The invention relates to devices for cleaning air entering engines, and more specifically to devices for cleaning gas turbine engines of land vehicles which operate in dusty air conditions and engines of vessels operated in sea conditions which engines are flooded with air.
Gas turbine vehicles consume large amounts of air, in addition to diesel. Dust and particles in the air cause abrasive wear of the flow path of such gas turbine engines. With such abrasive wear, the performance of the flow paths, and consequently of the engines, is reduced to an unacceptable level, at which point a scheduled refurbishment is necessary. In a similar manner, flow paths of engines of sea vessels, which are flooded with air during their operation, are damaged by exposure to salt particles in the air flowing through the engines.
One known method of cleaning dust and debris from the air involves use of inertial air-cleaning devices, such as cyclone or ballistic separators which are usually cylindrical. However, the effectiveness of such inertial air cleaning devices depends on the air velocity flowing through them. For each type of device, there is an optimal air flow velocity at which the efficiency of the device is maximal. Any deviation from the optimal air flow velocity leads to a decrease in the efficiency of the device. Typically, a multi-sectional block of parallel-operating devices are installed on the vehicle, often occupying the entire available area of the vehicle air inlet port orifice. The exact arrangement of the devices may depend on the air flow velocity expected when the engine operates at maximal power. However, even when the air-cleaning cylindrical devices are arranged in close proximity to each other, only approximately 75% of the orifice of the air inlet of the engine is used.
In practice, each vehicle has a spectrum of vehicle speeds, where each speed corresponds to a certain engine power: for example, these may include engine idling (i.e., no speed of the vehicle), as well as low, medium, or full speed of the vehicle. However, because of this spectrum, the maximal engine power is typically used less than 10% of the service life of the engine. Thus, during most of its operation time, the engine has air flowing through the air-cleaning devices at a velocity that is different from the optimal one. As a result, the quality of air cleaning is well below the maximal potential air cleaning. This inevitably leads to a decrease in the overall service life of the engine.
There is thus a need in the art for a system and a method for cleaning air flowing through engines, such that, in the entire vehicle speed spectrum and/or at any engine power of the vehicle, air flow velocity will be optimal, or close to optimal. Thus, the cleaning of the air entering the engine will be equally effective and at a maximal level for the entire engine power spectrum, which will significantly increase the overall service life of the engine.
The invention relates to devices for cleaning air entering engines, and more specifically to devices for cleaning gas turbine engines of land vehicles which operate in dusty air conditions and engines of vessels operated in sea conditions which engines are flooded with air. For the sake of simplicity, the following description relates to land vehicles; however, the disclosure is equally applicable, methodologically and constructively, to engines of sea vessels.
According to an aspect of the present invention, an engine includes a multi-section block of air-cleaning devices, which occupies the entire flow area of an air inlet port orifice into an engine, and the throughput of which corresponds to the air flow velocity at full engine power. According to the present invention, a partial air cleaning method includes passing air entering the engine for cleaning only through a subset of the sections in the multi-section block, which, in terms of their throughput, correspond to the air consumption of the engine at the power mode specifically installed on the vehicle at a given time. Additionally, at each power mode of the engine, the optimal air flow velocity through each section of air-cleaning devices is ensured. Thus, in all modes of engine power and at all speeds of the vehicle, maximal air cleaning quality is ensured.
According to another aspect of the present invention, in order to implement the method of air cleaning using parts of the multi-section block of air-cleaning devices, the entire multi-section block is structurally divided into sub-blocks, each of which includes devices designed to optimally clean air at a specific air-flow rate, which corresponds to a specific engine power mode. To do this, each sub-block is associated with an autonomous louvers/shatters apparatus, which controls the ability of air to flow into the sub-block synchronously with changes to the engine power.
According to another aspect of the present invention, there is provided an air-cleaning device including a ballistic-type separator, made as a plurality of vertical slots. The inlet of each of the slots is configured in the form of a linear confusor. The walls of each of the slots are profiled along a curvilinear cylinder of variable radius of curvature. A U-shaped vertical collection chamber is installed in the crevice of each slot. Such slotted sections fit tightly to each other and provide almost 100% utilization of the flow area of air inlet port orifice. In some embodiments, the walls of the confusor are profiled along a cylindrical Bernoulli Lemniscate. This assists in reducing hydraulic losses in the linear confusor by creating a laminar air flow without boundary-layer separation.
According to another aspect of the present invention, tubular elements are installed behind the input edges of each pair of adjacent separator slots. The tubular elements are adapted for pumping hot substances therethrough, such as hot engine oil or hot air. For example, hot engine oil may be used to combine the functions of air separation and oil cooling. As another example, hot engine oil or hot air may be used to combine the functions of air separation and anti-icing heating of inlet devices in winter.
According to the method of the invention, the air at any power mode is not cleaned simultaneously in the entire block of air separator sections, but only cleaned in that part of the block which (in terms of its performance) is substantially equal to the air consumption by the engine at the currently set power mode. This means that the air is simultaneously passed through only a part of the air separator sections and, at the same time, wherein the optimum air flow rate is always provided, i.e., provided the maximum cleaning at all power modes of the engine.
The system of the invention is based on separation of a block of air separation sections into sub-blocks in the amount equal to the number of fractional powers at a given range of engine power modes, so that each sub-block contains the number of air separation sections having the total capacity to be equal to the engine air consumption in a particular mode, for example: idling, power of small, medium, full speed of the vehicle.
Each sub-block is activated by rotary shutters synchronized with/by the engine controls. As an example, the provided drawings illustrate the common inertial sections of the cyclonic type having a cylindrical shape. The system of the invention comprises slotted ballistic air cleaner/separators having multiple other advantages.
According to one preferred embodiment of the invention a system for cleaning air flowing into an engine air inlet of an engine of a vehicle is provided having a plurality of sub-blocks. A plurality of air separators is arranged in the plurality of sub-blocks, with each sub-block including air separators having a predetermined optimal air flow velocity. At least one rotary louver/shutters functionally associated with at least one sub-block. The rotary louver/shatter has a closed mode in which the rotary louver/shatter blocks flow of air into the air separators in the at least one sub-block, and an open mode in which air flows into the air separators in the at least one sub-block. A controller, adapted to control transitioning of at least one rotary louver/shatter between the closed mode and the open mode is provided.
In another preferred embodiment for each predetermined velocity of a plurality of predetermined velocities of the vehicle the plurality of sub-blocks includes at least one sub-block having air separators whose optimal air flow velocity corresponds to that predetermined velocity. The controller is adapted, when the vehicle is at that predetermined velocity, to ensure that the rotary louver/shatter of the corresponding at least sub-block is in the open mode.
In a further preferred embodiment the plurality of separators comprises cylindrical cyclone separators, wherein the sub-blocks comprise horizontal rows of separators, and wherein the rotary louvers/shatters comprise horizontal rotary louvers/shatters.
In a still another preferred embodiment each of the plurality of ballistic separators comprises a vertical slot having an inlet configured as a linear confusor and having walls in the form of a curvilinear cylinder of variable radius of curvature. Each vertical slot includes, at a center thereof, a U-shaped vertical dust-collection chamber, the dust-collection chamber having a smaller depth at a high portion thereof and a greater depth at a low portion thereof. U-shaped dust collection chambers of the plurality of ballistic separators engage a collection manifold connected to a gas-air ejector powered by engine exhaust gases.
In a still further preferred embodiment the system further comprises vertical tubes disposed along edges of each pair of adjacent linear confusors, the vertical tubes adapted for flow of hot substances therethrough and facilitating cooling of the hot substances and anti-icing functionalities. Each rotary louver/shatter has a rotary hinge including a circular axis installed within a hinge sleeve in an elliptical horizontal hole, the elliptical horizontal hole having a first dimension substantially equal to a diameter of the circular axis, and a second, opposing dimension greater than the diameter of the circular axis, such that a gap is formed in the sleeve, and when a torque producing force is applied to the rotary louver/shatter, the circular axis and the associated louver/shatter are displaced within the gap before pivoting.
One of the preferred embodiments of the invention relates to a two-stage air inlet system which is typical for ships having substantial resource of engine operation.
The subject matter regarded as the invention is particularly pointed out and distinctly claimed in the concluding portion of the specification. The invention, however, both as to the system and method of operation, together with objects, features, and advantages thereof, may best be understood by reference to the following detailed description when read with the accompanying drawings in which:
Embodiments of the invention are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like reference numerals indicate corresponding, analogous or similar elements. It will be appreciated that for simplicity and clarity of illustration, elements shown in the figures have not necessarily been drawn to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity. Further, where considered appropriate, reference numerals may be repeated among the figures to indicate corresponding or analogous elements.
Reference is now made to
As seen in
Each separator may be based on cylindrical ballistic air separators, an example of which is shown in
The Bernoulli Lemniscate shown in
ρ2=2a2 cos2θ.
As seen, the curve is shaped like the number “8”, where the radius of curvature smoothly changes from the initial value “R1”, the position of which is determined by the value “a”, which determines the overall size of the Lemniscate, and up to the value “R5”, which is a straight line, i.e., having an infinite (cc) radius of curvature, so that:
R1<R2< . . . <R5(∞).
This characteristic of the Lemniscate is used to form the annular inlet sections of the curvilinear confusor 14 of the separator, shown in
Regardless of the hydrodynamic characteristics, in engines with high air consumption, it is necessary to install several groups of separators 10 arranged in blocks. Even with dense stacking of the cylindrical separators, non-working “dead zones” 20 are formed between the separators. As a result, only 75% of the orifice of the air-cleaning device 12 is actually used.
For each inertial separator, there is an optimal air flow velocity v (m/s), at which an efficiency k % is maximal; deviation from the optimal air flow velocity in any direction leads to a decrease in the efficiency of the separator. Specifically, a decrease in air velocity results in the centrifugal forces that throw dust particles to the periphery of the flow being insufficient. Conversely, an increase in air velocity causes secondary particle capture to occur, such that dust particles that have already come into contact with the surface of the curvilinear elements of the separator are again carried away by the air flow to the “clean” zone. Thus, for ideal operation of air-cleaning device 12, the optimal air-flow velocity for each separator 10 should be maintained.
The multi-section block of separators 10 is divided into sub-blocks by frame elements 22. Each sub-block has a height “h” and includes separators 10 designed to clean in-flowing air having an air flow velocity corresponding to one specific engine power mode. Stated differently, each sub-block is designed to clean a portion of air from the total amount of air consumed by the engine at maximum power, which portion of air corresponds to operation of the engine at a different power mode. For this purpose, each sub-block of sections is equipped with autonomous rotary louvers/shatters 24 (see “A”-“A” and “B”-“B”), which enable or disable air flow into the specific sub-block of sections synchronously with switches to the engine power. The number of separators 10 in each sub-block, which depends on the volume of the air portion to be cleaned by that sub-block, is selected to ensure the optimal air flow rate and maximum efficiency k % of the separator. Some sub-block sections, are designed for engine idling, are devoid of louvers/shatters 24, and are form an opening 26 for in-flow of air. This ensures that the engine is always ready to start.
With prolonged inactivity following operation in wet dust and dirt, some or all sections of louvers/shatters 24 may stick to walls of the corresponding frame 22. The same is true when operating in winter conditions, in which icing can, or does, occur. As shown in the enlarged views “F” and “G” of
Reference is now made to
In air-cleaning device 12 shown in
The aerodynamic operation of separation in the in-line separators 40 employing linear confusor 42 is similar to the operation of the annular separators 10 shown in
In a similar manner to that shown in
In some embodiments, and as illustrated in
The actuator of rotary louvers/shatters 48, shown in the enlarged views “L” and “M” in
A lower portion of some, or all, of dust collection chambers 44 are connected to each other via a manifold 58 having a built-in gas ejector 60. Using exhaust gases 62, gas ejector 60, dust 64 is sucked from collection chambers 44 and removed from the system.
In accordance with the present invention, the opening of the rotary louvers/shatters in each of the air-cleaning devices is selected to correspond to the needs of the engine in each power mode. Thus, the air flow velocity at all separator sections will be constant and will correspond to the optimal for that section, providing maximum and equally effective air cleaning in all modes.
In
On vessels where the water has a high air content, such as high speed craft, hovercraft and the like, a two-stage cleaning system can be installed, where a first stage (coarse air cleaning) is in the form of inertial separator as described hereinabove with respect to
As discussed above and illustrated in
While certain features of the invention have been illustrated and described herein, many modifications, substitutions, changes, and equivalents may occur to those skilled in the art. It is, therefore, to be understood that the appended claims are intended to cover all such modifications and changes as fall within the true spirit of the invention.
The present application claims priority of U.S. Provisional Patent Application No. 63/576,266 filed Jan. 30, 2023, and U.S. Provisional Patent Application No. 63/576,961 filed Mar. 20, 2023, both of which are hereby incorporated by reference in their entirety.
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4263027 | Varnas | Apr 1981 | A |
20100275561 | Lundquist | Nov 2010 | A1 |
20150135661 | MacDonald | May 2015 | A1 |
20150343366 | Wuebbeling | Dec 2015 | A1 |
20160045923 | Correia | Feb 2016 | A1 |
Number | Date | Country |
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20220073433 | Jun 2022 | KR |
221295 | Oct 2023 | RU |
Number | Date | Country | |
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63576961 | Mar 2023 | US | |
63576266 | Jan 2023 | US |