JPH11226363A - Method for cleaning circulating cold and hot waters for air conditioning - Google Patents

Abstract

PROBLEM TO BE SOLVED: To efficiently remove impurities such as metal oxides, bacteria or the like in circulating cold and hot water for air conditioning. SOLUTION: Cold water and hot water to be used for air conditioning by circulation is introduced, as a stock solution, into a hollow fiber membrane module 11 for cold water and a hollow fiber membrane module 8 for hot water respectively in such a state that both cold and hot waters are pressurized, and thereby, fine particles contained in the stock solution are filtered by the hollow fiber membrane, and further, these particles captured by the hollow fiber membrane during filtering are stripped by a physical means. In addition, the fine particles stripped are discharged, together with the stock solution, to the outside of a filtration system. The filtration rate by the hollow fiber membrane module is preferably within the range of 30-150 l/hr per 1 m<2> of effective membrane area of the hollow fiber membrane.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for purifying circulating chilled water for cooling and heating and a purifying apparatus used for the method.

[0002]

2. Description of the Related Art In recent years, a district cooling / heating system using circulating cooling / heating water has been introduced as a cooling / heating system capable of performing cooling / heating of a plurality of neighboring buildings as well as cooling / heating of a single building or the like. . A cooling and heating system using circulating chilled and hot water means that a large amount of hot water and cold water are made and stored in a heat storage tank using, for example, a heat pump operated by electric power, and the hot water is used where heating is required. A system that supplies and cools and cools water where it is needed, collects hot water whose temperature has decreased due to use and cold water whose temperature has increased, and uses it again as heat and cold water of a predetermined temperature using a heat pump etc. It is. It is generally assumed that the temperature of the hot water is 40 to 50 ° C and the temperature of the cold water is 5 to 10 ° C.

In this cooling / heating system, it is known that circulating cold / hot water is contaminated by metal oxides derived from pipes and bacteria mixed into water. For example, heat exchangers that exchange heat between circulating chilled water and indoor air use copper tubes with good thermal conductivity, but copper tubes are made of metal oxides such as iron rust. It is known to be affected by corrosion. In addition, the heat efficiency may decrease due to the adhesion of the scale derived from the metal oxide. Furthermore, the bacteria existing in the circulating cold and hot water may similarly cause corrosion of the copper tube and decrease in thermal efficiency.

[0004] As a countermeasure to prevent the generation of metal oxides and bacteria, it has been conventionally known to add chemicals such as anticorrosives, rust preventives and bactericides to circulating cold and hot water. It is also known to filter circulating cold / hot water with a wind-type or pleated-type filter in order to remove generated metal oxides and bacteria.

[0005]

When a chemical such as an anticorrosive, a rust inhibitor or a bactericide is added, a certain purification effect is recognized, but the generation of metal oxides and the growth of bacteria are completely suppressed. It is impossible. Furthermore, with the recent rise in disaster prevention awareness, there has been an increasing demand for using the circulating cold and hot water as emergency drinking water, and it can be said that the addition of chemicals is not preferred. In addition, the method of filtering circulating cold and hot water with a wind type or pleated type filter to remove mixed metal oxides, etc.
It is known that satisfactory separation accuracy is not always obtained, and that the filter needs to be replaced frequently due to clogging of the filter.

An object of the present invention is to provide a method for purifying circulating chilled water for cooling and heating, which is capable of efficiently removing impurities such as metal oxides and bacteria in the circulating cooling and heating water for cooling and heating, and a purification device used for the method. To provide.

[0007]

According to the purification method of the present invention, which solves the above-mentioned problems, cold or hot water circulated for cooling or heating is pressurized as a stock solution in a hollow fiber membrane module. And filtering the fine particles contained in the stock solution through a hollow fiber membrane, separating the fine particles captured by the hollow fiber membrane at the time of filtration by a physical method, and discharging the separated fine particles together with the stock solution to the outside of the filtration system. Features. The filtration rate in the hollow fiber membrane module is preferably in the range of 30 to 150 liter / hour per 1 m ² of the effective membrane area of the hollow fiber membrane.

Here, the separation of the trapped fine particles by the physical washing method means (1) a step of introducing a gas having a pressure lower than the pressure at which the gas is released from the stock solution side of the hollow fiber membrane into the filtrate side, and A method of washing the hollow fiber membrane with air bubbles for a predetermined time simultaneously with the start of the pressurization or after the pressurization for a predetermined time, (2) introducing a permeate into the filtrate using a pump. A permeate backwashing method, (3) a gas backwashing method in which a gas having a pressure higher than the pressure at which gas is released from the stock solution side of the hollow fiber membrane is introduced into the filtrate side and a gas is ejected to the stock solution side,
(4) a method of washing the surface of the hollow fiber membrane and the inside of the hollow fiber membrane module by repeating drain discharge and water filling; (5)
It means flushing cleaning and the like. Note that the type of the physical cleaning method can be appropriately selected according to the characteristics of the hollow fiber membrane module used.

A circulating chilled and hot water purifying apparatus for cooling and heating according to the present invention comprises a circulating chilled and hot water having a circulating pipe for circulating cold or hot water for cooling or heating, and a heat storage tank for storing the chilled or hot water. A device for use with a cooling and heating system, comprising: (1) a stock solution for cold and hot water that is provided near an outlet of a liquid sending pump that supplies cold or hot water to a location requiring cooling or heating and is connected to a hollow fiber membrane module; A pipe, (2) a hollow fiber membrane module into which cold water or hot water is introduced as a stock solution from the stock solution pipe in a pressurized state, and (3) physical cleaning of fine particles captured by the hollow fiber membrane module by filtration. And (4) a filtrate pipe for returning a filtrate obtained by filtering cold or hot water to a heat storage tank or a circulation pipe. .

Here, the cooling and heating system comprises a cooling water circulation pipe for circulating cold water, a hot water circulation pipe for circulating hot water, a cold water heat storage tank for storing cold water, and a hot water heat storage tank for storing hot water. In this system, the hollow fiber membrane module, the undiluted solution pipe and the filtrate pipe connected thereto, and the physical washing mechanism are respectively provided on the cold water circulation side and the hot water circulation side. It may be provided separately. Further, the cooling and heating system may have only one of a cooling water circulation system and a hot water circulation system,
Furthermore, as described later, one system may be switched between cold water and hot water. In addition, it is preferable that the average pore diameter of the hollow fiber membrane constituting the hollow fiber membrane module is 0.2 μm or less in order to completely remove bacteria.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS A purifying apparatus used in a method for purifying circulating chilled water for cooling and heating according to the present invention will be described with reference to the drawings. FIG. 1 schematically shows the flow of the circulating cooling / heating water for cooling / heating according to the present invention. In FIG. 1, heat exchange is performed by a heat pump A, and hot water and cold water (generally, hot water of 40 to 50 ° C. and cold water of 5 to 10 ° C.) at a predetermined temperature are produced. And stored in the cold water heat storage tank 2. Where heating is required (for example, a building)
, Hot water is sent from the hot water storage tank 1 of the cooling and heating system by the hot water sending pump 3. This hot water is returned to the heat pump A after heat exchange and cooling by the heater 4, and is again turned into hot water of a predetermined temperature by the heat pump A. On the other hand, chilled water is sent from a chilled water storage tank 2 of the cooling and heating system by a chilled water sending pump 5 to a place where cooling is required (for example, another building).
The chilled water is returned to the heat pump A after heat exchange and heating by the cooling machine 6, and is again cooled to a predetermined temperature by the heat pump A.

Here, the capacities of the hot water heat storage tank 1 and the cold water heat storage tank 2 do not have to be equal, and each capacity can be appropriately set according to the required amount of cold water and hot water. Also, cooling and heating requirements vary by season,
It is effective to make the capacities of the hot water heat storage tank 1 and the cold water heat storage tank 2 variable. For example, ten tanks for a heat storage tank are prepared, the tanks are put together, and the flow paths are connectable, and according to the required ratio of each of cold water and hot water,
In winter, for example, use 8 for heating and 2 for cooling,
Conversely, the cooling and heating system can be operated in such a way that two are used for heating and eight are used for cooling in summer.

The apparatus for purifying circulating cold / hot water for cooling / heating provided in the present invention filters the above-described cold water and hot water through a hollow fiber membrane. When purifying hot water,
A part of the hot water is taken out from the hot water feed pipe 7 at the rear of the hot water feed pump 3, and the hot water is supplied to the filtering device 8. The filtrate filtered by the filtration device 8 is returned directly to the hot water heat storage tank 1 by the filtrate pipe 9 as shown in FIG. 1, or is returned to the hot water feed pipe. Similarly, when purifying the chilled water, a part of the chilled water is taken out from the chilled water feed pipe 10 at the rear of the chilled water feed pump 5, and the chilled water is supplied to the filtration device 11. The filtrate filtered by the filtration device 11 is:
It is returned directly to the cold water storage tank 2 by the filtrate pipe 12 (FIG. 1), or is returned to the cold water supply pipe.

Next, an example of a filtration device used in the present invention will be described with reference to FIG. FIG. 2 shows a schematic sectional view of an example of a hollow fiber membrane module used as a filtration device in the present invention. In this filtration device, a filtration device (hollow fiber membrane module) 13 in which a hollow fiber membrane element 16 is housed.
Is separated by a partition plate 14 such that the upper portion is on the filtrate side B and the lower portion is on the undiluted solution side C. The protective plate 15 in which the hollow fiber membrane elements 16 are accommodated is attached to the partition plate 14 in a number corresponding to the number of the hollow fiber membrane elements 16. On the filtrate side B, the filtrate outlet 17 and the pressurized gas inlet 1
8, a stock solution side C is provided with a stock solution inlet 19, a gas outlet 20, a gas inlet 21 and a stock solution outlet 22. In the present invention, a filtration device is provided on each of the hot water side and the cold water side. On the hot water side, an undiluted solution inlet 19 is connected to the vicinity of the outlet of the hot water feed pump 3 by a predetermined pipe, and the filtrate outlet 17 is connected to the hot water heat storage tank 9 by a predetermined pipe.
Alternatively, on the chilled water side, an undiluted solution inlet 19 is connected near the outlet of the chilled water feeding pump 5 by a predetermined pipe, and a filtrate outlet 17 is connected to the chilled water heat storage tank 12 or the chilled water feeding pipe by a predetermined pipe. Connected to piping.

Next, an example of an operation method of the purification device of the present invention will be described with reference to FIG. 3 by taking an external pressure total filtration system as an example. With all valves closed, the gas outlet valve 26, the stock solution inlet valve 23 and the filtrate outlet valve 2
5, the undiluted solution is introduced into the undiluted solution side D of the filtering device 27, and after the undiluted solution overflows from the gas discharge valve 26, the gas discharge valve 26 is closed to start filtration. With the passage of the filtration time, metal oxides and bacteria adhere to the membrane surface of the hollow fiber membrane element 28, and the filtration ability is reduced.
Wash the hollow fiber membrane. That is, the filtration is stopped by closing the stock solution inlet valve 23 and the filtrate outlet valve 25 opened in the filtration step, and then opening the gas outlet valve 26 and the pressurized gas inlet valve 24 while operating the air compressor 31. The pressurized gas is filtered to the filtrate side D
And a pressurizing step is performed. At this time, the filtrate in the undiluted solution D and in the hollow fiber membrane is pushed out to the undiluted solution side E through the wall surface of the hollow fiber membrane, and is discharged to the outside through the gas discharge valve 26. Further, at the same time as the start of the pressurizing step or after the pressurizing step has been performed for a predetermined time, the gas inlet valve 30 is opened, and cleaning with air bubbles is performed for a predetermined time. After the above-described cleaning step, the gas inlet valve 30 is closed, and the undiluted liquid outlet valve 2 is closed.
After opening the drain 9 and discharging the drain, the process returns to the filtration step.

FIG. 4 shows the correlation between each step and the opening and closing of the working valve in the basic operation method of the filtration device illustrated in FIG. Here, in FIG. 4, when a circle is attached, it means that the valve is open. In addition to this basic operation method, by repeating drain discharge and water filling, other processes are added as necessary, such as a process of cleaning the surface of the hollow fiber membrane and the inside of the hollow fiber membrane module, a flushing cleaning process, etc. It is also possible.

The hollow fiber membrane used in the present invention includes a polysulfone resin hydrophilized by a polyvinyl alcohol resin, a polysulfone resin to which a hydrophilic polymer is added, a polyvinyl alcohol resin, and a polyacrylonitrile resin. , A material made of a hydrophilic material such as a cellulose acetate-based resin or a polyethylene-based resin subjected to hydrophilization has excellent hydrophilicity, so that the SS component is hardly adhered and the attached SS component is excellent in releasability. Is preferred,
Hollow fiber membranes made of other materials can also be used.
For example, polyolefin, polysulfone, polyethersulfone, ethylene-vinyl alcohol copolymer, polyacrylonitrile, cellulose acetate, polyvinylidene fluoride, polyperfluoroethylene, polymethacrylate, polyester, polyamide Hollow fiber membranes composed of organic polymer materials such as
A hollow fiber membrane made of an inorganic material such as a ceramic material can be selected according to the use conditions, desired filtration performance, and the like. Here, a polysulfone-based resin hydrophilically treated with a polyvinyl alcohol-based resin, a hollow fiber membrane made of a polysulfone-based resin or a polyvinyl alcohol-based resin to which a hydrophilic polymer is added, not only has the excellent hydrophilicity described above, It is particularly preferable because it has excellent heat resistance and can stably filter circulating hot water. When an organic polymer material is used, it may be a material obtained by copolymerizing other components in an amount of 30 mol% or less, or a material obtained by blending another material in an amount of 30 wt% or less.

When using an organic polymer type hollow fiber membrane,
The method for producing the hollow fiber membrane is not particularly limited, and a method appropriately selected from known methods can be adopted according to the properties of the material and the desired hollow fiber membrane performance. Generally, a melt spinning method, a wet spinning method, a dry-wet spinning method and the like are employed.

The pore size of the hollow fiber membrane used in the present invention is not particularly limited, but is preferably in the range of 0.001 μm to 1 μm because it has high water permeability and a small possibility that filtration efficiency is reduced. It is particularly preferable that the particle size is 0.2 μm or less, at which bacteria can be completely removed by filtration.
The term “average pore size” as used herein refers to a particle size of a reference substance from which 90% of a reference substance having a known particle diameter such as colloidal silica, emulsion, or latex is filtered out through a hollow fiber membrane. The pore diameter is preferably uniform. If it is an ultrafiltration membrane, based on the reference substance as described above,
Although it is impossible to determine the pore size, it is preferable that the molecular weight cut off is 3000 or more when the same measurement is performed using a protein having a known molecular weight.

In view of the mechanical properties of the hollow fiber membrane and the membrane area as a module, the outer diameter of the hollow fiber membrane fiber is 200
Preferably, it is set within the range of ~ 3000 µm.
More preferably, it is in the range of 00 to 2000 μm. Similarly, the thickness of the hollow fiber membrane is preferably in the range of 50 to 700 μm, and more preferably in the range of 100 to 600 μm.

In the present invention, the hollow fiber membrane is modularized and used for filtration. The form of the module can be appropriately selected according to the filtration method, filtration conditions, washing method, etc., for example, a bundle of tens to hundreds of thousands of hollow fiber membranes formed into a U-shape in the module, One end of the fiber bundle is sealed at once with a suitable sealing material, one end of the hollow fiber bundle is sealed one by one with a proper sealing material (free state), hollow fiber fibers A bundle having both ends opened is exemplified. As the hollow fiber membrane module of the present invention, it is possible to adopt a “one-end free” type module in which one end of a hollow fiber bundle is sealed in a free state one by one, as described above with reference to FIG. This is particularly preferable because the film surface cleaning effect by cleaning and gas reverse cleaning is extremely high, and the exfoliated SS component is efficiently discharged.

In the present invention, the hollow fiber membrane is housed in one or a plurality of hollow fiber membrane elements, and the hollow fiber membrane element is fixed in the housing, but the fixing method is not particularly limited. For example, the hollow fiber membrane element may be adhered to the housing, or the cartridge type hollow fiber membrane element may be fixed to the housing with a metal fitting or the like.

The purification method of the present invention has the essential step of washing the hollow fiber membrane by the physical washing method as described above. However, after filtration or back washing, the hollow fiber membrane is washed with a chemical solution to obtain a hollow fiber membrane. Organic substances, inorganic substances, and the like attached to the surface can be dissolved and removed. Here, as a method of chemical cleaning,
A method of treating with an alkali such as an aqueous sodium hydroxide solution to remove organic and inorganic substances, a method of treating with an acid such as an aqueous acid solution to remove metals, a method of treating with a cleaning agent, and a combination of these methods. There is a method of performing such a method, whereby the hollow fiber membrane can be regenerated.

A series of operations such as the filtration process, the cleaning process by a physical method, and the chemical solution cleaning process described above
It can be performed automatically by sequence control. For example, after performing filtration for a certain period of time, the membrane surface is washed once or several times by pressurization with gas and air bubbles, and then once or several times as necessary, followed by washing with a chemical solution. The washing step is automatically and continuously performed by sequence control, and the operation can be stably continued for a long period of time while alternately repeating the filtration and the washing steps of the hollow fiber membrane and the filtration line. Further, the filtration step and the washing step can be continuously repeated by sequence control, and the operation can be stably continued for a long period of time by a so-called select switch method in which back washing is manually performed when clogging becomes large. .

The filtration rate of the hollow fiber membrane module, which is the core of the purification method of the present invention, largely depends on factors such as the degree of contamination and temperature of the circulating cold and hot water as raw water, but the effective membrane area of the hollow fiber membrane is 1 m. It is preferably in the range of 30 to 150 liters / hour per ^{2 and} more preferably in the range of 50 to 100 liters / hour. When the filtration speed is set low, clogging is unlikely to occur, which is preferable in that the filtration life is prolonged. However, problems may occur in terms of installation space and apparatus cost. On the other hand, if the filtration speed is set high, it is preferable in terms of installation space and apparatus cost, but clogging proceeds early, which may cause a problem in filtration life.

The amount of circulating chilled and hot water to be purified by the purification method of the present invention can be appropriately set depending on factors such as the degree of contamination of the circulating chilled and heated water as raw water and the desired degree of purification. That is, if perfect purification is desired, the entire amount of the circulating chilled / hot water may be treated by the purification device, but in this case, there is a problem that the device becomes very large. Generally, in terms of the scale and slime reduction effect, it is preferable to install a purification device having a scale capable of treating the entire amount in about one day to one week.

As shown in FIG. 1, the purifying device according to the present invention is preferably installed in circulation lines of hot water and cold water, respectively. A method of alternately purifying both hot water and cold water may be employed. Also, in FIG.
Although the apparatus having the hot water circulation line and the cold water circulation line has been described, the cooling and heating system to which the present invention is applied may have a circulation line for only one of hot water and cold water. For example, FIG. 1 shows a cooling and heating system using a heat pump, but ice is made from water during the night using inexpensive electricity during the night, cold water is made from the ice during the day, and the cold water is circulated. The purification device as described above may be attached to the cooling system (ice storage air conditioning system).

[0028]

The present invention will be described in more detail with reference to the following examples. From the results of the following examples, it is clear that according to the present invention, it is possible to stably purify the circulating cooling and heating water for cooling and heating for a long period of time.

50 ° C. by a heat pump operated by electric power
Hot water and 5 ° C cold water, and the total capacity of the heat storage tank is 15
In a district cooling and heating system in which the ratio of hot water to cold water is 1: 1, hot water is taken out from the hot water feed pump outlet at 20 tons / hour, and a hollow fiber membrane module is used. A constant flow rate filtration was performed under the conditions of a total filtration method and a flow rate of 10 tons / hour. The hollow fiber membrane in the hollow fiber membrane module is
It is made of a polysulfone resin surface-hydrophilized with polyvinyl alcohol, has an average pore diameter of 0.1 μm, and a membrane area of 7.0 m ² . Washing of a filtration device having a total membrane area of 266 m ² containing 37 hollow fiber membrane modules composed of the “one end free” type hollow fiber membrane is performed once every 24 hours on the filtrate side of the hollow fiber membrane module. , Pressure 2.0kg
/ Cm ² by introducing air at a pressure of 60 seconds, and then blowing air at a pressure of 1.0 kg / cm ² at a flow rate of 22200 normal liters / hour for 1 minute from the lower portion of the hollow fiber membrane module on the stock solution side. After that, the whole liquid on the undiluted solution side was discharged to carry out the test. After continuous operation for one year under the above conditions, the transmembrane pressure was always stable at 0.5 kg / cm ² or less, and no corrosion of the piping was observed during this time. After continuous operation for one year, the state of scale adhesion in the pipe was confirmed, and the state was very good. In addition, the iron content, the number of common bacteria, and the number of coliforms in the filtrate throughout the entire period satisfied the water quality standards for drinking water.

Comparative Example 1 In the above example, the district heating and cooling system was operated without using the purification device according to the present invention. After 2 months, the heating efficiency decreased. After 3 months, the operation was stopped and the inside of the pipe was inspected. A large amount of scale was adhered and the copper pipe was corroded. Therefore, the copper pipe had to be updated. The iron content and general bacteria count in the circulating hot water exceeded the drinking water quality standards.

Comparative Example 2 In Example 1, instead of a filtration device using a hollow fiber membrane, a filtration device in which 12 thread-wound filters having a nominal pore diameter of 1 μm and a length of 75 cm were housed in a casing was used. Filtration of circulating hot and cold water for heating and cooling was performed at a flow rate of 10 tons / hour. As a result, the flow rate decreased due to clogging of the filter after 6 days, and the entire filter had to be replaced. After that, the operation was continued for one year, but the filter had to be replaced every 7 days on average. Further, the iron content and the number of general bacteria in the filtrate exceeded the water quality standards for drinking water.

[0032]

According to the method for purifying circulating hot and cold water for cooling and heating according to the present invention, impurities such as metal oxides and bacteria in the hot and cold water for cooling and heating can be removed with high accuracy, and the adhesion of scale by the metal oxide and Since it is possible to avoid slime generation by bacteria, it is possible to prevent corrosion of piping and a decrease in thermal efficiency due to scale and slime. Further, according to the present invention, since metal oxides and bacteria can be physically removed, it is possible to reduce the amount of conventionally added chemicals such as anticorrosives, rust preventives, and disinfectants. Becomes According to the present invention, it is possible to extend the life of the pipe and improve the thermal efficiency.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a cooling and heating system using circulating chilled water in which the present invention is used.

FIG. 2 is a schematic sectional view of an example of a hollow fiber module used in the present invention.

FIG. 3 is a diagram showing an example of an operation method of the purification device according to the present invention.

FIG. 4 is a diagram showing a basic operation method of the filtration device shown in FIG.

[Explanation of symbols]

 1: Hot water storage tank 2: Cold water storage tank 3: Hot water pump 4: Heating machine 5: Cold water pump 6: Cooler 7, 9, 10, 12: Piping 8, 11, 13, 27: Filtration Equipment (hollow fiber module)

Claims (5)

[Claims] 1. A method in which cold water or hot water circulated for cooling or heating is introduced into a hollow fiber membrane module under pressure as a stock solution, and fine particles contained in the stock solution are filtered through a hollow fiber membrane. A method for purifying circulating cold and hot water for cooling and heating, wherein fine particles captured by a hollow fiber membrane during filtration are separated by a physical washing method, and the separated fine particles are discharged out of a filtration system together with a stock solution. 2. The method according to claim 1, wherein the filtration rate of the hollow fiber membrane module is in the range of 30 to 150 liters / hour per 1 m ² of the effective membrane area of the hollow fiber membrane. 3. A purifying apparatus used together with a circulating cooling / heating water cooling / heating system having a circulation pipe for circulating cold or hot water for cooling or heating and a heat storage tank for storing the cold or hot water. A raw liquid pipe for cold / hot water that is provided near the outlet of a liquid feed pump that supplies cold or hot water to a location requiring cooling or heating and is connected to the hollow fiber membrane module. A hollow fiber membrane module respectively introduced in a pressurized state, a mechanism for separating fine particles trapped in the hollow fiber membrane module by filtration by a physical washing method, and a filtrate obtained by filtering cold or hot water. And a filtrate pipe for returning to a heat storage tank or a circulation pipe. 4. A circulating cold / hot water having a cold water circulation pipe for circulating cold water, a hot water circulation pipe for circulating hot water, a cold water heat storage tank for storing cold water, and a hot water heat storage tank for storing hot water. A purification device used together with a cooling / heating system, wherein a hollow fiber membrane module, undiluted piping and filtrate piping connected thereto, and a physical washing mechanism are separately provided on a cold water circulation side and a hot water circulation side. Claim 3
A purification device for circulating chilled and heated water for cooling and heating according to the above. 5. The apparatus according to claim 3, wherein the hollow fiber membrane constituting the hollow fiber membrane module has an average pore size of 0.2 μm or less.