TW201540162A - Heat dissipation device - Google Patents

Abstract

Provided is a heat dissipation device. A plurality of spray nozzles is arranged on the bottom surface of a gas hood, and each spray nozzle is connected to an air pressurizing device. A plurality of flow rate control valves are correspondingly connected between each spray nozzle and the air pressurizing device, and each flow rate control valve is connected to a controller respectively. As a result, the controller is used to control each flow rate control valve based on different surface temperatures of a large-area heating object, so that the spray nozzles corresponding to positions with different surface temperatures downwardly produce the spraying flows with different flow rates, thereby enabling heat dissipation on the surface of the large-area heating object to be uniform, raising the yield rate of products, and effectively increasing the heat dissipation speed.

Description

Heat sink

The invention relates to a heat dissipating device, in particular to a device which can uniformly dissipate the surface of a large-area heating element.

In the manufacture of metal materials such as carbon steel, in order to soften materials or workpieces that have been cast, forged, welded or machined to improve plasticity and toughness; to homogenize chemical components, to remove residual stress, or to obtain The expected physical properties are often heat treated by a metal such as an annealing process. It slowly heats the metal to a temperature that is maintained for a sufficient period of time and then cools at a suitable rate, usually slow cooling, and sometimes controlled cooling, whereby the cold forged product achieves the desired mechanical properties.

Among them, for large-area heating elements, such as the above-mentioned large-area steel, the traditional cooling and cooling method is mainly to directly impact the large-area steel surface by a continuous jet, so that the heat transfer mechanism by forced convection allows The flowing air carries away the heat from the surface of the heating element. However, although it can make the temperature boundary layer of the steel surface thinner to achieve the effect of heat dissipation, the heat dissipation effect is not very satisfactory; and in the process of heat dissipation, the surface temperature distribution of the large heating element is often uneven. However, there will be some phenomenon that the local temperature is high and some local temperatures are low. As a result, when the surface temperature of the steel is not uniform, thermal stress is formed on the surface of the steel material, causing the steel to deform or rupture.

In view of the above, in order to provide a structure different from the conventional technology and to improve the above disadvantages, the inventors have accumulated many years of experience and continuous development and improvement, and the present invention has been produced.

An object of the present invention is to provide a heat dissipating device which can control the structure of each nozzle by a plurality of nozzles on the bottom surface of the hood and control the structure of each nozzle by a plurality of flow control valves, thereby solving the problem that heat generation of a large area is easy to generate heat. The problem is uniform, and the surface of the large-scale heating element can be uniformly dissipated to prevent the occurrence of thermal stress, and the nature of the product is stabilized, thereby effectively improving the yield.

An object of the present invention is to provide a heat dissipating device which can solve the problem by providing a plurality of nozzles on the bottom surface of the hood, controlling the nozzles by a plurality of flow control valves, and allowing each nozzle to separately eject a pulse jet structure. The heat dissipation time of the area heating element is not fast enough, and the heat dissipation speed can be accelerated to increase the production shipment.

For the above purposes, a heat sink according to the present invention includes a hood and a plurality of flow control valves. Wherein, a plurality of nozzles are arranged on the bottom surface of the hood, and a plurality of nozzles are respectively connected to an air pressing device, wherein a plurality of nozzles respectively generate a downward jet flow; and a plurality of flow control valves are connected to the plurality of nozzles and air pressurized Between the devices, a plurality of flow control valves are connected to a controller for separately controlling the jet flow rate of each nozzle.

In implementation, the plurality of nozzles are distributed in an array on the bottom surface of the hood.

When implemented, the flow control valve performs a periodic opening and closing action for the nozzle to eject a jet of oscillating motion downward.

In order to further understand the present invention, the specific embodiments of the present invention and the effects achieved thereby are described in detail below with reference to the drawings and drawings.

1‧‧‧heating device

2‧‧‧ hood

21‧‧‧Air inlet

22‧‧‧Air pressurizing device

23‧‧‧Nozzles

3‧‧‧Flow control valve

4‧‧‧ Controller

9‧‧‧heating body

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a preferred embodiment of the present invention.

Fig. 2 is a schematic cross-sectional view taken along line A-A' of Fig. 1.

Figure 3 is a diagram showing the state of use of the preferred embodiment of the present invention.

Figure 4 is a graph of the jet velocity of a continuous jet as a function of time.

Figure 5 is a graph of the jet velocity of a pulse jet as a function of time.

Fig. 6 is a graph showing the surface temperature distribution of the planar heating element after continuous jet impingement on the planar heating element.

Figure 7 is a surface temperature distribution diagram of the cooling of the planar heating element on the planar heating element by the pulse jet.

The heat dissipating device of the present invention comprises an air hood, a plurality of nozzles are arranged on the bottom surface of the hood, and a plurality of nozzles are respectively connected to an air pressing device; and a plurality of flow control valves are correspondingly connected between the plurality of nozzles and the air pressing device, A plurality of flow control valves are connected to a controller for separately controlling each flow control valve to control the jet flow rate of each nozzle.

Referring to FIGS. 1 and 2, which is a preferred embodiment of the heat sink 1 of the present invention, an air hood 2, a plurality of flow control valves 3, and a controller 4 are included.

The air hood 2 is a hollow cylindrical body which is hollow inside. The air hood 2 can also be a short circular column or a polygonal cylinder. The top cover has an air inlet 21, and the air inlet 21 is connected to a gas storage cylinder. The air cylinder has pressurized air which is used as an air pressurizing device 22. When implemented, the air pressurizing device 22 can also be an air compressor. The bottom surface of the hood 2 has a plurality of nozzles 23 arranged in a rectangular array and having openings facing downwards. Each of the nozzles 23 is in a state of being in communication with the air pressurizing device 22, and each nozzle 23 can also be distributed in a circular array. On the underside of the hood 2, or as in the third The top surface shape of the large-area heat generating body 9 shown in the figure is arranged correspondingly, and the "large area" of the large-area heat generating body 9 is for the top surface of the heat generating body 9.

The flow control valve 3 is a solenoid valve, and the flow control valve 3 can also be other types of valves that can control the flow rate. Each of the flow control valves 3 is connected between the plurality of nozzles 23 and the air pressurizing device 22, and the control is controlled. Each of the flow control valves 3 is connected to each of the flow control valves 3, so that when the air pressurizing device 22 delivers the compressed air to the inside of the hood 2, the respective flow control valves 3 are controlled to have different opening and closing degrees, and the respective nozzles 23 are respectively controlled to be ejected downward. The jet flow.

Thereby, as shown in FIG. 3, when the flat-shaped large-area heat generating body 9 is placed below the hood 2, and the flow rate of each nozzle 23 is controlled by each of the flow rate control valves 3, the surface of the heat generating body 9 is provided. The higher temperature region enhances the flow rate of the jet stream, which can improve the heat dissipation performance, and the lower the flow rate of the jet stream in the lower temperature region, the heat dissipation performance can be reduced, and the large-area heat generating body 9 can not only cool down but also allow the overall surface to be cooled. The temperature is even.

The jet flow impingement cooling jet flow condition is a continuous jet flow. As shown in Fig. 4, the jet flow velocity changes with time to a fixed value. However, when the flow control valve 3 is adjusted to perform periodic opening and closing, or to perform periodic opening at a large opening degree and a small opening degree, the outlet speed of the nozzle 23 to be ejected downward is periodically oscillated, that is, A pulsed jet of oscillating form is formed. As shown in Fig. 5, the pulse jet means that the velocity of the jet exhibits a periodic velocity oscillation with time. When the nozzle 23 sprays the pulse jet downward, the temperature boundary layer on the surface of the heating element 9 is periodically destroyed by the pulse jet, so that the temperature boundary layer is continuously reconstructed continuously and the mechanism of the temperature boundary layer is reconstructed to improve the cooling performance. .

The numerical simulation method is used below to analyze the distribution of the surface temperature of the heating element 9 when a heating element 9 is subjected to a continuous jet and a pulse jet. Among them, using a jet from the top to the top The lower impact is on a planar heating element 9, the heat generation body 9 has a heat generation of 3 watts, and the jet flow pattern is divided into two types, one of which is the continuous jet flow shown in Fig. 4, and the jet outlet speed is 1 m/s. The other is the pulse jet shown in Fig. 5, the oscillation frequency of the jet is 1 Hz, the average speed is 1 m/s, the outlet temperature of the jet is 20 ° C, the ambient temperature is 20 ° C, and the ambient pressure is 101.3 kPa.

According to the above simulation conditions, a numerical simulation was performed using a commercial computational fluid dynamics software FloEFD to analyze the temperature distribution on the surface of the heating element 9. The results are as follows: Fig. 6 is a case where a continuous jet is used to impinge a planar heating element 9, The surface temperature distribution of the heating element 9 by the jet flow is low, and the center temperature of the surface is low, and continues to increase in the circumferential direction, the center temperature Tc = 196.6 ° C, and the average temperature of the surface Tav = 197 ° C. On the other hand, in the case of using a pulse jet to impinge a planar heating element 9, the surface temperature distribution of the heating element 9 by the jet flow is low, and the center temperature of the surface is low, and continues to increase in the circumferential direction, and the center temperature Tc = 144.7 ° C. The average temperature of the surface was Tav = 145.2 °C.

From the experimental results of Figs. 6 and 7, it can be seen that the heat transfer effect of the pulse jet is better, and the surface center temperature and the surface average temperature of the heat generating body 9 which is impinged by the jet flow are low. Therefore, when the array-shaped nozzles 23 respectively eject the pulse jets, the heat dissipation performance of the matrix jets can be effectively enhanced, and the surface of the heating element 9 can be made uniform and can be quickly dissipated.

Therefore, the present invention has the following advantages:

1. The present invention has a plurality of nozzles on the bottom surface of the hood, and the flow rate of each nozzle is controlled by each flow control valve. Therefore, the surface of the large-area heating element can be uniformly dissipated to prevent thermal stress. Let the nature of the product be stable, so as to effectively increase the yield.

2. The present invention has a plurality of nozzles on the bottom surface of the hood, and allows each nozzle to separately eject a pulse jet, thereby enabling the heat dissipation speed to be increased to increase the production shipment.

In summary, according to the above disclosure, the present invention can achieve the intended purpose, and provides a heat dissipating device which not only can uniformly dissipate the surface of a large-area heating element, but also accelerates the heat dissipation speed, and is highly utilized in the industry. The value of the invention, the invention patent application.

1‧‧‧heating device

2‧‧‧ hood

21‧‧‧Air inlet

22‧‧‧Air pressurizing device

23‧‧‧Nozzles

3‧‧‧Flow control valve

4‧‧‧ Controller

Claims (3)

A heat dissipating device comprises: a hood having a plurality of nozzles on a bottom surface thereof, wherein the plurality of nozzles are respectively connected to an air pressing device for respectively generating a jet flow downwardly; and the plurality of flow control valves are correspondingly connected Between the plurality of nozzles and the air pressurizing device, and the plurality of flow control valves are connected to a controller for respectively controlling the jet flow rate of each nozzle. The heat dissipating device of claim 1, wherein the plurality of nozzles are distributed in an array on a bottom surface of the hood. The heat dissipating device according to claim 1 or 2, wherein the flow control valve performs a periodic opening and closing operation for the nozzle to eject a jet of the oscillating form downward.