JPH0749268Y2 - Cooling fan mounting structure for heat exchanger - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION "Industrial field of application" The present invention relates to a structure for mounting a cooling fan for a heat exchanger, and particularly, to prevent the occurrence of an accident due to a large horizontal acceleration.

"Prior Art" For example, among various heat exchangers used in nuclear facilities, the type using a gas such as air as a cooling medium is
In order to improve the heat exchange efficiency, a finned heat transfer tube with fins integrally attached to the surface of the heat transfer tube is used, and cooling air is forcedly sent by a cooling fan to improve heat exchange with the heat transfer tube. Is done.

In this case, since the cooling air causes a difference in specific gravity depending on the temperature, it is necessary to set the flow of the cooling air so that the low temperature air is at the bottom and the high temperature air is at the top. In the heat exchanger that meets the requirements, the heat transfer tubes are installed horizontally, and therefore the flow of the cooling air is set from bottom to top.

Then, in order to increase the heat exchange efficiency with the heat transfer tube, a heat exchange section surrounding the heat transfer tube with a vertical partition is provided, and the cooling air flow is efficiently guided from the cooling fan to the heat exchange section. It is considered effective to have a structure in which the fan hood of the cooling fan is suspended from the vertical partition wall or the like.

[Problems to be solved by the invention] However, if the fan hood of the cooling fan is suspended from above, the support points of the fan hood and the cooling fan are installed in a state of being vertically separated from each other. The vibration system is divided into two parts based on the fact that the points are vertically separated, and when horizontal vibration is applied, the vibration characteristics become complicated, and the cooling fan and the fan hood vibrate apart,
There is a risk of impairing the soundness of the cooling fan, such as damage caused by contact between the blades of the cooling fan and the inner surface of the fan hood.On the other hand, if the gap between the blades of the cooling fan and the inner surface of the fan hood is increased, The efficiency of the cooling fan will be reduced.

The present invention has been made in view of these problems, and i. Improves the mounting strength of the fan hood against large acceleration.

ii. To increase seismic resistance by making the phases of the vibration system the same.

iii Prevent accidents due to large horizontal acceleration.

It is an object.

"Means for Solving the Problem" As a means for solving the problem, a plurality of heat transfer tubes are arranged in parallel with each other at intervals in the left, right, top and bottom, and cooling air is supplied to the heat exchange section below the heat exchange section. The cooling fan driven toward the motor, the motor driving the cooling fan to rotate, and the cooling fan and the speed reducer interposed between the motor are arranged to be supported by a common supporting portion, and the cooling fan is surrounded. Then, a fan hood that sets a flow path of cooling air to the heat exchange section is arranged in a state of being supported by a support section, and both support sections are in a erected state in which horizontal beams are combined and a support frame of the same vibration system. The cooling fan for the heat exchanger has a mounting structure that is mounted on the.

"Operation" When the cooling fan is started, as in the heat exchanger described in the conventional example, low-temperature air is sent to the heat exchange section via the fan hood, and the cooling air comes into contact with the heat transfer tubes. Perform heat exchange to cool.

When the support base vibrates in the horizontal direction due to an earthquake or the like, the support portions of the cooling fan and the fan hood vibrate in the horizontal direction like the support base, and in this case, the same vibration system is obtained. The cooling fan and fan hood that are connected to both support parts vibrate horizontally in the same vibration system.The gap between the cooling fan blades and the inner surface of the fan hood during horizontal vibration is the same support in the same vibration system. By supporting both supporting parts on the pedestal, there is no phase difference in the vibration waveform, and since they are separated by the same distance, the amplitude difference is zero.
Alternatively, it is set to a small range to reduce the occurrence of relative amplitude difference in the gap portion.

[Embodiment] An embodiment of the mounting structure of the cooling fan for the heat exchanger according to the present invention will be described below with reference to FIGS. 1 and 2.

In the figure, reference numeral 1 is a support stand in which a plurality of horizontal beams are combined in a grid pattern, 2 is a cooling fan, 3 is a fan driving motor, 4 is a speed reducer, 5 is blades, 6 is a fan hood, 7 is a support portion (common bed) for the motor 3 and the speed reducer 4, 8 is a support portion for the fan hood 6 (hood base),
Reference numeral 9 denotes a fan deck for covering the upper surface of the support pedestal 1 at the outer position of the fan hood 6 and for shutting off vertical air flow in the peripheral portion of the support pedestal 1, and 10 denotes a side portion of the entire framework of the heat exchanger. A column that is configured and supports the support frame 1 in an installed state, 11 is a partition wall that is attached to the column 10 and surrounds the cooling fan 2, and 12 is a horizontal beam that forms a part of the entire framework. The upper beam is a combination of the above, 13 is a part of the entire framework, and an intermediate beam is a horizontal beam that is erected between the columns 10 around the support base 1, and 14 is a plenum portion located above the cooling fan 2. , 15
Is a heat exchange part located above the plenum part 14, 16 is a plurality of heat transfer pipes which are horizontally installed in the heat exchange part 15 in parallel with each other at left and right and up and down, and 17 is below the support frame 1. Is an air introducing portion located at the position, 18 is a louver located above the heat exchanging portion 15 to discharge the air after heat exchange, and G is a gap (clearance) formed between the blade 5 and the fan hood 6. Is.

In the heat exchanger having such a structure, when the cooling fan 2 is started, the rotation of the motor 3 is transmitted to the blades 5 via the speed reducer 4, whereby the blades 5 rotate horizontally, and the arrows in FIG. As shown by, the air in the low temperature state is taken in from the air introduction part 17, passes through between the support bases 1, and the plenum part.
The heat is exchanged from 14 to the heat exchange section 15 to cool the heat transfer tube 16, and the air whose temperature has risen due to the heat exchange is discharged from the louver 18 to the outside.

It should be noted that although a phenomenon in which some air is stagnant occurs in the space portion located radially outward of the fan hood 6, as shown in FIGS. 1 and 2, the framework of the support frame 1 and the intermediate beam 13 The space is closed by the fan deck 9 and does not directly affect the air blown to the plenum portion 14 and the heat exchange portion 15.

Next, the seismic resistance near the cooling fan 2 is examined. When the support pedestal 1 has sufficient rigidity, each part exhibits the same behavior with respect to horizontal vibration, and the parts of the support pedestal 1 are the same. It can be handled as a vibration system.

That is, when the support base 1 vibrates in the horizontal direction indicated by AB in FIG. 1 due to an earthquake or the like, both support parts 7 and 8 move horizontally together, and the phase difference of the vibration waveform is Since it does not occur, the cooling fan 2 and the fan hood 6, which are supported by both the supporting portions 7 and 8, vibrate in a state of being synchronized in the horizontal direction. Then, a support base 1 for the cooling fan 2 and the fan hood 6 protruding upward from both the support portions 7 and 8
Is the same distance as seen in the gap G, and the amplitude difference when both support portions 7 and 8 vibrate horizontally is the same as when the cooling fan 7 and the fan hood 6 are rigid bodies and when they are vibrating springs. 0 when the coefficients are the same, that is, the gap G
Does not change. However, in actuality, there may be a case where a difference occurs in the amplitude amount due to a difference in the resonance frequency between the two and the like. Since the amplitude difference in this case has the same vibration waveform and the same phase, the gap G changes by the amount of the difference in the amplitude amount, and can be suppressed to a small change amount.

[Advantages of the Invention] As described above, according to the cooling fan mounting structure for a heat exchanger of the present invention, the following effects can be obtained.

Since the support portion of the fan hood is directly mounted on the support frame, the support structure for holding the weight of the fan hood is simplified, and the mounting strength against large acceleration can be improved.

Since both the cooling fan and fan hood support parts are mounted on a common support frame, there is no phase difference in the vibration waveform when horizontal vibration occurs, and the cooling fan blades and the inner surface of the fan hood Since the supporting distances to the gap between the blades are the same, the amplitude difference between the blades and the inner surface of the fan hood can be suppressed to a small value, and the occurrence of blade contact accidents and the like can be prevented.

With the above, it is possible to make the gap between the blades of the cooling fan and the fan hood small and easy, and improve the cooling efficiency.

[Brief description of drawings]

The drawings show an embodiment of a heat exchanger cooling fan mounting structure according to the present invention. FIG. 1 is a front sectional view of a main part with a part omitted, and FIG. 2 is a state in which a cooling fan is mounted. It is a perspective view which notched a part of whole heat exchanger. 1 ... Support stand, 2 ... Cooling fan, 3 ... Motor, 4
...... Reduction gear, 5 ...... blades, 6 ...... fan hood, 7 ...
… Support (common bed), 8… Support (hood base), 9… Fan deck, 10… Pillar, 11… Partition wall,
12 …… Upper beam, 13 …… Middle beam, 14 …… Plenum part, 15…
… Heat exchange part, 16 …… heat transfer tube, 17 …… air introduction part, 18 ……
Louver, G ... Clearance.

Claims (1)

[Scope of utility model registration request] 1. A plurality of heat transfer tubes (16) are arranged below the heat exchange section (15) arranged in parallel with each other with a space left, right, up and down.
A cooling fan (2) for driving cooling air toward the heat exchange section, and a motor (3) for rotationally driving the cooling fan.
And a speed reducer (4) interposed between the cooling fan and the motor are arranged to be supported by a common support portion (7), and the cooling air is provided to the heat exchange portion by surrounding the cooling fan. The fan hood (6) for setting the flow path of the is arranged in a state of being supported by the support part (8), and both support parts (7)
(8) is a mounting structure of a cooling fan for a heat exchanger, characterized in that the cooling fan is mounted on a support frame (1) of the same vibration system in a erected state in which horizontal beams are combined.