CN103775173B - A kind of engine exhaust cooling device - Google Patents

Abstract

The invention discloses an engine exhaust cooling device. The device includes an expansion chamber, a split flow chamber, and a rear expansion chamber connected in sequence. The trachea is connected upstream, and the rear end tube of the expansion chamber is a tapered expansion tube, which is connected to the diversion chamber. The sheet is tightly connected with the ejector tube. The cooling effect of the present invention is obvious, and the negative pressure generated by the device can suck a large amount of air into the exhaust gas, thereby greatly reducing the exhaust temperature; the application range is wide, and the device can mix normal-temperature air in the atmosphere as a cooling medium into the exhaust gas without Water or other cooling medium is required, which greatly expands the scope of application of the device; there is no negative effect, and the exhaust resistance generated by the device is reduced through diversion measures in the design, thus avoiding the impact on engine performance.

Description

Engine exhaust cooling device

technical field

The invention belongs to the technical field of exhaust cooling equipment, in particular to an engine exhaust cooling device.

Background technique

If the exhaust temperature of the engine is too high and the temperature difference between the engine and the surrounding environment is too large, it is easy to show obvious infrared features, which is conducive to the detection and locking of military targets by infrared detection devices. Therefore, engines for military use need to reduce the exhaust temperature for concealment considerations.

With the application of diesel particulate filter technology, the high-temperature exhaust during the regeneration of the particulate filter not only easily reduces the concealment of the engine, but also brings safety hazards to the surrounding environment, especially in flammable places. Foreign studies have been carried out on the cooling of the exhaust gas during the regeneration of the particulate filter. At present, domestic research on engine exhaust temperature cooling mainly focuses on marine diesel engines. Since marine diesel engines are easy to obtain cooling water, cooling water heat exchangers, water injection, vaporization and heat absorption are generally used for exhaust cooling, and the devices are relatively complicated. In addition, some studies have used the method of spraying water in the vehicle muffler to reduce the exhaust temperature. However, it is difficult to apply this method because ordinary vehicles have difficulty in obtaining water, and the generated steam condenses in the atmosphere and easily produces fog, which further exposes the target.

At present, the application range of exhaust cooling devices for marine engines and vehicle engines has certain limitations, and domestic research on general-purpose exhaust cooling technology for vehicles, construction machinery, and power generation engines is still in a blank stage.

Contents of the invention

The object of the present invention is to provide an engine exhaust cooling device to solve the defects of narrow application range, complex system structure and negative effects in the prior art.

In order to realize the purpose of the present invention, the present invention provides a kind of engine exhaust cooling device, and described device comprises expansion chamber, diversion chamber, post-expansion chamber connected successively, and the diameter of the front pipe of described expansion chamber is the same as that of engine exhaust pipe. , and connected to the upstream of the exhaust pipe of the engine, the rear end pipe of the expansion chamber is a tapered expansion pipe, and connected to the distribution chamber, the rear end of the distribution chamber is wavy, with the same number of convex and concave surfaces The shunts are arranged alternately, the splitters are closely connected with ejector tubes, the shape of the structure formed by the splitters and the ejector tubes is consistent with the inner shape of the shunt chamber, and they are fixedly connected to the shunt chamber. The concave surface cooperates to guide the exhaust gas to flow into the ejector tube. The ejector tube includes a plurality of tapered shrink tubes, and the inner side of the concave surface is connected with a tapered shrink tube. A tapered shrink tube, the rear expansion chamber is composed of a circular sleeve, its front end is fixedly connected to the rear of the distribution chamber, its rear end is fixedly connected to the downstream of the exhaust pipe, and the concave surface of the distribution chamber is outside It communicates with the post-expansion chamber.

Wherein, there are 4 convex surfaces and 4 concave surfaces; the ejector tube includes 5 tapered shrink tubes, of which 4 tapered shrink tubes are arranged on the 4 convex surfaces.

Wherein, the diversion chamber and the rear expansion chamber are fixedly connected by flanges and bolts, the expansion chamber and the diversion chamber are fixed by welding, and the expansion chamber is fixedly connected with the upstream of the engine exhaust pipe by a flange .

Compared with the traditional technology, the present invention has the following beneficial effects: the cooling effect is obvious, and the negative pressure generated by the device can suck and exhaust a large amount of air, thereby greatly reducing the exhaust temperature; the device has a simple structure, and the device is constructed through a spatial structure, namely It can realize the cooling function without designing sensing and actuators. It has a simple structure and can be integrated with the exhaust pipeline for easy installation. It has a wide range of applications, and the device can mix normal-temperature air in the atmosphere as a cooling medium into the exhaust. , without the need of water or other cooling media, greatly expanding the scope of application of the device; no negative effects, through the diversion measures in the design, the exhaust resistance generated by the device is reduced, thereby avoiding the impact on engine performance.

Description of drawings

Fig. 1 is a structural representation of the present invention;

Fig. 2 is the schematic structural view of the shunt chamber provided by the present invention;

Fig. 3 is the schematic structural view of the injection pipe and the shunt provided by the present invention;

Fig. 4 is the device connection schematic diagram utilizing the present invention to do experiment;

Fig. 5 is the test data that utilizes the present invention to do experiment and obtain;

In the figure, 1-expansion chamber, 2-splitter chamber, 3-injection tube, 4-flange, 5-bolt, 6-rear expansion chamber, 7-convex surface, 8-concave surface, 9-splitter.

detailed description

In order to make the purpose, technical solutions and beneficial effects of the present invention more clear, the present invention will be further described in detail below in conjunction with the examples. It should be understood that the specific embodiments described here are only used to explain the present invention, and are not intended to limit the protection scope of the present invention.

As shown in Fig. 1, Fig. 2, Fig. 3, a kind of engine exhaust cooling device provided by the present invention, said device comprises expansion chamber, diversion chamber, post-expansion chamber connected in sequence, and the diameter of the front end pipe of said expansion chamber is the same as that of the engine. The exhaust pipes have the same diameter and are connected to the upstream of the exhaust pipe of the engine. The rear end pipe of the expansion chamber is a tapered expansion pipe and is connected to the distribution chamber. A number of convex surfaces and concave surfaces are formed alternately in sequence, and the diverter is closely connected with an ejector tube, and the shape of the structure formed by the diverter and the ejector tube is consistent with the inner shape of the diverter chamber, and is fixedly connected to the diverter chamber, The diverter piece cooperates with the concave surface to guide the exhaust gas to flow into the ejector pipe, and the ejector pipe includes a plurality of conical shrinkage pipes, and the inner side of the concave surface is connected with tapered shrinkage pipes, wherein the diverter There is a tapered tube in the center of the sheet, the rear expansion chamber is composed of a circular sleeve, its front end is fixedly connected to the rear part of the distribution chamber, and its rear end is fixedly connected to the downstream of the exhaust pipe. The concave outside of the diversion chamber communicates with the rear expansion chamber.

The main feature of the present invention is that through the expansion and contraction of the exhaust gas, a pressure lower than the atmospheric pressure is generated, so that the air in the environment is mixed into the engine exhaust pipe, mixed with the engine exhaust gas, and the exhaust gas temperature is reduced. The invention utilizes the Venturi effect, through the combination of multiple throats and drainage devices, increases the contact area between the high-temperature exhaust and the inhaled ambient air, realizes the rapid mixing of ambient air and high-temperature exhaust, and reduces exhaust temperature without significantly increasing exhaust resistance.

The diameter of the front part of the expansion chamber is the same as that of the exhaust pipe, and then the tapered expansion pipe is connected to form an expansion chamber, whose function is to reduce the exhaust flow rate. The said diversion chamber is connected to the rear of the expansion chamber, and the rear of the diversion chamber is wavy, consisting of a plurality of convex surfaces and equal concave surfaces in sequence, wherein the convex surface is used to guide the exhaust gas to flow into the ejector pipe, and the concave surface is used to guide the environment The air in the air flows into the cooling device; there is also a shunt plate arranged in the shunt chamber, which cooperates with the concave surface to guide the exhaust gas to flow into the ejector pipe. The ejector tube is connected to the rear of the diversion chamber and is composed of multiple tapered shrink tubes. Its main function is to increase the exhaust flow rate, thereby forming a low pressure, and increasing the contact area between the high-temperature gas and the inhaled ambient air. The rear expansion chamber is connected to the ejector pipe and the rear part of the diversion chamber, and is composed of a circular sleeve, which is used to reduce the exhaust flow rate again, and to mix the air entering through the concave surface of the diversion chamber with the exhaust gas.

In a specific embodiment of the present invention, the rear part of the diversion chamber is wavy, and can be composed of four convex surfaces and four concave surfaces alternately in sequence, and a diverter plate is arranged in the diversion chamber, which cooperates with the concave surface to guide the exhaust gas to flow into the ejector pipe . The ejector tube is connected to the rear of the splitter chamber and consists of 5 tapered shrink tubes, of which 4 taper tubes are arranged on the 4 convex surfaces, and the other 1 taper tube is arranged at the center of the splitter. The rear expansion chamber is connected to the ejector pipe and the rear part of the distribution chamber, and is composed of a circular sleeve, the rear end of which is connected to the downstream of the exhaust pipe.

Working principle: When the exhaust gas of the engine flows into the expansion chamber through the exhaust pipe, the flow rate decreases due to the increase of the flow area. Under the guidance of the splitter, the exhaust gas enters the pipeline with gradually shrinking flow area. At this time, the flow velocity increases rapidly, and directly flows into the rear expansion chamber at the outlet. The flow area increases sharply again, and the flow velocity decreases greatly. According to Bernoulli's equation, a pressure difference is formed between the outlet of the pipeline and the inlet, and the pressure at the outlet is lower than that at the inlet. Under the action of low pressure, the air in the environment is guided into the exhaust pipe through the concave outside of the splitter chamber, and mixed with the engine exhaust at the rear expansion chamber, the temperature of the exhaust gas is lowered, and then they are discharged from the engine together with the exhaust pipe.

The key point of the present invention is to use the design structure of the device to reduce the exhaust resistance of the device while inhaling more air, and solve the contradiction between the exhaust resistance and the amount of inhaled air. The multi-injection tube structure is adopted to divide the high-temperature gas into multiple channels, which increases the contact area between the high-temperature gas and the inhaled air, and effectively solves the problem of uneven mixing.

Utilize the present invention to do following experiment: Experimental result proves the beneficial effect of this invention.

The performance bench test of the device was carried out on the Sinotruk WD615.96 engine, and the basic parameters of the test engine are shown in Table 1.

Table 1 The main technical parameters of the test engine

engine model WD615.96 Bore x stroke mm x mm 126×130 Total engine displacement L 9.726 Rated power/speed kW/r/min 276/2200 Maximum torque/speed N.m/r/min 1500 1100～1600 compression ratio 17.5

Figure 4 is a connection diagram of the test device. In the test, due to the removal of the influence of the heat conduction of the exhaust pipe on the test results, an insulation layer was added to the test pipeline, and the device was placed in a windless environment. Therefore, the cooling effect in practical application will be better than the cooling effect obtained in the test results. The test conditions are shown in Table 2.

Table 2 List of test conditions

Numbering Rotating speed torque Condition 1 1400 431 Condition 2 1600 540 Condition 3 1800 541 Condition 4 2000 577 Condition 5 2200 623

Figure 5 is the test data obtained in the test. In the 5 operating points mentioned in the figure, the temperature at the outlet of the exhaust cooling device drops significantly compared with the inlet, and as the outlet moves backward, the temperature drops slightly, which is further mixed with the exhaust and air. related. Under the conditions mentioned in the figure, the exhaust gas temperature can be reduced by 100-220°C.

The above is only a preferred embodiment of the present invention, it should be pointed out that, for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications can also be made. It should be regarded as the protection scope of the present invention.

Claims (3)

1. an engine exhaust cooling device, it is characterized in that, described device comprises the expansion chamber connected successively, diffluence room, rear expansion room, described expansion chamber front tube diameter is identical with engine exhaust pipe diameter, and be connected with described engine exhaust pipe upstream, the tapered expanding duct of described expansion chamber rear end pipe, and be connected with described diffluence room, described diffluence room rear end is wavy, form by the convex surface of equal number is alternate successively with concave surface, splitter compact siro spinning technology has induction tunnel, its profile with the structure that described induction tunnel is formed and described diffluence room interior shape consistent, and be fixedly connected on described diffluence room, described splitter coordinates directing exhaust gas to flow into described induction tunnel with described concave surface, described induction tunnel comprises the branched taper draw, all arrange inside described concave surface and be connected with the taper draw, wherein, described splitter center portion is provided with a taper draw, described rear expansion room is made up of circular sleeve, its front end is fixedly connected on described diffluence room rear portion, its rear end is fixedly connected with described tailpipe downstream, communicate with described rear expansion room outside the concave surface of described diffluence room.

2. engine exhaust cooling device according to claim 1, is characterized in that, described convex surface and concave surface are 4; Described induction tunnel comprises 5 taper draws, and wherein 4 taper draws are arranged at 4 described convex surfaces.

3. engine exhaust cooling device according to claim 2, it is characterized in that, described diffluence room is fixedly connected with bolt by flange with described rear expansion room, described expansion chamber and described diffluence room are by being welded and fixed, and described expansion chamber is fixedly connected with by flange with described engine exhaust pipe upstream.