Gas flow pulsation generating device

Abstract

The present application relates to combustion chamber technical field, provide a kind of gas flow pulsation generating device, comprising: generator main body, moving part and driving mechanism;The end face of generator main body is equipped with first through-hole, and generator main body has first cavity, and first cavity is communicated with first through-hole;The first end of moving part is located in first through-hole, and the first end of moving part is conical structure, moving part can reciprocate along first through-hole under the action of driving mechanism, and high-temperature combustion gas generated by combustion chamber enters first cavity through the gap between conical structure and first through-hole.The gas flow pulsation generating device described above, moving part is driven to reciprocate linearly along first through-hole by driving mechanism, to change the actual intake area of first through-hole, cause corresponding flow pulsation at the inlet of combustion chamber, and the gas flow pulsation generating device described above can not only cope with large flow condition, and simple structure, low manufacturing cost.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of combustion chamber, in particular to a gas flow pulsation generating device. BACKGROUND

[0002] In combustion engineering, gas flow pulsation generating device is used to simulate and control the gas flow pulsation in the combustion process, which is crucial for optimizing combustion efficiency, reducing emissions and improving combustion stability. The existing gas flow pulsation generating device has the following two kinds:

[0003] One is to use a loudspeaker as a pulsation generator to generate flow pulsation. The device is composed of a pulsation amplification module and a pulsation generation module. The pulsation amplification module includes at least one half-wavelength tube. The pulsation generation module includes a loudspeaker and a base, and a resonance cavity is formed between the loudspeaker and the base. The loudspeaker generates vibration to convert the airflow in the resonance cavity into pulsating airflow, and then adjusts the pulsation amplitude through the pulsation amplification module. The other is to insert a rotating shaft with a specific cross section into the outlet flow channel of the combustion chamber, which can periodically change the outlet area of the combustion chamber by rotating to generate flow pulsation.

[0004] The loudspeaker as a gas flow pulsation generating device can only deal with small flow, and the actual effect is not good in devices such as combustion test bench that require larger flow. The rotary flute type pulsation generating device generally needs to be inserted into the combustion chamber flow channel from the radial direction, which is difficult to install and arrange. In addition, it is difficult to seal and protect against heat in the high-temperature, high-pressure and high-turbulence environment, and the structure is complex. Therefore, it is necessary to provide a new gas flow pulsation generating device. SUMMARY

[0005] The present application provides a gas flow pulsation generating device to solve the defects of existing gas flow pulsation generating devices that can only deal with small flow and are difficult to install and arrange.

[0006] The present application provides a gas flow pulsation generating device, which comprises a generator main body, a moving part and a driving mechanism. One end of the generator main body is provided with a first through hole, and the generator main body has a first cavity which communicates with the first through hole. The first end of the moving part is located in the first through hole, and the first end of the moving part is in the form of a conical body. The moving part can reciprocate along the first through hole under the action of the driving mechanism, and the high-temperature combustion gas generated by the combustion chamber enters the first cavity through the gap between the conical body and the first through hole.

[0007] According to the gas flow pulsation generating device provided by the present application, the driving mechanism comprises a driver and a push rod, the driver is connected with the push rod, one end of the push rod extends into the first cavity and is connected with the moving part.

[0008] The gas flow pulsation generating device further comprises a water inlet joint, the inside of the push rod is provided with a first flow channel, and the water inlet joint is communicated with the first flow channel; the inside of the moving part is provided with a second flow channel, the second flow channel is communicated with the first flow channel, the surface of the moving part is provided with a plurality of second through holes, the second through holes are communicated with the second flow channel, and the second through holes are located in the first cavity.

[0009] The gas flow pulsation generating device further comprises a water inlet joint, the inside of the push rod is provided with a first flow channel, and the water inlet joint is communicated with the first flow channel; the inside of the moving part is provided with a second flow channel, the second flow channel is communicated with the first flow channel, the surface of the moving part is provided with a plurality of second through holes, the second through holes are communicated with the second flow channel, and the second through holes are located in the first cavity.

[0010] The gas flow pulsation generating device further comprises a cooling part and a water inlet pipe, the cooling part is sleeved outside the moving part, the cooling part has a second cavity, the water inlet pipe is communicated with the second cavity, and one end of the water inlet pipe extends to the outside of the generator main body; the surface of the cooling part is provided with a plurality of third through holes, and the third through holes are communicated with the second cavity.

[0011] The gas flow pulsation generating device further comprises a cooling part and a water inlet pipe, the cooling part is sleeved outside the moving part, the cooling part has a second cavity, the water inlet pipe is communicated with the second cavity, and one end of the water inlet pipe extends to the outside of the generator main body; the surface of the cooling part is provided with a plurality of third through holes, and the third through holes are communicated with the second cavity.

[0012] The gas flow pulsation generating device further comprises a cooling part and a water inlet pipe, the cooling part is sleeved outside the moving part, the cooling part has a second cavity, the water inlet pipe is communicated with the second cavity, and one end of the water inlet pipe extends to the outside of the generator main body; the surface of the cooling part is provided with a plurality of third through holes, and the third through holes are communicated with the second cavity.

[0013] The gas flow pulsation generating device further comprises a cooling part and a water inlet pipe, the cooling part is sleeved outside the moving part, the cooling part has a second cavity, the water inlet pipe is communicated with the second cavity, and one end of the water inlet pipe extends to the outside of the generator main body; the surface of the cooling part is provided with a plurality of third through holes, and the third through holes are communicated with the second cavity.

[0014] The gas flow pulsation generating device further comprises a cooling part and a water inlet pipe, the cooling part is sleeved outside the moving part, the cooling part has a second cavity, the water inlet pipe is communicated with the second cavity, and one end of the water inlet pipe extends to the outside of the generator main body; the surface of the cooling part is provided with a plurality of third through holes, and the third through holes are communicated with the second cavity.

[0015] The gas flow pulsation generating device further comprises a linear bearing sleeved on the outside of the push rod, and the linear bearing is in abutment with the gas sealing element.

[0016] The gas flow pulsation generating device provided by the application can cope with large flow conditions, and has simple structure and low manufacturing cost. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative effort on the basis of these drawings.

[0018] Figure 1 Fig. 1 is a structural schematic diagram of the gas flow pulsation generating device provided by the application.

[0019] Figure 2 Fig. 2 is a sectional view of the gas flow pulsation generating device provided by the application.

[0020] Figure 3 Fig. 3 is a structural schematic diagram of a moving element shown in Fig. 1. Figure 1

[0021] Fig. 4 is a structural schematic diagram of a cooling element shown in Fig. 1. Figure 4 Figure 2 Fig. 5 is a profile curve of the moving element.

[0022] Figure 5 Fig. 6 is a flow variation curve of the moving element with time.

[0023] Figure 6

[0024] Reference signs:

[0025] 1, generator main body; 2, moving element; 3, cooling element; 4, push rod; 5, water inlet connector; 6, gas sealing element; 7, linear bearing; 8, water inlet pipe;

[0026] 11, first flange; 12, connecting pipe; 13, second flange; 14, exhaust pipe; 15, end plate; 21, main flow channel; 22, branch flow channel; 31, third through hole; 41, first flow channel; 61, gas cavity;

[0027] ​​101, first through hole; 102, first cavity; 221, second through hole. DETAILED DESCRIPTION

[0028] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described clearly and completely below in conjunction with the drawings in the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the protection scope of the present application.

[0029] The gas flow pulsation generating device of the present application will be described below in conjunction with Figures 1-6 The gas flow pulsation generating device of the present application will be described below in conjunction with

[0030] As shown in Figure 1 and Figure 2 In the embodiments of the present application, the gas flow pulsation generating device comprises a generator main body 1, a moving part 2 and a driving mechanism. One end surface of the generator main body 1 is provided with a first through hole 101, and the generator main body 1 has a first cavity 102 which is in communication with the first through hole 101. The first end of the moving part 2 is located in the first through hole 101, and the first end of the moving part 2 is in a conical structure. The moving part 2 can reciprocate along the first through hole 101 under the action of the driving mechanism.

[0031] Specifically, the gas flow pulsation generating device provided by the embodiments of the present application is used to simulate the boundary conditions of the combustion dynamic characteristic test of the combustion chamber. The fuel is combusted in the combustion chamber, and the high-temperature combustion gas enters the first cavity 102 from the first through hole 101 and is then discharged. In the process of the high-temperature combustion gas entering the first cavity 102, the moving part 2 reciprocates linearly along the first through hole 101 under the action of the driving mechanism. Since the first end of the moving part 2 is in a conical structure, the area of the moving part 2 located in the first through hole 101 is different during the movement of the moving part 2, resulting in different actual inlet areas. Since the first through hole 101 is at the sound speed, the critical condition is reached. When the total temperature and total pressure upstream of the first through hole 101 are constant, the maximum flow through the first through hole 101 is only related to the actual inlet area of the first through hole 101. When the driving mechanism drives the moving part 2 to periodically move along the first through hole 101, the actual inlet area of the first through hole 101 is changed, resulting in corresponding flow pulsation at the inlet of the combustion chamber, thereby providing hardware support for the combustion dynamic characteristic test of the combustion chamber. When the part with the smallest cross-sectional size of the moving part 2 is located in the first through hole 101, the actual inlet area is the largest, and the flow of the high-temperature combustion gas entering the first cavity 102 is the largest, so that the large flow condition of the combustion chamber can be coped with.

[0032] The gas flow pulsation generating device provided in this embodiment of the invention designs the first end of the moving part as a conical structure, and drives the moving part to reciprocate linearly along the first through hole through a driving mechanism to change the actual air intake area of ​​the first through hole, thereby generating corresponding flow pulsation at the combustion chamber inlet. The gas flow pulsation generating device provided in this embodiment of the invention can not only cope with large flow conditions, but also has a simple structure and low manufacturing cost.

[0033] like Figure 2 As shown, in an embodiment of the present invention, the driving mechanism includes a driver and a push rod 4. The driver is connected to the push rod 4, and one end of the push rod 4 extends into the first cavity 102 and is connected to the moving member 2. In this embodiment, the driver can be a linear motor. When the driver is running, it drives the push rod 4 to move, thereby driving the moving member 2 to reciprocate linearly along the first through hole 101.

[0034] Optionally, in embodiments of the present invention, the first through hole 101 can be a cylindrical hole; the first through hole 101 can also be a conical hole. When the first through hole 101 is a conical hole, the cone orientation of the conical hole is opposite to the cone orientation of the moving member 2, so that the actual air intake area has multiple possibilities during the reciprocating motion of the moving member 2, thereby coping with different flow rate conditions.

[0035] like Figure 2 As shown, in an embodiment of the present invention, the gas flow pulsation generating device further includes a water inlet connector 5. The push rod 4 has a first flow channel 41 inside, and the water inlet connector 5 communicates with the first flow channel 41. The moving part 2 has a second flow channel inside, which communicates with the first flow channel 41. The surface of the moving part 2 has multiple second through holes 221, which communicate with the second flow channels and are located within the first cavity 102.

[0036] Specifically, cooling water enters the first flow channel 41 through the water inlet connector 5, then flows into the second flow channel from the first flow channel 41, and is discharged through the second through hole 221 to cool the moving part 2.

[0037] like Figure 3 As shown, in an embodiment of the present invention, the second flow channel includes a main flow channel 21 and a plurality of branch flow channels 22. The main flow channel 21 is disposed at the center of the moving member 2 and is connected to the first flow channel. The plurality of branch flow channels 22 surround the main flow channel 21. One end of each branch flow channel 22 is connected to the main flow channel 21, and the other end of each branch flow channel 22 is connected to the second through hole 221.

[0038] In this embodiment, each branch channel 22 is located close to the outer surface of the moving part 2. After the cooling water enters the main channel 21 from the first channel 41, it flows to each branch channel 22. Since the branch channels 22 are close to the surface of the moving part 2, they can provide good cooling for the moving part 2.

[0039] like Figure 2 As shown, in an embodiment of the present invention, the gas flow pulsation generating device further includes a cooling element 3 and a water inlet pipe 8. The cooling element 3 is sleeved on the outside of the moving element 2. The cooling element 3 has a second cavity, and the water inlet pipe 8 communicates with the second cavity. One end of the water inlet pipe 8 extends to the outside of the generator body 1. The surface of the cooling element 3 is provided with a plurality of third through holes 31, which communicate with the second cavity.

[0040] Specifically, the cooling element 3 is sleeved on the outside of the moving element 2, and there is a gap between the two. The cooling element 3 is disposed adjacent to the first through hole 101. Cooling water enters the second cavity of the cooling element 3 through the water inlet pipe 8, and then sprays out through the third through hole 31 to cool the end face of the generator body 1.

[0041] Furthermore, such as Figure 4 As shown, some of the third through holes 31 are disposed toward the moving member 2 to cool the moving member 2; the remaining third through holes 31 are disposed toward the end face of the generator body 1 where the first through hole 101 is located to cool the end face.

[0042] Optionally, in an embodiment of the present invention, the cooling element 3 is an annular regular polygonal structure, such as a regular octagonal structure. Each hollow rod of the regular octagonal structure is provided with a pair of third through holes 31, one third through hole 31 facing the moving element 2 and the other third through hole 31 facing the end plate 15. Optionally, the diameter of each third through hole 31 is 1.5 mm.

[0043] The gas flow pulsation generator provided in this embodiment of the invention, by setting a first flow channel inside the push rod, a second flow channel inside the moving part, and a cooling component inside the first cavity, can cool the end faces of the moving part and the generator body, ensuring that the outer surface temperature of the moving part is within a safe range and is not burned, thus ensuring that the moving part can be used for a long time.

[0044] like Figure 2 As shown, in an embodiment of the present invention, the generator body 1 includes: a first flange 11, a connecting pipe 12, a second flange 13, an exhaust pipe 14, and an end plate 15. The first flange 11 and the second flange 13 are connected by the connecting pipe 12, the connecting pipe 12 having a first cavity 102 inside, and the exhaust pipe 14 communicating with the first cavity 102. The end plate 15 is embedded in the first flange 11, and the end plate 15 has a first through hole 101, one end of the push rod 4 passing through the second flange 13 and connected to the moving part 2.

[0045] Specifically, the high-temperature combustion gas generated in the combustion chamber enters the first cavity 102 through the first through hole 101 and is then discharged through the exhaust pipe 14. In this embodiment, the first through hole 101 is formed on the end plate 15, so part of the third through hole 31 of the cooling element 3 is arranged facing the end plate 15 to cool the end plate 15.

[0046] like Figure 2 As shown, in an embodiment of the present invention, the gas flow pulsation generating device further includes a gas seal 6, which is sleeved on the outside of the push rod 4 and located outside the first cavity 102. The gas seal 6 is connected to the second flange 13, and a gas cavity 61 is formed between the gas seal 6 and the push rod 4. When the driver drives the push rod 4 to reciprocate linearly, the high-temperature gas in the first cavity 102 flows into the gas cavity 61 as the push rod 4 is pulled.

[0047] like Figure 2 As shown, in an embodiment of the present invention, the gas flow pulsation generating device further includes a linear bearing 7, which is sleeved on the outside of the push rod 4 and abuts against the gas seal 6. The gas chamber 61 of the gas seal 6 can prevent high-temperature gas from entering the linear bearing 7.

[0048] In an embodiment of the present invention, the design process of the conical surface parameters of the moving part 2 is as follows:

[0049] For the design of end plate 15, the key parameter is the diameter of the first through hole 101. When the airflow in the first through hole 101 is in a critical state, its flow rate... The calculation formula is:

[0050]

[0051] in, Here, R is the specific heat ratio, and R is the gas constant. Total pressure at the combustion chamber outlet. For total temperature, For flow coefficient, The area of ​​the first through hole, This is the flow function.

[0052] The motion curve of the driver is:

[0053] (2)

[0054] in, x For the drive stroke, f For frequency, t The time it takes for the moving part to move.

[0055] When the moving part 2 moves within the first through hole 101, the effective flow area of ​​the first through hole 101 is... A = A0cos(ωt)

[0056]

[0057] A = A0cos(ωt) A = A0cos(ωt) r A = A0cos(ωt) A = A0cos(ωt) A = A0cos(ωt)

[0058] A = A0cos(ωt) A = A0cos(ωt) A = A0cos(ωt)

[0059] A = A0cos(ωt) A = A0cos(ωt) A = A0cos(ωt) a, b, c A = A0cos(ωt) A = A0cos(ωt)

[0060] A = A0cos(ωt) A = A0cos(ωt) A = A0cos(ωt)

[0061] A = A0cos(ωt) c A = A0cos(ωt) A = A0cos(ωt)

[0062] A = A0cos(ωt) A = A0cos(ωt)

[0063] A = A0cos(ωt) A = A0cos(ωt) A = A0cos(ωt)

[0064] A = A0cos(ωt) A = A0cos(ωt)

[0065] A = A0cos(ωt) A = A0cos(ωt) A = A0cos(ωt)

[0066] A = A0cos(ωt) a A = A0cos(ωt) b A = A0cos(ωt) A = A0cos(ωt)

[0067] A = A0cos(ωt) A = A0cos(ωt)

[0068] Specifically, under the working condition of the combustion chamber inlet pressure of 0.5 MPa, the temperature of 600 K and the average flow of 0.38 kg / s, the radius of the section of the moving part 2 located in the first through hole 101 is as follows when the external excitation frequency is 20 Hz and the flow relative amplitude is 20%:

[0069] The geometric area of the first through hole 101 is calculated by formula (1) =1057.78 mm 2 , and the section radius of the moving part 2 located in the initial position is set as r 0 =10 mm, and the diameter of the first through hole 101 is D =41.78 mm.

[0070] The frequency of the selected driver is f =20 Hz, the stroke is x =12.5 mm, and the driver motion curve is y =6.25(1-cos(2πft)).

[0071] To achieve the flow of 20% of the flow pulsation, the minimum flow of 0.304 kg / s can be calculated according to the maximum flow of 0.456 kg / s. The minimum flow is substituted into formula (1) to obtain the corresponding effective flow area at this time , at this time the driver stroke reaches the maximum value, i.e. y =12.5 mm, the effective flow area is brought into formula (3) and (7) to determine the parameters a and b that satisfy the equation: According to the maximum flow of 0.456 kg / s and the initial radius setting value of the moving part , at this time the driver stroke reaches the minimum value, i.e. y =0 mm, and is obtained. Thus, the values of a and b are respectively: , .

[0072] Thus, the radius equation of the section of the moving part 2 located in the first through hole 101 is

[0073]

[0074] The profile curve of the moving part 2 is shown in Figure 5 , and the ideal flow-time curve generated by the moving part 2 is shown in Figure 6 .

[0075] According to the above calculation, the radius of the section of the moving part 2 in the first through hole can be determined according to formula (8) according to the required flow pulsation frequency and amplitude, and the frequency and stroke of the driver, and the radius of the section of the moving part 2 in the initial position and the calculated , that is, the conical structure of the moving part 2 can be determined.

[0076] The gas flow pulsation generating device provided by the embodiments of the present application adopts a driver to drive a moving part to reciprocate to change the effective flow area of the first through hole, has simple structure and low cost, and can stably generate flow pulsation with low frequency, high amplitude and specified waveform.

[0077] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A gas flow pulsation generating device, characterized in that, include: The generator body comprises a main body, moving parts, a drive mechanism, a water inlet connector, a cooling component, and a water inlet pipe; one end face of the generator body is provided with a first through hole, and the generator body has a first cavity, the first cavity being connected to the first through hole; The first end of the moving part is located in the first through hole. The first end of the moving part has a conical structure. The moving part can reciprocate along the first through hole under the action of the driving mechanism. The high-temperature gas generated in the combustion chamber enters the first cavity through the gap between the conical structure and the first through hole. The driving mechanism includes: a driver and a push rod, the driver being connected to the push rod, one end of the push rod extending into the first cavity and being connected to the moving part; The push rod has a first flow channel inside, and the water inlet connector is connected to the first flow channel; the moving part has a second flow channel inside, and the second flow channel is connected to the first flow channel; the surface of the moving part has a plurality of second through holes, the second through holes are connected to the second flow channels, and the second through holes are located in the first cavity. The cooling component is sleeved on the outside of the moving component. The cooling component has a second cavity. The water inlet pipe is connected to the second cavity. One end of the water inlet pipe extends to the outside of the generator body. The surface of the cooling component is provided with a plurality of third through holes, which are connected to the second cavity.

2. The gas flow pulsation generating device according to claim 1, characterized in that, The second flow channel includes a main flow channel and a plurality of branch flow channels. The main flow channel is located at the center of the moving part and is connected to the first flow channel. The plurality of branch flow channels surround the main flow channel. One end of each branch flow channel is connected to the main flow channel, and the other end of each branch flow channel is connected to the second through hole.

3. The gas flow pulsation generating device according to claim 1, characterized in that, A portion of the third through holes faces the moving part, while the remaining portion faces the end face of the generator body where the first through hole is located.

4. The gas flow pulsation generating device according to claim 1, characterized in that, The first through hole is a conical hole, and the cone shape of the conical hole is opposite to the cone shape of the moving part.

5. The gas flow pulsation generating device according to claim 1, characterized in that, The generator body includes: a first flange, a second flange, a connecting pipe, an end plate, and an exhaust pipe; The first flange and the second flange are connected by the connecting pipe, the connecting pipe having the first cavity inside, and the exhaust pipe communicating with the first cavity; The end plate is embedded in the first flange, and the end plate is provided with the first through hole; One end of the push rod passes through the second flange and is connected to the moving part.

6. The gas flow pulsation generating device according to claim 5, characterized in that, It also includes an air seal, which is sleeved on the outside of the push rod and located outside the first cavity; The air seal is connected to the second flange, and an air cavity is formed between the air seal and the push rod.

7. The gas flow pulsation generating device according to claim 6, characterized in that, It also includes a linear bearing, which is sleeved on the outside of the push rod and abuts against the air seal.

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