An air flow regulating mechanism with pressure sensing and bypass switching functions

Abstract

The present invention relates to an air flow regulating mechanism with pressure sensing and bypass switching functions, belonging to the field of mechanical design and flow control. An air flow regulating mechanism with pressure sensing and bypass switching functions includes a pressure regulating valve, a venturi tube, a pressure sensing element and a switching element. The pressure sensing element is installed at the inlet of the pressure regulating valve for sensing the bleed air pressure. When the bleed air pressure exceeds the pressure regulating threshold, the pressure sensing element controls the switching element to close, and the engine bleed air is pressure-regulated by the pressure regulating valve and then limited by the venturi tube; when the bleed air pressure is lower than the pressure regulating threshold, the pressure sensing element controls the switching element to open, and the engine bleed air passes through the pressure regulating valve and the bypass. The present invention has the following advantages: 1. The pressure switch feedback control path switching technology is adopted to avoid the pressure loss caused by the venturi tube when the engine is in a low state, thereby improving the system cooling capacity; 2. Better system cooling performance can be obtained under the same engine thrust loss.

Description

Technical Field

[0001] The invention relates to an air flow regulating mechanism with pressure sensing and bypass switching functions, belonging to the field of mechanical design and flow control. Background Art

[0002] Aircraft environmental control systems are mostly designed with air circulation systems. After cooling and regulating the high-temperature and high-pressure engine bleed air, it is supplied to various systems to meet the ventilation, pressurization and cooling needs of equipment and cabins. In order to prevent problems such as engine overheating and severe thrust loss caused by engine bleed air exceeding the limit, it is necessary to limit the engine bleed air flow. The engine bleed air flow limit is mostly limited by the pressure regulating valve first, and then the flow is limited by the venturi with appropriate inlet pressure and throat size. The venturi will produce a pressure loss of about 12% to 14% during the flow limiting process. When the engine bleed air pressure exceeds the pressure regulation threshold, although the pressure loss caused by the venturi is large, the outlet pressure of the venturi can still meet the air circulation refrigeration needs; when the engine is in a low state, the engine bleed air pressure decreases, and the pressure regulating valve and venturi no longer regulate pressure and limit flow, and only serve as system flow resistance. Among them, the pressure regulating valve has a small flow resistance and has little effect on the system refrigeration performance. However, since the venturi is a percentage pressure drop, the flow resistance loss is too large, which will seriously aggravate the decline in refrigeration capacity caused by the pressure reduction. Summary of the invention

[0003] The purpose of the present invention is to provide an air flow regulating mechanism with pressure sensing and bypass switching functions, which can avoid the pressure loss caused by the venturi when the engine is in a low state and improve the refrigeration capacity of the system.

[0004] In order to achieve the above-mentioned purpose, the present invention adopts the following technical scheme: an air flow regulating mechanism with pressure sensing and bypass switching functions, including a pressure regulating valve, a venturi, and also including a pressure sensing element and a switching element. The pressure sensing element is installed at the inlet position of the pressure regulating valve and is used to sense the bleed air pressure. When the bleed air pressure exceeds the pressure regulating threshold, the pressure sensing element controls the switching element to close, and the engine bleed air is pressure-regulated by the pressure regulating valve and then limited by the venturi; when the bleed air pressure is lower than the pressure regulating threshold, the pressure sensing element controls the switching element to open, and the engine bleed air passes through the pressure regulating valve and the bypass.

[0005] Preferably, the pressure-sensitive element is a pressure switch for determining the pressure regulation threshold.

[0006] Preferably, the switching element is a solenoid valve, which is installed between the pressure-sensitive element and the venturi; the bypass is connected in series with the solenoid valve.

[0007] Preferably, after the bypass is opened, the bypass, the solenoid valve and the venturi form a parallel passage.

[0008] Working principle: On the basis of the traditional pressure regulating valve and venturi flow limiting, a pressure switch and a solenoid valve are added, and the solenoid valve switch is controlled by the pressure switch. It can not only limit the engine bleed air flow when the bleed air pressure exceeds the threshold, but also avoid excessive pressure loss caused by the venturi in the non-flow limiting state, thereby improving the cooling capacity of the air circulation system when the engine bleed air pressure is low.

[0009] Compared with the prior art, the present invention has the following advantages:

[0010] 1. The technology of controlling the passage switching based on the feedback of the pressure switch can realize the switching of the air flow passage according to the on-off signal of the pressure switch at the outlet of the pressure regulating valve, thereby avoiding the pressure loss caused by the venturi tube when the engine is in a low state and improving the cooling capacity of the system;

[0011] 2. Able to obtain better system cooling performance under the same engine thrust loss. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the structure of an embodiment of the present invention;

[0013] Figure 2 It is a schematic diagram of an embodiment of the present invention;

[0014] Figure 3 A diagram showing the installation state of an embodiment of the present invention on a pipeline;

[0015] Figure 1-3 Among them, 1. Venturi tube; 2. Solenoid valve; 3. Bypass; 4. Pressure switch; 5. Pressure regulating valve. DETAILED DESCRIPTION

[0016] The following is combined with Figure 1-3 The present invention is further described in detail: an air flow regulating mechanism with pressure sensing and bypass switching functions, including a pressure regulating valve 5, a venturi 1, and also including a pressure sensing element and a switching element. The pressure sensing element is installed at the inlet position of the pressure regulating valve 5, and is used to sense the bleed air pressure. When the bleed air pressure exceeds the pressure regulation threshold, the pressure sensing element controls the switching element to close, and the engine bleed air is pressure-regulated by the pressure regulating valve and then limited by the venturi; when the bleed air pressure is lower than the pressure regulation threshold, the pressure sensing element controls the switching element to open, and the engine bleed air passes through the pressure regulating valve and the bypass.

[0017] The specific structure is as follows:

[0018] An air flow regulating mechanism with pressure sensing and bypass switching functions comprises a pressure regulating valve 5, a pressure switch 4, a venturi tube 1, a solenoid valve 2 and a bypass 3, etc.; the pressure switch 4 is installed at the inlet of the pressure regulating valve 5 as a pressure sensing element, and is used to judge the pressure regulating threshold value and provide an opening and closing signal for controlling the solenoid valve 2; the solenoid valve 2 is installed between the pressure switch 4 and the venturi tube 1 as a switching element; the bypass 3 is connected in series with the solenoid valve 2, and when the bypass 3 is opened, the bypass 3, the solenoid valve 2 and the venturi tube form a parallel passage.

[0019] When the bleed air pressure exceeds the pressure regulation threshold, the pressure switch 4 controls the solenoid valve 2 to close, and the engine bleed air is pressure-regulated by the pressure regulating valve 5 and then limited by the venturi 1; when the bleed air pressure is lower than the pressure regulation threshold, the pressure switch 4 controls the solenoid valve 2 to open, and the engine bleed air passes through the venturi 1 and the bypass 3 at the same time, thereby effectively reducing the percentage pressure loss caused by passing only through the venturi.

[0020] The product of the present invention is based on the pressure switch signal and combined with the bypass design. It realizes the function of venturi flow limiting when the engine bleed air is high pressure; and the bypass reduces the flow resistance when the engine bleed air is low pressure. The principle is simple and the reliability is good. The use of this structure can better improve the system refrigeration performance of the environmental control system under the condition of low engine state and reduce the cabin air supply temperature. It can be widely used in aircraft environmental control systems.

[0021] The implementation methods of the present invention are not limited to this. According to the above content of the present invention, using common technical knowledge and customary means in the field, without departing from the above basic technical ideas of the present invention, the present invention can also make other various forms of modification, replacement or change, all of which fall within the scope of protection of the present invention.

Claims

1. An air flow regulating mechanism with pressure sensing and bypass switching functions, comprising a pressure regulating valve and a venturi tube, characterized in that: It also includes a pressure-sensing element and a switching element. The pressure-sensing element is installed at the inlet of the pressure regulating valve and is used to sense the bleed air pressure. When the bleed air pressure exceeds the pressure regulating threshold, the pressure-sensing element controls the switching element to close, and the engine bleed air is pressure-regulated by the pressure regulating valve and then limited by the venturi. When the bleed air pressure is lower than the pressure regulating threshold, the pressure-sensing element controls the switching element to open, and the engine bleed air passes through the pressure regulating valve and the bypass.

2. The air flow regulating mechanism with pressure sensing and bypass switching functions according to claim 1, characterized in that: The pressure-sensitive element uses a pressure switch to determine the pressure regulation threshold.

3. The air flow regulating mechanism with pressure sensing and bypass switching functions according to claim 1, characterized in that: The switching element adopts a solenoid valve, which is installed between the pressure-sensitive element and the venturi tube; the bypass is connected in series with the solenoid valve.

4. The air flow regulating mechanism with pressure sensing and bypass switching functions according to claim 3, characterized in that: After the bypass is opened, the bypass, the solenoid valve and the Venturi tube form a parallel passage.

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