Multi-station engine test bench exhaust device

Abstract

The exhaust device of a multi-station engine test bench comprises a 1# engine test bench exhaust pipeline, a 2# engine test bench main exhaust pipeline, a 2# engine test bench auxiliary exhaust pipeline, a bleed pipeline, an exhaust main pipeline, a horizontal oil-gas separation device and a silencer; two ends of the horizontal oil-gas separation device are respectively connected with the outlet of the 2# engine test bench main exhaust pipeline and the inlet of the exhaust main pipeline; the 1# engine test bench exhaust pipeline and the 2# engine test bench auxiliary exhaust pipeline are arranged in parallel and are both connected with the inlet of the exhaust main pipeline; the outlet of the exhaust main pipeline is connected with the silencer; the bleed pipeline is connected with the silencer; the multi-station engine test bench exhaust device of the present invention is suitable for the working condition that the exhaust pipelines of multiple engine test benches or multiple stations of an engine test bench share the same silencer tower, so as to avoid mutual interference of airflows discharged from the outlet holes of multiple variable frequency diffusers, avoid secondary noise pollution, and reduce the difficulty of silencer.

Description

Technical Field

[0001] The invention relates to the technical field of engine testing, and in particular to an exhaust device of a multi-station engine test bench. Background Art

[0002] The noise source that pollutes the workplaces and surrounding environment of the engine test bench mainly comes from aerodynamic noise. This noise source only exists when the test bench is tested. When high-pressure, high-speed, high-temperature compressed air and gas flow in metal or other enclosures or are discharged into the atmosphere, noise of up to 130dB (A) or more is generated. Noise is a sound that people do not need. The sound frequency that the human ear can hear is within 20HZ to 20000HZ. This is the noise that people can directly feel. Noise outside this frequency is a silent killer that the human ear cannot feel and is also the object of noise control. At present, various countries stipulate that noise must be controlled within different sound pressure levels according to different environments. According to the relevant provisions of our country's Environmental Protection Law, the noise sound pressure level allowed for new enterprises working 8 hours a day is 85dB (A), and 94dB (A) is allowed for working 1 hour a day. For engine test benches with sound power greater than 130dB (A), short action time, and workplaces far away from towns and residential areas, the purpose of noise control is mainly to make the noise in the workplace of the test bench staff meet the specified indicators and to reduce the noise to the environment outside the test bench as much as possible.

[0003] In the existing engine test bench silencer, a variable frequency diffuser is arranged at the tail end of the exhaust pipe, and a variable frequency diffuser outlet hole in the form of a through hole is arranged on the surface of the variable frequency diffuser. The airflow passes through a number of variable frequency diffuser outlet holes to shift the noise frequency to high frequency, and the difficulty of noise control is reduced by using the principle that high frequency is easier to silence than low frequency. However, for exhaust pipes and / or bypass pressure relief pipes of multiple engine test benches or multiple workstations of an engine test bench, multiple silencer towers need to be set up, which will greatly increase the construction and maintenance costs. When entering the same silencer tower, that is, when multiple exhaust pipes and / or bypass pressure relief pipes enter the same silencer tower, a variable frequency diffuser is arranged at the tail end of each pipe, and the airflows discharged from the outlet holes of multiple variable frequency diffusers interfere with each other, resulting in secondary noise pollution, which increases the difficulty of silencer.

[0004] During the flame tube oil mist field test and nozzle thermal protection test, the exhaust gas contains a large amount of kerosene vapor and vapor droplets, which need to be discharged into the atmosphere after oil and gas separation. The fuel concentration in the exhaust gas should meet the secondary emission standard of the "Comprehensive Emission Standard of Air Pollutants" (GB16297-1996), that is, the maximum allowable emission concentration of non-methane total hydrocarbons is 120mg / m3, and the maximum allowable emission rate is 53kg / h (exhaust height 30m).

[0005] As early as the 1930s, people invented demisters for the needs of industrial production. According to the purpose or structure of demisters, they can be divided into many types, such as shutter separators, gravity sedimentation separators and cyclone plate separators, but these separators have low separation efficiency and are not easy to separate small-sized mist particles; although wire mesh demisters can separate general mist particles, they require clean mist particles, low air flow rate, large resistance drop, short service life, and large equipment investment.

[0006] Therefore, it is an urgent problem to be solved in the research and production of new high-efficiency demisters with high separation efficiency, small resistance drop, large allowable air flow velocity and strong anti-blocking function in the flame tube oil mist field test and nozzle thermal protection test. Summary of the invention

[0007] The technical problem solved by the present invention is to overcome the deficiencies of the prior art and provide an exhaust device for a multi-station engine test bench.

[0008] The technical solution of the present invention is:

[0009] The exhaust device of the multi-station engine test bench includes a 1# engine test bench exhaust pipeline, a 2# engine test bench main exhaust pipeline, a 2# engine test bench auxiliary exhaust pipeline, a bleed pipeline, an exhaust main pipeline, a horizontal oil-gas separation device and a silencer; the two ends of the horizontal oil-gas separation device are respectively connected with the outlet of the 2# engine test bench main exhaust pipeline and the inlet of the exhaust main pipeline; the 1# engine test bench exhaust pipeline and the 2# engine test bench auxiliary exhaust pipeline are arranged in parallel and are both connected with the inlet of the exhaust main pipeline; the outlet of the exhaust main pipeline is connected with the silencer; the bleed pipeline is connected with the silencer; the horizontal oil-gas separation device includes a demister and an activated carbon adsorption device; the gas outlet of the demister is connected with the air inlet of the activated carbon adsorption device; along the flow direction of the oil-gas mixture, the demister includes a horizontal expansion section, an equal straight section and a convergent section connected in sequence A shell is set; an air inlet is set at one end of the expansion section, and the air inlet is connected with the outlet of the main exhaust pipeline of the 2# engine test bench; along the flow direction of the oil-gas mixture, the equal straight section is sequentially provided with a baffle demister and a wire mesh demister; a first spray flushing device is set on the side wall of the expansion section, and a second spray flushing device is set on the side wall of the equal straight section between the baffle demister and the wire mesh demister; the baffle demister and the wire mesh demister are respectively provided with a first drain port and a second drain port at the bottom; the activated carbon adsorption device comprises a horizontally arranged activated carbon box; along the flow direction of the gas discharged from the gas outlet of the demister, a vertical activated carbon adsorption box and a horizontal activated carbon adsorption box are sequentially provided in the activated carbon box, and the activated carbon box is provided with a gas outlet, and the gas outlet of the activated carbon box is connected with the silencer through a pipeline; at the same time, a third drain port is provided at the bottom of the activated carbon box.

[0010] Furthermore, the silencer includes a tower body, a silencer plate assembly and two variable frequency diffusers, each of which has the same structure; each variable frequency diffuser includes a variable frequency diffuser cylinder and a variable frequency diffuser guide cone, the variable frequency diffuser cylinder is a hollow circular cylinder, a plurality of variable frequency diffuser air outlets are arranged on the surface of the cylinder, and the plurality of variable frequency diffuser air outlets are through holes that penetrate the circular cylinder; the variable frequency diffuser guide cone is a cone-shaped, the conical surface of the variable frequency diffuser guide cone is arranged inside the circular cylinder, and the bottom outer circle of the variable frequency diffuser guide cone is fixedly connected to one end surface of the circular cylinder; in each variable frequency diffuser, the projection of the variable frequency diffuser air outlet along its own axial direction is not on the variable frequency diffuser cylinder of the adjacent variable frequency diffuser; the exhaust main line outlet is connected to the silencer; the vent line is connected to the silencer; the vent line is connected to one variable frequency diffuser, and the exhaust main line outlet is connected to another variable frequency diffuser.

[0011] Furthermore, the spray flushing device includes a first spray flushing device, a second spray flushing device, a third spray flushing device and a fourth spray flushing device.

[0012] Furthermore, the baffle demister includes a baffle sheet and a barb, and the barb is arranged at a bending portion of the baffle sheet.

[0013] Furthermore, the baffle demister includes a plurality of baffle plates.

[0014] Furthermore, the opening rate of the variable frequency diffuser air outlet of each variable frequency diffuser is 30%-65%.

[0015] Furthermore, in each variable frequency diffuser, the sum of the areas of the air outlet holes of the variable frequency diffuser is greater than the cross-sectional area of ​​the barrel of the variable frequency diffuser.

[0016] Furthermore, in each variable frequency diffuser, the sum of the areas of the air outlet holes of the variable frequency diffuser is at least 1.1 times the cross-sectional area of ​​the barrel of the variable frequency diffuser.

[0017] Furthermore, a plurality of variable frequency diffusers are arranged in parallel.

[0018] The advantages of the present invention compared with the prior art are:

[0019] 1. In the exhaust device of the multi-station engine test bench of the present invention, the exhaust pipeline, the exhaust pipelines of different test benches and the exhaust pipelines of different stations of the same test bench are introduced into the same silencer, which reduces the construction and operation costs. At the same time, it avoids or reduces the mutual interference of the airflows discharged from the outlet holes of multiple variable frequency diffusers, avoids secondary noise pollution, and reduces the difficulty of silencer.

[0020] 2. In the exhaust device of the multi-station engine test bench of the present invention, the oil-gas separation silencer occupies a small area, is suitable for oil-gas separation of large-flow gas, is easy to install, simple to operate, has a good defoaming effect, and can achieve 99% removal of oil droplets; at the same time, it can adapt to any liquid-containing gas, effectively reduce the blockage of the defoamer, and ensure the long-term use of the defoamer.

[0021] 3. In the exhaust device of the multi-station engine test bench of the present invention, the oil-gas separation silencing device adopts a baffle demister to perform 100% effective separation of oil droplets and liquid droplets of 20um-50um, and adopts a wire mesh demister to perform 99% effective separation of oil droplets and liquid droplets of 5um-20um. In addition, the purpose of oil-gas separation can be achieved by adjusting the plate spacing of the baffles of the baffle demister and the thickness of the wire mesh demister according to different oil-gas separation requirements.

[0022] 4. In the exhaust device of the multi-station engine test bench of the present invention, the oil-gas separation silencer adopts a spray flushing device to flush the baffle demister, so as to flush and remove the scale attached to the baffle demister after long-term operation.

[0023] 5. In the exhaust device of the multi-station engine test bench of the present invention, the oil-gas separation silencing device is provided with an activated carbon adsorption device to adsorb oil droplets below 5 μm. The adsorption can make the organic waste gas purification efficiency as high as 90-95%, thereby ensuring that the gas treated by the horizontal oil-gas separation device of the present invention meets the national emission standards. In addition, after the activated carbon adsorption is saturated, it can be desorbed and regenerated by hot air so that the activated carbon can be put into use again or replaced.

[0024] 6. In the exhaust device of the multi-station engine test bench of the present invention, the silencer adopts two variable frequency diffusers. Since the projection of the variable frequency diffuser outlet hole in each variable frequency diffuser along its own axial direction is not on the variable frequency diffuser cylinder of the adjacent variable frequency diffuser, that is, the airflow discharged from the air outlet hole of the variable frequency diffuser in each variable frequency diffuser has no contact with the adjacent variable frequency diffuser cylinder, and will not impact the adjacent variable frequency diffuser cylinder, thereby avoiding or reducing the mutual interference of the airflows discharged from the air outlet holes of multiple variable frequency diffusers, avoiding secondary noise pollution, and reducing the difficulty of silencer.

[0025] 7. In the exhaust device of the multi-station engine test bench of the present invention, the silencer adopts two variable frequency diffusers, which increases the sum of the areas of the variable frequency diffuser outlet holes of each variable frequency diffuser and reduces the air flow velocity through the variable frequency diffuser outlet holes. Since the noise of the flowing gas decreases as the flow velocity of the flowing gas decreases, the original noise level of the air flow in the silencer tower is reduced, thereby reducing the difficulty of silencing.

[0026] 8. In the exhaust device of the multi-station engine test bench of the present invention, the silencer adopts two variable frequency diffusers, which is suitable for the working condition that the exhaust pipes and / or bypass pressure relief pipes of multiple engine test benches or multiple stations of an engine test bench share the same silencer tower, thereby avoiding mutual interference of the airflows discharged from the outlet holes of multiple variable frequency diffusers, avoiding secondary noise pollution, and reducing the difficulty of silencing. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the principle of the multi-station engine test bench of the present invention.

[0028] Figure 2 It is a structural schematic diagram of a horizontal oil-gas separation device in a multi-station engine test bench of the present invention.

[0029] Figure 3 The schematic diagram of the principle of the horizontal oil-gas separator with two barbed S2 baffle demisters in the multi-station engine test bench of the present invention.

[0030] Figure 4 It is a schematic diagram of the principle of a S3 type baffle demister with three barbs in a horizontal oil-gas separator in a multi-station engine test bench of the present invention.

[0031] Figure 5 It is a schematic diagram of the principle of a horizontal oil-gas separator with four barbed S4 baffle demisters in the multi-station engine test bench of the present invention.

[0032] Figure 6 The diagram is a schematic diagram of the working principle of the activated carbon adsorption device of the horizontal oil-gas separator in the multi-station engine test bench of the present invention.

[0033] Figure 7 It is a schematic structural diagram of the silencer device in the multi-station engine test bench of the present invention.

[0034] Figure 8 It is a structural schematic diagram of two variable frequency diffuser structures in the silencer device in the multi-station engine test bench of the present invention.

[0035] Fig. 9 It is a radial cross-sectional schematic diagram of two or more variable frequency diffuser structures in the silencer device in the multi-station engine test bench of the present invention.

[0036] Fig.10 It is a schematic structural diagram of a first variable frequency diffuser among two or more variable frequency diffusers in a muffler device in a multi-station engine test bench of the present invention.

[0037] Fig.11 for Fig.10 Schematic diagram of the structure of the first variable frequency diffuser guide cone in the first variable frequency diffuser.

[0038] Fig.12 It is a schematic structural diagram of the second variable frequency diffuser among the two or more variable frequency diffusers in the muffler device in the multi-station engine test bench of the present invention.

[0039] Fig.13 for Fig.12 Schematic diagram of the structure of the second variable frequency diffuser guide cone in the second variable frequency diffuser. DETAILED DESCRIPTION

[0040] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention. In addition, features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] like Figure 1-13 As shown, a multi-station engine test bench exhaust device includes a 1# engine test bench exhaust pipeline 10, a 2# engine test bench main exhaust pipeline 20, a 2# engine test bench auxiliary exhaust pipeline 30, a vent pipeline 40, an exhaust main pipeline 50, a horizontal oil-gas separation device 200 and a silencer 100; the two ends of the horizontal oil-gas separation device 200 are respectively connected to the outlet of the 2# engine test bench main exhaust pipeline 20 and the inlet of the exhaust main pipeline 50; the 1# engine test bench exhaust pipeline 10 and the 2# engine test bench auxiliary exhaust pipeline 30 are arranged in parallel and are both connected to the inlet of the exhaust main pipeline 50.

[0043] The horizontal oil-gas separation device 200 includes a demister 210 and an activated carbon adsorption device 220; the gas outlet of the demister 210 is connected to the gas inlet of the activated carbon adsorption device 220; along the flow direction of the oil-gas mixed gas, the demister 210 includes a horizontally arranged shell consisting of an expansion section 214, an equal straight section 215 and a convergence section 216 connected in sequence;

[0044] An air inlet 213 is provided at one end of the expansion section 214, and the air inlet 213 is connected to the outlet of the main exhaust pipe 20 of the 2# engine test bench; along the flow direction of the oil-gas mixture, the straight section 215 is sequentially provided with a baffle demister 211 and a wire mesh demister 212; the demister 210 innovatively adopts a combined high-efficiency demolding device of the baffle demister 211 and the wire mesh demister 212, wherein the baffle demister can effectively separate 100% of the oil droplets and liquid droplets of 20um-50um; the wire mesh demister can effectively separate 99% of the liquid droplets below 20um and above 5um; in view of the fact that the flow channel of the baffle demister is relatively large and not easy to be blocked, the gas first enters the baffle demister to preferentially remove the oil droplets and liquid droplets of 20um-50um, thereby protecting the subsequent wire mesh demister from being blocked due to the large amount of oil.

[0045] Preferably, the baffle demister 211 includes a baffle sheet 2111 and a barb 2112, and the barb 2112 is arranged at the bending part of the baffle sheet 2111; the baffle demister 211 includes a plurality of baffle sheets 2111 arranged in parallel, and a barb 2112 is arranged at the bending part of each baffle sheet 2111.

[0046] The baffle demister 211 involved in the present invention performs separation based on the principle of physical inertia. When the airflow carrying liquid droplets or solid particles passes through the specially designed baffle plate at a speed of 3-9 m / s, the liquid droplets or solid particles change their movement direction from the movement direction of the gas under the action of inertia at the turning point of the baffle plate, so that the liquid droplets or solid particles are separated from the gas. The separation process can be divided into the following three steps:

[0047] 1. The gas is divided into many single flow channels.

[0048] 2. The inertial force causes the droplets to collide with the baffles.

[0049] 3. The dripping film moves forward to the barb and is separated.

[0050] Its structural feature is that the form of the baffle demister is different depending on the purpose. Among them, the S type is an impact-type high-efficiency demister mainly used for horizontal airflow. It allows a higher surface velocity under low resistance drop and high-efficiency separation. According to the size of the maximum droplet diameter of the mist, the droplet load and whether there is dust in the airflow, it can be set to an S2 baffle demister with two barbs, an S3 baffle demister with three barbs and an S4 baffle demister with four barbs according to actual needs. The principle schematic diagram is shown in the attached figure.

[0051] The baffle demister 211 can effectively remove droplets of different sizes by changing the baffle plate form, such as a baffle angle of 60°, 90° or 120°, and a grooved plate, etc., and can achieve the best defoaming effect for 30μm droplets by adjusting the baffle spacing.

[0052] The wire mesh demister 212 can achieve the best defoaming effect of 5 μm droplets by changing the type of wire mesh and the thickness of the wire mesh demister. For example, the types of wire mesh include SP type, HP type, DP type and HR type.

[0053] The side wall of the expansion section 214 is provided with a first spray flushing device 217, and the side wall of the straight section 215 is provided with a second spray flushing device 218 between the baffle demister 211 and the wire mesh demister 212; preferably, the first spray flushing device 217 and the second spray flushing device 218 are both provided with two groups of nozzles. The two groups of nozzles are provided to flush the baffle demister 211 and the wire mesh demister 212 respectively, and the scale attached to the baffle demister 211 and the wire mesh demister 212 after long-term operation is flushed and removed.

[0054] The baffle demister 211 and the wire mesh demister 212 are provided with a first drain port 2171 and a second drain port 2181 at the bottom. The baffle demister 211 and the wire mesh demister 212 are provided with a first drain port 2171 and a second drain port 2181 at the bottom. In order to discharge the discharged liquid in a centralized manner, the first drain port 2171 and the second drain port 2181 are connected through a drain pipe to discharge the liquid.

[0055] The activated carbon adsorption device 220 includes a horizontally arranged activated carbon box 221, and along the flow direction of the gas discharged from the gas outlet of the demister 210, a vertical activated carbon adsorption box 222 and a horizontal activated carbon adsorption box 223 are sequentially arranged in the activated carbon box 221, and the activated carbon box 221 is provided with a gas outlet 225, and the gas outlet 225 of the activated carbon box 221 is connected to the silencer through a pipeline; at the same time, a third liquid discharge port 224 is arranged at the bottom of the activated carbon box 221. Preferably, a support leg 226 is arranged at the bottom of the activated carbon box 221.

[0056] An activated carbon adsorption device is provided to adsorb oil droplets below 5 μm. The adsorption can make the organic waste gas purification efficiency as high as 90-95%, thereby ensuring that the gas treated by the horizontal oil-gas separation device of the present invention meets the national emission standards. In addition, after the activated carbon is saturated with adsorption, hot air can be used for desorption and regeneration so that the activated carbon can be put into use again or replaced.

[0057] The silencer device comprises a tower body 130, a silencer plate assembly 140, a first variable frequency diffuser 110 and a second variable frequency diffuser 120, each variable frequency diffuser having the same structure; each variable frequency diffuser comprises a variable frequency diffuser cylinder and a variable frequency diffuser guide cone, the variable frequency diffuser cylinder is a hollow circular cylinder, a plurality of variable frequency diffuser air outlets are arranged on the surface of the cylinder, and the plurality of variable frequency diffuser air outlets are all through holes penetrating the circular cylinder; the variable frequency diffuser guide cone is a cone, the conical surface of the variable frequency diffuser guide cone is arranged inside the circular cylinder, and the bottom outer circle of the variable frequency diffuser guide cone is fixedly connected to one end face of the circular cylinder. In each variable frequency diffuser, the projection of the variable frequency diffuser outlet along its own axial direction is not on the variable frequency diffuser cylinder of the adjacent variable frequency diffuser; the exhaust pipe 40 is connected to the first variable frequency diffuser 110, and the outlet of the exhaust main pipe 50 is connected to the second variable frequency diffuser 120.

[0058] The gas discharged from the exhaust pipe 10 of the 1# engine test bench and the gas outlet 225 of the activated carbon box 221 enters from the end face of the open end of the variable frequency diffuser cylinder, is guided by the variable frequency diffuser guide cone, and is discharged from a number of variable frequency diffuser outlet holes. The gas entering the variable frequency diffuser cylinder is guided by setting a conical variable frequency diffuser guide cone, so that the gas entering the variable frequency diffuser cylinder is evenly discharged from a number of variable frequency diffuser outlet holes, which is convenient for subsequent silencing and improves the silencing effect.

[0059] Preferably, the first variable frequency diffuser 110 and the second variable frequency diffuser 120 have the same structure. Further preferably, the first variable frequency diffuser 110 and the second variable frequency diffuser 120 are arranged in parallel.

[0060] The first variable frequency diffuser 110 includes a first variable frequency diffuser cylinder 111 and a first variable frequency diffuser guide cone 113. The first variable frequency diffuser cylinder 111 is a hollow circular cylinder. A plurality of first variable frequency diffuser air outlet holes 112 for exhausting gas are arranged on the surface of the cylinder. The plurality of first variable frequency diffuser air outlet holes 112 are all through holes penetrating the circular cylinder. The first variable frequency diffuser guide cone 113 is a cone. The conical surface of the first variable frequency diffuser guide cone 113 is arranged inside the circular cylinder. The outer diameter of the bottom of the first variable frequency diffuser guide cone 113 is the same as the inner diameter of the circular cylinder. The outer diameter of the bottom of the first variable frequency diffuser guide cone 113 is fixedly connected to one end face of the circular cylinder to close one end of the first variable frequency diffuser cylinder 111.

[0061] The second variable frequency diffuser 120 includes a second variable frequency diffuser cylinder 121 and a second variable frequency diffuser guide cone 123. The second variable frequency diffuser cylinder 121 is a hollow circular cylinder. A plurality of second variable frequency diffuser air outlet holes 122 for exhausting gas are arranged on the surface of the cylinder. The plurality of second variable frequency diffuser air outlet holes 122 are all through holes penetrating the circular cylinder. The second variable frequency diffuser guide cone 123 is a cone. The conical surface of the second variable frequency diffuser guide cone 123 is arranged inside the circular cylinder. The outer diameter of the bottom of the second variable frequency diffuser guide cone 123 is the same as the inner diameter of the circular cylinder. The outer diameter of the bottom of the second variable frequency diffuser guide cone 123 is fixedly connected to one end face of the circular cylinder to close one end of the second variable frequency diffuser cylinder 121.

[0062] In the radial cross-section of the first variable frequency diffuser 110 and the second variable frequency diffuser 120, the cross-section of the first variable frequency diffuser cylinder 111 is a first circle, which is defined as the first circle here, and the cross-section of the second variable frequency diffuser cylinder 121 is a second circle, which is defined as the second circle here. A first tangent line L of the first variable frequency diffuser tangent to the second circle is drawn from the center O1 of the first circle to the second circle. 21 and the second tangent line L of the first variable frequency diffuser 22 , the first tangent line L of the first variable frequency diffuser 21 and the second tangent line L of the first variable frequency diffuser 22 The angle between the first variable frequency diffuser and the first variable frequency diffuser is the first variable frequency diffuser cutting angle θ1. The first variable frequency diffuser cutting angle θ1 corresponds to the portion S1 on the first variable frequency diffuser cylinder 111 without the first variable frequency diffuser outlet hole 112. Correspondingly, the second variable frequency diffuser first tangent L tangent to the first circle is drawn from the center O2 of the second circle to the first circle. 11 and the second tangent line L of the second variable frequency diffuser 12 , the first tangent line L of the second variable frequency diffuser 11and the second tangent line L of the second variable frequency diffuser 12 The angle between the first variable frequency diffuser and the second variable frequency diffuser is the second variable frequency diffuser cutting angle θ2, and the portion S2 on the second variable frequency diffuser cylinder 121 corresponding to the second variable frequency diffuser cutting angle θ2 does not have the second variable frequency diffuser air outlet 122. Therefore, the gas discharged from the first variable frequency diffuser air outlet 112 of the first variable frequency diffuser 110 will not impact the second variable frequency diffuser cylinder 121, and similarly, the gas discharged from the second variable frequency diffuser air outlet 122 of the second variable frequency diffuser 120 will not impact the first variable frequency diffuser cylinder 111, even if a small part of the gas discharged from the first variable frequency diffuser air outlet 112 of the first variable frequency diffuser 110 and the gas discharged from the second variable frequency diffuser air outlet 122 of the second variable frequency diffuser 120 collide, the collision will not generate secondary noise pollution.

[0063] Preferably, the aperture ratio of the variable frequency diffuser outlet holes of each variable frequency diffuser is 30%-65%. By increasing the aperture ratio of the variable frequency diffuser outlet holes of each variable frequency diffuser, the air flow velocity through the variable frequency diffuser outlet holes is reduced. Since the noise of the flowing gas decreases as the flow velocity of the flowing gas decreases, the original noise level of the air flow in the silencer tower is reduced, and the difficulty of silencing is reduced.

[0064] Preferably, in each variable frequency diffuser, the sum of the areas of the variable frequency diffuser outlet holes is greater than the cross-sectional area of ​​the variable frequency diffuser cylinder. Further preferably, in each variable frequency diffuser, the sum of the areas of the variable frequency diffuser outlet holes is at least 1.1 times the cross-sectional area of ​​the variable frequency diffuser cylinder. By increasing the sum of the areas of the variable frequency diffuser outlet holes of each variable frequency diffuser, the air flow velocity through the variable frequency diffuser outlet holes is reduced. Since the noise of the flowing gas decreases as the flow velocity of the flowing gas decreases, the original noise level of the air flow in the silencer tower is reduced, and the difficulty of silencing is reduced.

[0065] Preferably, a plurality of variable frequency diffusers are arranged in parallel.

[0066] Preferably, the tower body 130 is a reinforced concrete structure or a steel frame structure.

[0067] The silencer assembly, the installation method of the silencer assembly and the connection method with the tower body, and the connection method between the variable frequency diffuser and the tower body in this application are prior arts, and for details, please refer to the applicant's prior applications CN201420056662.6, CN201420056663.0, and CN201420057351.1.

[0068] The working process of the multi-station engine test bench exhaust device of the present invention is as follows:

[0069] The excess gas from the gas source enters the muffler 100 through the exhaust pipe, and the gas from the auxiliary pipes of the 1# engine test bench and the 2# engine test bench respectively passes through the 1# engine test bench exhaust pipe 10 and the 2# engine test bench auxiliary exhaust pipe 30 and then merges into the exhaust main pipe 50 and enters the muffler;

[0070] The gas discharged from the main exhaust pipe 20 of the 2# engine test bench enters the shell of the demister 210 through the air inlet 213, and the airflow enters the baffle demister 211 at a flow rate of 3m / s-6m / s. The baffle demister 211 divides the airflow into many single-stream flow channels through the baffle plate 2111. After changing the direction of the airflow, the oil droplets collide with the baffle plate 2111 through inertia, and the oil droplet film moves forward to the barb and is separated. After the 20um-50um oil droplets entrained in the airflow are removed, it enters the silk screen. The net demister 212 separates the oil droplets and liquid droplets of 5um-20um; however, the combined demister of the baffle demister 211 and the wire mesh demister 212 in the demister 210 has not yet effectively removed the oil droplets below 5um, so the gas outlet of the demister 210 is connected to the activated carbon adsorption device 220 through a pipeline, and the gas discharged from the gas outlet of the demister 210 adsorbs the organic waste gas through the fine pores of the activated carbon, so that the gas emission meets the emission standard and then flows into the exhaust main pipeline 50 to enter the silencer;

[0071] The gas discharged from the venting pipeline 40 and the main exhaust pipeline 50 enters through the end face of one end of the variable frequency diffuser cylinder opening through the pipeline, is guided by the guide cone of the variable frequency diffuser, and is discharged from a number of variable frequency diffuser outlets. The airflow passes through the dry variable frequency diffuser outlet to shift the noise frequency to high frequency, and the difficulty of noise control is reduced by using the principle that high frequency is easier to control than low frequency. The gas discharged from the outlets of the several variable frequency diffusers is silenced and noise-reduced through the staggered airflow channels composed of three layers of silencer plate components, and then is discharged from the outlet on the top of the tower body.

[0072] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0073] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A multi-station engine test bench exhaust device, characterized in that: It includes the exhaust pipeline of the 1# engine test bench, the main exhaust pipeline of the 2# engine test bench, the auxiliary exhaust pipeline of the 2# engine test bench, the venting pipeline, the main exhaust pipeline, the horizontal oil-gas separation device and the silencer; The two ends of the horizontal oil-gas separation device are connected to the main exhaust pipeline outlet and the exhaust main pipeline inlet of the 2# engine test bench respectively; the exhaust pipeline of the 1# engine test bench and the auxiliary exhaust pipeline of the 2# engine test bench are arranged in parallel and are both connected to the exhaust main pipeline inlet; the exhaust main pipeline outlet is connected to the silencer; the venting pipeline is connected to the silencer; The horizontal oil-gas separation device includes a demister and an activated carbon adsorption device; the gas outlet of the demister is connected to the air inlet of the activated carbon adsorption device; along the flow direction of the oil-gas mixture, the demister includes a horizontally arranged shell consisting of an expansion section, an equal straight section and a convergent section connected in sequence; an air inlet is arranged at one end of the expansion section, and the air inlet is connected to the outlet of the main exhaust pipeline of the 2# engine test bench; along the flow direction of the oil-gas mixture, the equal straight section is sequentially provided with a baffle demister and a wire mesh demister; a first spray flushing device is arranged on the side wall of the expansion section, and a second spray flushing device is arranged on the side wall of the equal straight section between the baffle demister and the wire mesh demister; a first liquid discharge port and a second liquid discharge port are respectively arranged at the bottom of the baffle demister and the wire mesh demister; The activated carbon adsorption device comprises an activated carbon box body arranged horizontally; along the flow direction of the gas discharged from the gas outlet of the defoamer, a vertical activated carbon adsorption box and a horizontal activated carbon adsorption box are arranged in sequence in the activated carbon box body, and a gas outlet is arranged in the activated carbon box body, and the gas outlet of the activated carbon box body is connected to the silencer device through a pipeline; at the same time, a third liquid discharge port is arranged at the bottom of the activated carbon box body; The silencer device includes a tower body, a silencer sheet assembly and two variable frequency diffusers, each variable frequency diffuser having the same structure; Each variable frequency diffuser includes a variable frequency diffuser cylinder and a variable frequency diffuser guide cone. The variable frequency diffuser cylinder is a hollow circular cylinder, and a plurality of variable frequency diffuser air outlet holes are arranged on the surface of the cylinder. The plurality of variable frequency diffuser air outlet holes are through holes penetrating the circular cylinder. The variable frequency diffuser guide cone is a cone-shaped, and the conical surface of the variable frequency diffuser guide cone is arranged inside the circular cylinder. The outer circle of the bottom of the variable frequency diffuser guide cone is fixedly connected to one end surface of the circular cylinder. In each variable frequency diffuser, the projection of the variable frequency diffuser outlet along its own axis direction is not on the variable frequency diffuser cylinder of the adjacent variable frequency diffuser; The outlet of the exhaust main line is connected to the silencer; the vent line is connected to the silencer; the vent line is connected to a variable frequency diffuser, and the outlet of the exhaust main line is connected to another variable frequency diffuser; The first spray flushing device and the second spray flushing device are both provided with two groups of spray heads.

2. The device according to claim 1, characterized in that The baffle demister comprises a baffle sheet and a barb, wherein the barb is arranged at a bending position of the baffle sheet.

3. The device according to claim 2, characterized in that The baffle demister includes a plurality of baffle plates.

4. The device according to claim 1, characterized in that: The opening rate of the variable frequency diffuser air outlet of each variable frequency diffuser is 30%-65%.

5. The device according to claim 1, characterized in that: In each variable frequency diffuser, the sum of the areas of the air outlet holes of the variable frequency diffuser is greater than the cross-sectional area of ​​the barrel of the variable frequency diffuser.

6. The device according to claim 5, characterized in that: In each variable frequency diffuser, the sum of the areas of the air outlet holes of the variable frequency diffuser is at least 1.1 times the cross-sectional area of ​​the barrel of the variable frequency diffuser.

7. The device according to claim 1, characterized in that: Multiple variable frequency diffusers are arranged in parallel.

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