KR100263144B1 - Flow separator of a fluid - Google Patents

Abstract

PURPOSE: A fluid flow separator is provided to restrain pressure in a fluid flow system within a predetermined level although a flow rate increases and to determine opening timing of a piston valve by adjusting a ratio of the area of a main supply pipe to the area of the piston valve. CONSTITUTION: A fluid flow separator(30) includes a main supply pipe(31), a first tube(32) branched from the main supply pipe, a second tube(33) branched from the main supply pipe and opened and closed depending on a predetermined pressure, and a piston valve(34) opening the second tube by using elasticity of a piston(35). The area where a fluid in the main supply pipe acts to the piston valve while the piston valve closes the second tube is smaller than the area where the fluid acts while the piston valve opens the second tube. Herein, possibility of generation of high pressure in a fluid flow line is avoided. As the fluid acting area of the piston valve is varied according to opening and shutoff of a valve, opening timing of the valve is adjustable.

Description

Fluid flow separator

1 is a schematic diagram of a fluid flow separator according to the prior art.

FIG. 2 is a graph showing the change in flow rate with respect to the pressure of the fluid flow separator shown in FIG.

3 is a schematic diagram of a fluid flow separator according to the present invention.

4 is a graph showing the change in flow rate with respect to the pressure of the fluid flow separator shown in FIG.

* Explanation of symbols for main parts of the drawings

11: main supply pipe 12: first tube

13: second tube 14: piston valve

15: spring 31: main supply pipe

32: first tube 33: second tube

34: piston valve 35: spring

36: cylinder P: pressure

Q: flow rate

The present invention relates to a fluid flow separator, and more particularly to a fuel flow separator used in a gas turbine engine of an aircraft.

Fluid flow separators are used in fuel supply systems in most aircraft gas turbine engines. In aircraft gas turbines, the flow rate of the fuel to be supplied depends on the operating conditions of the aircraft. For example, a small amount of fuel is required during initial start-up, while a large amount of fuel is required during start-up or cruise, unlike during start-up. In the gas turbine engine for the aircraft, it is essential to employ a fluid flow separator in the fuel supply system due to the fuel quantity control condition that the fuel supply must be adjusted according to the operating conditions of the engine.

Fluid flow separators are designed to allow fluids to flow through separate flow paths according to conditions. In an aircraft gas turbine engine, a flow separator is disposed in the path from the fuel inlet to the nozzle for injecting fuel into the gas turbine engine. This is to separate the fuel supply nozzle into the first nozzle and the second nozzle, and to supply fuel only by the first nozzle or by using both nozzles according to the engine operating state.

FIG. 1 schematically shows the configuration of a fuel flow separator for a gas turbine engine according to the prior art.

The fuel flow separator 10 includes a first tube 12 and a second tube 13 branched from the main feed canal 11. The first tube 12 and the second tube 13 are connected to the first nozzle and the second nozzle, respectively. The fuel flow separator 10 is arranged with a piston valve 14 which is subjected to an elastic force of the spring 15. The piston valve 14 may open or close the fuel flow through the second tube 13 according to the flow rate of the fuel supplied from the main supply pipe 11. The fuel flow to the first tube 12 is not subjected to the opening and closing action by the valve and is always kept open. Typically, the fuel injection cross section of the first tube 12 is smaller than the second tube 13. When a small amount of fuel supply to the gas turbine engine is to be maintained, i.e., when starting the engine, only the first tube 12 with a small cross-sectional area is used.When fuel is introduced into the main supply pipe 11 through the inlet, it is always open. Fuel flows to the first nozzle through the first tube 12 maintained in the state and is injected into the gas turbine engine. As the flow rate of fuel increases, the pressure in the main supply pipe 11 also increases, thus increasing the pressure on the piston valve 14. When the force exerted on the front face of the piston 14 by the fluid pressure in the main supply pipe 11 is greater than the elastic force of the spring 15, the piston 14 moves in the opposite direction to the elastic force of the spring 15, so that the piston 14 The second tube 13 which has been closed by () is opened. Therefore, the fuel flowing into the main supply pipe 11 flows not only to the first tube 12 but also to the second tube 13. In the normal driving state of the aircraft, a large amount of fuel is supplied to the gas turbine engine through both the first tube 12 and the second tube 13.

FIG. 2 is a graphical representation of the change in flow rate versus pressure in the fuel flow separator 10 shown in FIG. In the graph, the life axis (P) is the pressure and the vertical axis is the flow rate (Q). At initial start-up, pressure and flow rate increase linearly. When the pressure increases as the flow rate increases to Q1 and the pressure P1 is reached, the force acting on the piston valve 14 is equal to the area (A) where the fluid (fuel) and the valve contact are multiplied by the pressure P1 (F). ) When the force generated by this fluid flow exceeds the elastic force of the spring 15, the piston valve 14 is pushed back and the second tube 16 is opened as described above. Since the open state of the second tube 13 is usually a normal driving state of the aircraft, a large amount of fuel should be supplied to the engine.

Therefore, the flow rate of fuel to the engine continues to increase until Q3. When the total flow rate flowing into the main supply line is Q3, the flow rate through the first tube does not differ much from the original flow rate Q1, but the pressure increases rapidly to P3. On the other hand, since the cross-sectional area of the second tube 13 is relatively larger than that of the first tube 12, the flow rate through the second tube 13 increases proportionally as the flow flowing through the main supply pipe increases. And the pressure increases to P3 like the first tube 12.

In the fuel flow separator 10 of the prior art as described above, the pressure on the first tube 12 and the second tube 13 increases proportionally when the flow rate flowing into the main supply pipe 11 increases. There are various problems in technology. That is, as the flow rate of the fuel supplied to the gas turbine engine increases, the pressure of the entire fuel supply line increases proportionally, and there is no countermeasure to avoid this in the prior art. Therefore, in order to prevent the destruction of the system due to pressure increase, the pressure resistance of the tube disposed in the fuel supply system must be large, the outlet pressure of the fuel pump supplying fuel to the main supply pipe must be increased, and the electric motor driving the pump must You must use This is disadvantageous not only in terms of design difficulty but also in cost.

It is an object of the present invention to provide a fluid flow separator in which the pressure in the fluid flow system does not increase above a set value even if the flow rate increases.

Another object of the present invention is to provide a fluid flow separator capable of determining the opening timing of a piston valve by adjusting the ratio of the area of the main supply pipe to the area of the piston valve.

In order to achieve the above object, according to the present invention, a main supply pipe into which fluid is introduced, a first tube branched from the main supply pipe and always open, branched from the main supply pipe and opened or closed according to a set pressure A fluid flow separator comprising a second tube, which may be, and a piston valve receiving an elastic force of a piston to open or close the second tube, wherein the piston valve is closing the second tube. A cross-sectional area in which the fluid in the supply pipe acts on the piston valve is provided, wherein the fluid flow separator is smaller than the cross-sectional area in which the fluid acts on the piston valve with the piston valve open.

According to a feature of the invention, the cross-sectional area of the second tube is larger than that of the first tube.

According to another feature of the invention, the cross-sectional area in which the fluid acts on the piston valve in the state in which the piston valve closes the second tube, and the fluid acts on the piston valve in the state in which the piston valve opens the second tube. By adjusting the ratio of the cross-sectional area, the opening and closing timing of the piston valve can be adjusted.

According to another feature of the present invention, there is provided a fluid flow separator for an aircraft gas turbine engine in which the fluid flow separator is disposed in a fuel flow line so as to increase or decrease the supply of fuel to the gas turbine engine of the aircraft.

In addition, according to the present invention, in the fluid flow control method for controlling the flow into the second tube by moving the piston valve under the spring force of the spring flow by the pressure of the fluid flowing in the main supply pipe, the piston valve is a second By increasing the cross sectional area in which the fluid acts on the piston valve in a state where the piston valve opens the second tube, the cross section area in which the fluid acts on the piston valve in the state of closing the tube makes the piston valve second. The fluid flow characterized in that the pressure in the entire fuel supply system, including the main supply line, the first tube and the second tube, is not greater than the pressure at the opening of the second tube, even if the fluid inlet is increased into the main supply line after the tube is opened. Separation methods are provided.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 schematically shows the configuration of a fluid flow separator 30 according to the present invention. The fluid flow separator 30 includes a first tube 32 and a second tube 33 separated from the main supply pipe, and includes a piston valve 34 which is subjected to elastic force by the spring 35. The first tube 32 is connected to the first nozzle, the second tube 33 is connected to the second nozzle, the fuel is injected to the gas turbine engine as the fuel flows through each tube. The piston valve 34 is formed to have a cross-sectional area of the accommodation tube cylinder 36 larger than that of the main supply pipe 31. In a state in which no fluid flow occurs in the main supply pipe 31, that is, no fuel is supplied at all, or the fluid flow is below a predetermined pressure, the piston valve 34 causes the second tube to be driven by the force of the spring 35. The entrance of 33 is closed.

As the flow rate of the fuel fluid flowing into the main supply pipe 31 increases, the pressure in the main supply pipe 31 increases, and the increased pressure acts on the surface of the piston valve 34 to reverse the elastic force of the spring 35. Works. Therefore, when the pressure in the main supply pipe 31 increases above a predetermined pressure, the piston valve 34 opens the second tube 33. With the piston valve 34 closing the inlet of the second tube 33, the area where the piston valve 34 contacts the fluid flow is A1 as indicated in FIG. However, once the piston valve 34 begins to be pushed by the fluid pressure, the area in contact with the fluid flow is A2. Since the area A2 is wider than the area A1, the pressure in the main supply pipe 31 can be reduced while the force due to the fluid pressure that repels the elastic force of the spring 35 associated with the piston valve 34 is kept constant. Expressed in the formula, F is a force applied to the piston valve 34 by hydraulic pressure, and the main supply pipe 31 applied to the valve surface area A1 when the piston valve 34 is closing the second tube 33. When the internal pressure is P1 and the pressure in the main supply pipe 3l applied to the valve surface area A2 when the piston valve 34 opens the second tube 33 is P2, F = P1 x A1 = P2 × A2. If A1 <A2, then P1> P2.

Therefore, when the flow rate in the main supply pipe 31 increases and the second tube 33 is opened, the pressure of the entire fuel system including the main supply pipe 31 and the first tube 32 and the second tube 33 becomes second. It may be kept lower than before the tube 33 is opened. In addition, since the force exerted by the pressure varies depending on the size of the area subjected to the pressure of the fluid, the cross-sectional area A1 of the piston valve 34 can be increased to increase the force applied to the piston valve, resulting in a ratio of A1 / A2. It is also possible to adjust the opening time of the piston valve 34 by adjusting.

FIG. 4 graphically shows the change in flow rate Q relative to the pressure P of the fluid flow separator 30 shown in FIG. 3.

Before the piston valve 34 is opened, the pressure and flow rate of the fluid in the main supply pipe 3l increase linearly in proportion. If the force exerted on the piston valve 34 by the fluid pressure is Q1 and the fluid pressure is P1 immediately before opening the second tube 33, the fluid pressure is P2 immediately after the piston valve 34 is opened. Descends. As described above, the fuel acts only on the cross-sectional area A1 of the piston valve 34 when the fuel flows only in the main supply pipe 31, but once the hydraulic pressure acting on the piston valve 34 becomes larger than that of the spring 35, the piston is moved backward. This is because the cross sectional area of the piston valve 34 on which the fluid acts is extended to A2. Thereafter, the pressure in the main supply pipe 31 increases from P2 to P3 again as the flow rate flows in, but this is not greater than the pressure of P1, which is the pressure at the first piston valve opening, and the pressure is equal to P1, which is the pressure at valve opening. Can be increased to '.

Employing the fluid flow separator as described above has the advantage that the configuration of the flow line is easier because there is no room for high pressure unlike the prior art in the fluid flow line. In addition, since the cross-sectional area of the piston valve acting on the pressure of the fluid flowing there is a difference between opening and closing the valve, it is possible to adjust the opening and closing timing of the valve by adjusting this.

Although the present invention has been described with only the embodiments shown in the drawings, those skilled in the art will understand that various modifications are possible therefrom. In particular, the present invention has been described with respect to a system for supplying fuel from a gas turbine engine for an aircraft, but the flow separator of the present application may be used for various purposes in all systems in which fluid flow occurs. Therefore, the protection scope of the present application should be defined based on the appended claims.

Claims (5)

The first supply pipe 31 is branched from the main supply pipe 31, the main supply pipe 31, the fluid is introduced into the first tube 32, which is always kept open, branched from the main supply pipe 31, which is opened and closed according to a set pressure In a fluid flow separator comprising a two tube and a piston valve (34) subjected to an elastic force of a spring (35) to open and close the second tube (33), The cross-sectional area where the fluid in the main supply pipe 3l acts on the piston valve 34 while the piston valve 34 is closing the second tube 33 is such that the piston valve 34 is connected to the second tube. Fluid flow separator (30), characterized in that the fluid is smaller than the cross-sectional area acting on the piston valve (34) with the (33) open. The fluid flow separator (30) of claim 1, wherein the cross-sectional area of the second tube (33) is larger than that of the first tube (32). The cross-sectional area Al in which fluid acts on the piston valve 34 in a state in which the piston valve 34 closes the second tube 33, and the piston valve 34 is formed in the second valve. Fluid flow separator 30, characterized in that the opening and closing timing of the piston valve can be adjusted by adjusting the ratio of the cross-sectional area (A2) that the fluid acts on the piston valve (34) while the tube is open. The fluid flow separator (30) according to any one of claims 1 to 3, characterized in that the fluid flow separator (30) is arranged in a fuel flow line so as to increase or decrease the supply of fuel to the gas turbine engine of the aircraft. Fluid flow separator 30 for an aircraft gas turbine engine. In the fluid flow control method of controlling the flow into the second tube (33) by moving the piston valve (34) under the elastic force of the spring (35) by the pressure of the fluid flowing in the main supply pipe (31), The piston valve 34 opens the second tube 33 rather than the cross-sectional area where the fluid acts on the piston valve 34 while the piston valve 34 closes the second tube 33. By increasing the cross-sectional area where the fluid acts on the piston valve 34 in the state, even if the fluid inflow is increased into the main supply pipe 31 after the piston valve 34 opens the second tube 33, the main supply pipe (31), the pressure in the entire fuel supply system including the first tube (32) and the second tube (33) is not greater than the pressure at the opening of the second tube (22).