WO2011070807A1

WO2011070807A1 - Method for cooling heat exchanger

Info

Publication number: WO2011070807A1
Application number: PCT/JP2010/058428
Authority: WO
Inventors: 笠井庸三; 加藤直史; 岩崎哲也
Original assignee: ダイセン・メンブレン・システムズ株式会社
Priority date: 2009-12-10
Filing date: 2010-05-19
Publication date: 2011-06-16
Also published as: CN102159898B; CN102159898A

Abstract

Water treated with a reverse osmosis membrane device (12) is introduced into a circulation line (23) and sprinkled from spray nozzles (14) onto outdoor units (heat exchangers) (15a to 15d). Since the treated water contains none of Ca, Mg, and Cl ions and the like, scale deposition does not occur on the heat exchangers (15a to 15d) and a high cooling effect can be maintained.

Description

Cooling method of heat exchanger

The present invention relates to a heat exchanger cooling method capable of significantly reducing power consumption by increasing cooling efficiency, and an apparatus suitable for implementing the method.
Background art

The cooling device is composed of a combination of an indoor unit and an outdoor unit for radiating the indoor heat to the outside, and the outdoor unit is provided with a heat exchanger for radiating heat.

Normally, outdoor units are often installed on the rooftop in urban office buildings, and many outdoor units (heat exchangers) are concentrated in a limited space on the rooftop in large buildings. There are many. Since the roof is exposed to strong sunlight in the summer, the temperature of the outdoor unit (heat exchanger) itself rises, and the heat dissipation characteristics deteriorate. Especially when a large number of outdoor units (heat exchangers) are concentrated in a narrow space, the heat generated from each outdoor unit is confined to a narrow space, causing further increase in the temperature of the outdoor unit installation location. As a result, the heat dissipation characteristics are greatly reduced. In addition, when other installations are placed close to each other and the air flow is poor, the heat generated from the entire outdoor unit raises the temperature of the installation atmosphere, resulting in heat dissipation characteristics. There is also the problem of a significant drop. If the heat dissipation characteristics are lowered in this way, the indoor cooling becomes insufficient, and a vicious cycle of increasing the cooling capacity and increasing the power consumption is caused.

In large-scale factories, even if an outdoor unit is installed on the north side of the building, the cooling space may be too large, which may reduce cooling efficiency in the summer. Thus, when it is necessary to maintain a constant temperature, it may be necessary to lower the cooling set temperature and perform cooling operation.

The invention of Japanese Patent Laid-Open No. 2000-65409 discloses a control device for increasing the cooling efficiency by spraying water on an outdoor unit (heat exchanger). The invention of Japanese Patent Laid-Open No. 2001-317821 Similarly, a cooling device that can control the spraying of water to the outdoor unit (heat exchanger) is disclosed. In the invention of Japanese Patent Application Laid-Open No. 2004-317064, soft water is similarly supplied to the outdoor unit (heat exchanger). A spraying cooling system is disclosed. In addition, in the inventions of JP-A-5-223364, JP-A-10-213361, JP-A-11-142202, and JP3739530, there is a technique for cooling the heat exchanger by spraying water. It is disclosed.
Summary of the Invention

In the invention of Japanese Patent Laid-Open No. 2000-65409, there is no description about the water source to be used, but it is considered that it is tap water in common sense. For example, if tap water is continuously sprayed on the heat exchanger during the summer, a large amount of scale derived from Ca ions, Mg ions, silica components, etc. contained in the tap water will adhere to the surface of the heat exchanger. . In this case, since the heat dissipation characteristics of the heat exchanger deteriorate and it does not function normally, in order to prevent this, the invention of Japanese Patent Application Laid-Open No. 2000-65409 requires strict control when spraying water. Therefore, the apparatus for that purpose is also complicated. For this reason, the price of the device itself increases, and the power consumption for operating the device also increases. Moreover, the problem that a scale adheres to a heat exchanger or a heat exchanger is corroded by the chlorine ion in tap water remains.

In the invention of Japanese Patent Laid-Open No. 2001-317821, it is apparent that tap water is sprayed on the heat exchanger in consideration of the description of the water bill in paragraphs [0027] and [0039]. Then, as already mentioned, there is a problem that the heat exchanger is corroded by chlorine ions in tap water, in addition to the problem of adhesion of scale.

In the invention of Japanese Patent Application Laid-Open No. 2004-317064, it is described that the soft water obtained by the soft water generator is sprayed on the heat exchanger. Therefore, the scale problem derived from Ca ions and Mg ions is to some extent. Although it can be solved, the problem of scale adhesion due to the silica component is not solved. Further, since the soft water generator uses an ion exchange resin, the amount of Ca ions and Mg ions in the generated soft water is reduced. There is a possibility that higher corrosion proceeds due to the action of a salt (NaCl) generated by mixing Na ions with a total molar equivalent of Ca ions and Mg ions generated by the exchange and combined with chlorine ions.

As described above, in the inventions of JP-A-2000-65409, JP-A-2001-317821, and JP-A-2004-317064, the problems of scale adhesion to the heat exchanger and corrosion of the heat exchanger can be solved. It also adversely affects the power consumption reduction effect. In addition, the removal of scale and the maintenance management of rust removal become complicated, and the life of the heat exchanger is shortened, so that it cannot sufficiently contribute to the overall cost reduction.

JP-A-2000-65409, JP-A-2001-317821, JP-A-2004-317064, JP-A-5-223364, JP-A-10-213361, JP-A-11-142222, The inventions of Japanese Patent No. 3739530 all detect predetermined elements by various sensors such as temperature and electric power, intermittently spray water (tap water), and individually cool the heat exchanger. However, in such a cooling method, as described in paragraph No. 38 of Japanese Patent Application Laid-Open No. 2001-317821 and shown in FIG. 5, when the amount of water is increased, when a certain amount is reached, It is known that the cooling effect is not improved any more and becomes a sideways state.

The present invention provides a cooling method for a heat exchanger, which can significantly reduce power consumption, and can be equivalent to a case where the life of the heat exchanger is not sprinkled, and an apparatus suitable for carrying out the method. The issue is to provide.

The invention of the present application is a method for cooling a heat exchanger of the outdoor unit as a means for solving the problem during operation of a cooling device combining an indoor unit and an outdoor unit, and at least for the heat exchanger, A cooling method for a heat exchanger that sprays treated water by a reverse osmosis membrane treatment apparatus is provided.

The invention of the present application is a cooling device for cooling the heat exchanger of the outdoor unit during operation of the cooling device combining the indoor unit and the outdoor unit as a means for solving other problems,
A reverse osmosis membrane treatment device, a water spray means for spraying water treated by the reverse osmosis membrane treatment device to the heat exchanger, and a water recovery tray for arranging the outdoor unit as necessary. A cooling device for a heat exchanger is provided.

By applying the heat exchanger cooling method of the present invention,
(I) The power consumption that has been required for cooling can be significantly reduced in the past, so that the electricity bill can be greatly reduced and the amount of carbon dioxide generated can be greatly reduced.
(II) Since the scale does not adhere to the heat exchanger and does not corrode the heat exchanger, the equipment life can be as long as when water is not sprayed.
(III) Water can be sprayed without problems of scale adhesion, and at the same time as the cooling of the heat exchanger, the temperature of the entire outdoor unit installation site can be lowered by cooling the water around the outdoor unit equipped with the heat exchanger. When a large number of outdoor units are centrally arranged on a building rooftop or the like, it is possible to obtain each effect that the temperature lowering effect of the installation place atmosphere is large and effective in mitigating the heat island phenomenon in the city.

It is a conceptual diagram of the cooling device of the outdoor unit (heat exchanger) suitable for implementation of the operation method of a cooling device. It is a conceptual diagram of the cooling device of the outdoor unit (heat exchanger) suitable for implementation of other embodiment of the operating method of a cooling device. In Experiment 1, the photograph which shows the state of the heat exchanger after sprinkling RO process water for 14 days. In Experiment 1, the photograph which shows the state of the heat exchanger after watering tap water for 14 days.

In the figure, reference numeral 10 is a cooling device for the outdoor unit (heat exchanger), 11 is a water source, 12 is an RO treatment device, 13 is a control valve, 14 is a water spray nozzle, 15a to 15d. Denotes an outdoor unit (heat exchanger), 16a to 16d denote outdoor units (heat exchangers), 20 denotes a water recovery tray, 23 denotes a circulation line, and 24 denotes a water recovery line.
Detailed Description of the Invention

<Cooling method by cooling device for outdoor unit (heat exchanger) shown in FIG. 1>
FIG. 1 is a conceptual diagram of a cooling device 10 for an outdoor unit (heat exchanger) that is suitable for implementing the cooling method for a heat exchanger according to the present invention.

If the water source 11 has a water intake, it may be used, or if it is a building or the like, a water storage tank installed on the roof may be used. The water source 11 itself is not included in the cooling device 10 of the outdoor unit (heat exchanger).

From the water source (tap water, industrial water or well water) 11 through the line 21, the tap water is sent to the reverse osmosis membrane treatment device (RO treatment device) 12 equipped with a pump for treatment, and the treated water (RO treatment water) is treated. obtain. The treated water at this time preferably has an electric conductivity of less than 20 μS / cm, more preferably 4 to 10 μS / cm, and Ca ions, Mg ions, Na ions, Cl ions, ionic silica, etc. are substantially contained. Is excluded.

As the RO processing apparatus 12, a known apparatus can be used. For example, an apparatus model VCR40 series, VCR80 series, NER40 series, NER80 series, SHR series, etc. sold by Daisen Membrane Systems Co., Ltd. can be used. Can do.

Next, the RO treatment water is sent from the RO treatment device 12 to the circulation line 23 via the water supply line 22. At this time, the stop and start of water supply, control of the amount of water supply, etc. can be performed with the control valve 13 installed as needed.

A plurality of outdoor units (heat exchangers) 15a to 15e (sometimes collectively referred to as "heat exchangers 15") connected to indoor units through lines not shown are placed on a suitable pedestal. Thus, the water collection tray 20 is provided to collect the sprinkled water.

The circulation line 23 is provided with a large number of watering nozzles 14, and the watering nozzles 14 are arranged so as to face the upper part of the side surface side where the cooling fins of the heat exchanger 15 are located. The circulation line 23 may be supported by a support material (not shown), may be directly fixed to the outdoor units (heat exchangers) 15a to 15e, or simply the outdoor units (heat exchangers) 15a to 15a. It may be placed on 15e.

1, the control valve 13, the watering nozzle 14, the water supply line 22, the circulation line 23, the recovery line 24, and the pump serve as watering means.

In FIG. 1, the circulation line 23 is disposed on the side surface side of the heat exchanger 15, but is disposed so as to pass through the ceiling surface of the heat exchanger 15 (so as to pass directly above the heat exchanger 15). In this case, the watering nozzle 14 is also located immediately above the heat exchanger 15. In addition, you may provide combining the circulation line which passes just above such a heat exchanger 15, and the circulation line 23 which passes the side surface side of the heat exchanger 15 as shown in FIG.

During the cooling operation, the RO treated water flowing through the circulation line 23 is sprinkled on the heat exchanger 15 whose temperature is rising due to heat radiation. The watering referred to in the present invention includes the sprays of the inventions of JP-A-2000-65409, JP-A-2001-317821, and JP-A-2004-317064. It is a concept that also includes

The amount of watering can be increased or decreased as appropriate according to the temperature, the intensity of sunlight, etc. In addition, it is desirable to continuously sprinkle water during the cooling operation, but it may be temporarily stopped depending on the time zone or weather conditions. The cooling effect on the heat exchanger 15 is mainly due to water evaporating and taking heat of vaporization. However, when water is continuously sprinkled during the cooling operation, the heat of the heat exchanger 15 is transferred to water. In this case, the cooling effect is further enhanced.

Since the sprinkled RO treated water accumulates in the water collection tray 20, it is collected by the collection line 24 and sent again to the RO treatment device 12 for reprocessing. The RO treated water obtained by reprocessing is supplied to the circulation line 23 through the water supply line 22 again. A filter for removing sand, dust and the like can be installed in the middle of the collection line 24.

The water recovery tray 20 is composed of a bottom surface portion 20a and a side wall portion 20b formed around the bottom surface portion, and by attaching a gentle slope from the heat exchanger 15a toward the heat exchanger 15e side, You may make it easy to collect | recover the accumulated water. The depth of the water recovery tray 20 is preferably 10 cm or less, and the water depth in the water recovery tray 20 is preferably about 1 to 5 cm. The length and width of the bottom surface portion of the water recovery tray 20 may be appropriately set according to the installation status of the outdoor unit. For example, as shown in FIG. 1, the length of the outdoor units (heat exchangers) 15a to 15e is approximately 1.2 to 1.5 times as long as the entire length in the length direction, and 1.5 mm of the width. The width can be about 2 times.

When the water collection tray 20 is used, it is preferable from the viewpoint of effective use of water resources because collected water can be collected and reused. From the viewpoint of saving water charges when the water source is tap water. Is also preferable.

When the water recovery tray 20 is used, the heat of vaporization is lost even when the water collected in the water recovery tray 20 evaporates, so that the temperature of the entire space in which the entire heat exchanger 15 is installed may be lowered. In addition, the cooling effect on the individual heat exchangers is enhanced.

Further, by using the heat of vaporization of the water accumulated in the water recovery tray 20 as described above, the necessary cooling effect can be maintained even if the amount of water spray is reduced. For this reason, for example, even when the sprinkling is performed while repeating the cycle of watering for 30 seconds and stopping the watering for 30 seconds, the heat of vaporization is taken away by evaporation of the water collected in the water recovery tray 20 even during the watering stop. Therefore, the cooling effect can be maintained and water can be saved.

If water does not accumulate in the water collection tray 20 at the beginning of operation or the amount of water is small, water is continuously sprinkled from the start of operation until water accumulates. Considering this, it is possible to appropriately carry out a combination of continuous watering and intermittent watering.

The water recovery tray 20 is formed not only with the heat exchanger 15 by forming a hole in a part of the side wall portion 20b or forming a recessed portion, and intentionally overflowing water after sprinkling. In addition, water may be sprayed also in the vicinity (outside of the water collection tray 20). Alternatively, water spray nozzles directed outward may be provided at a plurality of locations in the circulation line 23 so that water can be sprayed to the outside of the water collection tray 20 as well.

Although the cooling device 10 shown in FIG. 1 includes a water recovery tray 20, water is directly sprayed from the water nozzle 14 to the floor on which the heat exchangers 15a to 15e are placed without using the water recovery tray 20. Then, a cooling method can also be applied. In the case of such a method of directly spraying water on the floor surface, the water collection tray 20 is not used, so that the installation of the apparatus is easy, and the same high cooling effect as when the water collection tray 20 is used can be exhibited. .

<Cooling method by cooling device for outdoor unit (heat exchanger) shown in FIG. 2>
FIG. 2 is a conceptual diagram of a cooling device 100 for an outdoor unit (heat exchanger), which is suitable for carrying out a heat exchanger cooling method according to another embodiment of the present invention. The same reference numerals as those in FIG. 1 mean the same elements as those in FIG. 2 does not include the water collection tray 20 shown in FIG.

In the cooling device 100, the heat exchangers 15 a to 15 e and the heat exchangers 16 a to 16 e are arranged in two rows on a pedestal placed on the floor surface 30.

In the cooling device 100, when opening and closing valves (solenoid valves or the like) are provided at the connection portion between the water supply line 22 and the circulation line 23, and when the RO treatment water is sent from the RO treatment device 12 to the circulation line 23 via the water supply line 22, Water may be supplied in any one direction (in FIG. 2, counterclockwise or clockwise), or alternatively, water may be supplied alternately in both directions.

In the cooling device 100, the number of heat exchangers increases to ten, and the amount of heat generated from each heat exchanger increases the temperature (air temperature) of the entire installation site compared to the case of the device shown in FIG. Becomes larger. The temperature rise reduces the heat exchange efficiency of each heat exchanger. Also, depending on the installation situation, there may be a wall or other installation in front of the heat exchangers 15a to 15e or 16a to 16e, and in that case, the temperature rise due to the reflected hot air is also taken into consideration. Must. For this reason, conventional techniques (Japanese Patent Laid-Open Nos. 2000-65409, 2001-317821, 2004-317064, 5-223364, 10-213361, 11- Sufficient cooling is difficult in the method of intermittently spraying water for each individual heat exchanger as in the case of Japanese Patent No. 142022 and Japanese Patent No. 3739530).

However, in the cooling device 100 shown in FIG. 2, water is sprayed from the plurality of water spray nozzles 14 to the heat exchangers 15a to 15e and the heat exchangers 16a to 16e. The surface 30 (the floor surface surrounded by the circulation line 23) will also be wetted. For this reason, the floor surface 30 and the space on the floor surface 30 can be simultaneously cooled, and the ambient temperature around the outdoor unit installation location can be lowered, so that the cooling effect of the heat exchanger itself can be enhanced.

Further, in the cooling device 100 shown in FIG. 2, water can be sprayed to both the inside and outside of the circulation line 23 from a part or all of the plurality of watering nozzles 14, and simultaneously or alternately to the inside and outside of the circulation line 23. By doing so, the floor area wetted by water may be increased. By doing in this way, said cooling effect can be heightened more.

In the cooling device 100 shown in FIG. 2, one circulation line 23 is disposed so as to surround the same as the cooling device 10 shown in FIG. 1, but according to the increase in the number of heat exchangers, two systems, Three circulation lines can be arranged, and the number of pumps can be increased as the number of circulation lines increases.

In the cooling method for the heat exchanger according to the present invention, it is preferable that water is sprayed around the heat exchanger included in the outdoor unit and the floor surface where the outdoor unit is installed.
In the cooling method for the heat exchanger of the present invention, it is preferable that 10 or more outdoor units are arranged in two or more rows, and that water is sprayed around the floor including all the outdoor units.
In the cooling method of the heat exchanger according to the present invention, the outdoor unit is installed in a water recovery tray placed on the floor surface, and the water recovery tray is provided with the exception of when the cooling by the heat exchanger is started. It is preferable that water is accumulated by watering.
In the above heat exchanger cooling method of the present invention, the outdoor unit is installed in a water recovery tray placed on the floor surface, and water is sprayed on the heat exchanger and one of the water accumulated in the water recovery tray. It is preferable that the portion is recovered, treated again by the reverse osmosis membrane treatment apparatus, and reused as treated water for watering.
In the cooling method for the heat exchanger of the present invention, it is preferable that the outdoor unit is installed on the roof of the building, and the raw water for processing by the reverse osmosis membrane treatment apparatus is taken from the water source installed on the roof.
In the cooling method for the heat exchanger of the present invention, it is preferable that the electrical conductivity of the treated water by the reverse osmosis membrane treatment apparatus is less than 20 μS / cm.
In the heat exchanger cooling method of the present invention, for example, since the RO treatment water is sprinkled using the cooling device shown in FIG. 1 or FIG. 2, the scale is attached to the heat exchanger as in the prior art, or heat exchange is performed. The vessel will not be corroded. For this reason, during the cooling operation period in summer, maintenance such as scale removal and rust removal becomes unnecessary, and the life of the heat exchanger can be made to be the same level as when water is not sprinkled.

In addition, the cooling method of the heat exchanger of the present invention does not corrode the scale and heat exchanger, can spray water like a shower instead of “spray” as in the prior art, and continues during cooling operation. Since water can be sprinkled, the cooling effect of the heat exchanger can be greatly improved.

The heat exchanger cooling method according to the present invention combines the water recovery tray as in the cooling device shown in FIG. 1 to remove the heat of vaporization by evaporation of the water accumulated in the water recovery tray, and the heat exchanger is installed. Since the whole place can be cooled, the cooling effect of the heat exchanger itself can be enhanced. Further, by combining the water recovery tray, the amount of water spray can be reduced by using the heat of vaporization.

Further, the cooling method of the heat exchanger according to the present invention can cool the entire place where the heat exchanger is installed by spraying water directly on the floor surface like the cooling device shown in FIG. The cooling effect of the vessel itself can also be enhanced.

Furthermore, in the cooling method of the heat exchanger according to the present invention, the difference between the power consumption of the RO processing apparatus and the power consumption for cooling reduced by applying the present invention is very large. The effect of reducing power is increased. There are many alternative means for heating in winter (kerosene, gas, etc.), but as an alternative means for cooling in summer, a gas heat pump that has recently become widespread is known, and cooling of the heat exchanger of the present invention By applying the method, the peak value of power consumption in the summer will be greatly reduced, so that it becomes possible to contract with an electric power company with a smaller amount of power, leading to savings in basic charges. In addition, since the gas heat pump also includes a heat exchanger, it can be expected that the energy consumption can be reduced by applying the cooling method of the present invention.

Furthermore, by implementing the cooling method of the heat exchanger of the present invention in a wide area, it becomes effective for the carbon dioxide reduction effect and temperature decrease (for example, mitigation of the heat island phenomenon) in the entire area.

The cooling method of the heat exchanger according to the present invention is for cooling a large number of outdoor units centrally installed on the rooftop of a building, such as an urban building (especially 10 or more outdoor units are arranged in two or three rows). It is particularly suitable for cooling an outdoor unit of a cooling device that cools a large space such as a large-scale factory.
Example

Example 1
Under the following conditions, the power consumption for cooling when the present invention is not applied and the maximum demand power as the basis of the contract electricity charge, and the power consumption for cooling and the maximum demand power when the present invention is applied were estimated.

Location: Food factory in Nagano Prefecture, 40 outdoor units, total power consumption 272kwh
Period: 4.5 months from May 15th to September 30th, 2008 Time: From 7am to 7pm Sprinkling set temperature: 25 ° C
RO treatment device: manufactured by Daisen Membrane Systems Co., Ltd. (throughput: 3000 L / hr, electrical conductivity 6-8 μS / cm)
The total power consumption required for cooling when the present invention is not applied is approximately 4,115,000 KW, and the total power consumption required for cooling when the present invention is applied is approximately 3,919,000 KW. Meanwhile, the power consumption of the RO processing apparatus is about 9000 KW. The maximum demand power when the present invention is not applied is 850 KW, and the maximum demand power when the present invention is applied is 755 KW.

Example 2
An outdoor unit and a water recovery tray of a cooling device (MBZ-J228 manufactured by Mitsubishi Electric Corporation) installed outside the laboratory were installed in a laboratory adjusted to a temperature of 27.4 ° C. (outside temperature shown in Table 1). . While performing cooling operation in this state, RO treated water was sprinkled on the outdoor unit under the following conditions. The results are shown in Table 1.

(Watering conditions)
Water: Tap water (water temperature about 25 ° C)
Water spray rate: 400ml / min
Number of nozzles for watering outdoor unit: 2 Watering type: Regular watering RO device: NRX20-P (manufactured by Daisen Membrane Systems Co., Ltd.)
RO membrane: SW02200-DRA982P
RO permeation conductivity: 5 μS / cm

The cold air temperature is a temperature assumed to be implemented in a processing factory that handles fresh food.

Example 3
For two outdoor units (heat exchangers) of the same product for 14 days (total of about 100 hours) under the same sprinkling conditions, RO treated water (obtained with the same apparatus as in Example 2. Electrical conductivity 6 -8μS / cm) and tap water (Tokyo tap water) using 4 water spray nozzles (7.2 L / hr × 4 per nozzle = 28.8 L / hr) The condition was tested. As shown in FIG. 3, no sprinkling of scale was observed on the fin surface when the RO-treated water was sprinkled. As shown in FIG. 4, it was confirmed that a white scale adhered to the fin surface of the water sprayed with tap water. When tap water is sprinkled, scale adherence was observed even after 14 days of sprinkling. Therefore, if water spraying is continued during the summer season, cooling efficiency may decrease unless the scale is removed appropriately. Easily guessed.

Example 4
The cooling method for the heat exchanger of the present invention was carried out under the following test methods and conditions.

Equipment used (room air conditioner)
Indoor unit: MSZ-J228-W (Mitsubishi Electric Corporation)
Outdoor unit: MUZ-J228 (Mitsubishi Electric Corporation)
Room air conditioner rating: Single phase 100V, 435W, 50-60Hz, rated cooling capacity 2.2kW
Refrigerant piping length: 5m (indoor 2m, outdoor 3m)
Refrigerant type: R410A (total refrigerant amount: 0.75 kg)

Operation mode: Normal operation mode (50
Hz), set temperature 16 ° C, sudden air flow, fixed wind direction

The indoor unit is installed in an atmosphere of dry bulb temperature 29 ± 0.2 ° C (wet bulb temperature 19 ± 0.2 ° C), and the outdoor unit is installed in an atmosphere of dry bulb temperature 46 ± 0.2 ° C (wet bulb temperature 24 ± 0.2 ° C). Drove.
RO treatment water (with electrical conductivity of 8 μS / cm obtained by the same apparatus as in Example 2) is sprayed for 20 seconds (spraying amount: 400 ml / min) for the heat exchanger of the outdoor unit, and 30 seconds of rest is 1 As a cycle, the items shown in Table 2 were measured for those that were repeated for 1.5 hours and those that were not sprayed with RO-treated water.

Example 5
The same method and conditions as in Example 4 were used. However, with respect to the heat exchanger of the outdoor unit, the RO treated water was sprayed for 20 seconds (spray amount 400 ml / min) and the 60-second pause was set as one cycle, and this was repeated for 1.5 hours. The results are shown in Table 3.

Example 6
The method of cooling a heat exchanger according to the present invention was carried out at a food factory in Shizuoka Prefecture for about 5 months from May to September 2009. The results are shown in Table 4 for three days with similar temperature conditions on the same date in 2009 and 2008, taking into account the same sunshine conditions.

Factory floor area: Approximately 9600m ²
Air conditioner: 80 outdoor units (installed on the southwest side of the factory building)
RO treatment device and treated water: Emizu-3000 manufactured by Daisen Membrane Systems Co., Ltd. (throughput: 3000 L / hr, electrical conductivity 6-8 μS / cm)
Watering condition: 80 outdoor units were divided into two lines of 40 units, watering for 20 seconds with respect to the first 40 units, and then watering for 20 seconds to the next 40 units as one cycle was repeated.
Watering time: 6 am to 10 pm (16 hours)
Sprinkling amount per outdoor unit: 0.8L / min (2 sprinkling nozzles / unit)
Watering conditions (varied as follows according to the outside air temperature)
1) 20 ° C. to less than 25 ° C .: 20 seconds water spray—60 seconds pause 2) 25 ° C. to less than 27 ° C .: 20 seconds water spray—50 seconds pause 3) 27 ° C. to less than 29 ° C .: 20 seconds water spray—40 seconds pause 4) 29 ° C to less than 21 ° C: 20 seconds water spray-30 seconds pause 5) 31 ° C or more: 30 seconds water spray-30 seconds pause

After the implementation for about 5 months, all the heat exchangers of 80 outdoor units were observed both visually and by touch, but no scale adhesion was observed in all the outdoor units. This fact means that the scale removal process is not necessary, and it is not necessary to perform the scale removal process on the heat exchanger even after the completion of the present invention. Further, next year (2010). Indicates that the present invention can be implemented as it is. When the conventional method of sprinkling tap water is carried out, it is necessary to remove the scale 3 or 4 times in 5 months, or compared with the need to replace the heat exchanger parts. The cost reduction effect is very large.

Claims

A method of cooling a heat exchanger of the outdoor unit during operation of a cooling device that combines an indoor unit and an outdoor unit, wherein water treated by a reverse osmosis membrane treatment device is sprinkled on at least the heat exchanger. To cool the heat exchanger.
The method for cooling a heat exchanger according to claim 1, wherein water is sprayed around a heat exchanger of the outdoor unit and a floor surface on which the outdoor unit is installed.
The cooling method for a heat exchanger according to claim 1, wherein 10 or more outdoor units are arranged in two or more rows, and water is sprayed around the floor including all the outdoor units.
The outdoor unit is installed in a water recovery tray placed on a floor surface, and water is accumulated in the water recovery tray except when starting cooling by water spraying of the heat exchanger. The method for cooling a heat exchanger according to any one of claims 1 to 3.
The outdoor unit is installed in a water collection tray placed on the floor, sprinkles water on the heat exchanger, collects a part of the water accumulated in the water collection tray, and again reverse osmosis membrane treatment equipment The method of cooling a heat exchanger according to any one of claims 1 to 3, wherein the heat exchanger is reused as treated water for watering after being treated by the method.
The heat exchanger according to any one of claims 1 to 5, wherein an outdoor unit is installed on the roof of the building, and takes raw water for treatment by the reverse osmosis membrane treatment device from a water source installed on the roof. Cooling method.
The method for cooling a heat exchanger according to any one of claims 1 to 6, wherein the electrical conductivity of the treated water by the reverse osmosis membrane treatment apparatus is less than 20 µS / cm.
A cooling device for cooling the heat exchanger of the outdoor unit during operation of the cooling device combining the indoor unit and the outdoor unit,
A reverse osmosis membrane treatment device, a water spray means for spraying water treated by the reverse osmosis membrane treatment device to the heat exchanger, and a water recovery tray for arranging the outdoor unit as necessary. Heat exchanger cooling system.