JP2005049059A - Air-conditioning system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an air-conditioning system capable of minimizing drain piping such as a drain pipe to provide a high freedom in layout of a sensible heat cooling unit in the case of performing introduction of the outside air. <P>SOLUTION: This air-conditioning system 10a comprises an indoor unit 1, an outside air supplying unit 12, and an outdoor unit 15. The indoor unit 11 comprises a sucked air temperature/relative humidity detection part 21 and a control part 22, and calculates the absolute humidity of the indoor space based on the detection result of the detection part 21. The outside air supplying unit 12 comprises a blown air temperature/relative humidity detection part 31 and a control part 38, and calculates the absolute humidity of the outside air supplied to the indoor space based on the detection result of the detection part 31. A target evaporation temperature arithmetic part 46 calculates a target evaporation temperature of refrigerant for performing a proper latent heat treatment to the present air in the indoor space in the outside air supplying unit 12, based on the respective absolute humidities calculated in the control parts 22 and 38. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an air conditioning system, and more particularly to an air conditioning system including a sensible heat cooling unit that performs sensible heat cooling.

  In recent years, in an air conditioning system installed in a building such as a building, indoor units are often arranged at appropriate intervals on the ceiling of each room on each floor. These indoor units exchange heat between a heat source (such as a refrigerant) supplied from an outdoor unit or the like and room air, and, for example, at the time of cooling, cool air after heat exchange is blown out into the indoor space. .

  In such an indoor unit of a conventional air conditioning system, if the heat source is equal to or lower than the dew point temperature of the indoor air during cooling, moisture contained in the indoor air is condensed in the heat exchanger of the indoor unit. For this reason, in order to discharge the condensed water (hereinafter referred to as drain water) to the outside, a drain pipe is laid on the ceiling of the building where the indoor unit is installed, and the drain water generated in the indoor unit is discharged to the outside. Are discharged.

The invention according to Patent Literature 1 has been proposed for the purpose of saving the design and construction associated with the laying of such a drain pipe. Here, a sensible heat cooling indoor unit is installed in the room together with a dehumidifying indoor unit. A drain pipe is laid only in the dehumidifying indoor unit, and in the sensible cooling indoor unit installed on the ceiling, the coolant temperature is basically higher than the dew point temperature so that drain water is not generated. This eliminates the need for a drain pipe.
JP-A-6-101894

However, the conventional air conditioning system has the following problems.
That is, in a building such as a building, generally, ventilation is performed for the purpose of discharging contaminated indoor air to the outside and taking in uncontaminated air from the outside. For this reason, outside air is also introduced into a space (room) in a building where air conditioning such as cooling is performed. This outdoor air usually contains more moisture than room air, such as in summer when cooling is required. That is, during cooling, the absolute humidity of the outside air is often higher than the absolute humidity of the room air. The magnitude of the latent heat load (dehumidification amount) during cooling depends on the amount of outside air introduced into the indoor space by ventilation.

  However, in the air conditioning system disclosed in Patent Document 1, it is difficult to say that consideration is given to the outside air containing a lot of moisture (water vapor), although consideration is given to latent heat generated in the space. Therefore, when outside air containing a lot of moisture is introduced into the room, the latent heat load due to the moisture is processed by the dehumidifying indoor unit, so the dehumidifying indoor unit is compatible with the maximum ventilation. High processing capacity is required. In addition, sensible heat cooling is usually performed by adjusting the temperature of the heat source such as refrigerant above the dew point temperature of the intake air, but the sensible heat is not dehumidified when the outside air introduced into the indoor space having a relatively large latent heat load is not dehumidified. When sucked into the cooling room unit, the dew point temperature increases and the cooling capacity (sensible heat cooling capacity) decreases. In order to mitigate such a decrease in cooling capacity, the sensible heat cooling indoor unit must be placed in a place where it is less susceptible to outside air as much as possible in consideration of the outside air introduction position. Therefore, in the air conditioning system of Patent Document 1, the installation position of the sensible heat cooling indoor unit is limited by the outside air introduction position.

  An object of the present invention is to provide an air conditioning system that can reduce drain piping such as a drain pipe and has a high degree of freedom in arrangement of sensible heat cooling units even when outside air is introduced.

  An air conditioning system according to a first aspect is an air conditioning system for cooling a predetermined space, and includes a sensible heat cooling unit and an outside air supply unit. The sensible heat cooling unit controls the cooling source so as to be equal to or higher than the dew point temperature of the air in the space in the space, and sensible heat cools the space. The outside air supply unit is a unit that supplies outside air to the space, and reduces the absolute humidity of the outside air supplied to the space to reduce the latent heat load of the outside air.

  Here, the outside air supply unit supplies outside air to a predetermined space that is the target of the sensible heat cooling unit. The outside air supply unit does not simply supply outside air to the space, but supplies the outside air in a state in which the absolute humidity is reduced and the latent heat load is reduced to the space. Therefore, the outside air supplied to the space is relatively free of moisture (water vapor). Therefore, even if it is assumed that this outside air is directly sucked into the sensible heat cooling unit as air in the space, the dew point temperature of the air is not so high, and the sensible heat is controlled so that the cold heat source is higher than the dew point temperature. Air conditioning units are rarely limited in their capabilities. That is, even if the sensible heat cooling unit is placed in a space where the influence of outside air is large, the outside air flows in after being subjected to a latent heat treatment, so that the sensible heat cooling unit is exposed to the latent heat of the outside air. Less susceptible to adverse effects. That is, it can be said that the air conditioning system according to the present invention has a high degree of freedom in arrangement of the sensible heat cooling units.

On the other hand, for drain piping, even if it is necessary to install an outside air supply unit that performs latent heat treatment, outside air with reduced humidity is supplied indoors. As a result, drain piping is unnecessary. Therefore, in the air conditioning system of the present claim, the number of drain pipes can be reduced as compared with the conventional case.
Even when the degree of reduction of the outside air latent heat load by the outside air supply unit is not sufficient for a predetermined space, by installing a latent heat cooling unit having a dehumidifying capacity in that space in addition to the sensible heat cooling unit, The drain piping corresponding to the sensible heat cooling unit in the space can be eliminated. Also in this case, since the latent heat load of the outside air supplied to the space is reduced to some extent, the degree of freedom of arrangement of the sensible heat cooling unit can be increased as compared with the air conditioning system of Patent Document 1.

An air conditioning system according to a second aspect is the air conditioning system according to the first aspect, wherein the outside air supply unit makes the absolute humidity of the outside air supplied to the space smaller than the absolute humidity of the air in the space.
Here, outside air having a lower absolute humidity than the air in the space (air in the space) is supplied to the space. For this reason, when the outside air supply unit supplies outside air, the latent heat in the space is thereby reduced. Therefore, the latent heat in the space can be reduced by using the ability of the outside air supply unit without separately providing the latent heat cooling unit for processing the latent heat in the space during cooling. Thereby, even when only the sensible heat cooling unit is provided in the space, the outside air having a lower absolute humidity than the air in the space is supplied, so that the latent heat in the space can be kept low. In this way, the outside air supply unit processes latent heat, and the sensible heat cooling unit installed in the space processes sensible heat, so that it is always comfortable while ventilating in the space subject to air conditioning. Air conditioning environment can be secured.

  In addition, as described above, since the latent heat in the space can be processed and a comfortable air-conditioning environment can be ensured without separately providing a latent heat cooling unit for latent heat treatment in the space, the drain pipe can be connected to the outside air as necessary. When an outside air supply unit that is installed only in the supply unit or does not require a drain pipe is adopted, an air conditioning system in which no drain pipe is installed can be realized. As a result, it is possible to greatly reduce the construction costs required to install the drain piping on the ceiling or the like when installing an air conditioning system in a building, etc., and as a result, provide a low-cost air conditioning system Can do.

  An air conditioning system according to a third aspect is the air conditioning system according to the second aspect, comprising an air sensor in the space, a space absolute humidity calculation unit, an outside air sensor, and an outside air absolute humidity calculation unit. . The space air sensor detects the temperature and relative humidity of the space air. The space absolute humidity calculation unit calculates the absolute humidity of the air in the space from the temperature and relative humidity of the air in the space. The outside air sensor detects the temperature and relative humidity of the outside air supplied to the space. The outside air absolute humidity calculation unit calculates the absolute humidity of the outside air supplied to the space from the temperature and relative humidity of the outside air supplied to the space.

  Here, the absolute humidity of the air in the space is calculated by the space absolute humidity calculation unit based on the detection result of the air sensor in the space, and the absolute humidity of the outside air supplied to the space by the outside air absolute humidity calculation unit based on the detection result of the outside air sensor. Find accurately. For this reason, it is possible to recognize how much the absolute humidity of the taken-out outside air should be lowered in order to supply outside air lower than the absolute humidity of the air inside the space. Therefore, the latent heat treatment can be performed so that the absolute humidity is lower than the desired absolute humidity, and the outdoor air always lower than the absolute humidity of the indoor air can be supplied to the room indoors. However, it is possible to suppress the occurrence of a problem in which outside air having a high absolute humidity is sucked and the cooling capacity of the sensible heat cooling unit is lowered.

The air conditioning system according to claim 4 is the air conditioning system according to any one of claims 1 to 3, wherein the outside air supply unit cools the outside air supplied to the space to a dew point temperature or less and condenses moisture. Remove.
Here, when the outside air supply unit removes part of the moisture contained in the outside air to reduce the latent heat load of the outside air, the outside air supplied to the space is simultaneously cooled. Therefore, since the outside air which has been processed for sensible heat as well as latent heat and has a low temperature and humidity can be supplied to the room, the load on the sensible heat cooling unit installed in the space can be reduced.

An air conditioning system according to a fifth aspect is the air conditioning system according to any one of the first to third aspects, wherein the outside air supply unit dehumidifies the outside air supplied to the space using an adsorbent.
Here, for example, moisture in the outside air is removed by a solid adsorbent such as silica gel impregnated in the honeycomb rotor, or dehumidification is performed by bringing a hygroscopic liquid (liquid adsorbent) such as lithium chloride into contact with the outside air. I do. When the former method is used, the moisture in the outside air adsorbed by the adsorbent is heated and released outside the space, so that the drain pipe is eliminated not only from the indoor unit 11 but also from the outside air supply unit. Air conditioning system can be realized.

In the air conditioning system according to the first aspect, it is possible to prevent a decrease in the processing capacity of the sensible heat cooling unit due to the supply of the outside air with high humidity. Furthermore, the sensible heat cooling unit can be freely arranged regardless of the outside air supply position.
In the air conditioning system according to claim 2, since the latent air heat treatment is simultaneously performed in the outside air supply unit together with the supply of the outside air, the air conditioning system having a simple configuration having only the sensible heat cooling unit in the space is comfortable. Air conditioning environment can be secured. Furthermore, it is not necessary to drain the drain water from the sensible heat cooling unit in the space. For example, when the sensible heat cooling unit is placed on the ceiling, there is no need for drain piping installation work to install a drain pipe on the back of the ceiling. Can be. Therefore, the installation cost for installing the air conditioning system in a building or the like can be greatly reduced.

In the air conditioning system according to the third aspect, the outside air supply unit can supply outside air having an absolute humidity optimum for the air in the current space. Therefore, it is possible to prevent the outside air having an absolute humidity higher than that of the air in the space from being sucked into the sensible heat cooling unit and the sensible heat cooling capacity from being lowered.
In the air conditioning system according to the fourth aspect, since the outside air supplied into the space is supplied in a state where the temperature is lowered together with the humidity, the sensible heat of the outside air is also reduced. Therefore, the load applied to the sensible heat cooling unit can be reduced.

  In the air conditioning system according to the fifth aspect, since the humidity in the outside air is released using the adsorbent in the outside air supply unit, a drain pipe is eliminated from the outside air supply unit, and a so-called drainless air conditioning system can be realized.

<Overall configuration of air conditioning system>
The air conditioning system 10 which shows one Embodiment which concerns on this invention is shown in FIG.
An air conditioning system 10 according to the present embodiment is an air conditioning system installed to perform indoor air conditioning control of a building or the like. As shown in FIG. 1, an indoor unit (sensible heat cooling unit) 11, an outdoor air supply A unit 12, a water supply pipe 13, a drain pipe 14, and an outdoor unit 15 (see FIG. 2) to be described later are provided.

In the present embodiment, the air conditioning system 10 including two indoor units 11 and one outdoor air supply unit 12 will be described. However, each unit 11, 12, 15 including the number of outdoor units 15 described later is included. Is not limited to the examples given in the present embodiment.
The indoor unit 11 is installed behind the ceiling of an indoor space S such as a building, and performs heat exchange between refrigerant supplied from an outdoor unit 15 and the like, which will be described later, and indoor air, thereby processing a sensible heat load. To do. Thereby, for example, the temperature of the air in the indoor space S can be lowered by lowering the temperature of the air in the indoor space S sucked during cooling and sending it out to the indoor space S.

  The outside air supply unit 12 is installed in a machine room or the like of a building, and supplies the outside air to the indoor space S to ventilate the indoor space S and perform a latent heat treatment on the outside air. As will be described later, in order to make the absolute humidity of the outside air supplied to the indoor space S lower than the absolute humidity of the air in the indoor space S, the outside air supply unit 12 consequently also processes the latent heat of the indoor space S. It will be.

  Here, sensible heat is the heat obtained by the product of the amount of temperature rise (or fall) of a substance and the heat capacity of that substance (the amount of heat necessary to change the temperature by 1 ° C. per unit weight) This is the heat used to raise the temperature. The sensible heat load is due to sensible heat in the heating / cooling load, and is referred to as vertical movement of temperature due to the entry and exit of sensible heat. The temperature difference from solar radiation and outside air, OA equipment installed indoors, and the like are the generation sources. On the other hand, latent heat refers to heat required when a substance changes its phase from solid to liquid or liquid to solid, or from liquid to gas or from gas to liquid. The latent heat load is due to latent heat in the heating / cooling load, and means an increase / decrease due to the flow of water vapor. Water vapor contained in the human body, intake outside air, drafts, and the like becomes a source of latent heat load.

The water supply pipe 13 is connected to a humidifying element (not shown) provided in the outside air supply unit 12 and supplies moisture to the humidifying element as necessary during heating operation.
The drain pipe 14 discharges drain water generated by the latent heat treatment (outside air dehumidification) in the outside air supply unit 12 to the outside.
<Configuration of indoor unit>
The indoor unit 11 functions as a sensible heat cooling unit that performs sensible heat cooling of the indoor space S. In the air conditioning system 10a shown in FIG. 2, the intake air temperature / relative humidity detector (in-space air sensor) 21 and the control Unit (space absolute humidity calculation unit) 22, evaporation pressure control valve 23, evaporation temperature detection unit 24, outlet temperature detection unit 25, electronic expansion valve 26, indoor fan 27, and heat exchanger 28.

The intake air temperature / relative humidity detector 21 detects the temperature and relative humidity of the air in the indoor space S sucked into the indoor unit 11.
The control unit 22 adjusts the temperature of the air in the indoor space S by controlling the operation of each unit constituting the indoor unit 11. Further, the control unit 22 calculates the dew point temperature of the air in the indoor space based on the detection result in the intake air temperature / relative humidity detection unit 21 and calculates the absolute humidity of the air in the indoor space.

The evaporation pressure control valve 23 is provided in the refrigerant pipe sent out from the heat exchanger 28 to the outdoor unit 15, and evaporation of the refrigerant sent out from the heat exchanger 28 to the outdoor unit 15 based on the calculation result in the control unit 22. Adjust pressure.
The evaporation temperature detector 24 is provided between the heat exchanger 28 and the electronic expansion valve 26 and detects the evaporation temperature of the refrigerant.

The outlet temperature detector 25 is provided in a refrigerant pipe between the heat exchanger 28 and the evaporation pressure control valve 23 and detects the temperature of the refrigerant after passing through the heat exchanger 28.
The electronic expansion valve 26 adjusts the opening degree based on an instruction from the control unit 22 to reduce the pressure of the refrigerant sent from the outdoor unit 15 to the heat exchanger 28.
The indoor fan 27 takes the air in the indoor space S into the indoor unit 11, sends the air to the heat exchanger 28, and sends the heat-exchanged air to the indoor space S again.

The heat exchanger 28 exchanges heat between the refrigerant decompressed by the electronic expansion valve 26 and the air sent from the indoor fan 27.
<Operation of indoor unit>
Here, the operation | movement at the time of the cooling operation of the indoor unit 11 in the air conditioning system 10 of this embodiment is demonstrated.

  In the indoor unit 11, the refrigerant sent from the outdoor unit 15 is decompressed by the electronic expansion valve 26 and sent to the heat exchanger 28. Then, in the heat exchanger 28, sensible heat cooling of the room air is performed by performing heat exchange between the refrigerant and the room air sent by the room fan 27. The refrigerant evaporates by heat exchange, and then is sent back to the outdoor unit 15 via the evaporation pressure control valve 23.

  In the air conditioning system 10, in such sensible heat cooling, the control unit 22 calculates the dew point temperature of the air in the indoor space S based on the detection result in the intake air temperature / relative humidity detection unit 21. Then, the control unit 22 adjusts the opening degree of the electronic expansion valve 26 based on the calculated dew point temperature and the detection results in the evaporation temperature detection unit 24 and the outlet temperature detection unit 25, and sends the compressor 45 to the outdoor unit 15. Or send a signal regarding capacity control. Specifically, the temperature of the refrigerant in the heat exchanger 28 does not become lower than the dew point temperature of the air in the indoor space S, and condensation occurs on the surface of the heat exchanger 28 to generate drain water. To prevent it.

In the present embodiment, the control unit 22 further calculates the absolute humidity of the air in the indoor space S based on the detection result in the intake air temperature / relative humidity detection unit 21, and sends it to the target evaporation temperature calculation unit 46 in the outdoor unit 15. Send.
<Configuration of outside air supply unit>
The outside air supply unit 12 functions as an outside air processing air conditioner, and as shown in FIG. 2, a blown air temperature / relative humidity detector (outside air sensor) 31, an evaporation temperature detector 32, an outlet temperature detector 33, and an electronic expansion valve 34 , A drain pan 35, an outside air supply fan 36, a heat exchanger 37, and a control unit (outside air absolute humidity calculation unit) 38.

The blown air temperature / relative humidity detector 31 is installed near the air outlet of the outside air supply unit 12 and detects the temperature and relative humidity of the outside air supplied to the indoor space S.
The evaporation temperature detector 32 detects the evaporation temperature of the refrigerant sent from the outdoor unit 15.
The outlet temperature detector 33 detects the refrigerant temperature after heat exchange is performed between the outside air and the refrigerant in the heat exchanger 37.

The electronic expansion valve 34 adjusts the opening degree based on an instruction from the control unit 38 to reduce the pressure of the refrigerant supplied from the outdoor unit 15 to the heat exchanger 37.
The drain pan 35 collects drain water generated by heat exchange performed between the outside air and the refrigerant in the heat exchanger 37 of the outside air supply unit 12 and discharges it to the outdoors.
The outside air supply fan 36 takes outside air into the outside air supply unit 12 and supplies the outside air heat-exchanged with the refrigerant in the heat exchanger 37 to the indoor space S.

The heat exchanger 37 exchanges heat between the outside air taken into the outside air supply unit 12 by the outside air supply fan 36 and the refrigerant flowing through the heat exchanger 37.
The control unit 38 calculates the absolute humidity of the outside air supplied to the indoor space S based on the temperature and humidity of the outside air detected by the blown air temperature / relative humidity detection unit 31. And the control part 38 controls the electronic expansion valve 34 based on the detection result in the evaporation temperature detection part 32 and the exit temperature detection part 33, or sends the signal regarding the capacity | capacitance control of the compressor 45 to the outdoor unit 15, The amount of heat exchange between the outside air and the refrigerant in the heat exchanger 37 is controlled. Further, in the air conditioning system 10 of the present embodiment, the control unit 38 is based on the calculation result received from the target evaporation temperature calculation unit 46 of the outdoor unit 15 and the outside air detected by the blown air temperature / relative humidity detection unit 31. Is controlled to be lower than the absolute humidity of the air in the indoor space S.

<Operation of outside air supply unit>
Here, the operation of the outside air supply unit 12 during cooling in the air conditioning system 10 of the present embodiment will be described.
In the outside air supply unit 12, the outside air supply fan 36 takes in outside air into the outside air supply unit 12, and heat exchange is performed between the outside air in which the heat exchanger 37 is taken in and the refrigerant sent from the outdoor unit 15, Heat exchanged outside air is supplied to the indoor space S. At this time, drain water is generated by condensation from the outside air cooled by heat exchange between the outside air and the refrigerant and adheres to the heat exchanger 37 and the like. The drain water is collected in the drain pan 35 and discharged to the outside. The

  The heat exchange is performed based on detection results in the blown air temperature / relative humidity detection unit 31, the evaporation temperature detection unit 32, and the outlet temperature detection unit 33, and in the present embodiment, a control signal received from the target evaporation temperature calculation unit 46. 38. Specifically, the evaporation temperature of the refrigerant that exchanges heat with the outside air in the outside air supply unit 12 based on the target evaporation temperature received from the outdoor unit 15 (target evaporation temperature calculation unit 46) described in detail later. And the taken-in outside air is cooled by heat exchange so that the outside air supplied to the indoor space S is equal to or lower than the dew point temperature. Then, the latent heat treatment is performed by discharging the moisture in the outside air that aggregates and adheres to the surface of the heat exchanger 37 as drain water and removes the moisture in the outside air. In particular, in the present embodiment, the latent heat treatment is performed so that the absolute humidity of the outside air supplied to the indoor space S is lower than the current absolute humidity of the indoor space S.

<Configuration of outdoor unit>
As shown in FIG. 2, the outdoor unit 15 includes an outdoor fan 41, a heat exchanger 42, an outdoor expansion valve 43, a four-way switching valve 44, a compressor 45, and a target evaporation temperature calculation unit (indoor absolute humidity calculation unit, outdoor air absolute (Humidity calculation unit) 46.
The outdoor fan 41 supplies air to the heat exchanger 42, and the heat exchanger 42 exchanges heat between the air sent from the outdoor fan 41 and the evaporated refrigerant. Here, the refrigerant heat-exchanged with the air becomes a liquid refrigerant, and is sent to the indoor unit 11 and the outdoor air supply unit 12 via the outdoor expansion valve 43.

The four-way switching valve 44 switches the refrigerant flow between the cooling operation and the heating operation.
The operation frequency of the compressor 45 is controlled according to various conditions during operation. That is, the capacity control of the compressor 45 is performed in the outdoor unit 15.
The target evaporating temperature calculation unit 46 performs latent heat treatment in the outdoor air supply unit 12 based on the detection results in the intake air temperature / relative humidity detection unit 21 of the indoor unit 11 and the blown air temperature / relative humidity detection unit 31 of the outdoor air supply unit 12. The target evaporation temperature is calculated and transmitted to the control unit 38 of the outside air supply unit 12.

<Operation of outdoor unit>
Here, operation | movement of the outdoor unit 15 at the time of air_conditioning | cooling in the air conditioning system 10 of this embodiment is demonstrated.
In the outdoor unit 15, the refrigerant sent from the indoor unit 11 and the outdoor air supply unit 12 is compressed by the compressor 45 and sent to the heat exchanger 42 via the four-way switching valve 44. Subsequently, the refrigerant exchanges heat between the outdoor air sent by the outdoor fan 41 and the refrigerant in the heat exchanger 42 to become a liquid refrigerant, and then the indoor unit 11 and the outdoor air supply unit via the outdoor expansion valve 43. 12 is sent.

  In the air conditioning system 10 of the present embodiment, the target evaporation temperature calculation unit 46 is provided in the outdoor unit 15. The target evaporation temperature calculation unit 46 receives the detection result in the intake air temperature / relative humidity detection unit 21 in the indoor unit 11 and the detection result in the blown air temperature / relative humidity detection unit 31 in the outside air supply unit 12. And regarding the latent heat processing performed in the outside air supply unit 12 with respect to the outside air supplied to the indoor space S, the target evaporation temperature of the refrigerant in the heat exchanger 37 of the outside air supply unit 12 is calculated based on each detection result, It transmits to the control part 38 in the external air supply unit 12. At this time, the calculated target evaporation temperature is obtained as a value such that the absolute humidity of the outside air supplied to the indoor space S is lower than the absolute humidity of the air in the indoor space S received from the indoor unit 11. It is transmitted to the unit 12.

<Characteristics of air conditioning system>
(1)
In the conventional air conditioning system 100, as shown in FIG. 5, outside air load processing is performed in the outside air supply unit 12, and sensible heat cooling and latent heat treatment of the indoor space S are performed in the indoor unit 101.

  For this reason, in order to discharge the drain water generated by the latent heat treatment in the indoor unit 101, it is necessary to provide the drain pipe 103 in the indoor unit 101 and discharge the drain water to the outdoors. In particular, in an air conditioning system installed in a building or the like, in general, the indoor unit 101 is often installed on the back of the ceiling, and a drain pipe needs to be disposed on the back of the ceiling. The installation work of the system 100 was time consuming and expensive.

  On the other hand, in the air conditioning system 10 of the present embodiment, the current absolute humidity of the indoor space S and the absolute humidity of the outside air supplied to the indoor space S are calculated. Then, a latent heat treatment is performed in the outdoor air supply unit 12 so that the absolute humidity of the outside air supplied to the indoor space S is lower than the absolute humidity of the air in the indoor space S. Thereby, since the outdoor air whose absolute humidity is lower than that of the indoor space S is always supplied to the indoor space S, the indoor unit 11 only needs to perform sensible heat cooling. Therefore, no drain water is generated from the indoor unit 11, and the drain pipe installed on the back of the ceiling for the indoor unit 11 can be eliminated.

(2)
In addition, the conventional air conditioning system that operates the refrigerant in the indoor unit at a temperature equal to or higher than the dew point of the air in the indoor space has the advantage of eliminating the need for drain piping, while the humidity of the indoor space S in the outdoor air supply unit, etc. Regardless of the outside air was supplied to the indoor space S. For this reason, when the outside air contains a large amount of moisture, a large amount of latent heat is supplied to the indoor space S together with the outside air. In this case, since the dew point temperature of the air in the indoor space rises, the indoor unit cannot sufficiently perform sensible heat cooling, and there is a possibility that the cooling capacity may be significantly reduced.

  On the other hand, in the air conditioning system 10 of the present embodiment, the current absolute humidity of the indoor space S and the absolute humidity of the outside air supplied to the indoor space S are calculated. Then, the outdoor air supply unit 12 performs a latent heat treatment so that the absolute humidity of the outside air supplied to the indoor space S is lower than the absolute humidity of the room air. Thereby, since the latent heat treatment with respect to the outside air is collectively performed in the outside air supply unit 12, a large amount of latent heat is not supplied to the indoor space S together with the outside air. Moreover, since the outside air whose absolute humidity is lower than that of the air in the indoor space S is supplied to the indoor space S, the latent heat processing in the indoor space S is thereby performed. Therefore, the indoor unit 11 only needs to have a function as a sensible heat cooling unit that performs only sensible heat cooling, and drain piping is not required, and by supplying outside air including a large amount of latent heat to the indoor space S. It can prevent that the capability of sensible heat cooling falls. Further, since the outdoor air having a higher humidity than the indoor space S is not adversely affected, the indoor unit 11 can be freely arranged regardless of the outdoor air introduction position.

[Other Embodiments]
(A)
In the above-described embodiment, an example in which a latent heat treatment is performed until the absolute humidity of the outside air supplied to the indoor space S in the outside air supply unit 12 becomes lower than the absolute humidity of the air in the indoor space S, and the outside air is supplied to the indoor space S. And explained. However, the present invention is not limited to this. For example, regardless of the absolute humidity of the air in the indoor space S, the load on the indoor unit 11 can be reduced even when outside air that has undergone a certain amount of latent heat treatment is supplied to the indoor space S. However, since the indoor unit 11 has only the sensible heat cooling function by performing the latent heat treatment so that the absolute humidity is lower than the air in the indoor space S as in the above embodiment, the indoor unit The drain pipe for 11 can be made unnecessary, and the configuration of the indoor unit 11 can be simplified as compared with the conventional air conditioning system.

(B)
In the said embodiment, although the example in which the target evaporation temperature calculating part 46 was provided in the outdoor unit 15 was given and demonstrated, this invention is not limited to this. For example, the target evaporation temperature may be calculated in the control unit 22 of the indoor unit 11 or the control unit 38 of the outside air supply unit 12.

(C)
In the said embodiment, although the outside air supply unit 12 demonstrated and demonstrated the example which cools outside air to below dew point temperature and removes the coagulated water | moisture content from outside air, and performed an example, this invention is limited to this. It is not a thing. For example, the outside air supply unit 12 may perform a latent heat treatment for removing moisture in the outside air without cooling the outside air. However, as in the above embodiment, the outside air supplied to the indoor space S is subjected to both latent heat and sensible heat processing by cooling the outside air and performing latent heat treatment in the outside air supply unit 12. Since it is supplied to the indoor space S, the sensible heat cooling burden of the indoor unit 11 can be reduced, which is more preferable.

  An example of the latent heat treatment without sensible heat cooling is a method using a hygroscopic liquid (liquid adsorbent) such as liquid lithium. Alternatively, a method of dehumidifying the outside air by adsorbing moisture contained in the outside air through a honeycomb rotor impregnated with a solid adsorbent such as silica gel may be employed. When the method of dehumidifying the outside air using a solid adsorbent is adopted, drain water is not generated from the outside air supply unit 12 by heating and releasing the adsorbed moisture, and the outside air supply unit 12 also has a drain pipe. Is unnecessary, and a drainless air conditioning system can be realized.

(D)
In the said embodiment, although the example which uses the outdoor unit 15 common in the indoor unit 11 and the external air supply unit 12 was given and demonstrated, the air conditioning system of this invention is shown in FIG. And the outdoor air supply unit 12 may be an air conditioning system 10b provided with separate outdoor units (heat sources) 15a and 15b. Thus, even when the outdoor unit is provided in each of the indoor unit 11 and the outdoor air supply unit 12 and the heat source (refrigerant) is supplied, the same effect as described above is obtained.

In addition, in the air conditioning system 10b shown in FIG. 3, the target evaporation temperature calculating part 46 may be provided in outdoor unit 15a * 15b, and may be provided in any one.
(E)
In the above embodiment, the example in which the evaporation pressure adjustment module (dew point temperature calculation unit 2 and evaporation pressure control valve 3) is provided in the indoor unit 11 has been described. However, the present invention is not limited to this. Absent. For example, the evaporation pressure control is different from the air conditioning systems 10a and 10b of the above embodiment, and the evaporation pressure adjustment module (dew point temperature calculation unit 2, evaporation pressure control valve 3) 29 is connected to the indoor unit 11 as shown in FIG. Even the air conditioning system 10c provided separately from the sensible heat cooling unit 11 ′ has the same effect as described above.

  According to the present invention, since a drainless air conditioning system can be realized, application to an air conditioning system installed in a building or the like that requires large-scale drain piping work on the ceiling is particularly effective.

Schematic which shows the structure of the air conditioning system which shows one Embodiment of this invention. Schematic which shows the internal structure of the indoor unit, the outdoor air supply unit, and outdoor unit which comprise the air conditioning system of FIG. Schematic which shows embodiment different from the structure of FIG. Schematic which shows other embodiment different from FIG. 2, FIG. Schematic which shows the structure of the conventional air conditioning system.

Explanation of symbols

10.10a-10c Air conditioning system 11 Indoor unit (sensible heat cooling unit)
12 Outside air supply unit 13 Water supply pipe 14 Drain pipe 21 Suction air temperature / relative humidity detector (air sensor in space)
22 Control part (space absolute humidity calculation part)
23 Evaporation pressure control valve 24/32 Evaporation temperature detection unit 25/33 Outlet temperature detection unit 26/34 Electronic expansion valve 27 Indoor fan 28/37/42 Heat exchanger 31 Blowing air temperature / relative humidity detection unit (outside air sensor)
35 Drain pan 36 Outside air supply fan 38 Control unit (outside air absolute humidity calculation unit)
41 Outdoor Fan 43 Outdoor Expansion Valve 44 Four-way Switching Valve 45 Compressor 46 Target Evaporation Temperature Calculation Unit

Claims (5)

An air conditioning system (10) for cooling a predetermined space,
A sensible heat cooling unit (11) for controlling the chilled heat source to be equal to or higher than a dew point temperature of the air in the space in the space,
An outside air supply unit (12) for supplying outside air to the space;
With
The outside air supply unit (12) reduces the absolute humidity of the outside air supplied to the space and reduces the latent heat load of the outside air;
Air conditioning system (10). The outside air supply unit (12) makes the absolute humidity of the outside air supplied to the space smaller than the absolute humidity of the air in the space.
The air conditioning system (10) according to claim 1. An air sensor (21) in the space for detecting the temperature and relative humidity of the air in the space;
A space absolute humidity calculating section (22) for calculating the absolute humidity of the space from the temperature and relative humidity of the air in the space;
An outside air sensor (31) for detecting the temperature and relative humidity of the outside air supplied to the space;
An outside air absolute humidity calculating section (38) for calculating the absolute humidity of the outside air supplied to the space from the temperature and relative humidity of the outside air supplied to the space;
The air conditioning system (10) of claim 2, further comprising: The outside air supply unit (12) removes the condensed moisture by cooling the outside air supplied to the space to a dew point temperature or lower.
The air conditioning system (10) according to any one of claims 1 to 3. The outside air supply unit (12) performs dehumidification of outside air supplied to the space using an adsorbent.
The air conditioning system (10) according to any one of claims 1 to 3.

Images