JP5417213B2 - Indirect evaporative cooling type external air conditioning system - Google Patents

Description

  The present invention relates to an external air conditioning system for drainless air conditioning of buildings such as hospitals and hotels, and more particularly to an indirect evaporative cooling external air conditioning system using a desiccant dehumidifier and an indirect evaporative cooler.

  Conventionally, when air-conditioning a room in a building such as a hospital or a hotel, air that has been subjected to an external air load treatment by an external air conditioner is introduced into an indoor unit such as a fan coil unit (FCU) installed in each room. Air conditioning is used. However, during cooling in summer, due to latent heat load processing, condensation occurs in the cooling coils of the external air conditioner and indoor unit due to dehumidification, and there is a problem of IAQ (air quality) degradation due to microbial contamination.

  Therefore, in order to improve the problem of dew condensation inside the external air conditioner and the indoor unit, the present inventor used the indoor unit as it is as an existing air conditioner and built a desiccant dehumidifier into the existing air conditioner. A system was proposed (Patent Document 2).

  This drainless air-conditioning system uses a desiccant dehumidifier to dehumidify (latent heat treatment), cool it with a cooling coil (sensible heat treatment), and blow it into the room to prevent the conditioned air from dropping below the dew point temperature. doing.

  However, the desiccant dehumidifier uses a refrigeration cycle such as a refrigerator or a heat pump in order to cool the air whose temperature has been increased by dehumidification, so that the COP tends to decrease, and improvement is necessary from the viewpoint of energy saving.

  From the viewpoint of energy saving, as shown in Patent Document 1, it is preferable to cool the dehumidified air that has been dehumidified by the desiccant dehumidifier and raised in temperature with an evaporative heat exchanger. This evaporative heat exchanger is composed of alternately laminated channels through which dehumidified air passes and channels through which clean water passes, and evaporates by exchanging the clean water with dehumidified air, and uses the latent heat of evaporation to remove dehumidified air. It is what cools. However, since clean water is required for cooling the dehumidified air and is drained after heat exchange and is not collected and used, there is a problem of wasteful use of clean water. In addition, since an indirect heat exchanger uses a paper-based material, there is a concern that bacteria and bacterial growth cannot be avoided.

  Therefore, cooling water such as a cooling tower is used as cooling water, and the cooling water and dehumidified air dehumidified by the desiccant dehumidifier are cooled by indirect heat exchange using an indirect evaporative cooler. In addition, an energy-saving indirect evaporative cooling type system can be obtained.

JP 2007-24467 A Japanese Patent No. 3559255

  However, in the cooling by a general cooling tower for introducing outside air, the temperature of the cooling water can be cooled only to 30 ° C., and the cooling water of about 30 ° C. cannot be cooled to the room temperature level (about 26 ° C.) necessary for cooling, Since the cooling capacity is insufficient, there is a problem that the load on the existing air conditioner becomes large.

  Accordingly, an object of the present invention is to provide an indirect evaporative cooling type external air conditioner system that can solve the above-mentioned problems and can combine existing air conditioners and desiccant dehumidifiers to cool the dehumidified air from the desiccant dehumidifiers to a room temperature level. is there.

  In order to achieve the above object, the invention of claim 1 combines an existing air conditioner for air-conditioning an air-conditioning space with a desiccant dehumidifier, introduces outside air with the desiccant dehumidifier and dehumidifies it through a ventilation air supply line. The dehumidified air is supplied to the air conditioner, and the air in the air-conditioned space is exhausted to the desiccant dehumidifier via the ventilation air exhaust line, and the exhaust air is exhausted by exchanging heat with the dehumidified air. In an indirect evaporative cooling external air conditioning system for cooling and supplying dehumidified air heat-exchanged to an existing air conditioner, an indirect evaporative cooler that cools the dehumidified air is connected to the ventilation air supply line. A cooling tower that circulates and circulates cooling water is connected to the indirect evaporative cooler, and a portion of the cooled dehumidified air cooled by the indirect evaporative cooler is introduced into the cooling tower and exhausted to the atmosphere. An indirect evaporative cooling type outer conditioner system characterized by connecting a line.

  The invention of claim 2 introduces 0.1 to 0.5 times of the outside air into the desiccant dehumidifier with respect to the circulated air circulation amount of the existing air conditioner, and at the same time, introduces the same amount of air as the introduced outside air from the conditioned space to the desiccant. 2. The outside of the indirect evaporative cooling type according to claim 1, wherein the dehumidified air is exhausted to the dehumidifier and 0.2 to 0.4 times the cooled dehumidified air cooled by the indirect evaporative cooler is caused to flow to the cooling tower. It is a regulation system.

  In the invention of claim 3, the cooling tower and the indirect evaporative cooler are connected by a cooling water circulation line, and the cooling water is cooled to 19-24 ° C. with cooling dehumidified air introduced into the cooling tower, and the indirect 3. The indirect evaporative cooling external air conditioning system according to claim 2, which is supplied to the evaporative cooler.

  The invention of claim 4 uses an existing outside air introduction type cooling tower as the cooling tower, forms an introduction chamber covering the outside air introduction part of the outside air introduction type cooling tower, and the dehumidified air exhaust line is provided in the introduction chamber. It is the indirect evaporative cooling type external air conditioning system in any one of Claims 1-3 connected.

  According to the present invention, the cooling dehumidified air having a low wet bulb temperature cooled by the indirect evaporation cooler is passed through the cooling tower and directly exchanged with the cooling water supplied and circulated to the indirect evaporation cooler. Evaporation of water is promoted, and the temperature of the cooling circulating water can be reduced efficiently. Supplying and circulating this cooling water to the indirect evaporation type cooler to cool the dehumidified air, the load on the existing air conditioner is reduced. It has the excellent effect of being able to air-condition with little drain.

It is a figure which shows one embodiment of this invention. It is the figure which showed the state of the air exhausted by the cooling tower from the desiccant dehumidifier in the indirect evaporative cooling type external air conditioning system of this invention with the air diagram.

  A preferred embodiment of the present invention will be described below in detail with reference to the accompanying drawings.

  In FIG. 1, reference numeral 10 denotes an air-conditioned space that is a room of a building such as a hotel or office. The air-conditioned space 10 is provided with an existing air conditioner 11 such as a fan coil unit (FCU).

  In the existing air conditioner 11, a coil 15 to which a refrigerant liquid (cold water or hot water or the like) is supplied and a circulation fan 16 are provided in a main body 14 having a suction port 12 and an outlet 13, and the coil 15 of the existing air conditioner 11 is provided. Is connected to a cold / hot water generator or the like (not shown) via a refrigerant supply pipe 17 and a refrigerant discharge pipe 18.

  The existing air conditioner 11 sucks the indoor air RA from the suction port 12 with the circulation fan 16, adjusts the indoor air RA to the set temperature with the coil 15, and cools the air (or warm air), and blows the conditioned air SA. The air-conditioning space 10 is blown out from the outlet 13 to the air-conditioned space 10 to air-condition the air-conditioned space 10 to a set temperature.

  A desiccant dehumidifier 20 is connected to the existing air conditioner 11 via a ventilation air supply line 21, and a ventilation air exhaust line that exhausts a part of room air from the air-conditioned space 10 to the desiccant dehumidifier 20 as ventilation air VA. 22 is connected.

  The desiccant dehumidifier 20 is configured by a dehumidification rotor 26 and a sensible heat rotor 27 that are partitioned into an outside air introduction passage 24 and an exhaust passage 25 inside the casing 23 and are rotatably provided so as to cross both the passages 24 and 25. Is done.

  A push-in fan 28 is provided in the outside air introduction passage 24, a suction fan 29 is provided in the exhaust passage 25, a damper 30 is provided on the exhaust side thereof, and solar heat is provided between the sensible heat rotor 27 and the dehumidification rotor 26 in the exhaust passage 25. A heater 31 that uses a heat medium heated by natural energy, electricity, gas or the like is provided.

  In the desiccant dehumidifier 20, the outside air OA is introduced from the pushing fan 28, dehumidified by the dehumidifying rotor 26, cooled through the sensible heat rotor 27, supplied to the ventilation air supply line 21, and ventilated air in the conditioned space 10. In the VA, the heat is recovered from the ventilation air exhaust line 22 through the sensible heat rotor 27, heated by the heater 31, the dehumidification rotor 26 is regenerated by the heated ventilation air, and the exhaust air is exhausted through the exhaust fan 29 and the damper 30. It is discharged into the atmosphere as EA.

  In the present invention, the temperature of the outside air OA dehumidified by the dehumidification rotor 26 of the desiccant dehumidifier 20 is increased by the heat of adsorption (about 60 ° C.), and the sensible heat rotor 27 collects the cold heat of the ventilation air VA. Even after cooling, the temperature of the dehumidified air is 30 ° C. or more. Therefore, the dehumidified air is connected to a ventilation air supply line 21 between the desiccant dehumidifier 20 and the existing air conditioner 11, It cools to -24 degreeC.

  The circulating cooling water of the indirect evaporative cooler 32 is air-cooled by the cooling tower 33, but can be cooled only to about 30 ° C. even if it is air-cooled by a general external air introduction type cooling tower as described in the conventional example.

  Therefore, in the present invention, when the cooling water of the cooling tower 33 is air-cooled, a part of the cooling dehumidified air that is cooled by the indirect evaporation cooler 32 and supplied to the existing air conditioner 11 is introduced into the cooling tower 33. After air cooling, it is discharged into the atmosphere.

  Hereinafter, the indirect evaporation type cooler 32 and the cooling tower 33 will be described.

  First, the cooling tower 33 may be a new cooling tower or an existing cooling tower. In the figure, the existing outside air introduction type cooling tower is improved to be a cooling tower 33.

  The cooling tower 33 is provided with a water sprinkling pipe 35 at the top of the tower main body 34 and an exhaust fan 36 on the tower main body 34, and the water sprinkled by the water sprinkling pipe 35 and the air exhausted by the exhaust fan 36 are directly connected. A heat exchanging portion 37 made of a filler 37 a that is brought into contact with each other to exchange heat is provided, and a mist eliminator 38 is provided above the heat exchanging portion 37.

  The cooling tower 33 and the indirect evaporative cooler 32 are connected by a cooling water circulation line 40, and the cooling water in the cooling water reservoir 39 of the tower body 34 is supplied to the indirect evaporation cooler 32 via the inlet side cooling water circulation line 40a. The supplied cooling water after the heat exchange is supplied from the cooling water circulation line 40b on the outlet side to the sprinkling pipe 35 via the circulation pump 41 and circulated.

  In the figure, the heat exchanging portion 37 is formed by filling a filler 37a for improving gas-liquid contact, and an exhaust fan 36 is provided below the heat exchanging portion 37. The heat exchanging unit 37 may be formed in a space where the gas-liquid contact is simply made, and the exhaust fan 36 may be a general cylindrical cooling tower located above the heat exchanging unit 37.

  The outside air introduction section 44 below the heat exchanging section 37 of the cooling tower 33 is open to the atmosphere in a general outside air introduction type cooling tower, but in the present invention, the outside air introduction section 44 is covered so as to cover the outside air introduction section 44. The dehumidified air exhaust line 46 branched from the ventilation air supply line 21 on the downstream side of the indirect evaporation cooler 32 is connected to the introduction chamber 45.

  On the downstream side of the dehumidified air exhaust line 46 and the ventilation air supply line 21 to which the dehumidified air exhaust line 46 is connected, dampers 47 and 48 for distributing the cooled dehumidified air are connected.

  In the present invention, when the existing air conditioner 11 is to be drainless air conditioner, the external air conditioner 50 including the desiccant dehumidifier 20, the indirect evaporative cooler 32, and the cooling tower 33 is surrounded by the two-dot chain line. By connecting to the machine 11, an indirect evaporative cooling external air conditioning system can be constructed.

  Next, air conditioning in the indirect evaporative cooling external air conditioning system will be described.

  First, a cooling liquid operation is performed by supplying a refrigerant liquid (cold water) to the coil 15 of the existing air conditioner 11 from a cold / hot water generator or the like. At this time, if the cooling is performed only with the coil 15 of the existing air conditioner 11, dew condensation occurs, which causes a reduction in IAQ. Therefore, the outside air OA is passed through the desiccant dehumidifier 20 so that dew condensation does not occur in the coil 15. Drainless air conditioning is performed by introducing the dehumidified air into the existing air conditioner 11. The outside air OA introduced as ventilation air is introduced 0.1 to 0.5 times the conditioned air circulation amount of the existing air conditioner 11, and the same amount of air as the outside air introduction amount is used as the ventilation air VA from the conditioned space 10. Exhaust to desiccant dehumidifier 20.

  The introduced outside air OA is dehumidified through the dehumidifying rotor 26 of the desiccant dehumidifier 20, and is dehumidified air of about 60 ° C. by adsorption heat and passes through the sensible heat rotor 27. Since the ventilation air VA in the space 10 is introduced through the ventilation air exhaust line 22, the dehumidified air and the ventilation air are indirectly heat-exchanged via the sensible heat rotor 27.

  Ventilation air heated through the sensible heat rotor 27 is heated by a heater 31 heated by natural energy such as solar heat, electricity, gas, etc., desorbs moisture adsorbed on the dehumidifying rotor 26, and dehumidifies the rotor 26. After regeneration, it is exhausted.

  Next, the dehumidified air cooled by the sensible heat rotor 27 is cooled to 19 to 24 ° C. by the indirect evaporation type cooler 32, and is supplied to the existing air conditioner 11 side through the ventilation air supply line 21, where the inlet 12 And is introduced into the existing air conditioner 11, cooled to a set temperature by the coil 15, and blown out from the air outlet 13.

  By supplying the cooled dehumidified air to the existing air conditioner 11 in this way, air conditioning with a high IAQ can be performed without causing condensation in the coil 15.

  In the present invention, 20 to 40% of the cooled dehumidified air cooled by the indirect evaporative cooler 32 is introduced into the cooling tower 33 through the dehumidified air exhaust line 46, and the circulating cooling water in the cooling tower 33 is cooled by air. Since the evaporation of water is promoted and the temperature of the cooling water in the cooling tower 33 can be effectively reduced, the amount of heat to be cooled by the coil 15 of the existing air conditioner 11 is small, and the COP can be improved. it can.

  During heating, a refrigerant liquid (hot water) is supplied to the coil 15 for heating. In this heating operation, the external air conditioner 50 is basically in a stopped state, but when supplying ventilation air, it may be supplied through the desiccant dehumidifier 20.

  Next, the state of the dehumidified air until the outside air is dehumidified and cooled by the cooling tower will be described with reference to the air diagram of FIG.

First, in FIG. 2, the circulating cooling water amount of the cooling tower 33 is 5.4 l / min, the air volume to the cooling tower 33 is 230 m ³ / H, the main air volume of the ventilation air supply line 21 is 600 m ³ / H, and the water / air ratio is 1.2. This is an example when

  In FIG. 2, the outside air at point A (30.5 ° C., absolute humidity 0.020 kg / kgDA) is dehumidified by the dehumidifying rotor 26 of the desiccant dehumidifier 20 to obtain point B (56 ° C., absolute humidity 0.010 kg / kgDA). In the sensible heat rotor 27, the point C (32 ° C., absolute humidity 0.010 kg / kgDA) is obtained. This dehumidified air is set to point D (27 ° C.) by the indirect evaporation type cooler 32 and is introduced into the cooling tower 33 to directly exchange heat with the circulating cooling water, and the cooling water evaporates, so that the point E (temperature 24 ° C. and relative humidity 100%).

  Here, the circulating cooling water of the cooling tower 33 is cooled to 24 ° C. or less, which is the same as the exhaust air at the point E, and is supplied and circulated to the indirect evaporation type cooler 32 so that the dehumidified air is made 24 ° C. or less and is already installed. It will be supplied to the air conditioner 11 side.

  In general, when an outside air introduction type cooling tower is used, the temperature of water can be cooled only to the wet air bulb temperature (about 25 ° C. in summer) + about 5 ° C. = about 30 ° C. In the present invention, the desiccant dehumidifier 20 is used. By introducing a part of the produced dehumidified air having a low wet bulb temperature (about 19 ° C.) into the cooling tower 33, water evaporation can be promoted and the circulating cooling water temperature can be lowered to about 24 ° C.

  In an external air conditioner incorporating a desiccant dehumidifier, it is generally required to lower the supply air temperature to a room temperature setting temperature level (about 26 to 27 ° C.). Although water cannot be used, the present invention can be applied to cooling dehumidified air in the indirect evaporative cooler 32 because cooling water of about 24 ° C. can be used.

  Since the cooling by the indirect evaporative cooler 32 does not use a refrigerator for cooling, it becomes a chlorofluorocarbon external air conditioning system and the indirect evaporative cooler 32 is an indirect cooling system through a cooling coil. Therefore, it is possible to cool the dehumidified air while keeping the absolute humidity low.

  Further, in the present invention, when the external air conditioner 50 is incorporated into the existing air conditioner 11, the desiccant dehumidifier 20 is used, and the cooling tower 33 can be constructed only by improving the existing cooling tower. Thus, the equipment cost can be reduced.

DESCRIPTION OF SYMBOLS 10 Air-conditioned space 11 Existing air conditioner 20 Desiccant dehumidifier 21 Ventilation air supply line 32 Indirect evaporative cooler 33 Cooling tower 46 Dehumidification air exhaust line

Claims (4)

  Combine existing air conditioner and air desiccant dehumidifier for air-conditioning space, introduce external air with the desiccant dehumidifier and supply dehumidified air to the existing air conditioner via the ventilation air supply line. Air is exhausted to the desiccant dehumidifier through the ventilation air exhaust line, and the exhaust air is exhausted by exchanging heat with the dehumidified air, and the dehumidified air heat-exchanged with the exhaust air is cooled to the existing air conditioner. In an indirect evaporative cooling external air conditioning system for supplying, a cooling tower for connecting an indirect evaporative cooler for cooling dehumidified air to the ventilation air supply line and supplying and circulating cooling water to the indirect evaporative cooler Indirect evaporation, characterized in that a dehumidified air exhaust line for introducing a part of the cooled dehumidified air cooled by the indirect evaporative cooler and exhausting it into the atmosphere is connected to the cooling tower.却型 outside the control system.   While introducing outside air to the desiccant dehumidifier 0.1 to 0.5 times the conditioned air circulation amount of the existing air conditioner, the same amount of air as the introduced outside air is exhausted from the conditioned space to the desiccant dehumidifier, The indirect evaporative cooling type external air conditioning system according to claim 1, wherein 0.2 to 0.4 times the cooling dehumidified air cooled by the indirect evaporative cooler is caused to flow through the cooling tower.   The cooling tower and the indirect evaporative cooler are connected by a cooling water circulation line, and the cooling water is cooled to 19 to 24 ° C. with the cooling dehumidified air introduced into the cooling tower and supplied to the indirect evaporative cooler. The indirect evaporative cooling external air conditioning system according to claim 2.   An existing outside air introduction type cooling tower is used as the cooling tower, an introduction chamber is formed to cover an outside air introduction part of the outside air introduction type cooling tower, and the dehumidified air exhaust line is connected to the introduction chamber. The indirect evaporative cooling external air conditioning system according to any one of the above.

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