JP2013064578A - Cooling device and cooling method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device capable of achieving high cooling effect even when an atmospheric temperature rises.SOLUTION: This cooling device includes a cooling fan 12 disposed at a lower side of an air fin cooler 40 performing cooling by heat transfer, and an atomization nozzle 22 jetting water droplets to be mixed in the cooling air generated by the cooling fan 12. The water droplets jetted from the atomization nozzle 22 is constituted of water droplets having particle diameters to vaporize before reaching the air fin cooler 40, and water droplets having particle diameters to vaporize after colliding with and attaching to the air fin cooler 40. Further, a particle diameter control means is preferably disposed to control content rates of the particle diameters in the water droplets.

Description

  The present invention relates to a cooling device for a heat transfer type cooling mechanism such as an air fin cooler and a cooling method therefor.

  As a cooling device in a heat transfer type cooling mechanism that performs heat exchange without contact, such as an air fin cooler, those disclosed in Patent Documents 1 and 2 are known. The cooling device disclosed in Patent Document 1 has a configuration in which a cooling fan is provided on the lower side and a louver is provided on the upper side with an air fin cooler as a base point. The air fin cooler is provided with temperature detection means, and both the cooling fan and the louver are controlled based on the temperature detected by the temperature detection means. The cooling device disclosed in Patent Document 2 is configured such that a movable electric heater is provided between an air fin cooler and a cooling fan provided on the lower side of the air fin cooler. Even in the cooling device having such a configuration, temperature detecting means for detecting the temperature of the fluid flowing in the air fin cooler is provided, and when the fluid in the air fin cooler is solidified at a low temperature in a cold district or the like. The electric heater is operated, and the cooling fan is operated when the temperature of the fluid rises.

  However, in any cooling device having such a configuration, the fluid acting on the air fin cooler is air (single-phase flow) in the environmental atmosphere. For this reason, when atmospheric temperature rises, the temperature of the airflow sent to an air fin cooler also becomes high and the cooling efficiency by heat exchange falls. In view of such circumstances, a cooling device as disclosed in Patent Document 3 has been proposed.

  The cooling device disclosed in Patent Document 3 is provided with a spray nozzle for spraying minute water droplets (mist) between an air fin cooler and a cooling fan provided on the lower side of the air fin cooler. It is a feature. According to the cooling device having such a feature, the water droplets ejected from the spray nozzle ride on the cooling air from the cooling fan toward the air fin cooler. At this time, the water droplets evaporate before reaching the air fin cooler, and the ambient temperature is lowered by the heat of vaporization. For this reason, the temperature of the cooling air acting on the air fin cooler is lowered, and the cooling efficiency by heat exchange can be kept good.

JP 2000-249390 A JP 2006-145071 A JP 2002-122387 A

  Certainly, a cooling device having the characteristics as disclosed in Patent Document 3 is considered to be able to enhance the cooling effect as compared with the prior art. However, if the mist carried by the cooling air evaporates before reaching the air fin cooler, the temperature of the cooling air can be lowered by the heat of vaporization, but it is not possible to take heat directly from the air fin cooler by the heat of vaporization. Can not. For this reason, when the ambient temperature rises, there is a possibility that a sufficient cooling effect cannot be obtained.

  Therefore, an object of the present invention is to provide a cooling device and a cooling method capable of solving the above problems and obtaining a good cooling effect even when the ambient temperature is increased.

  A cooling device according to the present invention for solving the above-described problem includes a blowing unit disposed opposite to a cooling target surface of a cooling target to be cooled by heat transfer, and cooling air generated by the blowing unit. A fine mist nozzle for ejecting water droplets to be turbid, a water droplet ejected from the fine mist nozzle with a particle size that vaporizes before reaching the cooling object, and a particle that vaporizes after adhering to the cooling object It is characterized by having a diameter.

In addition, the cooling device having the above-described characteristics may be provided with particle size control means for controlling the content ratio of the particle size in the water droplets.
By setting it as such a structure, it becomes possible to obtain the cooling action suitable for the temperature of the cooling target object.

Moreover, in the cooling device having the above-described features, the air blowing means is a cooling fan, and the fine fog nozzle can be disposed on the suction side of the cooling fan.
With this configuration, water droplets are diffused by the rotation of the cooling fan. Thereby, it becomes possible to spray water droplets in a wider range.

Moreover, in the cooling device having the above-described characteristics, the air blowing means is a cooling fan, and the fine fog nozzle can be disposed between the ejection side of the cooling fan and the object to be cooled.
With such a configuration, there is no possibility that water droplets adhere to the cooling fan.

  In the cooling device having the above-described characteristics, a water supply port and an air supply port are provided in the supply port of the fine fog nozzle, and a two-phase flow of droplets and air is ejected from the ejection port. It is good to have a configuration.

  With such a configuration, it is possible to spray water droplets due to a difference in air pressure. For this reason, the pump for pumping water becomes unnecessary. Moreover, when it is set as such a structure, the particle size of the water droplet to eject can be made minute by adjusting the ejection pressure of air. For this reason, compared with spraying by a liquid single phase, the particle size of a water droplet is small and vaporization efficiency is high. Therefore, even when the fine mist nozzle is disposed on the suction side of the cooling fan, it is difficult for water droplets to adhere to the cooling fan.

  Furthermore, it is desirable that a plurality of the fine fog nozzles are arranged for one cooling fan. By setting it as such a structure, it becomes possible to suppress the deviation of the sprayed water droplet.

  Furthermore, the object to be cooled is an air fin cooler, and a plurality of the cooling fans are provided from the upstream side to the downstream side along the flow of fluid flowing in the air fin cooler with respect to the air fin cooler, It is desirable that a large number of nozzles be arranged in the cooling fan provided on the upstream side than the cooling fan provided on the downstream side. This is because, by adopting such a configuration, it is possible to increase the amount of water droplets sprayed on the upstream side at a higher temperature.

  A cooling method according to the present invention for solving the above problem is a cooling method in which cooling air is blown against a cooling object to be cooled by heat transfer, and the cooling air is applied to the cooling air. The water droplets having a particle size that evaporates before the cooling air reaches the object to be cooled and the water droplets having a particle size that evaporates after the cooling air reaches the object to be cooled are turbid. .

In the cooling method having such a feature, the object to be cooled is an air fin cooler, the upstream side and the downstream side are defined along the flow of fluid flowing in the air fin cooler, and the upstream side of the air fin cooler, It is preferable to spray more water droplets than on the downstream side.
By doing in this way, it becomes possible to spray many water droplets, and to raise the cooling effect by vaporization heat, so that the upstream side with higher temperature.

  According to the cooling device and the cooling method having the above-described characteristics, a good cooling effect can be obtained even when the ambient temperature rises.

It is a side view which shows the structure of the cooling device which concerns on 1st Embodiment. It is a top view which shows the structure of the cooling device which concerns on 1st Embodiment. It is a top view which shows the structure of the air fin cooler used by 1st Embodiment. It is sectional drawing which shows an example of the fine fog nozzle which concerns on embodiment. It is a block diagram which shows the structure for automatically controlling the cooling device which concerns on embodiment. It is a side view which shows the structure of the cooling device which concerns on 2nd Embodiment. It is a top view of a cooling fan which shows arrangement composition of a nozzle header in the case of providing a fine fog nozzle in a nozzle header. It is a side view which shows the relationship between a nozzle header and a fine fog nozzle. It is a top view of the cooling fan which shows the arrangement configuration of the nozzle header in the case of using a straight type nozzle header. It is sectional drawing which shows the relationship between a nozzle header, a support, and a fine fog nozzle.

  Hereinafter, embodiments according to a cooling device and a cooling method of the present invention will be described in detail with reference to the drawings. In the following embodiments, an air fin cooler will be described as an example of an object to be cooled by the cooling device according to the present invention.

  An air fin cooler 40 to be cooled is a heat exchanger having a pipeline 42 for inserting a fluid to be cooled, and a plurality of cooling fins 44 arranged in parallel on the outer periphery of the pipeline 42. is there. The air fin cooler 40 used in the embodiment has a configuration in which a plurality of pipelines 42 are arranged in parallel as shown in FIG.

  The cooling device 10 according to the present embodiment is configured based on a cooling fan 12 for cooling an object to be cooled, such as the air fin cooler 40 described above, and a fine fog nozzle 22.

  The cooling fan 12 is a blower for sending cooling air to the air fin cooler 40 (an object to be cooled). The cooling fan 12 is configured based on a casing 14, a fan 18, and a motor 20. The casing 14 is a frame for housing and fixing the fan 18 and the motor 20 whose details will be described later. In the example shown in FIG. 1, the casing 14 is also provided with a hood 16 for preventing unnecessary diffusion of the cooling air. The fan 18 is a wing that blows air by rotation, and its specific shape and the like can be variously selected, and wings of various known configurations can be employed. The motor 20 is a drive source for rotating the fan 18, and is connected to a power source (not shown).

  The fine fog nozzle 22 plays a role of ejecting fog. In the case of the present embodiment, the fine fog nozzle 22 is provided on the lower side (suction side) of the cooling fan 12 and is ejected from the cooling fan 12 to the air fin cooler 40 along the suction flow of the cooling fan 12. With such a configuration, water droplets ejected from the fine mist nozzle 22 are diffused by the rotation of the cooling fan 12. This eliminates unevenness of water droplets (for example, uneven distribution of water droplets), and enables spraying over a wide range compared to direct spraying from the fine mist nozzle 22.

  As shown in detail in FIG. 4, the fine mist nozzle 22 according to the present embodiment is provided with two supply ports 24 a and 26 a and one jet port 28 a. Specifically, as the supply port, water supply port 24a for supplying water constituting the water droplet to be sprayed, and air for adjusting the particle size of the water droplet to be ejected by creating a pressure difference in the fine mist nozzle 22 An air supply port 26a for supply is provided. Moreover, the mist-like water (water droplet) is ejected from the ejection port 28a. As an example of the form of the fine mist nozzle 22, as shown in FIG. 4, a nozzle 24 provided with a water supply port 24a, a diffuser 28 having an ejection port 28a, and a chamber 26 provided with an air supply port 26a It is composed on the basis. The chamber 26 is disposed between the nozzle 24 and the diffuser 28, and the air supplied from the air supply port 26 a is compressed in the chamber 26 and flows out to the diffuser 28. On the other hand, when the water flowing into the chamber 26 from the nozzle 24 flows out into the diffuser 28, it is diffused into a fine mist (micro water droplet) due to a pressure difference between the inside of the chamber 26 and the diffuser 28. Become.

  In the fine mist nozzle 22 having such a configuration, the particle diameter φ of the water droplets (fine mist) to be ejected can be varied depending on the ratio of air and water. Specifically, when the ratio of air: water is 6: 4, the particle diameter φ of the water droplets to be ejected is about 0 <φ ≦ 30 μm. On the other hand, when the ratio of air: water is 4: 6, the particle diameter φ of the water droplets to be ejected is about 30 <φ ≦ 90 μm. In the case of water droplets having such a particle size, for example, water droplets having a particle size φ larger than 0 and not more than 30 μm are vaporized in the air after being sprayed from the fine mist nozzle 22 and before reaching the air fin cooler 40. It will be. On the other hand, when the particle diameter φ is larger than 30 μm and equal to or smaller than 90 μm, the water droplet is sprayed from the fine mist nozzle 22 and then vaporized after adhering to the air fin cooler 40. Such adjustment of the ratio of air and water can be realized by the following configuration, for example. That is, an adjustment valve (particle size control means) (not shown) may be provided in the front stage of the water supply port 24a of the nozzle 24 in the fine fog nozzle 22. The ratio of air and water can be controlled as described above by adjusting the amount of water supplied (spouted) while keeping the air supply amount (spout pressure) constant.

  It is desirable to provide a plurality of fine fog nozzles 22 for one cooling fan 12. The vaporization time of the sprayed water droplets varies depending on the temperature of the object to be cooled. For this reason, by disposing the optimum number of fine fog nozzles 22 according to the vaporization time, it is possible to effectively improve the cooling efficiency while preventing the droplets from dropping. For this reason, as shown in FIGS. 1 and 2, when a plurality of cooling fans 12 are arranged from the upstream side to the downstream side of the air fin cooler 40, the fineness provided on the cooling fan 12 arranged on the upstream side. The number of mist nozzles 22 may be larger than the number of mist nozzles 22 provided in the cooling fan 12 disposed on the downstream side. The fluid flowing in the air fin cooler 40 that is cooled by heat exchange has a higher temperature toward the upstream side. For this reason, the vaporization time of water droplets sprayed from the fine mist nozzle 22 is earlier on the upstream side of the air fin cooler 40 than on the downstream side. Therefore, by increasing the number of fine mist nozzles 22 to be installed and increasing the amount of sprayed water droplets, it is possible to prevent water droplets from dropping while improving the cooling efficiency.

  As in the present embodiment, it is known that mist cooling by a multiphase flow in which micro droplets (water droplets) are suspended in an air flow brings about significant heat transfer enhancement compared to cooling by a single phase flow. In addition, there is a limit to the cooling effect due to vaporization of water droplets in the air stream, and vaporization on the cooling fins 44 is promoted by promoting the adhesion of water droplets to the cooling fins 44 by controlling the water droplet diameter (amount of water to be sprayed). The cooling effect by can be obtained, and the cooling effect can be dramatically improved. Furthermore, the formation of a liquid film on the surface of the cooling fin 44 (air fin cooler 40) by adhesion of water droplets is known to be effective in promoting heat transfer for obtaining a cooling effect. In consideration of the above, it is necessary to suppress the dropping of the droplet after the liquid film is formed.

  For this reason, it is desirable to set mc = me in order to appropriately maintain environmental conditions, to suppress the occurrence of defects such as rust, and to promote effective cooling. Here, mc is the mass of water droplets (the mass of water) collected by collision with the air fin cooler 40 (cooling fins 44), and me is the mass by which water droplets evaporate and diffuse from the air fin cooler 40 (cooling fins 44). It is a flux.

  Taking these into consideration, the amount of spray water ejected from the fine mist nozzle 22 is vaporized before reaching the air fin cooler 40 from the fine mist nozzle 22 to obtain a cooling effect. What is necessary is just to determine based on the amount of spray water mc collided and collected by the fin 44. As for the spray water amount mc, it is necessary to consider the ratio x% of the amount of water collided and collected by the air fin cooler 40 among the water droplets ejected from the fine fog nozzle 22.

Therefore, the total amount of water sprayed from the fine fog nozzle 22 is

Can be obtained as

  When a plurality of fine fog nozzles 22 are arranged for one cooling fan 12, it is desirable to arrange them radially with the center of the fan 18 as a base point, as shown in FIG. This is because the distribution of sprayed water droplets is not biased by adopting such an arrangement form.

  When automating the cooling device 10 having such a basic configuration, the following configuration is preferable. That is, the temperature detection means 32, the flow rate control means (particle size control means) 34, and the spray amount control means 30 may be provided. Specifically, the temperature detecting means 32 may be any means for detecting the temperature of the fluid flowing in the air fin cooler 40. Specifically, it may be a means capable of outputting the detected temperature as an electric signal, such as a thermocouple. The temperature detection means 32 has its temperature detection part disposed inside the air fin cooler 40 and is connected so as to be able to output a detection signal to the spray amount control means 30 described later in detail. The arrangement position of the temperature detection unit can be in the pipeline 42 constituting the air fin cooler 40 or in the outer periphery of the pipeline 42, but is desirably upstream in the pipeline 42. This is because it is desirable to adjust the spray amount (spray water amount and water droplet particle size) based on the fluid temperature before cooling.

  The flow rate control means 34 is a means for adjusting the amount of water supplied to the nozzle 24 and may be any means that can control the amount of water flow based on an electrical signal, such as a proportional control valve. The flow rate control unit 34 is disposed in the water supply path in the preceding stage of the nozzle 24 in the fine fog nozzle 22 and is electrically connected to the spray amount control unit 30. With such a configuration, it is possible to adjust the amount of water supplied to the nozzle 24 according to the output signal from the spray amount control means 30.

  The spray amount control means 30 determines the particle size and water volume of the fine mist sprayed from the fine mist nozzle 22 based on the temperature (electric signal indicating temperature) detected by the temperature detection means 32 described above, and the flow rate control means. 34 plays a role of outputting a control signal. In addition, about the particle size ratio of a fine mist (water droplet), what is necessary is just to determine the magnitude | size etc. of a particle size by the several fine mist nozzle 22 unit. The spray amount control means 30 includes at least a storage unit 38 and a calculation unit 36. The storage unit 38 plays a role of storing various data used for calculation by the calculation unit 36, which will be described in detail later. The storage unit 38 stores, for example, a control ratio of the flow rate control unit 34 based on the detected temperature, a mixing ratio of fine mist particle sizes (small particle size and large particle size) corresponding to the detected temperature, and the like. The calculation unit 36 derives the control ratio of the flow rate control unit 34 from the storage unit 38 based on the electrical signal corresponding to the temperature detected by the temperature detection unit 32, and generates a control signal for performing control according to the control rate. calculate. The calculated control signal is output to the flow rate control means 34.

  In the cooling device 10 having such a configuration, first, the temperature of the fluid in the air fin cooler 40 is detected by the temperature detection means 32. The detected temperature is input to the spray amount control means 30 as an electrical signal. The spray amount control means 30 derives a control signal to the flow rate control means 34 corresponding to the input detected temperature, and outputs this to the flow rate control means 34 as a control signal. The flow rate control means 34 that receives the control signal from the spray amount control means 30 opens and closes the flow path based on the control signal, and controls the amount of water supplied to the nozzle 24.

  By performing such control, spray amount control according to the fluid temperature in the air fin cooler 40 becomes possible. As a result, it is possible to prevent water droplets from the air fin cooler 40 and prevent deterioration such as rust while realizing high cooling efficiency.

  Next, 2nd Embodiment which concerns on the cooling device of this invention is described with reference to FIG. Most of the configuration of the cooling device according to the present embodiment is the same as that of the cooling device according to the first embodiment described above. Therefore, portions having the same function are denoted by the same reference numerals in the drawings, and detailed description thereof is omitted.

  The difference between the cooling device 10a according to the present embodiment and the cooling device 10 according to the first embodiment is the arrangement of the fine fog nozzles 22. Specifically, the fine fog nozzle 22 in the cooling device 10 according to the first embodiment is arranged on the suction side (lower side) of the cooling fan 12. On the other hand, the fine fog nozzle 22 in the cooling device 10a according to the present embodiment is provided between the air fin cooler 40 and the fan 18 constituting the cooling fan 12. With such a configuration, it is possible to prevent water droplets from adhering to the fan 18 constituting the cooling fan 12.

  Even when the fine mist nozzle 22 is disposed on the suction side of the cooling fan 12 as in the first embodiment, water droplets attached to the fan 18 constituting the cooling fan 12 are affected by centrifugal force. It will be thrown off to the outer peripheral side. For this reason, water drops do not adhere to the motor 20 having the rotation shaft at the center of the fan 18.

  Further, when the fine fog nozzle 22 is arranged on the suction side of the cooling fan 12, even if it is a case where water drops are not attached to the fan 18 itself, the problem can be solved for the following reason. That is, as in the present embodiment, when the fine mist nozzle 22 that ejects water droplets by gas-liquid mixed flow is employed, the particle size of the water droplets to be ejected can be made minute by adjusting the air ejection pressure. . For this reason, water droplets are small and vaporization efficiency is high compared to spraying water droplets with a single liquid phase. Therefore, by adjusting the particle size as described above, it is possible to vaporize before the water droplets reach the cooling fan 12, and it is possible to prevent the water droplets from adhering to the fan 18. In this case, the cooling effect due to the vaporization of water droplets adhering to the air fin cooler 40 cannot be expected, but the spray from the fine mist nozzle 22 is taken into consideration in consideration of the cooling state, use conditions, work environment, and the like. There is no problem in appropriately selecting the state.

  Even with such a configuration, as with the cooling device 10 according to the first embodiment described above, it is possible to obtain a high cooling effect and to improve the working environment such as dripping of droplets. It becomes.

  In the said embodiment, it has shown that the form of a fine fog nozzle is made into a single body, and a plurality of fine fog nozzles are connected by piping. However, as shown in FIGS. 7 and 8, the fine mist nozzle 22 may be provided in the nozzle header 21 to simplify the piping. 7 is a plan view showing an arrangement form of the nozzle header 21 with respect to the cooling fan 12, and FIG. 8 is a side view showing a relationship between the nozzle header 21 and the fine fog nozzle 22. As shown in FIG.

  In FIG. 7, the nozzle header 21 having a circular plane shape is arranged on a concentric circle. However, as an arrangement form of the nozzle header 21, a straight type is used as shown in FIG. 9. You may make it arrange | position to. In addition, FIG. 10 is sectional drawing which shows the relationship between the nozzle header 21 and a fine fog nozzle.

  Moreover, in the said embodiment, the fine mist (water droplet) was refine | purified by supplying both water and air with respect to the fine mist nozzle 22. FIG. However, the formation of fine mist is not limited to such means, and purification may be performed only by supplying water. That is, water may be pumped to the nozzle 24, and the water may be diffused and discharged as fine water droplets using the pressure difference when water is discharged from the diffuser 28. When such a means is employed, a pump for pumping water may be provided instead of eliminating the air supply path. With such a configuration, the piping provided around the cooling fan 12 is simplified, and it becomes possible to improve the maintainability.

  In the said embodiment, the air fin cooler was mentioned as an example and demonstrated as a cooling target object. However, the object to be cooled in the cooling device according to the present invention is not limited to the air fin cooler. For example, a rotary kiln or the like that can be externally cooled by heat transfer from the inside can be applied as a cooling object of the cooling device according to the present invention. A cooling method can be implemented.

  Moreover, in the cooling device shown in the embodiment, the cooling fan is shown as a configuration arranged on the lower side of the air fin cooler that is the object to be cooled, but this is an example of the cooling device according to the present invention. The relationship between the fan and the object to be cooled may be such that the cooling fan faces the surface to be cooled so that the blown air (cooling air) from the cooling fan reaches the surface to be cooled of the object to be cooled.

10, 10a ......... Cooling device, 12 ... ... Cooling fan, 14 ... ... Casing, 16 ... ... Hood, 18 ... ... Fan, 20 ... ... Motor, 21 ... ... Nozzle header, 22 ... ... Fog nozzle, 23 ......... Support, 24 ......... Nozzle, 24a ......... Water supply port, 26 ......... Chamber, 26a ......... Air supply port, 28 ......... Diffuser, 28a ......... Jet Outlet, 30... Spray amount control means, 32... Temperature detection means, 34... Flow control means, 36. ……… Pipeline, 44 ……… Cooling fins.

Claims (9)

Blower means disposed opposite the cooling target surface of the cooling target to be cooled by heat transfer;
A fine mist nozzle for ejecting water droplets to be turbid in the cooling air generated by the blowing means;
The water droplets ejected from the fine mist nozzle have a particle size that vaporizes before reaching the object to be cooled and a particle size that vaporizes after adhering to the object to be cooled. apparatus.   The cooling device according to claim 1, further comprising a particle size control unit that controls a content ratio of the particle size in the water droplets. The air blowing means is a cooling fan;
The cooling apparatus according to claim 1, wherein the fine fog nozzle is disposed on a suction side of the cooling fan. The air blowing means is a cooling fan;
The cooling device according to claim 1 or 2, wherein the fine fog nozzle is disposed between the ejection side of the cooling fan and the object to be cooled.   The supply port in the fine mist nozzle is provided with a water supply port and an air supply port, and a two-phase flow of droplets and air is ejected from the ejection port. 5. The cooling device according to any one of 4 above.   The cooling device according to any one of claims 3 to 5, wherein a plurality of the fine fog nozzles are arranged for one cooling fan. The cooling object is an air fin cooler,
A plurality of the cooling fans are provided from the upstream side to the downstream side along the flow of the fluid flowing in the air fin cooler with respect to the air fin cooler,
The cooling device according to claim 6, wherein a number of the fine fog nozzles are arranged on a cooling fan provided on the upstream side of a cooling fan provided on the downstream side. A cooling method that performs cooling by blowing cooling air to a cooling object to be cooled by heat transfer,
Water droplets having a particle diameter that vaporizes before the cooling air reaches the object to be cooled.
A cooling method, wherein water droplets having a particle diameter that evaporates after the cooling air reaches the object to be cooled are turbid. The cooling object is an air fin cooler,
An upstream side and a downstream side are defined along the flow of fluid flowing in the air fin cooler,
The cooling method according to claim 8, wherein more water droplets are sprayed on the upstream side of the air fin cooler than on the downstream side.