KR20110054613A - Jet fan for tunnels - Google Patents

Abstract

PURPOSE: A jet fan for tunnels is provided to increase a classifying speed at low cost since a flow diffuser and a muffler are coupled by one of welding, screwing and forcible fitting. CONSTITUTION: A jet fan for tunnels comprises a motor, an impeller, a noise chamber(5), and a flow diffuser(8). The motor is accepted in a case(1). The impeller is connected to the motor. The noise chamber is extended to the case. The flow diffuser is formed in a cylinder shape and is coupled to the end of the noise chamber. The upper part of the flow diffuser is extended to be relatively longer than its lower part, the upper part of the flow diffuser slopes downwardly toward the horizontal axis of the case, and the lower part of the flow diffuser is parallel to the horizontal axis.

Description

 Jet fan for tunnels}

The present invention relates to a jet fan that discharges high-temperature flames, smoke, toxic gases, etc., in the event of fire and fire contaminated with dust, moisture, and automobile exhaust gas inside a tunnel. It relates to a jet fan for a tunnel that can increase the speed.

In general tunnels, only the inlet and outlet are open, so that the longer the tunnel length, the more natural circulation phenomenon that the air inside the tunnel is replaced by the outside air does not occur.

Accordingly, the tunnel is forced through a separate ventilation system to secure the breathing and visibility of drivers and passers-by by polluted air such as exhaust gas, dust, and moisture generated from various automobiles or railway vehicles running inside the tunnel. It must be discharged to the outside.

In particular, in case of a fire due to a traffic accident such as a collision or collision between cars in the tunnel, fresh air from outside is protected to protect people in the tunnel from hot flames and smoke and to secure an escape route. A flue gas plant is introduced that can be used in combination with the above-described ventilation system to inflow and to quickly discharge flames and smoke in the tunnel.

Until now, a method of forcibly circulating air in the tunnel with external air by installing jet fans fixedly on the ceiling surface of the tunnel having an arched or rectangular structure has been mainly applied. In addition, when the length of the tunnel is long, the jet fan is installed at a predetermined distance to blow the polluted air and dust inside the tunnel step by step to exhaust to the outside.

In recent years, there has been an increased demand for increased thrust and increased ventilation in tunnels due to increased traffic or increased power consumption in tunnels.

An example of such a jet fan is disclosed as follows.

Republic of Korea Patent No. 0850345, as shown in Figure 1, in the jet fan for the tunnel, the impeller (30) capable of converting the angle of the three aluminum alloy casting braid is assembled as a holder on the inner surface of the hub made of stainless steel, Forged steel or cast steel boss directly connected the rotating shaft of the motor unit 20, the silencer 60, the support 70 and the hub and the motor unit 20 for driving the impeller 30 forward or reverse rotation ( 50), wherein the braid has an assembling portion formed at one side, and a trapezoidal wing portion which is gradually widened in the other direction is formed, and the cross-sectional shape of both sides of the wing portion is one side with respect to the central axis bisecting in the longitudinal direction. The upper end of the tunnel is formed convexly than the lower portion, the other end of the lower end is formed protrudingly convex than the upper tunnel, characterized in that to increase the average velocity The jet fan is started.

In addition, the Republic of Korea Patent Publication No. 1997-0021784 is a jet fan comprising a case, an electric motor housed in the case and an impeller connected to the electric motor, located downstream of the case with respect to the air flow direction and is installed coaxially with the case A jet fan with at least one booster is disclosed. The booster ring is fixed to be coaxial to the cylindrical rear silencer by a plurality of radial ribs.

In particular, in the Republic of Korea Patent Publication No. 1997-0021784, the booster has an arcuate or airfoil cross-sectional profile when viewed in a direction transverse to the longitudinal axis of the casing. The booster also has an upper surface of an arcuate or airfoil profile as the inner surface and also has a trailing edge of a diameter smaller than the diameter of the base but larger than the diameter of the air outlet and a base facing the air outlet.

The structure then generates a lift and drag in the booster by using air flow from the ambient air drawn into the high speed jet. The combined force of lift and drag is opposite to the jet direction and has an axial component that generates thrust in the booster. It is possible to increase the air pressure inside the tunnel as compared to a conventional jet fan in which the jet does not have boosting in its direction.

In other words, because the jet is boosted in the direction of the jet due to the reaction of the thrust generated in the booster ring, the installation of the booster can increase the air pressure in the tunnel because the jet fan has improved thrust and higher efficiency.

However, such a jet fan is installed to be fixed to the ceiling surface of the tunnel, as well as to increase the cost of installing the booster, so that the air flow direction of the jet fan is directed in a straight line. The jet fan takes a long time to exhaust the entire air inside the tunnel to the outside, there is a problem that the ventilation efficiency is lowered.

Therefore, there is a need for a highly efficient jet fan capable of increasing the jet fan's jet velocity without increasing the operating power of the jet fan under the same conditions such as the jet area. That is, in the prior art as described above, since the air flow direction is in a straight line as shown in Fig. 2, there is a problem that an effective air exhausting effect is not achieved by background speed loss and wall friction loss.

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems as described above, and to provide a jet fan for a tunnel in which the fractionation speed is increased by adding a means for adjusting the speed and direction of the intake and exhaust air.

Another object of the present invention is to provide a jet fan for a tunnel that can control the direction of the air sucked and discharged in a cheap and simple way to the existing jet fan.

In order to achieve the above object, a jet fan for a tunnel according to the present invention comprises a case, a motor accommodated in the case, an impeller connected to the motor, a noise chamber and a cylinder extending to the case, and coupled to an end of the noise chamber. It characterized in that it comprises a flow diffuser.

In the tunnel jet fan according to the present invention, the flow diffuser has an upper portion extending relatively longer than the lower portion when viewed from the side, the upper portion is inclined downward with respect to the horizontal axis of the case, the lower portion is Characterized in that parallel to the horizontal axis.

In the tunnel jet fan according to the present invention, the upper part of the flow diffuser is inclined downward by 4 to 15 degrees with respect to the horizontal axis of the case.

In the tunnel jet fan according to the present invention, the upper portion of the flow diffuser is inclined 5 ° downward with respect to the horizontal axis of the case.

In the tunnel jet fan according to the present invention, the noise chamber is composed of a suction noise chamber and an exhaust noise chamber, and the flow diffuser is coupled to the suction noise chamber and / or the discharge noise chamber.

In the tunnel jet fan according to the present invention, the flow diffuser and the silencer may be coupled to each other by welding, screwing, or interference fitting.

In the tunnel jet fan according to the present invention, the flow diffuser and the noise chamber are made of the same material.

As described above, according to the tunnel jet fan according to the present invention, when the flow diffuser is viewed from the side as described above, the upper portion extends relatively longer than the lower portion, and the upper portion is inclined downward with respect to the axis of the case. With its shape, the linear air discharged by the impeller hits the upper inclined downward of the flow diffuser and is discharged downward while decreasing the speed, thereby increasing the fractionation speed while minimizing the loss under the same commercial power. The effect can be obtained.

In addition, according to the tunnel jet fan according to the present invention, in the structure of the pre-installed jet fan, by combining the flow diffuser and the silencer by any one of welding, screwing, and interference fitting, the fractionation speed is relatively low. The effect of increasing is obtained.

These and other objects and novel features of the present invention will become more apparent from the description of the present specification and the accompanying drawings.

First, the concept of the present invention will be described.

Typically, three hypotheses apply to the efficiency of tunnel jet fans. One of them is the Wall effect or Kempt principle, since the discharged jets come into contact with the ceiling within a few meters of the rear of the fan. will be.

Another is the Coanda effect, which has the property of flowing close to the surface as the fluid flows along the curved surface. The Coanda effect thus accounts for a phenomenon in which jets "stick" to the ceiling or wall, where airflow flows slowly along the periphery of the tunnel, resulting in less frictional losses.

The final hypothesis concerns background velocity correction. In other words, the background speed reduces the effective increase of the airflow speed and thus brings about a loss of thrust. If the airflow speed below the ceiling is low, the correction for thrust is minimal.

The present invention is to provide a structure that can increase the flow rate while lowering the speed of the air flow by a separate flow diffuser (flow diffuser) so as to reduce the loss caused by the above hypothesis.

EMBODIMENT OF THE INVENTION Hereinafter, the structure of this invention is demonstrated according to drawing.

In addition, in description of this invention, the same code | symbol is attached | subjected to the same part and the repeated description is abbreviate | omitted.

Figure 3 is a side exterior perspective view showing a jet fan for the tunnel according to the invention, Figure 3 is a side sectional view showing a jet fan for the tunnel according to the invention, Figure 5 is a tunnel according to the invention shown in Figure 3 It is sectional drawing which cut the jet fan along A-A ', and FIG. 6 is a figure which shows the velocity distribution of the air volume which concerns on this invention.

One embodiment of the tunnel jet fan according to the present invention, the case 1, the motor 3 accommodated in the case 1, the motor support 4 for supporting the motor, the impeller connected to the motor ( 2) to reduce the noise caused by the intake and exhaust air due to the operation of the motor (3) and the internal silencer (6), the motor (3) and the impeller (2) mounted on the motor (3) to reduce the noise caused by the rotational force of the motor It is made of a configuration comprising a pair of flow diffusers (8, 18) made of a noise chamber (5, 15) and a cylindrical and extending to the case (1) coupled to the end of the silencer.

The flow diffuser 8, 18 extends relatively longer than the bottom when viewed from the side, and the top is inclined downward with respect to the horizontal axis H of the case, as shown in FIG. 3. The lower portion is made parallel to the horizontal axis.

The silencer consists of a suction silencer 5 and a discharge silencer 15, and the pair of flow diffusers 8, 18 are coupled to the suction silencer 5 and the discharge silencer 15. . However, the present invention is not limited thereto, and may be provided in either the suction silencer 5 or the discharge silencer 15, and when only one flow diffuser is provided, wall friction due to a coanda effect upon discharge. In consideration of the loss, it is preferable to provide on the discharge noise chamber 15 side. Meanwhile, the suction silencer 5 and the discharge silencer 15 may be an air inlet or an air outlet according to the forward or reverse rotation of the motor 3 and the impeller 2. It is not limited. The inner diameter of the air inlet or the air outlet of the jet fan according to the present invention is 1,030mm.

A plurality of anti-shake eye bolts 7 are disposed on the outer surface of the case 1, and a turnbuckle (not shown) connected to a plurality of anchors installed on the ceiling surface of the tunnel is connected to the plurality of eye bolts 7. I support it.

As shown in FIG. 5, a terminal box 10 is installed on an outer surface of the case 1, and electricity is supplied to the motor 3 from the outside through the terminal box 10. The motor 3 is supported by the motor support 4.

The motor 3 is a double squirrel-shaped three-phase induction motor having an output of 30 kW, and a stainless steel lead pipe 11 is installed between the motor 3 and the case 1 and connected through the terminal box 10. The lead wires are routed so that they do not come into direct contact with the fluid.

Sound chambers 5 and 15 are coupled to the case, and a pair of internal silencers 6 are disposed at the front and rear ends of the impeller 2. The pair of internal silencers 6 are gradually narrowed in the opposite direction of the impeller 2 so that the suction air flows smoothly into the impeller 2 side, and the side facing the impeller 2 is formed in a wide conical shape. do.

A safety plate 9 is provided between the case 1 and the noise chamber 5.

The flow diffuser 8 is coupled to the end of the silencer 5 in the direction in which air flows, and when viewed from the side, the upper part extends relatively longer than the lower part, and the upper part has a horizontal axis ( It is inclined downward with respect to H).

In addition, the coupling of the flow diffusers 8 and 18 and the noise chambers 5 and 15 is performed by the screw coupling portion 80 as shown in FIG. However, the combination of the flow diffusers 8 and 18 and the noise chambers 5 and 15 is not limited to the above embodiment but may be performed by either welding or interference fitting. In addition, when the flow diffusers 8 and 18 and the noise chambers 5 and 15 are joined by welding, the flow diffuser may be formed of the same material as the noise chamber.

As the flow diffuser 8 of the jet fan for tunnel according to the present invention has the shape as described above, the linear air discharged by the impeller 2 is inclined downward of the flow diffuser 8. It hits and discharges downward as the speed decreases. Therefore, the jets thus modified could increase the jet fan's fractionation speed while minimizing the losses caused by the three hypotheses mentioned above.

In particular, when the top slope of the flow diffuser 8 is set to 4 to 15 ° downward, preferably 5 ° downward, as a velocity distribution as shown in FIG. 6, a tunnel jet fan having an internal diameter of 1,030 mm. It was confirmed that the fractional air volume of was 28.6 m 3 / sec.

That is, according to the present invention as a result of comparing the loss between the jet fan equipped with the flow diffuser 8 and the conventional jet fan, the difference shown in the following table was found.

<Table>

Conventional jet fan Jet fan according to the present invention Friction loss due to Coanda effect 20-30% 15-30% Background speed loss 8-20% 3-15% Wall friction loss 5-30% 0-3%

Therefore, the jet fan according to the present invention was determined to generate 20 to 35% more thrust than the conventional jet fan. This reduces power loss by 20-35% to drive the motor and reduces noise.

As mentioned above, although the invention made by this inventor was demonstrated concretely according to the said Example, this invention is not limited to the said Example and can be variously changed in the range which does not deviate from the summary.

The invention applies to a jet fan for tunnels.

1 is a cross-sectional view showing a conventional jet fan for the tunnel.

2 is a view showing a speed distribution of a conventional jet fan for tunnels.

3 is a side exterior perspective view of a tunnel jet fan according to the present invention;

Figure 3 is a side cross-sectional view showing a jet fan for the tunnel according to the present invention,

5 is a cross-sectional view taken along the line AA ′ of the tunnel jet fan according to the present invention shown in FIG. 3;

6 is a view showing a speed distribution of the air volume according to the present invention.

Claims (7)

case, A motor housed in the case, An impeller connected to the motor, A noise chamber extending to the case; A cylindrical jet fan, characterized in that it comprises a flow diffuser coupled to the end of the silencer. The method of claim 1, The flow diffuser has an upper portion extending relatively longer than the lower side when viewed from the side, the upper portion is inclined downward with respect to the horizontal axis of the case, the lower portion is a jet for the tunnel, characterized in that made in parallel with the horizontal axis Pan. The method of claim 2, The upper portion of the flow diffuser is a jet fan for the tunnel, characterized in that the inclined 4 to 15 ° downward with respect to the horizontal axis of the case. The method of claim 3, An upper portion of the flow diffuser is inclined downward by 5 ° with respect to the horizontal axis of the case. The method according to any one of claims 1 to 4, The noise chamber is composed of a suction noise chamber and an exhaust noise chamber, The flow diffuser is coupled to the suction silencer and / or the discharge silencer. The method of claim 5, The coupling of the flow diffuser and the silencer is performed by any one of welding, screwing and interference fitting. The method of claim 6, The flow diffuser and the silencer jet fan, characterized in that made of the same material.

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