CN110940085A

CN110940085A - Ejector, cold beam end, cold beam system

Info

Publication number: CN110940085A
Application number: CN201911326884.9A
Authority: CN
Inventors: 黄玉优; 王子平; 谢文利; 李超
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2019-12-20
Filing date: 2019-12-20
Publication date: 2020-03-31

Abstract

The invention provides an ejector, a cold beam tail end and a cold beam system. The ejector comprises a nozzle shell and a thimble, wherein the nozzle shell is provided with a nozzle throat part, and the ejector further comprises a driving part, the driving part comprises a cylinder body and a piston connected in the cylinder body in a sliding mode, the piston is connected with the thimble, the piston divides an inner cavity of the cylinder body into a first cavity and a second cavity which are mutually independent, and the piston drives the thimble to move towards or away from the nozzle throat part under the action of pressure difference between the first cavity and the second cavity so as to change the flow area of the nozzle throat part. The ejector, the cold beam tail end and the cold beam system provided by the invention can self-adaptively adjust the flow area of the throat part of the ejector by means of pressure difference, and have the advantages of simple structure, high reliability, convenience in maintenance and low cost.

Description

Ejector, cold beam end, cold beam system

Technical Field

The invention belongs to the technical field of air conditioning, and particularly relates to an ejector, a cold beam tail end and a cold beam system.

Background

The existing active chilled beam utilizes a nozzle to make primary air jet at high speed to induce secondary return air in a room, and the primary air and the secondary air are mixed and then are sent into the room. Under the same refrigeration capacity condition, the larger the induction ratio (secondary air volume: primary air volume, generally about 3:1, namely the injection coefficient) is, the smaller the primary air volume is, but the larger the pressure loss and noise value of the primary air is.

In the variable air volume system, the change of the injection coefficient of an injector in the tail end of a cold beam is large, and the injector often departs from a design value to cause performance reduction and even failure, so that the problems are avoided by frequently adopting a quality control or quantity control mode, wherein the quality control mainly reduces the working pressure of fluid, but the throttling and pressure reduction mode causes energy loss; the quantity adjustment is to change the throat area of the ejector, and has the advantages of wide adjustment range, low energy loss and the like, the ejector pins in various shapes are usually arranged on the central axis of the throat of the ejector, the area of the throat of the ejector is changed by changing the stroke of the ejector pin, and the working state of the ejector is further influenced, and the adjustment mode is widely applied.

The existing mode for driving the ejector thimble (pintle) mainly comprises an electromagnetic driving mode, which is similar to the driving principle of an electronic expansion valve, the corresponding technology of the mode is the most mature and reliable design and is suitable for the use condition with very high precision requirement, but the requirements of the control technology and the detection feedback technology are high, the application cost is higher and is not too large and necessary under the general application occasion, and the design of the cold beam tail end of the ejector with the adjustable throat area, which has the advantages of high reliability, simple structure and convenient maintenance, is very necessary.

Disclosure of Invention

Therefore, the technical problem to be solved by the invention is to provide an ejector, a cold beam tail end and a cold beam system, which can self-adaptively adjust the flow area of the throat part of the ejector by means of pressure difference, and have the advantages of simple structure, high reliability, convenience in maintenance and low cost.

In order to solve the above problems, the present invention provides an injector, which includes a nozzle housing, a thimble, the nozzle housing has a nozzle throat, and further includes a driving component, the driving component includes a cylinder and a piston slidably connected in the cylinder, the piston is connected with the thimble, the piston divides an inner cavity of the cylinder into a first cavity and a second cavity which are independent of each other, and the piston drives the thimble to move towards or away from the nozzle throat under the action of a pressure difference between the first cavity and the second cavity to change a flow area of the nozzle throat.

Preferably, the first chamber has a first pressure tapping pipe for introducing a first pressure gas into the first chamber, the second chamber has a second pressure tapping pipe for introducing a second pressure gas into the second chamber, the pressure of the first pressure gas being lower than the pressure of the second pressure gas.

Preferably, one end of the second pressure tapping pipe facing the second cavity extends into the second cavity for a first preset distance, and the first preset distance is greater than zero; and/or one end, facing the first cavity, of the first pressure tapping pipe is positioned in the side wall of the cylinder body corresponding to the first cavity.

Preferably, the first cavity and/or the second cavity are filled with a lubricating medium.

Preferably, the material of the cylinder and/or the piston is polytetrafluoroethylene plastic.

Preferably, the injector further comprises a mounting between the nozzle housing and the cylinder.

Preferably, a plurality of through holes are formed in the mounting frame, and the through holes penetrate through the inner side and the outer side of the nozzle shell.

The invention also provides a cold beam tip comprising the ejector.

Preferably, the tail end of the cold beam further comprises a tail end shell, a partition plate is arranged in the tail end shell, the partition plate divides the tail end shell into a static pressure box and an induced air cavity, the ejector is connected with the partition plate through the mounting frame, the mounting frame is located on one side of the static pressure box, and the nozzle shell is located on one side of the induced air cavity.

Preferably, the partition plate is provided with a through hole, and the mounting frame is in threaded connection with the partition plate through the through hole.

The invention also provides a cold beam system which comprises the cold beam tail end.

According to the ejector, the cold beam tail end and the cold beam system, the telescopic motion generated by the cylinder and the piston under the action of the pressure difference is adopted to drive the movement of the ejector pin, an electromagnetic driving mode in the prior art is not adopted any more, and compared with an electromagnetic driving mode in the prior art, the ejector, the cold beam tail end and the cold beam system are simpler in structure and more convenient to maintain, can be understood, are simple in structure and are easy to improve the reliability of parts.

Drawings

FIG. 1 is a schematic illustration of an injector according to an embodiment of the present invention;

FIG. 2 is a schematic view of the mounting of the ejector of FIG. 1 with a bulkhead at the end of the chilled beam;

fig. 3 is a schematic view of a chilled beam end according to another embodiment of the present invention.

The reference numerals are represented as:

1. a nozzle housing; 11. a nozzle throat; 12. a nozzle air outlet section; 13. a nozzle gas inlet section; 2. a thimble; 3. a drive member; 31. a cylinder body; 32. a piston; 33. a first chamber; 331. a first pressure tapping pipe; 34. a second chamber; 341. a second pressure tapping pipe; 4. a mounting frame; 41. a through-flow aperture; 100. a tip housing; 101. a partition plate; 102. a static pressure box; 103. and an air inducing cavity.

Detailed Description

Referring to fig. 1 to 3 in combination, according to an embodiment of the present invention, there is provided an injector, which is applied to a cold beam end, and includes a nozzle housing 1, a thimble 2, wherein the nozzle housing 1 has a nozzle throat 11, and a nozzle outlet section 12 and a nozzle inlet section 13 located at two sides of the nozzle throat 11, and further includes a driving member 3, the driving member 3 includes a cylinder 31 and a piston 32 slidably connected in the cylinder 31, the piston 32 is connected to the thimble 2, the piston 32 divides an inner cavity of the cylinder 31 into a first cavity 33 and a second cavity 34 which are independent of each other, the piston 32 drives the thimble 2 to move toward or away from the nozzle throat 11 under a pressure difference between the first cavity 33 and the second cavity 34 to change a flow area of the nozzle throat 11, the thimble 2 is also referred to as an axial needle, a needle valve, etc., and has a tapered tip portion, the relative position of the tapered tip portion and the nozzle throat 11 will define the flow area of the nozzle throat 11. In the technical scheme, the relative position of the ejector pin 2 relative to the nozzle throat 11 is driven by the driving part 3, and different from the prior art, the invention adopts the telescopic motion generated by the cylinder 31 and the piston 32 under the action of pressure difference to drive the movement of the ejector pin 2, and does not adopt the electromagnetic driving mode in the prior art.

Preferably, the first cavity 33 has a first pressure tapping pipe 331, the first pressure tapping pipe 331 being used for introducing a first pressure gas into the first cavity 33, the second cavity 34 having a second pressure tapping pipe 341, the second pressure tapping pipe 341 being used for introducing a second pressure gas into the second cavity 34, the pressure of the first pressure gas being lower than the pressure of the second pressure gas. Specifically, for example, when the pressure measuring device is applied to the end of the chilled beam shown in fig. 3, the inlet of the first pressure sampling pipe 331 is communicated with the negative pressure region formed by the injection of the injector, and the inlet of the second pressure sampling pipe 341 is communicated with the static pressure tank 102 provided at the end of the chilled beam, that is, the first pressure gas is the gas pressure in the negative pressure region, and the second pressure gas is the gas pressure in the static pressure tank 102. As shown by the arrow in fig. 3, the primary air, that is, the air flow entering the nozzle housing 1 from the plenum chamber 102 enters the plenum chamber 102 through the air pipe connection, flows from the nozzle inlet section 13C of the nozzle housing 1 to the nozzle outlet section B, and is ejected at high speed, which causes a negative pressure region D (part of the air guide chamber 103) to be generated at the outer peripheral side of the nozzle inlet section 13 under the venturi effect, the indoor return air (secondary air) passes through the filter and the heat exchanger from the return air inlet E under atmospheric pressure and is sucked into the negative pressure region D, the indoor return air performs heat exchange (is cooled or heated or does not perform heat exchange) on the heat exchanger, and the primary air and the secondary air are mixed and then is guided to the indoor through the air guide plate from the air outlet a. Wherein the inlet of the first pressure tap 331 is at the D and the inlet of the second pressure tap 341 is at the C.

Further, one end of the second pressure tapping pipe 341, which faces the second cavity 34, extends into the second cavity 34 for a first preset distance, where the first preset distance is greater than zero, that is, an air outlet of the second pressure tapping pipe 341 is designed to protrude out of an inner cavity wall of the cylinder body 31, and the air outlet can limit a downward stroke of the piston 32, so as to prevent a phenomenon that the first pressure gas and the second pressure gas are communicated due to an excessively large downward displacement of the piston 32; and/or one end of the first pressure tapping pipe 331 facing the first cavity 33 is positioned in the cylinder side wall corresponding to the first cavity 33.

In order to ensure the movement fluency of the piston 32, it is preferable that the first cavity 33 and/or the second cavity 34 is filled with a lubricating medium, for example, a liquid lubricating medium such as lubricating oil; in the case that there is a solid lubricating medium, such as graphite, paraffin, etc., it is preferable that a distance between a bottom side surface of one end of the second pressure sampling pipe 341 facing the second chamber 34 and an end (bottom end) of one end of the cylinder 31 is greater than a height position of the lubricating medium filled in the second chamber 34 (when the lubricating medium is lubricating oil, a level of the lubricating oil is provided accordingly).

The better the density of the thimble 2, the piston 32 and the lubricating medium is, the better the density is, so as to reduce the mass of the three parts as much as possible, which is beneficial to fully utilize the pressure difference between the upper surface and the lower surface of the piston 32; meanwhile, it is also important to reduce the friction between the piston and the cylinder, for example, polytetrafluoroethylene plastic with a very small friction coefficient is used as the material of the cylinder 31 or the piston 32, and when the nozzle does not eject the working fluid, the piston 32 and the thimble 2 can slowly descend to the lower limit position under the action of gravity to wait for the next operation.

Further, the ejector further comprises a mounting frame 4, the mounting frame 4 is located between the nozzle housing 1 and the cylinder 31, the shape of the mounting frame 4 is matched with the design of the nozzle housing 1 and the cylinder 31, for example, the mounting frame 4 is designed to be circular, and the ejector can be conveniently and fixedly mounted, for example, a through hole is formed in the partition plate 101 in the tail end of the cold beam, the mounting frame 4 is in threaded connection with the partition plate 101 through the through hole, the threaded connection is preferably a threaded connection with a sealing function, and other connection modes can be adopted, but care should be taken to perform necessary sealing operation to ensure the isolation function of the partition plate 101, and it can be understood that the first pressure tapping pipe 331 can also pass through the partition plate 101 to communicate with the position D, and at the same time, care should also be taken to perform sealing operation, such as adopting a sealing thread design, and the ejector can be used for example, The pipe joints are sleeved, welded or sealed and connected by glue curing and the like.

Preferably, a plurality of through holes 41 are formed in the mounting bracket 4, the through holes 41 penetrate through the inner side and the outer side of the nozzle housing 1, and the plurality of through holes 41 are preferably arranged at regular intervals along the outer circumferential direction of the mounting bracket 4, so that primary air in the static pressure box 102 can enter the nozzle housing 1 more uniformly.

There is also provided, in accordance with an embodiment of the present invention, a chilled beam end including the above-described injector. Specifically, the tail end of the cold beam further comprises a tail end shell 100, a partition plate 101 is arranged in the tail end shell 100, the partition plate 101 divides the tail end shell 100 into a static pressure box 102 and an induced air cavity 103, the ejector is connected with the partition plate 101 through the mounting frame 4, the mounting frame 4 is located on one side of the static pressure box 102, and the nozzle shell 1 is located on one side of the induced air cavity 103.

The adjusting principle of the throat flow area of the ejector nozzle in the invention is as follows:

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

when the primary air volume is larger than the minimum primary air volume, the air pressure in the static pressure box 102 is gradually increased, the negative pressure generated by the ejector is larger, the pressure difference between the upper surface and the lower surface of the piston 32 is gradually increased, the piston gradually moves upwards to drive the thimble 2 to move upwards, the injection area of the throat part of the nozzle is increased to adapt to the increase of the primary air injection flow, and the piston 32 is still at a certain position under the balanced state, which indicates that the primary air volume and the air pressure in the static pressure box 102 are in a stable state.

When the primary air volume reaches the maximum, the piston moves upwards to the highest point, the thimble 2 completely leaves the nozzle throat 11, and the spraying area of the nozzle throat is the maximum.

When the primary air volume is gradually reduced from the maximum, the process is opposite to the process of increasing the air volume. Regardless of the increase or decrease of the air quantity, when the primary air quantity is stable and unchanged, the ejector pin always has a fixed corresponding height position and the area of the throat part of the nozzle is also a corresponding value, so that the injection coefficient of the ejector pin is ensured to be in a better range.

There is also provided, in accordance with an embodiment of the present invention, a chilled beam system including the chilled beam end described above.

It is readily understood by a person skilled in the art that the advantageous ways described above can be freely combined, superimposed without conflict.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalent substitutions and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. The ejector is characterized by comprising a nozzle shell (1) and a thimble (2), wherein the nozzle shell (1) is provided with a nozzle throat (11), the ejector further comprises a driving part (3), the driving part (3) comprises a cylinder body (31) and a piston (32) connected in the cylinder body (31) in a sliding mode, the piston (32) is connected with the thimble (2), the piston (32) divides an inner cavity of the cylinder body (31) into a first cavity (33) and a second cavity (34) which are independent of each other, and the piston (32) drives the thimble (2) to move towards or away from the nozzle throat (11) under the action of pressure difference between the first cavity (33) and the second cavity (34) so as to change the flow area of the nozzle throat (11).

2. The injector according to claim 1, characterized in that the first chamber (33) has a first pressure tapping pipe (331), the first pressure tapping pipe (331) being used for introducing a first pressure gas into the first chamber (33), the second chamber (34) having a second pressure tapping pipe (341), the second pressure tapping pipe (341) being used for introducing a second pressure gas into the second chamber (34), the pressure of the first pressure gas being lower than the pressure of the second pressure gas.

3. The injector according to claim 2, characterized in that the second pressure tapping pipe (341) projects into the second chamber (34) towards one end of the second chamber (34) by a first preset distance, which is greater than zero; and/or one end of the first pressure taking pipe (331) facing the first cavity (33) is positioned in the cylinder side wall corresponding to the first cavity (33).

4. Injector according to claim 2, characterized in that the first chamber (33) and/or the second chamber (34) is filled with a lubricating medium.

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

6. The injector of any one of claims 1 to 5, further comprising a mounting (4), the mounting (4) being between the nozzle housing (1) and the cylinder (31).

7. The injector as claimed in claim 6, characterized in that a plurality of throughflow holes (41) are provided in the mounting (4), the throughflow holes (41) penetrating the interior and exterior of the nozzle housing (1).

8. A chilled beam end comprising an ejector, wherein the ejector is the ejector of any one of claims 1 to 7.

9. The chilled beam end according to claim 8, further comprising an end housing (100), wherein a baffle (101) is disposed in the end housing (100), the baffle (101) divides the end housing (100) into a plenum (102) and a draft chamber (103), the ejector is connected to the baffle (101) by the mounting bracket (4), and the mounting bracket (4) is located on the plenum (102) side and the nozzle housing (1) is located on the draft chamber (103) side.

10. The chilled beam end of claim 9, wherein the bulkhead (101) has a through hole therein through which the mounting bracket (4) is threadably connected to the bulkhead (101).

11. A chilled beam system comprising a chilled beam end, wherein the chilled beam end is the chilled beam end of any of claims 8 to 10.