved performance, especially in shunting conditions and ice conditions of the vessel, by eliminating the use of non-linear pulse-width energy converters, replacing the electric generator and the propeller motor to an electrodynamic variator with a unipolar generator, a rowing electric motor, a flywheel drive machine and a flywheel in its composition.

The technical result achieved is:

- to increase efficiency through the use of stored energy;

- in reducing the weight and dimensions of the installation;

- to increase reliability and reduce the level of electromagnetic interference, harmonic components and losses in a ship propulsion system.

The tasks are solved by changing the functional diagram of the installation.

The inventive marine propulsion and propulsion system (DDU) comprises a heat engine equipped with a speed control unit and connected by a first shaft to a variator, which is connected to the propeller by a second shaft. The shafts are not mechanically interconnected. The variator comprises a first unipolar machine mechanically connected to the first shaft, a second unipolar machine mechanically connected to the second shaft, and comprises a flywheel and a third unipolar machine fixed to the third shaft. This shaft is hollow and can be installed coaxially with the first or second shaft. The third shaft is mounted on the first or second shaft on a rotation support (bearings or magnetic suspension). All three unipolar machines are electrically interconnected. A speed sensor is installed on each shaft, they are connected to the control system of the installation, to which the excitation windings of unipolar machines are also connected, and the control unit for the rotation speed of the heat engine is connected.

The invention is illustrated by drawings, on which:

Figure 1 - diagram of a propulsion system with a flywheel installed at the output of the variator, Figure 2 is the same with the flywheel at the input of the variator.

The inventive installation, shown in Fig. 1, comprises a heat engine 1 (for example, a turbine), which is mechanically connected by a first shaft 2 to a variator 3, and specifically, to a first unipolar machine operating in a generator mode (hereinafter referred to as a unipolar generator 4), which includes part of the variator 3. Thus, the heat engine 1 and the unipolar generator 4 of the variator are mounted on the same shaft (first shaft 2). The variator also includes a second unipolar machine operating in engine mode (hereinafter referred to as unipolar motor 5) mounted on a second shaft 6, on which a fixed pitch propeller 7 is also mounted. On the shafts 2 and 6, the first and second rotational speed sensors are installed - 8 and 9, respectively. The shafts 2 and 6 are not mechanically interconnected and can be located on the same geometric axis and in the same plane, as shown in figure 1, or at a given angle and also in the same or different planes. Unipolar machines 4 and 5 are electrically connected to each other by buses 10, and their field windings 11 are connected to a control system 12, which is connected with its other inputs to rotational speed sensors 8 and 9, and also to a control unit 13 of the rotation speed of the heat engine 1. In this an embodiment, a hollow shaft 15 is mounted on the second shaft 6 coaxially, using bearings and / or an electromagnetic suspension 14. Thus, all the shafts are not connected to each other. A third unipolar machine 16 (its rotor) of the variator 3 is installed on the hollow shaft 15, an energy storage device — a flywheel 17, and a third rotation speed sensor 18 is installed. The current leads of the third unipolar machine 16 are also connected via busbars 19 to the corresponding current leads of the unipolar machines 4 and 5 of the variator 3. The field winding 20 of the third unipolar machine, the output of the rotation speed sensor 18 is connected to the control system 12 of the ship propulsion system. The control system 12 on the interface is connected with the control system 21 of the upper level.

In some cases, as shown in Figure 2, the location of the third unipolar machine with a flywheel and a rotation speed sensor in the variator can be changed. In this embodiment, in the variator 3, the set of machines remains unchanged - also the unipolar generator 4 located on the first shaft 2, the unipolar motor 5 located on the second shaft 6, on which the propeller 7 is also installed. Other listed circuit elements are also present. But in this embodiment, the third unipolar machine 16 with the flywheel 17 and the third rotation speed sensor 18 is mounted on the third hollow shaft 15, which coaxially covers the first shaft 2, and mounted on it using bearings and / or electromagnetic suspension 14. Connections of elements with the system controls 12 remain, as in the first embodiment.

The proposed ship DDU with energy storage (flywheel), presented in figure 1, works as follows.

According to the signals of the control system 21 of the upper level, arriving at the control system 12, the control unit 13 sets the rotation speed of the heat engine 1, which is controlled by the sensor 8 of the rotation speed by the control system 12.

After the acceleration of the thermal motor 1 of the excitation winding 11 of the unipolar machines — the generator 4 and the motor 5 — the currents set (in magnitude and direction) by the control system 12 are received. The unipolar generator 4 generates a current transmitted to the input of the unipolar motor 5 via buses 10. The unipolar motor 5 is driven into rotation with a predetermined speed control system 12, controlled by the second sensor 9. Changing the magnitude of the excitation current of unipolar machines 4 and 5 changes the power at the output terminals of the unipolar generator 4 and the power on the shaft 6 unipolar motor 5. Changing the direction of the excitation current of unipolar machines changes the direction of their rotation. On the instructions of the control system 21 of the upper level, for the operation of the remote control at low speeds of rotation of the propeller 7, by the signal of the control system 12 to the control unit 13, the rotation speed of the heat engine 1 can be reduced. Reducing the rotational speed of the propeller 7, the control system 12 can provide a corresponding decrease in the excitation currents of the unipolar generator 4 and the unipolar engine 5, as well as the redistribution of the currents of the generator 4 between the engine 5 and the third unipolar machine 16 with the flywheel 17 on the hollow shaft 15.

At the beginning of the operation of the remote control, the specified excitation current of the third machine 16 ensures the equality of the EMF at its terminals and the voltage on the tires 10. In this case, the hollow shaft 15 of the third machine 16 together with the flywheel 17 rotate at a certain speed with a minimum of current consumed by the machine 16. Decrease in the speed of rotation of the prop screw 7 with energy storage by the flywheel 17 is as follows. The control system 12 for reducing the excitation current of the third machine 16 puts it into motor mode, and it takes on some of the power from the unipolar motor 5, the rotation speed of which decreases. At the same time, by decreasing the excitation current, the unipolar generator 4 reduces the output electric power, and the third machine 16 accelerates the flywheel 17, which stores mechanical energy under the control of the control system 12. When the rotational speed of the propeller 7 is reduced to the specified (control system 21 of the upper level) excitation currents of unipolar machines 5 and 16 are set at a level that provides free rotation of machine 16 without energy consumption, and machine 5 operates in motor mode, consuming all the power from the generator 4. If the external impact speed of rotation of the propeller 17 decreases emf unipolar motor 5 is also reduced and the machine 16 as a generator with the flywheel 17 returns the stored energy. In this case, the excitation currents of the generator 4 and the machine 16 can be changed to limit the torque on the propeller 7 according to the signal of the second sensor 9 and for the full use of the energy stored by the flywheel 17.

Upon receipt of a command to change the direction of rotation (reverse) of the propeller 7, the control system 12 controls the excitation currents of the unipolar machines of the variator 3 so that the unipolar generator 4 is in the minimum load (idle) mode, the second unipolar machine (unipolar motor 5) goes into the generator mode, and the third unipolar machine 16 went into motor mode with the transfer of energy to the flywheel 17. The supporting mode of the second unipolar machine while lowering the speed of rotation of the propeller 7 supporting etsya increase its excitation current. When reaching the specified limit values of the rotation speed of the flywheel 17 or the excitation current of the second unipolar machine, the control system 12 turns off the excitation of the variator 3. For the heat engine 1, the minimum speed is set, the unipolar generator 4 is idling, and the flywheel 17 and the machine rotor 16 (hollow shaft 15) rotate with stored mechanical energy. The control system 12 changes the polarity of the excitation currents of the machines of the variator 3 and controls them as follows. Machine 16, operating in the generator mode, provides an increase in the speed of rotation of the propeller 7 by the motor-engine 5 to the maximum reduction in the speed of rotation of the flywheel 17. After this, the machine 16 is put into idle mode, and a further increase in speed and movement is carried out by the heat engine 1 and unipolar generator 4 and unipolar motor 5.

In the second embodiment of the DDU shown in FIG. 2, the third unipolar machine 16 with the flywheel 17 has the same electrical connections with the machines 4 and 5 in the absence of rigid mechanical connections between their shafts as in the DDU in FIG. 1, and works similarly set out above.

Thus, the use of an electrodynamic variator in a marine propulsion system based on two unipolar electric machines and the introduction of a third unipolar machine with a hollow shaft coaxially mounted on rotation bearings on the first or second shaft of the variator, as well as the presence of a flywheel as an energy storage device on the hollow shaft, allows you to:

- increase energy efficiency;

- to exclude from its traditional structure non-linear pulse-width frequency converters designed for full power, which allows to increase reliability and reduce the level of electromagnetic interference, harmonic components and losses;

- reduce energy loss during the operation of the vessel in ice conditions and in shunting modes;

- to reduce the weight and dimensions of the installation by replacing the generator and the propeller motor with an electrodynamic variator with a unipolar generator and the propeller motor and excluding the frequency converter designed for full power;

- to provide the ability to set the axis of the output shaft of the variator with the propeller at a given angle with respect to the input shaft.

Claims (3)

1. Marine propulsion system, characterized in that it contains a heat engine equipped with a speed control unit and connected by a first shaft to a variator, which is connected to the propeller by a second shaft, the shafts are not mechanically connected to each other, while the variator contains a first unipolar machine mechanically connected to the first shaft, the second unipolar machine mechanically connected to the second shaft, and contains a flywheel and a third unipolar machine, mounted on a third shaft made hollow and installed on the rotation support coaxially to the first or second shaft, all three unipolar machines are electrically connected to each other, the installation also contains a control system, a rotation speed sensor is installed on each shaft, the sensors are connected to a control system to which the excitation windings of unipolar machines are also connected and the unit is connected control the speed of rotation of the heat engine. 2. Ship propulsion system according to claim 1, characterized in that bearings are used as a support for the rotation of the hollow shaft. 3. Ship propulsion system according to claim 1, characterized in that a magnetic suspension is used as a support for the rotation of the hollow shaft.

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