RU2734148C1 - Ship engine, primarily, electric motor cooling system - Google Patents

Abstract

FIELD: shipbuilding.

SUBSTANCE: invention relates to water cooling systems of marine power plants. Marine engine, primarily, electric motor cooling system comprises internal fresh water circuit, external outline water circuit, marine engine temperature sensor and electronic control unit. Inner circuit comprises fresh water pipeline, fresh water circulating pump and expansion tank. Outer circuit comprises connected in series receiving and drain pipelines, seawater circulating pump and heat exchanger. Engine temperature sensor is connected to the electronic control unit and through it is additionally connected to the circulating seawater pump. Heat exchanger is water-water, which is a reservoir with the possibility of pumping through it seawater, inside which part of the pipeline of fresh water passes.

EFFECT: higher effective power and reliable operation of engine for a long time.

3 cl, 1 dwg

Description

The invention relates to the field of shipbuilding, in particular, to water cooling systems for ship power plants.

A useful model is known "Cooling device for a marine diesel engine" according to RF patent No. 152215 with a priority of 06.10.2014, IPC V63N 21/14, 21/38, F01P 5/10, published on 05/10/2015.

The specified cooling device for a marine diesel engine contains an open circuit of seawater and a closed circuit for cooling the charge air and oil.

The open seawater circuit, in turn, contains a self-priming seawater pump, seawater supply and discharge pipelines, a seawater heat exchanger, and a closed charge air and oil cooling circuit contains a heat exchanger. The cooling device also contains an expansion tank, divided by a partition into two isolated cavities: one cavity is intended for connection with a closed cooling circuit of a diesel engine, the other for connection with a closed circuit for cooling the charge air and oil. The seawater pump supplies seawater through a pipeline to the seawater heat exchanger. The seawater heat exchanger is divided into four isolated compartments. The extreme compartments are connected by inlet - outlet by means of pipelines with corresponding closed circuits, and the two compartments located between them are connected to the pipelines for supplying and discharging seawater. The outside water in the heat exchanger removes heat from the coolant circulating in the closed cooling circuit of the diesel engine and the closed circuit for cooling the charge air and oil, and then it is discharged overboard through the pipeline. If the coolant of the circuits does not exceed the set temperature and does not require cooling, then it enters the diesel engine, heat exchangers through thermostats, bypassing the heat exchanger. In the expansion tank, the pressure of the coolant is compensated when it is heated or cooled in closed cooling circuits of the diesel engine and charge air and oil.

In addition to cooling systems for diesel power plants used in shipbuilding, solutions are also known that characterize the cooling of electric machines by means of coolants circulating through pipelines introduced into the design of electric machines.

For example, the utility model "Stator cooling jacket of an electric machine" is known, described in RF patent No. 169095 with a priority of 09/30/2016, IPC N02K 9/16, published 03.03.2017.

The stator cooling jacket of the electric machine is made in the form of a spiral tubular element with coolant inlet and outlet pipes and is installed between the stator and the electric machine body. The spiral tubular element is made in such a way that the turns of the second branch with the outlet pipe are placed between the turns of one spiral branch with the inlet branch pipe, while both branches are hydraulically connected to each other from the end opposite to the branch pipes. In the cooling jacket of the stator of the electric machine, a coolant flow is created by means of the inlet pipe and the outlet pipe. For example, water is used as a heat carrier with the addition of anti-corrosion agents. As it moves along the tubular jacket, the coolant takes the heat from the stator of the electric machine and heats up. At the same time, due to the opposite arrangement of the branches of the branches, the average temperature of the heat exchanger tends along the entire length to the equilibrium value, which ensures a uniform decrease in temperature along the entire length of the stator.

Known RF patent No. 2631677 for the invention "System and method of cooling an electric motor" with a priority of 04/10/2012, IPC N02K 9/19, N02K 19/06, N02K 5/20, published on September 26, 2017

According to the invention, the motor housing is provided with an outer and an inner shell, between which a coolant channel is located, which has an inlet and an outlet. The inner shell of the housing has an opening for allowing air to pass from the air channel in the rotor of the electric motor along the second air channel, which runs between the inner and outer shells of the housing, transversely to the coolant channel, each of which passes through the outer shell and the second air channel.

Known RF patent No. 2369519 for the invention "Electric motor vessel with ambient water cooling" with a priority of 07.10.2005, IPC В63В 35/74, В63Н 21/17, Н01М 10/50, published 10.10.2009.

The invention relates to a motor ship with a flow channel passing through the ship's hull, with a propeller driven by an electric motor. The flow channel starts with an inlet in the bow of the ship's hull and ends with an outlet in the stern of the ship's hull, while the underwater drive unit is installed in the flow channel in the form of a pusher and suction device. An electric motor, batteries, an electric motor control device and a propeller are located in the flow channel. The batteries are installed in a waterproof casing and in some areas are in heat-conductive contact with the casing, the casing partly consisting of a heat-conducting material and in contact with the flowing water. Effective cooling is facilitated by the large volume flow of cooling water.

The described engine cooling systems are structurally complex. In addition, they lack the ability to regulate the thermal state of the ship engine.

Closest to the claimed technical solution is the utility model "Marine engine cooling system", described in the patent of the Russian Federation No. 183697 with a priority of 10.11.2017, IPC B63J 2/12, F01P7 / 16, published 01.10.2018 (prototype) ...

The cooling system of the marine engine contains an internal fresh water circuit for direct cooling of the marine engine and an external seawater circuit that maintains the required fresh water temperature in the internal circuit with the help of a refrigerator (heat exchanger). At the same time, a fresh water circulation pump, a temperature sensor at the outlet of the ship engine and an expansion tank are included in the internal circuit. The external circuit contains inlet and drain pipelines connected in series, a hinged seawater circulating pump mounted on a mounting frame and mechanically connected to the ship's engine shaft by means of a slip clutch, which is installed on the frame between the hinged seawater pump and the marine engine, controlled by an electronic control unit and connected to the shaft of the marine engine and to the shaft of the seawater pump by flange connections. The temperature sensor is installed in the internal fresh water circuit and connected to an electronic control unit, which, based on signals from the temperature sensor, controls the speed of the hinged seawater circulation pump. The controllable slip clutch automatically maintains the required fresh water temperature at the engine outlet by changing the speed of the outboard cold water passing through the heat exchanger at a constant speed of the ship's engine shaft.

If the control unit does not send a signal to the controlled slip clutch, it is fully engaged and the impeller of the mounted seawater circulation pump rotates at the speed of the ship's engine shaft. At a maximum fresh water temperature of 85 ° C at the outlet of the ship's engine, the steerable clutch operates with minimal slip. When the temperature of the engine and, accordingly, the temperature of fresh water in the internal circuit drops below 70 ° C, the controlled clutch works with maximum slip.

In this cooling system, the thermal state of the marine engine is controlled by changing the seawater feed rate by changing the speed of the mounted pump at a constant speed of the crankshaft of the marine engine. Temperature control is carried out mechanically by means of a controlled slip clutch, which determines the rate of circulation in the cooling circuit. The steerable clutch begins to operate with minimum slip at a maximum fresh water temperature of 85 ° C at the outlet of the ship engine. The minimum temperature of fresh water at the engine outlet is 70 ° C. When the engine temperature drops below 70 ° C, the controlled clutch works with maximum slip. This operating mode is typical for internal combustion engines, the efficiency of which is influenced by the thermal operating mode of the engine, depending on the characteristics of the fuel used, the stability of thermal gaps, etc. Maintaining the engine temperature in the range from 70 ° C to 85 ° C is accompanied by constant power take-off to the cooling system, which contributes to engine wear.

With the advent of new types of highly efficient electric machines, the issue of cooling them in order to increase efficiency arises.

Known methods of cooling electrical machines using coolants circulating through pipelines embedded in the design of electrical machines. In this case, the selection of heat from the coolant is carried out using an air radiator-heat exchanger, in turn cooled by an incoming air flow, or using a forced fan. As a rule, such systems are capable of cooling the stator windings only to a temperature of + 80 ° C.

The objective of the proposed technical solution is to create a cooling system for a marine engine, mainly electric, which allows to lower the engine temperature to the level of the seawater temperature, which rarely exceeds + 25 °, which improves its thermal balance, increases the effective power and ensures reliable engine operation for a long time. ...

The problem is solved by the fact that in the cooling system of the marine engine, which contains an internal fresh water cooling circuit for direct cooling of the marine engine, an external seawater circuit, a marine engine temperature sensor and a control unit, while the internal circuit contains a fresh water pipeline, a fresh circulation pump water and expansion tank; and the external circuit contains inlet and drain pipelines connected in series, a seawater circulation pump, a heat exchanger, and the engine temperature sensor is connected to the control unit, according to the invention, the engine temperature sensor is connected through the control unit to the internal circuit fresh water circulation pump and the external circuit seawater pump, and the heat exchanger is made water-to-water.

In the internal circuit, with the help of a circulation pump, a closed circulation of fresh water is made, which directly cools the ship's engine. The expansion tank serves to compensate for pressure drops due to thermal expansion of fresh water in the internal circuit.

In the inventive system, a water-to-water heat exchanger is used, which is a container inside which a part of the internal circuit pipeline passes (for example, in the form of a coil or a spiral), and the container is made with the possibility of pumping outboard water through it, washing part of the internal circuit pipeline immersed in the heat exchanger container.

In the external circuit, with the help of another circulation pump, intake and drain pipelines equipped with fittings on the bottom of the vessel below the waterline, outboard water is pumped through the tank of the water-to-water heat exchanger.

The temperature sensor is not installed in the internal circuit, as in the prototype, to measure the temperature of fresh water, but is installed inside a ship engine, for example, for an electric motor - inside the stator next to the winding, to measure the temperature of the engine itself.

When the marine engine is completely cold (at low power), the internal fresh water circulation pump and the external seawater circulation pump do not work. With an increase in engine power and, accordingly, an increase in its temperature, the signal from the temperature sensor goes to the control unit, on command from which the circulation pump of the internal circuit is turned on and the cooling of the engine begins due to the heat capacity of the fresh water circulating in it. If the temperature of the marine engine continues to rise, the control unit will activate the external circuit seawater circulation pump. In this case, the colder seawater circulating in the external circuit through the heat exchanger tank cools the fresh water circulating in the internal circuit, cooling the ship engine directly.

The control unit, depending on the engine temperature, regulates the intensity of the operation of both circulation pumps, which reduces the total operating time and increases the resource of the entire cooling system.

In the claimed cooling system, there are no mechanical connections between the circulation pumps and the marine engine, which allows the pumps to be located in any convenient places, forming a compact system.

The claimed cooling system, in contrast to the prototype, does not maintain a stable engine temperature, but ensures its operating temperature at the level of the seawater temperature, which rarely exceeds + 25 ° C, which is especially important for marine electric motors.

In a particular case, the cooling system of the marine engine, mainly the electric motor, additionally contains in the external circuit at the inlet of the receiving pipeline a seawater temperature sensor connected to the control unit. Depending on the readings of this sensor, the control unit changes the intensity of the seawater pump: the colder the seawater, the less the pump works.

In a particular case, the cooling system of a ship engine, mainly an electric motor, allows all elements of the external seawater circuit to be located inside the ship, which has a positive effect on the reliable operation of the engine.

Thus, the claimed cooling system of a marine engine, mainly an electric motor, characterized by a combination of these essential features, allows the engine temperature to be lowered to the level of the seawater temperature, which allows to increase the effective power and ensure reliable engine operation for a long time.

The claimed invention is illustrated in the drawing (Fig.) Diagram of the cooling system of a marine engine.

The cooling system of a marine engine, mainly an electric motor, generally comprises an internal circuit for direct cooling of a marine engine 1, including a fresh water pipeline 2, a fresh water circulation pump 3 and an expansion tank 4; contains a temperature sensor 5 of the engine 1, contains an external circuit, including connected in series inlet and outlet pipelines 6, 7 with fittings at the inlet and outlet, a water-to-water heat exchanger 8 and a seawater circulation pump 9; and also a control unit 10, wherein the temperature sensor 5 is connected through the control unit 10 to the fresh water pump 3 of the internal circuit and to the pump 9 of the external circuit seawater.

In a particular case of execution, the engine cooling system has the same elements as in the general case, and additionally contains at the inlet of the intake pipeline 6, in front of the external circuit pump 9, a seawater temperature sensor 11 connected to the control unit 10.

In this case, in particular, all elements of the external seawater contour can be installed inside the vessel.

The claimed cooling system for a marine engine, mainly an electric motor, operates as follows.

In cases where the marine engine 1 is cold (at low power), the internal circuit fresh water circulation pump 3 and the external circuit seawater circulation pump 9 do not work. With an increase in the power of engine 1 and, accordingly, an increase in its temperature, the signal from the temperature sensor 5 goes to the control unit 10, on command from which the pump 3 of the internal circuit is switched on, fresh water begins to circulate through the pipelines 2 of the closed internal circuit and cools the engine 1 due to its specific heat.

At the same time, the expansion tank 4 is compensated for pressure drops caused by thermal expansion of fresh water in the internal circuit.

With a further increase in the temperature of the marine engine 1, the control unit 10 connects the seawater pump 9, with the help of which seawater is circulated in the external circuit through the intake and drain pipelines 6, 7 connected in series with fittings at the inlet and outlet. In this case, the seawater through the intake pipeline 6 enters the tank of the water-to-water heat exchanger 8, washes the part of the pipeline 2 of the internal circuit immersed in it, for example, in the form of a coil or spiral, with fresh water circulating in it with the help of pump 3, then leaves the heat exchanger 8 and through the drain pipeline 7 it is discharged overboard.

As a result, colder seawater circulating in the external circuit through the heat exchanger tank 8 cools the fresh water circulating in the internal circuit, cooling the ship's engine 1 directly.

In a particular case of execution, when the cooling system additionally contains a seawater temperature sensor 11 at the inlet of the intake pipeline 6, before the pump 9 of the external circuit, which is connected to the control unit 10, the system works the same as in the general case, except that in depending on the readings of this sensor 11, the control unit 10 changes the intensity of the seawater pump 9: the colder the seawater, the less the pump 9 works.

Thus, the control unit 10, as required, regulates the intensity of operation of both circulation pumps 3 and 9 according to the selected algorithms, depending on the temperature of the engine 1 and the temperature of the seawater.

In this case, in particular, all elements of the external seawater circuit, including pump 9 and sensor 11, can be installed inside the vessel.

The claimed cooling system for a marine engine, mainly an electric motor, can be manufactured and assembled from ready-made components, blocks, assemblies using known materials, fasteners and technologies.

So, for a marine electric motor 1 of type DVIT 300, the cooling system can be assembled, for example, from the following blocks and parts.

As pipelines 2 coolant can be used, for example, copper pipes with an inner diameter of 10 mm.

As the coolant circulation pump 3, for example, a pump of the Jabsco V-FLO 5.0 type can be used.

As the expansion tank 4 can be used, for example, any automobile expansion tank with a volume of at least 5 liters.

As temperature sensor 5 on a marine engine, for example, STP-1X 1/8 '' - 27NPT sensor or Autonics TW-V can be used.

As intake and drain pipelines 6, 7 of sea water, for example, copper or HDPE pipes with an internal diameter of at least 1 '' can be used.

As a seawater circulation pump 9, for example, a pump of the Jabsco V-FLO 5.0 type can be used.

As a water-to-water heat exchanger 8, for example, a VOLVO-PENTA D4 / D6 refrigerator can be used.

As a seawater temperature sensor 11, for example, a STP-1X 1/8 '' - 27NPT sensor or Autonics TW-V can be used.

As a control unit 10 can be used, for example, a temperature controller of the Autonics T4WM type.

Claims (3)

1. The cooling system of a marine engine, mainly an electric motor, containing an internal fresh water circuit, an external seawater circuit, a marine engine temperature sensor and an electronic control unit, while the internal circuit contains a fresh water pipeline, a fresh water circulation pump and an expansion tank, and the external circuit contains sequentially connected intake and drain pipelines, a seawater circulation pump, a heat exchanger, and the engine temperature sensor is connected to an electronic control unit, characterized in that the engine temperature sensor is additionally connected to the seawater circulation pump through an electronic control unit, and the heat exchanger is made of water-to-water type, representing a container with the possibility of pumping outboard water through it, inside which a part of the fresh water pipeline passes. 2. The cooling system of the marine engine, mainly the electric motor, according to claim 1, characterized in that it further comprises a seawater temperature sensor installed at the inlet of the seawater intake pipeline in front of the external circuit circulation pump, which is connected to the electronic control unit. 3. The cooling system of a marine engine, mainly an electric motor, according to claims 1, 2, characterized in that all elements of the external seawater circuit are installed inside the vessel.

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