Injector, cold beam end, cold beam system

Abstract

The present invention provides an injector, a cold beam end, and a cold beam system. Among them, an injector includes a nozzle housing and a thimble. The nozzle housing has a nozzle throat, and further includes a driving component. The driving component includes a cylinder block and a piston slidably connected in the cylinder block. The piston is connected to the thimble. The piston divides the inner cavity of the cylinder block into independent first and second chambers. Under the pressure difference between the first chamber and the second chamber, the piston drives the thimble to move towards or away from the nozzle throat to change the flow area of the nozzle throat. The injector, cold beam end, and cold beam system provided by the present invention can adaptively adjust the flow area of the injector throat depending on the pressure difference, with simple structure, high reliability, convenient maintenance, and low cost.

Description

Technical Field

[0001] The present invention belongs to the technical field of air conditioning, and particularly relates to an ejector, a cold beam terminal, and a cold beam system. Background Art

[0002] Existing active cold beams use nozzles to make the primary air jet at a high speed to induce the secondary return air in the room. After the primary air and the secondary air are mixed, they are sent into the room. Under the condition of the same cooling capacity, the larger the induction ratio (secondary air volume: primary air volume, generally about 3:1, that is, the injection coefficient), the smaller the primary air volume, but the greater the pressure loss and noise value of the primary air.

[0003] In a variable air volume system, the injection coefficient of the ejector in the cold beam terminal changes greatly, often deviating from the design value, resulting in performance degradation or even failure. Therefore, quality adjustment or quantity adjustment methods are often used to avoid the occurrence of the above problems. Among them, quality adjustment mainly reduces the working pressure of the fluid, but this throttling and pressure-reducing method will cause energy loss; while quantity adjustment changes the throat area of the ejector, which has the advantages of a wide adjustment range and small energy loss. Commonly, various-shaped thimbles are arranged on the central axis of the nozzle throat, and the throat area of the nozzle is changed by changing the thimble stroke, thereby affecting the working state of the ejector. This adjustment method is widely used.

[0004] The existing methods for driving the ejector thimble (shaft needle) are mainly electromagnetic driving type, which is similar to the driving principle of an electronic expansion valve. This method has the most mature corresponding technology and the most reliable design, and is suitable for use conditions with very high precision requirements. However, the requirements for its control technology and detection feedback technology are also high. For general application occasions, its application cost is high and it is not very necessary. It is extremely necessary to design a cold beam terminal of an ejector with an adjustable throat area that has high reliability, a simple structure, and is easy to maintain. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present invention is to provide an ejector, a cold beam terminal, and a cold beam system, which can adaptively adjust the flow area of the ejector throat depending on the pressure difference, have a simple structure, high reliability, easy maintenance, and low cost.

[0006] To solve the above problems, the present invention provides an ejector, including a nozzle housing and a thimble. The nozzle housing has a nozzle throat, and further includes a driving component. The driving component includes a cylinder body and a piston slidably connected in the cylinder body. The piston is connected to the thimble. The piston divides the inner cavity of the cylinder body into independent first and second chambers. The piston drives the thimble to move towards or away from the nozzle throat under the pressure difference between the first chamber and the second chamber to change the flow area of the nozzle throat.

[0007] Preferably, the first chamber has a first pressure-taking pipe for introducing a first pressure gas into the first chamber, the second chamber has a second pressure-taking pipe for introducing a second pressure gas into the second chamber, and the pressure of the first pressure gas is lower than that of the second pressure gas.

[0008] Preferably, one end of the second pressure-taking pipe facing the second chamber extends into the second chamber by a first preset distance greater than zero; and / or, one end of the first pressure-taking pipe facing the first chamber is located inside the side wall of the cylinder body corresponding to the first chamber.

[0009] Preferably, the first chamber and / or the second chamber is filled with a lubricating medium.

[0010] Preferably, the material of the cylinder body and / or the piston is polytetrafluoroethylene plastic.

[0011] Preferably, the injector further includes a mounting bracket located between the nozzle housing and the cylinder body.

[0012] Preferably, the mounting bracket is provided with a plurality of flow holes that penetrate the inner and outer sides of the nozzle housing.

[0013] The present invention also provides a cold beam end including the above-mentioned injector.

[0014] Preferably, the cold beam end further includes an end housing, and a partition is provided inside the end housing to divide the end housing into a static pressure chamber and an air guiding chamber. The injector is connected to the partition through the mounting bracket, and the mounting bracket is located on one side of the static pressure chamber, and the nozzle housing is located on one side of the air guiding chamber.

[0015] Preferably, the partition has a through hole, and the mounting bracket is threadedly connected to the partition through the through hole.

[0016] The present invention also provides a cold beam system including the above-mentioned cold beam end.

[0017] For the injector, cold beam end, and cold beam system provided by the present invention, the telescopic movement generated by the cylinder body and the piston under the pressure difference is used to drive the movement of the thimble, instead of using the electromagnetic drive method in the prior art. Compared with the electromagnetic drive method in the prior art, the structure of the present invention is simpler and more convenient to maintain. At the same time, it can be understood that a simple structure is easy to improve the reliability of components. Description of the Drawings

[0018] Figure 1 It is a schematic diagram of the injector according to the embodiment of the present invention;

[0019] Figure 2 ForFigure 1 Installation schematic diagram of the ejector in

[0020] Figure 3 Structural schematic diagram of the end of the cold beam according to another embodiment of the present invention.

[0021] The reference numerals are shown as:

[0022] 1. Nozzle housing; 11. Nozzle throat; 12. Nozzle outlet section; 13. Nozzle inlet section; 2. Thimble; 3. Driving component; 31. Cylinder block; 32. Piston; 33. First chamber; 331. First pressure tapping pipe; 34. Second chamber; 341. Second pressure tapping pipe; 4. Mounting bracket; 41. Flow-through hole; 100. End housing; 101. Partition plate; 102. Static pressure box; 103. Air induction chamber. Detailed implementation manners

[0023] Referring to Figures 1 to 3 As shown, according to an embodiment of the present invention, an ejector is provided, which is applied to the end of a cold beam and includes a nozzle housing 1 and a thimble 2. The nozzle housing 1 has a nozzle throat 11 and a nozzle outlet section 12 and a nozzle inlet section 13 on both sides of the nozzle throat 11. The ejector further includes a driving component 3. The driving component 3 includes a cylinder block 31 and a piston 32 slidably connected in the cylinder block 31. The piston 32 is connected to the thimble 2. The piston 32 divides the inner cavity of the cylinder block 31 into two independent first chamber 33 and second chamber 34. The piston 32 drives the thimble 2 to move towards or away from the nozzle throat 11 under the pressure difference between the first chamber 33 and the second chamber 34 so as to change the flow area of the nozzle throat 11. The thimble 2 is also called a shaft needle, a needle valve, etc., and has a tapered tip. The relative position of the tapered tip and the nozzle throat 11 will define the flow area of the nozzle throat 11. In this technical solution, the relative position of the thimble 2 with respect to the nozzle throat 11 is realized by being driven by the driving component 3. Different from the prior art, the present invention uses the telescopic movement generated by the cylinder block 31 and the piston 32 under the pressure difference to drive the movement of the thimble 2, instead of using the electromagnetic driving method in the prior art. Compared with the electromagnetic driving method in the prior art, the structure of the present invention is simpler, more convenient to maintain, and has a lower cost. At the same time, it can be understood that the simple structure is easy to improve the reliability of the components.

[0024] Preferably, the first chamber 33 has a first pressure tapping pipe 331 for introducing a first pressure gas into the first chamber 33, and the second chamber 34 has a second pressure tapping pipe 341 for introducing a second pressure gas into the second chamber 34. The pressure of the first pressure gas is lower than the pressure of the second pressure gas. Specifically, for example, when it is applied toFigure 3 When referring to the middle of the cold beam end, at this time, the air inlet of the first pressure-taking pipe 331 is connected to the negative pressure area formed by the injection of the injector, and the air inlet of the second pressure-taking pipe 341 is connected to the static pressure box 102 of the cold beam end. That is, the first pressure gas is the gas pressure in the negative pressure area at this time, and the second pressure gas is connected to the static pressure box 102. Continue to refer to Figure 3 As shown by the arrow in the figure, the primary air, that is, the air flow entering the nozzle housing 1 from the static pressure box 102, enters the static pressure box 102 through the air duct interface, flows from point C of the nozzle intake section 13 of the nozzle housing 1 to point B of the nozzle outlet section and is ejected at high speed. Under the Venturi effect, a negative pressure area D (a part of the induced air chamber 103) is generated on the outer peripheral side of the nozzle intake section 13. The indoor return air (secondary air) is sucked into the negative pressure area D from the return air outlet E through the filter and the heat exchanger under the atmospheric pressure. The indoor return air exchanges heat (is cooled or heated or does not exchange heat) on the heat exchanger. After the primary air and the secondary air are mixed, they are guided by the deflector to the indoor from the air outlet A. The air inlet of the first pressure-taking pipe 331 is at point D, and the air inlet of the second pressure-taking pipe 341 is at point C.

[0025] Further, one end of the second pressure-taking pipe 341 facing the second chamber 34 extends into the second chamber 34 by a first preset distance, and the first preset distance is greater than zero. That is, the air outlet of the second pressure-taking pipe 341 is designed to protrude from the inner cavity wall of the cylinder block 31, which can limit the downward stroke of the piston 32, thereby preventing the phenomenon of the first pressure gas and the second pressure gas from penetrating due to excessive downward displacement of the piston 32; and / or, one end of the first pressure-taking pipe 331 facing the first chamber 33 is located inside the side wall of the cylinder block corresponding to the first chamber 33.

[0026] In order to ensure the smooth movement of the piston 32, preferably, the first chamber 33 and / or the second chamber 34 is filled with a lubricating medium. The lubricating medium includes, for example, a liquid lubricating medium, such as lubricating oil; and a solid lubricating medium, such as graphite, paraffin, etc. At this time, preferably, there is a certain distance between the bottom side of one end of the second pressure-taking pipe 341 facing the second chamber 34 and one end head (bottom end) of the cylinder block 31, and this distance is higher than the height position of the lubricating medium filled in the second chamber 34 (when the lubricating medium is lubricating oil, it corresponds to the liquid level of the lubricating oil).

[0027] A better design principle is that the density of the ejector pin 2, piston 32, and lubricating medium should be as small as possible to minimize the mass of these three components, which is beneficial to making full use of the pressure difference between the upper and lower surfaces of the piston 32. At the same time, reducing the friction between the piston and the cylinder block is also very important. For example, polytetrafluoroethylene plastic with a particularly small coefficient of friction is used as the material of the cylinder block 31 or piston 32. When there is no working fluid jet from the nozzle, the piston 32 and ejector pin 2 can slowly descend to the lower limit position under the action of gravity and wait for the next operation.

[0028] Furthermore, the injector further includes a mounting bracket 4, which is located between the nozzle housing 1 and the cylinder block 31. The shape of the mounting bracket 4 is designed to match the nozzle housing 1 and the cylinder block 31, for example, designed as a circle, so as to facilitate the installation and fixation of the injector. For example, there is a through hole on the partition 101 in the end of the cold beam. The mounting bracket 4 is threadedly connected to the partition 101 through the through hole. The threaded connection is preferably a threaded connection with a sealing function. Of course, other connection methods can also be used, but necessary sealing operations should be noted to ensure the isolation function of the partition 101. It can be understood that the first pressure-taking pipe 331 can also pass through the partition 101 and communicate with the D position. At this time, sealing operations should also be noted, such as using a sealed thread design, pipe joint socket connection, welding, or sealed glue curing connection, etc.

[0029] Preferably, the mounting bracket 4 is provided with a plurality of through-flow holes 41, which penetrate the inside and outside of the nozzle housing 1. The plurality of through-flow holes 41 are preferably arranged at equal intervals along the outer circumferential direction of the mounting bracket 4 to make the primary air in the plenum chamber 102 enter the nozzle housing 1 more evenly.

[0030] According to an embodiment of the present invention, a cold beam end is also provided, including the above-mentioned injector. Specifically, the cold beam end further includes an end housing 100. A partition 101 is provided in the end housing 100. The partition 101 divides the end housing 100 into a plenum chamber 102 and an air induction chamber 103. The injector is connected to the partition 101 through the mounting bracket 4, and the mounting bracket 4 is on one side of the plenum chamber 102, and the nozzle housing 1 is on one side of the air induction chamber 103.

[0031] The adjustment principle of the through-flow area of the nozzle throat of the injector in this invention is as follows:

[0032] In the initial stage, when the primary air volume (corresponding to the wind pressure, the same below) is not greater than the minimum primary air volume, the piston 32 is in a static lower limit state, the ejector pin 2 is at the lowest point, and the jet area of the nozzle throat 11 is the smallest;

[0033] When the primary air volume is greater than the minimum primary air volume, the air pressure in the plenum chamber 102 gradually increases, the negative pressure generated by the ejector is greater, the pressure difference between the upper and lower surfaces of the piston 32 gradually increases, the piston gradually moves upward to drive the thimble 2 upward, and the injection area of the nozzle throat increases to adapt to the increase in the primary air injection flow rate until the piston 32 stops at a certain position under the balanced state, indicating that the primary air volume and air pressure in the plenum chamber 102 are in a stable state.

[0034] When the primary air volume reaches the maximum, the piston moves upward to the highest point and the thimble 2 completely leaves the nozzle throat 11, and the injection area of the nozzle throat is the largest.

[0035] When the primary air volume gradually decreases from the maximum, the process forms an opposite phenomenon to the process of the above-mentioned air volume increase. Whether the air volume increases or decreases, when the primary air volume is stable, the thimble always has a fixed height position corresponding to it, and the nozzle throat area is also a corresponding value, so as to ensure that its injection coefficient is in a relatively optimal range.

[0036] According to an embodiment of the present invention, a chilled beam system is further provided, including the above-mentioned chilled beam end.

[0037] It is easy for those skilled in the art to understand that, on the premise of no conflict, the above-mentioned advantageous ways can be freely combined and superimposed.

[0038] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. The above is only the preferred implementation manner of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can still be made, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An injector, characterized in that, it includes a nozzle housing (1) and a thimble (2). The nozzle housing (1) has a nozzle throat (11), and further includes a driving component (3). The driving component (3) includes a cylinder block (31) and a piston (32) slidably connected in the cylinder block (31). The piston (32) is connected to the thimble (2). The piston (32) divides the inner cavity of the cylinder block (31) into two independent first chamber (33) and second chamber (34). The piston (32) drives the thimble (2) to move towards or away from the nozzle throat (11) under the pressure difference between the first chamber (33) and the second chamber (34) to change the flow area of the nozzle throat (11). The first chamber (33) has a first pressure tapping pipe (331) for introducing a first pressure gas into the first chamber (33). The second chamber (34) has a second pressure tapping pipe (341) for introducing a second pressure gas into the second chamber (34). The pressure of the first pressure gas is lower than that of the second pressure gas. One end of the second pressure tapping pipe (341) facing the second chamber (34) extends into the second chamber (34) by a first preset distance greater than zero. There is a certain distance between the bottom side of one end of the second pressure tapping pipe (341) facing the second chamber (34) and the bottom end of the cylinder block (31). When the nozzle does not inject working fluid, the piston (32) and the thimble (2) can slowly drop to the lower limit position formed by the second pressure tapping pipe (341) under the action of gravity. It further includes a mounting bracket (4). The mounting bracket (4) is located between the nozzle housing (1) and the cylinder block (31). The mounting bracket (4) is provided with a plurality of through holes (41) that penetrate the inner and outer sides of the nozzle housing (1).

2. The injector according to claim 1, characterized in that, one end of the first pressure tapping pipe (331) facing the first chamber (33) is located inside the side wall of the cylinder block corresponding to the first chamber (33).

3. The injector according to claim 1, characterized in that, the first chamber (33) and / or the second chamber (34) is filled with a lubricating medium.

4. The injector according to claim 1, characterized in that, the material of the cylinder block (31) and / or the piston (32) is polytetrafluoroethylene plastic.

5. A cold beam end includes an injector, characterized in that, the injector is the injector according to any one of claims 1 to 4.

6. The cold beam end according to claim 5, characterized in that, It further includes a terminal housing (100), a partition plate (101) is provided inside the terminal housing (100), the partition plate (101) divides the terminal housing (100) into a static pressure chamber (102) and an air induction chamber (103), the ejector is connected to the partition plate (101) through the mounting bracket (4), and the mounting bracket (4) is on one side of the static pressure chamber (102), and the nozzle housing (1) is on one side of the air induction chamber (103).

7. The cold beam terminal according to claim 6, wherein, the partition plate (101) has a through hole, and the mounting bracket (4) is threadedly connected to the partition plate (101) through the through hole.

8. A cold beam system, comprising a cold beam terminal, wherein, the cold beam terminal is the cold beam terminal according to any one of claims 5 to 7.

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