JP2000312889A - Fouling preventing system of cooling water of air conditioning equipment - Google Patents

Abstract

PROBLEM TO BE SOLVED: To easily suppress the growth of various bacteria and algae in cooling water by simple equipment while avoiding the injection of a chemical agent which becomes a source of fouling of waste water in an air conditioning equipment. SOLUTION: An org. matter decomposing unit 10 is arranged to at least one of pipelines 4, 5 for circulating cooling water between a heat exchanger 2 and a cooling tower 3 and photoconductive membranes 11 are provided in the org. matter decomposing unit 10 as a photocatalyst and the photocatalytic reaction of the photoconductive membranes 11 is unilized to decompose org. matter in flowing cooling water. The photoconductive membranes 11 are held to a plate shape to form a zigzag bypass water flow channel in the org. matter decomposing unit 10 and arranged in a case having a light permeable surface. Therefore, flowing cooling water receives photocatalytic action repeatedly by a plurality of the photoconductive membranes 11 and the org. matter contained in cooling water is decomposed. As a result, various bacteria are killed and the generation of algae is suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a system for preventing contamination of cooling water used for air conditioning equipment, and more particularly to a system for preventing the contamination of cooling water with a simple facility by avoiding the injection of a chemical which is a source of pollution of wastewater. The present invention relates to a cooling water pollution control system in an air conditioner that can suppress the generation of algae.

[0002]

2. Description of the Related Art Air conditioning equipment for cooling and heating using an absorption refrigerator is widely used as an air conditioning equipment for hospitals, public facilities, and other buildings. That is, the air conditioning equipment using the absorption refrigerator has a lower operating noise and quieter than the heat pump air conditioning equipment, and does not use the cooling tower for the refrigerator during the heating operation. This is because, when the outside air temperature drops too much in winter, there is no need to worry about a decrease in the heating capacity caused by the heat pump method.

[0003] In an air conditioning system for cooling and heating using an absorption refrigerator, a water-cooled condenser is used as a heat exchanger, so that a cooling tower is required. This cooling tower sprays and drops hot water sent from a condenser of a refrigerator and applies it to outdoor air to cool it and reuse it as cooling water for the condenser. In this configuration, since the amount of water decreases due to evaporation of water, approximately 3% of the amount of circulating water is supplied to the cooling water as replenishment water every hour during normal operation.

[0004] Such an air conditioner for cooling and heating using an absorption refrigerator requires a circulation line for cooling water that connects the condenser and the cooling tower. In this circulation line, the temperature of the hot water flowing from the condenser to the cooling tower is about 35 degrees Celsius, and the temperature of the cold water flowing from the cooling tower to the condenser is about 32 degrees Celsius. Such a temperature is optimal as a condition under which various bacteria or algae grow and grow in the water tank and the circulation pipeline of the cooling tower.

[0005] For this reason, there is a danger that the circulating cooling water may become a hotbed of various bacteria such as Legionella bacteria. Therefore, disinfection of cooling water is indispensable. On the other hand, if algae occur in the cooling water,
Algae adheres to the inner surface of the cooling tower or the circulation pipeline, causing clogging of the piping, which reduces the cooling water circulation efficiency,
In addition, the operating efficiency of the equipment is also reduced. Therefore, injecting a drug is performed to prevent the generation of algae in the cooling water.

On the other hand, fresh water is successively added to the cooling water in order to replenish the evaporation, but an analyte such as silica contained in the new water is generated in the piping of the circulation pipe, and the content is gradually increased. Therefore, the total amount of cooling water after being used for a certain period of time must be replaced.

However, since this cooling water contains a disinfectant for preventing the occurrence of various bacteria and a chemical for preventing the generation of algae, if it is discharged as wastewater as it is, it contaminates the natural environment such as sewage, river water, lake water, and seawater. Become a source of pollution.

Conventionally, in a cooling water contamination prevention system for an air conditioner of this type, the cooling water to be replaced is subjected to a chemical neutralization treatment prior to its release.

[0009]

The above-mentioned conventional system for preventing the contamination of cooling water in an air conditioner requires a troublesome work and a lot of time for drainage treatment and management of the contaminated cooling water to be replaced. There is a point.

[0010] The reason is that a chemical for inhibiting the generation of various bacteria or algae generated in the cooling water that needs to be replaced is a source of pollution of the natural environment. Require drainage equipment for neutralization treatment, monitor surrounding environmental conservation, and require administrative work to spray neutralization chemicals when chemical neutralization treatment is required Because.

An object of the present invention is to solve the above problems,
An object of the present invention is to provide a cooling water contamination prevention system in an air conditioner which can easily prevent the generation of various bacteria and algae of the cooling water with a simple facility while avoiding the injection of a chemical which is a polluting source of wastewater.

[0012]

A pollution control system for cooling water in an air conditioner according to the present invention is provided in an air conditioner and connects a heat exchanger in a building and an outdoor cooling tower to supply cooling water. It has an organic matter decomposition unit that is inserted into the circulating piping and that decomposes organic matter flowing through the cooling water using a photocatalytic reaction.

[0013] The photocatalytic reaction of the organic matter decomposing unit prevents the generation of various bacteria or algae generated in the cooling water, so that it is not necessary to inject the chemical which has been a pollutant to nature into the cooling water. Therefore, the cooling water can be drained without neutralization. As a result,
It is possible to eliminate the necessity of the neutralization processing equipment and to greatly reduce the work of pollution control for the surrounding natural environment.

One of the specific means is that the organic substance decomposing unit uses an optical semiconductor film as a photocatalyst, and this optical semiconductor film enables at least one of receiving natural light and artificial ultraviolet irradiation. It is to be installed in place.

The organic substance decomposing unit has an optical semiconductor film which uses titanium oxide as a photocatalyst and maintains a predetermined shape. The optical semiconductor film has a cooling water flowing channel formed by the optical semiconductor film therein, and at least an optical semiconductor film. The semiconductor film includes a case having a light transmitting surface for transmitting light, and the optical semiconductor film having a predetermined shape includes a plurality of optical semiconductor films, and a bypass flow channel for cooling water from a water inlet to a water outlet inside the case. Are formed and are detachably fixed.

Further, the optical semiconductor film has a planar shape which is maintained on a flat surface of the substrate and has a surface substantially perpendicular to the pipe direction in which the cooling water flows, and the adjacent ends alternately have the tips. It is preferable to form a zigzag bypass flow passage which is arranged near the other party's base and meanders the cooling water, and is further formed on both surfaces of the substrate.

[0017]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a diagram showing a cooling water pipe and a system according to an embodiment of the present invention.

The system for preventing contamination of cooling water in the air conditioner shown in FIG. 1 is for an air conditioner for cooling and heating using an absorption refrigerator, and a heat exchanger using a water-cooled condenser inside a building 1. 2, and a cooling tower 3 for cooling cooling water to be sent to the heat exchanger 2 outdoors.

The cooling tower 3 is provided with a water tank 7, a shower 8, and a blower 9. In addition, as a circulation pipe line for the cooling water, a pipe line including a water supply pipe 4 for sending the heat exchanger 2 from the cooling tower 3 and a return pipe 5 for sending the heat exchanger 2 to the cooling tower 3 is provided. I have.

A pump 6 is provided in the water supply pipe 4, and the pump 6 pumps out cooling water filled in a water tank 7 in the cooling tower 3 and sends it to the heat exchanger 2 of the building 1. The wastewater returned from the heat exchanger 2 to the cooling tower 3 is sent to the shower 8 of the cooling tower 3 and is ejected from the shower 8 in the form of a mist. The sprayed wastewater is cooled by receiving the outdoor air sucked by the rotation of the blower 9 and stored in a water tank. The cooling water in the water tank 7 flows through the water supply pipe 4 again by the pump 6 and is sent to the heat exchanger 2 to circulate repeatedly in the pipe path.

In the middle of the return pipe 5, an organic matter decomposition unit 10 according to the present invention is provided. The location of the organic matter decomposition unit 10 is not limited to the return pipe 5 as long as it can be inserted into the pipe.

The organic matter decomposing unit 10 utilizes a photocatalytic reaction in order to avoid the administration of chemicals to the cooling water. That is, the organic matter decomposition unit 10 is installed in a place where natural light can be received in the piping. Of course, ultraviolet irradiation may be artificially performed instead of natural light.

Next, referring to FIG. 2, the mechanism of the decomposition of organic substances by the photocatalyst in the optical semiconductor film 11 using titanium oxide as the photocatalyst will be described.

The optical semiconductor film 11 is formed of titanium oxide deposited on the surface of the substrate 13 at a low temperature. Optical semiconductor film 11
When ultraviolet rays shorter than 400 nanometers are applied to the crystal, electrons (e ⁻ ) and holes (h ⁺ ) are generated inside the titanium oxide crystal.

On the other hand, oxygen dissolved in the air or water receives electrons from the titanium oxide of the optical semiconductor film 11 to cause a reduction reaction, thereby generating a superoxide anion (· O ₂ ) as active oxygen, The holes oxidize the water adsorbed on the surface of the titanium oxide to form hydroxyl radicals (.O
H).

The mechanism of the decomposition of organic substances by the photocatalyst is that these chemical species having a large oxidizing power decompose organic compounds, and eventually decompose organic substances into carbon dioxide and water. In the system for preventing contamination of cooling water in an air conditioner according to the present invention, the photosemiconductor film 11 made of titanium oxide is used as a photocatalyst, and various bacteria on the photosemiconductor film are killed by the action of decomposing organic substances of the photocatalyst.
At the same time, the activity of the algal species in the cooling water was stopped,
It suppresses the occurrence of algae.

Next, the organic matter decomposition unit 10 in FIG. 1 will be described with reference to FIG.

FIG. 3A is a plan view of the organic matter decomposition unit 10, FIG. 3B is a side view of the organic matter decomposition unit 10,
FIG. 3C is a side view showing an outline of a fixed attachment portion of the optical semiconductor film 11. Parts that are not related to the present invention are not shown.

In the illustrated organic matter decomposition unit 10,
Appearance is a rectangular parallelepiped structure in which five surfaces excluding the top surface in the plan view are the case body 15 and the top surface is the transparent cover 16, and the inlet 17 is provided on one end surface perpendicular to the pipe direction, and is provided on the other end surface. Each of the water ports 18 is provided and opened, and is connected to a pipe line.

Inside the organic matter decomposition unit 10, a guide 19 as shown in FIG.
The substrate (14 in FIG. 4) having the optical semiconductor film 11 on both planes is detachably held by the guide 19 as a partition plate for flowing cooling water in the direction of the piping.

Here, an embodiment of the structure of the optical semiconductor film 11 and the substrate 14 will be described with reference to FIG.

The optical semiconductor film 11 is formed by welding titanium oxide at a low temperature on the surface of the base material 13 using a polyester nonwoven fabric as the base material 13. The base material 13 on which the optical semiconductor film 11 is welded is adhered to both surfaces of the substrate 14 to maintain the shape.
The substrate 14 has a flat plate shape on both sides, and holds the shapes of the base material 13 and the optical semiconductor film 11 in a planar shape. Substrate 14
By using a transparent plate such as a transparent vinyl chloride plate, light incident on the inside of the transparent plate can be effectively used for a photocatalytic reaction.

Returning to FIG. 3, the case structure and the function of the organic matter decomposition unit 10 will be described with reference to FIG.

The case is, as described above, the case body 15.
And a transparent cover 16 for covering the upper surface. The transparent cover 16 is made of a material such as an acrylic plate and covers the opening of the case body 15 in a watertight manner. The hollow rectangular parallelepiped of the case body 15 is the water inlet 1
A water channel for flowing cooling water from 7 to the water outlet 18 is formed.

A guide 19 is provided on the inner side surface of the case body 15.
Is provided, and the guide 19 inserts and fixes the substrate 14 having the optical semiconductor film 11 as a partition plate of the flowing water channel in a posture of maintaining a plane perpendicular to the pipe direction from the water inlet 17 to the water outlet 18. At this time, the plurality of substrates 14 alternately open the upper and lower edges to form a zigzag bypass flow passage for meandering the cooling water.

It should be noted that, as shown in FIG.
Is connected to the building 1 on the upstream side of the return pipe 5, and the water outlet 18 is connected to the cooling tower 3 on the downstream side.
It is desirable that a diffuser 20 for converting the cooling water into a low-speed high-pressure is installed in the case facing the case 7.

Returning to FIG. 1, the functional operation of the organic matter decomposition unit 10 will be described with reference to FIGS.

The cooling water warmed in the heat exchanger 2 by the condenser installed in the building 1 flows through the return pipe 5 as waste water, flows into the case of the organic matter decomposition unit 10 from the water inlet 17, and After passing through a bypass flow channel formed inside the case by the substrate 14 serving as a flow channel partition plate, the water flows out of the outlet 18 again to the return pipe 5 and is sent to the cooling tower 3.

In the case of the organic matter decomposition unit 10, cooling water is supplied to the optical semiconductor film 1 on a plurality of substrates 14.
Since the organic matter contained in the water is decomposed by the photocatalysis due to the repeated touch of the surface 1, the bacteria in the water are killed and the activity of the algae species is stopped.

In the above description and drawings, the organic substance decomposing unit has a rectangular shape and the substrate has a rectangular shape. Further, the materials of the optical semiconductor film, the base material, and the substrate are not limited to the above description as long as they satisfy the above functions. Further, it has been described that the optical semiconductor film is formed on both sides of the substrate, and that the substrate is a transparent plate.
One side of the substrate or an opaque plate may be used. In this case, the function is reduced, but the effect of solving the conventional problems can be exerted.

In the above description, only the upper cover of the case of the unit is a transparent cover, but the position of the transparent portion may be at least a surface in the light incident direction. However, from the aspect of promoting photocatalysis, the entire surface of the case is transparent so that incident light can irradiate the optical semiconductor film over a wide range.
The partition plate is desirably transparent so that the optical semiconductor film can be irradiated from the inside.

It is desirable to use natural light for the energy required for photocatalysis, but when natural light cannot be used, the photocatalytic treatment can be performed by artificially irradiating ultraviolet rays.

As described above, the cooling water is repeatedly subjected to photocatalysis by the optical semiconductor film serving as a plurality of flow channel partition plates while passing through the bypass flow channel formed inside the case of the organic matter decomposition unit. The organic matter contained in the cooling water is decomposed. By this decomposition action, various bacteria in the cooling water are killed, and the generation of algae is suppressed. That is, all organic substances in water, such as germs and algae, are repeatedly subjected to photocatalysis, and are eventually decomposed into carbon dioxide and water, so that there is almost no residue in the cooling water.

Normally, the ratio between the amount of cooling water and the area of the optical semiconductor film varies depending on the quality of the water for treatment. In this embodiment, the amount of the optical semiconductor film made of titanium oxide is 1 square meter with respect to the amount of water of 1 to 3 tons. It is arranged in the ratio of.

[0046]

Here, an organic matter decomposition unit according to the present invention was installed in a cooling water circulation line in a cooling and heating system in a hospital using a water-cooled condenser as a heat exchanger, and the generation of Legionella bacteria changed with time. Was measured. In this embodiment, the optical semiconductor film is provided at a rate of 0.5 square meters per 1 ton of cooling water. Tap water was used as cooling water.
The period is one month from October 4 to November 4.

FIG. 5 shows the measurement results. In this result, in addition to Legionella bacteria, the total silica content, electric conductivity, and the pH value of the cooling water were measured.

First, five days before the start of the measurement, the measurement was performed for the sterilization treatment by injection of the drug which had been performed so far. As a result, no Legionella bacteria were detected, but the total silica concentration reached approximately 35 mg / l, indicating the necessity of changing the cooling water at a predetermined time as described above.

After the replacement of the cooling water, the organic matter decomposition unit of the present invention was installed in the circulation line, and the operation of the cooling and heating equipment was started and the measurement was started.

As a result of the measurement over 31 days, there was no detection of Legionella bacteria, and the same effect as the conventional drug injection was obtained.
That is, the effectiveness of the photocatalytic action of the titanium oxide optical semiconductor film was proved.

According to the measurement results, the electric conductivity shows a low value because there is no influence by the injection of the drug. Notably, the total silica concentration in the cooling water shows a significant reduction, by a factor of two or more, relative to the value at the time of drug injection. As described above, since the amount of silica in the cooling water can be kept low, the interval of the cooling water replacement time can be made longer and the replacement time can be delayed.

According to such a result, even if the cooling water is sprayed into the air by the shower of the cooling tower, there is no danger that various bacteria will be sprayed into the air. Also, since no algae are generated, there is no hindrance to operation due to clogging of the piping.

[0053]

As described above, according to the present invention, the structure of a unit provided for eliminating various bacteria and suppressing the generation of algae is simple, and the generation of algae is eliminated by eliminating various bacteria in cooling water. The effect that there is no need to inject a chemical which is a polluting source of the natural environment in order to suppress it is obtained.

The reason is that an optical semiconductor film is inserted into the cooling water flow channel to effectively utilize the photocatalytic action on the cooling water, thereby killing various bacteria in the cooling water and suppressing the generation of algae. Because you can.

Further, since the amount of silica generated in the cooling water can be suppressed by using the photocatalyst, the effect that the system can be continuously operated for a long time can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cooling water pipe and a system configuration showing an embodiment of the present invention.

FIG. 2 is an explanatory view showing one mode of a mechanism of an organic substance decomposition action by a photocatalyst.

FIG. 3 is a plan view, a side view, and an explanatory view showing an attached state of an optical semiconductor film showing one configuration of the organic matter decomposition unit in FIG.

4A and 4B are a perspective view and a side view showing one mode of the shape holding structure of the optical semiconductor film in FIG.

FIG. 5 is a graph showing measurement results in one example of the present invention.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 building 2 heat exchanger (condenser) 3 cooling tower 4 water supply pipe 5 return pipe 6 pump 7 water tank 8 shower 9 blower 10 organic matter decomposition unit 11 optical semiconductor film 13 base material 14 substrate 15 case body 16 transparent cover 17 water inlet 18 Outlet 19 Guide 20 Diffuser

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Teruo Konishi 1933-10 Shimonumabe, Nakahara-ku, Kawasaki-shi, Kanagawa Prefecture Within NEC Environmental Engineering Co., Ltd. (72) Inventor Hiroshi Ida 6-5-1, Nishishinjuku, Shinjuku-ku, Tokyo (72) Inventor Hideo Arai 2--17-17 Akasaka, Minato-ku, Tokyo F-Term in GP Corporation (reference) 3L054 BE03 BE10 4D037 AA08 AB02 AB03 BA16 BA18 BB04 CA11 4D050 AA08 AB06 BB01 BC06 BC09 BD02 CA09

Claims (6)

[Claims] 1. A system for preventing contamination of cooling water used in an air conditioner, wherein the system is inserted and disposed in a piping for connecting a heat exchanger in a building and an outdoor cooling tower to circulate the cooling water, A pollution control system for cooling water in an air conditioner, comprising: an organic matter decomposing unit that decomposes organic matter contained in the cooling water flowing inside using a photocatalytic reaction. 2. The organic matter decomposing unit according to claim 1, wherein the organic substance decomposing unit includes an optical semiconductor film used as a photocatalyst, and the optical semiconductor film is installed in a place where at least one of natural light reception and artificial ultraviolet irradiation is enabled. A pollution control system for cooling water in air conditioning equipment. 3. The organic matter decomposition unit according to claim 1, further comprising an optical semiconductor film having a predetermined shape using titanium oxide as a photocatalyst, wherein the cooling water flow channel formed by the optical semiconductor film is provided inside. And a case having a light transmitting surface for transmitting light to at least the optical semiconductor film. 4. The optical semiconductor film according to claim 3, wherein a plurality of optical semiconductor films having a predetermined shape are provided, and a detour flow channel for cooling water is formed inside the case from a water inlet to a water outlet to be detachable. A pollution control system for cooling water in an air conditioner, which is fixed. 5. The optical semiconductor film according to claim 4, wherein the optical semiconductor film forms a partition plate having a planar shape held on a flat surface of the substrate and having a surface substantially perpendicular to a piping direction in which the cooling water flows. A cooling water pollution prevention system for an air conditioner, wherein the zigzag bypass flow passage for meandering the cooling water is formed by alternately arranging the tips in the vicinity of the base of the partner. 6. The system according to claim 5, wherein the optical semiconductor film is formed on both surfaces of the substrate.