An ejector device for enhanced mixing

Abstract

The present invention provides an ejector device for enhanced mixing, belonging to the field of fluid technology. The ejector device mainly includes an ejector tube, a wind hood and a guide vane. The ejector tube includes an outer wall of the ejector tube, an inner wall of the ejector tube, an inner spiral guide rib, an ejection hole and an ejection slit. The inner spiral guide rib is a hollow thin-wall structure and is fixedly connected to the outer wall of the ejector tube to form an ejection slit. The ejection holes are uniformly distributed on the inner spiral guide rib. The wind hood forms an annular passage for the ejection gas with the outer wall of the ejector tube, and the radial distance of the annular passage is the same as the radius of the inner wall of the ejector tube. The wind hood completely covers the axial length of the ejection slit. The present invention can achieve full and efficient mixing of high and low temperature gases within a short distance, solves the problem of insufficient gas mixing in the existing ejector device, and has great advantages in the case of cramped space.

Description

Technical Field

[0001] The present invention belongs to the technical field of fluid control, and particularly relates to a fluid ejector mixing device, which is particularly applicable to the aircraft cockpit air conditioning system. Background Art

[0002] The operating environment temperature of a helicopter is generally -40°C to +50°C. To ensure the normal physiological functions and comfort of the crew and passengers, it is necessary to heat the cockpit in a low-temperature environment and cool the cockpit in a high-temperature environment. At present, most of the helicopter cockpit heating uses engine bleed air heating, and the cockpit cooling mainly uses an evaporation cycle system. The gases for bleed air heating and evaporation cycle cooling need to eject air before entering the cockpit, so that the high-temperature / low-temperature gas and air are fully mixed to an appropriate temperature. The inner wall of the current ejector device is smooth. To fully mix the two airflows, it is usually necessary to increase the mixing chamber, which results in a relatively large space required for the structure and is not conducive to the requirement of local weight reduction of the system.

[0003] In the publicly disclosed patented technologies, Patent CN110822424B proposes a static air mixer, which uses a Venturi structure to introduce recirculated air and combustion-supporting air and completely mixes the two under the Venturi effect; the gas is first ejected into the pipeline and then mixed, and it is mainly used to improve the combustion efficiency. Patent CN110803288A discloses a cockpit heating ejector mixer. The gas is first ejected into the pipeline and then mixed through inclined guide vanes. Although this patent also belongs to the aircraft cockpit temperature mixing device, based on the Venturi structure, it necessarily requires a long mixing distance to achieve full mixing of the gas; a long mixing distance means a larger accommodation space is required, which is not conducive to the design requirements of the aircraft for a compact structure and light weight. Summary of the Invention

[0004] The object of the present invention is to propose a fluid ejector mixing device to adapt to the narrow space and lightweight design requirements of the helicopter cockpit.

[0005] The technical solution of the present invention: A fluid ejector mixing device, which includes an ejector pipe, a wind hood and guide vanes; the ejector pipe includes an inlet section, a mixing section and an outlet section; a number of internal spiral guide ribs are arranged on the inner wall of the mixing section; the internal spiral guide ribs are of a hollow thin-wall structure, are fixedly connected to the outer wall of the ejector pipe, and are communicated with the outside through ejection slots; the ejection holes are evenly distributed on the internal spiral guide ribs; the wind hood and the mixing section of the ejector pipe form an annular passage for the ejected gas, and the annular passage completely covers the axial length of the ejection slots; an inlet for the gas to be ejected is opened in the tangential direction of the annular passage of the wind hood, and its opening degree is controlled by the guide vanes.

[0006] Optionally, the ejector tube is located at an eccentric position in the arc area of the air shroud, which helps to make the pressure uniform throughout the air shroud, so that the flow rate of the entrained gas flowing into each ejector hole is uniform. When the external air enters the air shroud, the gas flow rate is large and the pressure is high near the inlet, and the gas flow rate is small far from the inlet. The eccentric design compresses the gas flow space in this area, so that the pressure in this area remains at a relatively high level, avoiding the problem of uneven mixing caused by a large pressure difference.

[0007] Optionally, the guide vane can be controlled electronically to control its rotation opening; when necessary, the guide vane can close the air inlet of the air shroud.

[0008] Optionally, a pressure regulating mechanism is added at the inlet and outlet of the ejector tube. The pressure regulating mechanism controls the velocity of the ejecting fluid, thereby affecting the velocity of the entrained gas and the temperature and velocity of the mixed gas.

[0009] Optionally, a flow regulating valve is added at the inlet of the ejector tube. By regulating the flow rate of the ejecting gas, the velocity of the entrained gas and the temperature and velocity of the mixed gas can be affected.

[0010] Optionally, the ejector tube and the inner spiral guide fins are both made of materials with high thermal conductivity. The ejecting gas and the entrained gas can achieve rapid heat exchange before mixing, so as to achieve rapid temperature equalization.

[0011] Optionally, the air shroud is made of low thermal conductivity material to avoid heat loss of the entrained gas.

[0012] Optionally, the air shroud has an arc-shaped outer form, and the entrained gas flows in along the tangential direction of the ejector tube wall from the inlet.

[0013] The working principle of this device is as follows: When high / low temperature gas is introduced into the ejector tube, a negative pressure is formed in the ejector slit and the air shroud driven by the kinetic energy of the gas. The external gas enters the air shroud from the entrained gas inlet under the action of the pressure difference. The gas entering the air shroud rotates and flows around the outer wall of the ejector tube on the one hand, and exchanges convective heat with the outer wall; on the other hand, it enters the inside of the ejector tube through the ejector slit and the ejector holes, and is strongly mixed with the high / low temperature gas rotating and flowing under the action of the inner spiral guide fins, thus greatly improving the mixing effect. When the rotation opening of the guide vane is controlled electronically, the flow rate of the external gas entering the air shroud can be controlled, so as to control the ratio of the high / low temperature gas to the entrained gas and achieve the purpose of temperature control.

[0014] Advantages of the present invention: By adding multiple internal spiral rib strips in the ejector pipeline to divert and eject the gas, and at the same time, the entrained gas enters the pipeline through the ejection holes, the two airflows are strongly mixed under the action of the internal spiral diversion rib strips, so that the temperature is quickly uniform. At the same time, by changing the opening degree of the diversion vane, the gas flow rate entering the ejector device is controlled to achieve the purpose of temperature control. The present invention can achieve full and efficient mixing of high and low temperature gases within a short distance, solves the problem of insufficient gas mixing in the existing ejector device, and has great advantages in the case of cramped space. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 Structural diagram of the enhanced mixing ejector device

[0016] Figure 2 Axial view of the ejector tube in the enhanced mixing ejector device

[0017] Figure 3 Structural diagram of the ejector tube

[0018] Figure 4 Schematic diagram of the eccentric design structure of the ejector tube

[0019] Among them, 1: ejector tube; 101: outer wall of the ejector tube; 102: inner wall of the ejector tube; 103: internal spiral diversion rib; 104: ejection hole; 105: ejection slot; 2: air hood; 201: inlet of the entrained gas; 3: diversion vane. SPECIFIC EMBODIMENTS

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] The present invention designs a fluid ejector mixing device in a confined space. The device includes an ejector tube, an air hood and a diversion vane; the ejector tube includes an inlet section, a mixing section and an outlet section; a number of internal spiral diversion ribs are arranged on the inner wall of the mixing section; the internal spiral diversion ribs are of a hollow thin-walled structure, are fixedly connected to the outer wall of the ejector tube, and are communicated with the outside through ejection slots; the ejection holes are evenly distributed on the internal spiral diversion ribs; the air hood forms an annular passage for the ejecting gas with the mixing section of the ejector tube, and the annular passage completely covers the axial length of the ejection slot; an inlet for the entrained gas is opened in the tangential direction of the annular passage of the air hood, and its opening degree is controlled by the diversion vane.

[0022] In one of the implementation cases, such as Figure 1As shown in the figure, the structural diagram of the enhanced hybrid ejector device with a specific design is presented; the device mainly includes an ejector tube 1, a wind hood 2, and a guide vane 3. The ejector tube 1 includes an outer wall 101 of the ejector tube, an inner wall 102 of the ejector tube, an inner spiral guide rib 103, an ejection hole 104, and an ejection slot 105. The inner spiral guide rib 103 is a hollow thin-walled structure and is fixedly connected to the outer wall 101 of the ejector tube to form the ejection slot 105. The ejection holes 104 are uniformly distributed on the inner spiral guide rib 103. The wind hood 2 forms an annular passage for the ejecting gas with the outer wall 101 of the ejector tube, and the wind hood 2 completely covers the axial length of the ejection slot 105. An inlet 201 for the entrained gas is provided in the tangential direction of the annular passage of the wind hood 2, and its opening degree is controlled by the guide vane 3; it can rotate within a certain range to control the flow rate of the external entrained gas.

[0023] In the specific design, the guide vane 3 can be controlled electrically. The guide vane 3 can rotate flexibly around a fixed rotating shaft to control its rotation opening degree, and the rotation opening degree is used to achieve the purpose of controlling the flow rate of the external entrained gas. In some specific application scenarios, the maximum opening degree of the guide vane 3 is to close the air inlet of the wind hood 2 to achieve extreme adjustment in specific application environments.

[0024] As Figure 1 shown in the figure, in the structure, the wind hood 2 is arranged in the gas mixing section of the ejector tube 1 and adopts a fully enclosed design form. The air flow between the wind hood 2 and the ejector tube 1 is conducted through the ejection slot 105; the air inlet direction of the wind hood 2 is along the tangential direction of the ejector tube 1. Such a design can effectively reduce the gas flow resistance; the wind hood 2 adopts an arc-shaped outer form.

[0025] In the specific design, according to the air flow direction, the ejector tube 1 in the ejector device includes an inlet section, a mixing section, and an outlet section; the inlet and outlet of the ejector tube 1 are improved in design, and a pressure regulating mechanism is added at the inlet and outlet of the ejector tube 1. According to the requirements of the cockpit environment, the pressure regulating mechanism controls the speed of the ejecting fluid, thereby affecting the flow rate of the entrained gas and the temperature and flow rate of the mixed gas to obtain the required environmental temperature and pressure. Similarly, a flow regulating valve can also be added at the inlet of the ejector tube 1 to affect the flow rate of the entrained gas and the temperature and flow rate of the mixed gas by adjusting the flow rate of the ejecting gas.

[0026] Example 2, based on the design of the structure of the enhanced hybrid ejector device, as Figure 2 、 Figure 3As shown, the ejector tube 1 includes an ejector tube outer wall 101, an ejector tube inner wall 102, inner spiral guide ribs 103, ejection holes 104, and ejection slits 105; wherein, the inner spiral guide ribs 103 adopt a hollow thin-wall structure, and the inner spiral guide ribs 103 can generally be designed to be 4 pieces, which are evenly distributed along the ejector tube inner wall 102; a plurality of ejection holes 104 are opened on the two side surfaces of the inner spiral guide ribs 103, and the ejection holes 104 are selected in a circular or elliptical form with less effect on flow resistance, and are evenly distributed on the two side surfaces of the inner spiral guide ribs 103. After the external normal temperature air flows into the wind hood, it enters the ejection pipe 1 after passing through the ejection slit 105 and the ejection hole 104, and is fully mixed with the high / low temperature gas in the ejection pipe 1; the spiral fins used in the device have excellent flow guidance performance, and the high / low temperature gas entering the ejection pipe 1 rotates and flows under the action of the inner spiral guide fins, thereby achieving the purpose of being fully mixed with the external normal temperature air.

[0027] In terms of temperature regulation, in the ejector device, the ejector tube 1 and the inner spiral guide fins 103 are made of high thermal conductivity materials, and the ejector gas and the ejected gas can achieve rapid heat exchange before mixing, thereby achieving rapid temperature equalization. The wind hood 2 is made of low thermal conductivity material to avoid heat loss of the ejected gas; generally speaking, the ejector tube 1 uses high-temperature gas obtained by engine bleed air, and the high-temperature gas is reduced to a lower temperature through heat exchange before mixing. Such a design can make it easier for the mixed gas to reach the appropriate temperature required by the cabin.

[0028] Furthermore, Figure 4 As shown, the ejector pipe 1 is located at an eccentric position in the arc area of ​​the wind hood 2. Such a design structure is conducive to ensuring the pressure balance at various locations inside the wind hood 2, so that the flow rate of the ejected gas flowing into the ejection holes 104 at various locations is uniform; when external air enters the wind hood 2, the gas flow rate is large and the pressure is relatively high near the entrance, while the gas flow rate is small far from the entrance. The eccentric design compresses the gas flow space in this area, so that the pressure in this area is still in a relatively high state, avoiding the problem of uneven mixing caused by large pressure differences.

[0029] The working principle of the device is as follows: when high / low temperature gas is introduced into the ejector tube 1, driven by the kinetic energy of the gas, negative pressure is formed in the ejector slit 105 and the wind hood 2. Under the action of the pressure difference, the external gas enters the wind hood 2 from the ejected gas inlet 201. On the one hand, the gas entering the wind hood 2 rotates around the ejector tube outer wall 101 and conducts convection heat exchange with the outer wall; on the other hand, it enters the ejector tube 1 through the ejector slit 105 and the ejection hole 104, and is strongly mixed with the rotating high / low temperature gas under the action of the inner spiral guide rib 103, thereby greatly improving the mixing effect. When the rotation opening of the guide blade 3 is electrically controlled, the flow rate of the external gas entering the wind hood 2 can be controlled, thereby controlling the ratio of the high / low temperature gas and the ejected gas, and achieving the purpose of controlling the temperature.

[0030] The main feature of the enhanced mixing ejection device proposed in the present invention is that it adopts a combined design of a wind hood and an ejection tube, and guides the ejection gas by adding multiple inner spiral ribs in the ejection pipeline. At the same time, the ejected gas enters the pipeline through the ejection hole, and the two airflows are strongly mixed under the action of the inner spiral guide ribs, so that the temperature is quickly uniform. At the same time, the gas flow entering the ejection device is controlled by changing the opening of the guide blade to achieve the purpose of controlling the temperature. Different from the conventional gas mixing structure that requires a large mixing space to achieve sufficient mixing of multiple airflows, the airflow temperature and flow rate greatly affect the final mixing effect; the fluid ejection mixing device proposed in the present invention can achieve sufficient and efficient mixing of high and low temperature gases within a relatively short distance, which solves the problem of insufficient gas mixing in existing ejection devices and has great advantages under cramped space conditions. It is particularly suitable for aircraft cabin air conditioning systems with limited installation space and high requirements for lightweight. Of course, as an ordinary technician in this field, in the specific design process, in order to better control the working efficiency of the entire mechanism, the guide vane in the ejection device can be controlled by electronic control to control its rotation opening; when necessary, the guide vane can close the air inlet of the wind hood. In addition, a pressure regulating mechanism is added to the inlet and outlet of the ejection pipe, and the pressure regulating mechanism controls the speed of the ejection fluid, thereby affecting the flow rate of the ejected gas and the temperature and flow rate of the mixed gas. At the same time, a flow regulating valve is added at the inlet of the ejection pipe to adjust the ejection gas flow rate, thereby affecting the flow rate of the ejected gas and the temperature and flow rate of the mixed gas; the control logic of these control mechanisms can be designed accordingly according to the needs, and there can be several coordinated control combinations between them. In essence, they all take the problem of insufficient gas mixing in the existing ejection device under cramped space as the design foothold.

[0031] As described above, the above are only specific embodiments of the present invention. The present invention has been described in detail, and the parts not elaborated are conventional technologies. However, the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention. The protection scope of the present invention shall be subject to the protection scope of the claims described above.

Claims

1. An ejector device for enhanced mixing, characterized in that, the device includes an ejector tube, a wind hood and a guide vane; the ejector tube includes an inlet section, a mixing section, and an outlet section; a number of internal spiral guide fins are arranged on the inner wall of the mixing section; the internal spiral guide fins are of a hollow thin-walled structure, are fixedly connected to the outer wall of the ejector tube, and are communicated with the outside through an ejector slit; ejector holes are uniformly distributed on the internal spiral guide fins; the wind hood and the mixing section of the ejector tube form an annular passage for the entrained gas, and the annular passage completely covers the axial length of the ejector slit; an inlet for the entrained gas is opened in the tangential direction of the annular passage of the wind hood, and its opening degree is controlled by the guide vane.

2. The ejector device for enhanced mixing according to claim 1, characterized in that, the ejector tube is in an eccentric position in the arc area of the wind hood. When external air enters the wind hood, the gas flow rate is large and the pressure is high near the inlet, and the gas flow rate is small far from the inlet; the gas flow space far from the inlet is compressed, and the pressure in this area is still in a relatively high state.

3. The ejector device for enhanced mixing according to claim 1, characterized in that, the guide vane can be controlled electrically to control its rotational opening degree, so as to control the flow rate of the gas entering the wind hood.

4. The ejector device for enhanced mixing according to claim 1, characterized in that, a pressure regulating mechanism is added at the inlet and outlet of the ejector tube, and the pressure regulating mechanism controls the velocity of the ejecting fluid.

5. The ejector device for enhanced mixing according to claim 4, characterized in that, a flow regulating valve is additionally arranged at the inlet of the ejector tube to regulate the flow rate of the ejecting gas.

6. The ejector device for enhanced mixing according to claim 1, characterized in that, both the ejector tube and the internal spiral guide fins are made of materials with high thermal conductivity.

7. The ejector device for enhanced mixing according to claim 1, characterized in that, the wind hood adopts an arc-shaped form, and the entrained gas flows in along the tangential direction of the ejector tube wall from the inlet.

8. The ejector device for enhanced mixing according to claim 7, characterized in that, the wind hood is made of a low thermal conductivity material.

Images