JP2626278B2 - Air conditioning system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air conditioning system using both an air conditioner and a heat exchange ventilator.

[0002]

2. Description of the Related Art In recent years, in order to achieve energy saving of air conditioning and to achieve comfortable air conditioning, heat exchange is performed between air supplied from the outside to the room and air exhausted from the room to the outside. A heat exchange ventilator that is used is used together with an air conditioner.

As shown in FIG. 7, the heat exchange ventilator has an air supply path 90 for guiding air supply K from outside to indoors (see a solid arrow) and exhaust H from indoors to outside (see a broken arrow). Path 91 for guiding heat and a heat exchanger 9 for performing heat exchange between the supply air K and the exhaust H passing through both paths 90 and 91.
2, a bypass path 99 for guiding the exhaust H to the outside without passing through the heat exchanger 92, a switching damper 98 for selectively guiding the exhaust H to the bypass path 99 and the heat exchanger 92, and sirocco fans 93 and 94. (See, for example,
No. 210544).

The above heat exchange ventilator uses an indoor temperature detector for detecting the indoor temperature Tr and an outdoor air temperature detector for detecting the outdoor air temperature To, and uses the switching damper 98 based on the detected temperature of each detector. By switching the
Heat exchange ventilation for exchanging heat between the supply air K and the exhaust air H,
Ordinary ventilation, which performs ventilation without performing heat exchange, is selectively performed. The normal ventilation mode and the heat exchange ventilation mode are executed as follows based on the room temperature Tr and the outside air temperature To during the cooling and heating operation of the air conditioner.

[0005] That is, in the summer, the operation mode of the air conditioner is regarded as cooling operation, and when the room temperature Tr is higher than the outside air temperature To, normal ventilation is performed to cool the room by the supply air K (hereinafter referred to as outside air). Energy saving), and the room temperature Tr is equal to the outside air temperature To.
When the temperature is lower, the air supply K
Is exchanged by the heat exchanger 92 to reduce heat loss on the indoor side, thereby achieving energy saving. On the other hand, in winter, the operation mode of the air conditioner is regarded as heating operation,
When the room temperature Tr is higher than the outside air temperature To, the above-mentioned heat exchange ventilation is performed to eliminate the feeling of draft of the cool air, to obtain comfort and achieve energy saving. When the room temperature Tr is lower than the outside air temperature To, the room is warmed by the supply air K by performing ordinary ventilation (hereinafter, referred to as outside air heating) to achieve energy saving.

However, according to the operation control of the heat exchange ventilator, the switching operation between the heat exchange ventilation mode and the normal ventilation mode is performed without monitoring the operation information of the air conditioner, that is, the indoor operation by the air conditioner. Since the operation is performed based on only the indoor temperature Tr and the outside air temperature To without incorporating the operation information such as the set temperature Ts and the operation mode, an appropriate judgment is not performed, and the comfort and the energy saving are insufficient. There are cases. For example, when the air conditioner is used in an office or the like where many OA devices are used, during the cooling operation, (1) ordinary ventilation (outdoor air cooling) is performed when the room temperature Tr is higher than the outside air temperature To. When the outdoor air cooling is performed when the temperature is lower than the set temperature Ts of the air conditioner, that is, when the set temperature Ts> the indoor temperature Tr> the outside air temperature To, the indoor temperature Tr becomes smaller than the set temperature Ts. In addition, the occupants are given a sense of draft and the comfort is impaired. (2) Heat exchange ventilation is performed when the room temperature Tr is lower than the outside air temperature To. However, when the room temperature Tr is lower than the set temperature Ts, that is, outside air temperature To> room temperature Tr set temperature Ts. If the above-mentioned heat exchange ventilation is performed at the time of the room temperature Tr, the supply air K is cooled by the exhaust H and introduced into the room, so that the room temperature Tr lower than the set temperature Ts is reduced to the set temperature Ts. The inconvenience that it cannot be approached quickly occurs.

[0007] A similar inconvenience occurs during the heating operation. That is, (3) heat exchange ventilation is performed when the room temperature Tr is higher than the outside air temperature To, but when the outside air temperature To is higher than the set temperature Ts, that is, when the room temperature Tr> the outside air temperature To> If the heat exchange ventilation is performed at the set temperature Ts, the supply air K becomes exhaust H
And is introduced into the room, so that the set temperature T
There is a disadvantage that the room temperature Tr higher than s cannot be brought close to the set temperature Ts quickly, and the comfort is insufficient. (4) When the room temperature Tr is lower than the outside air temperature To, ordinary ventilation (outside air heating) is performed. However, when the room temperature Tr is higher than the set temperature Ts, that is, the outside air temperature To> the room temperature Tr> setting. If the outside air heating is performed at the temperature Ts, the indoor temperature Tr further increases with respect to the set temperature Ts, and the air supply K higher than the indoor temperature Tr is introduced. It gives a feeling and impairs comfort.

[0008] In view of such problems, the present applicant has
First, the operation information of the air conditioner is monitored, and based on the monitor information and the room temperature Tr and the outside air temperature To,
An air conditioning system that switches the mode of the heat exchange ventilator has been proposed (see Japanese Patent Application No. 2-5522). In the air conditioning system, in the cooling operation mode, the heat exchange ventilation mode is performed when the indoor temperature Tr is in the intermediate range between the indoor set temperature Ts and the outside air temperature To. Is configured to be performed. As described above, in the air conditioning system, the heat exchange ventilation mode and the normal ventilation mode are switched in consideration of the indoor set temperature information and the operation mode information of the air conditioner in addition to the indoor temperature Tr and the outside air temperature To. Therefore, the switching is appropriately performed, the comfort can be improved, and more energy saving can be achieved.

[0009]

By the way, a large number of OA
In a room where the equipment is installed, air conditioning may be used for cooling even in winter. However, in the air conditioning system according to the above proposal, even in the cooling operation mode in winter, the normal ventilation mode is performed when the room temperature Tr is not in the middle range between the room set temperature Ts and the outside air temperature To. When the outside air temperature To is equal to or lower than the predetermined temperature, the cold supply air K is supplied into the room without exchanging heat with the exhaust H, so that dew condensation occurs in a predetermined portion along the supply air path 90, and particularly, Condensation generated on the outer wall of the air supply duct 96 communicating with the room is determined by the duct 9
6, it is guided to the air supply grill on the indoor side and drops into the room, and in the worst case, there is a problem that the OA equipment is damaged. In order to address such problems, the duct 9
Although the dew-condensed portion such as 6 is covered with a heat insulating material, there is a problem that the cost is high because the heat insulating material needs to be considerably thick.

The present invention has been made in view of the above problems, and has as its object to provide an air conditioning system that can suppress the occurrence of dew condensation with a simple configuration.

[0011]

According to the present invention, there is provided an air conditioner for cooling and heating, and ventilation by exchanging heat between indoor exhaust air and outdoor air supply. A heat exchange ventilator that selectively performs heat exchange ventilation and normal ventilation that performs ventilation without heat exchange, and the indoor set temperature and operation mode information of the air conditioner, as well as the outside air temperature and the indoor temperature, In the air conditioning system including an operation control unit that switches between heat exchange ventilation and ordinary ventilation, the operation control unit can suppress the occurrence of dew condensation in a predetermined portion along the air supply path when the outside air temperature To is in the cooling operation mode. Determining means for determining whether the temperature is lower than the temperature Ta; and determining that the temperature is lower than the temperature Ta at which the occurrence of dew condensation can be suppressed. In which and a mode setting means for setting the over-de.

[0012]

According to the air conditioning system having the above-described structure, in the cooling operation mode, the determining means determines that the outside air temperature To is the temperature Ta at which the occurrence of dew condensation at a predetermined portion along the air supply path can be suppressed.
If it is determined to be lower than
Set the heat exchange ventilator to heat exchange ventilation mode. For this reason, the cold outdoor supply air can be warmed by the exhaust gas and introduced into the room, and the occurrence of dew condensation can be suppressed in a predetermined portion along the air supply path downstream of the heat exchanger.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. FIG. 2 is a schematic diagram showing the air conditioning system of the present invention. The air conditioning system includes an air conditioner 1 that cools and heats the room R, and a heat exchange ventilator 2 that ventilates the air in the room R and the air in the outdoor O so that they can exchange heat.

The heat exchange ventilator 2 is shown in FIGS.
As shown in FIG. 2, two paths 21 and 22 for air supply and exhaust are formed in the casing 20.
A heat exchanger 23 is arranged at the center of the first and second 22. The air supply path 21 is for guiding the air supply K from the outdoor O to the indoor R as shown by a solid arrow in the figure, and a duct D1 communicating with the outdoor O is connected on the upstream side (left side in the figure), A duct D communicating with the room R on the downstream side (right side in the figure)
2 are connected. A sirocco fan 24 for circulating the supply air K in the air supply passage 21 is disposed downstream of the heat exchanger 23 in the air supply passage 21.

The exhaust path 22 is for guiding the exhaust H from the room R to the outdoor O as indicated by a broken line arrow in the figure, and has a duct D communicating with the room R on the upstream side (right side in the figure).
3 is connected, and a duct D4 communicating with the outdoor O is connected on the downstream side (left side in the figure). Further, the exhaust path 22
Downstream of the heat exchanger 23, the exhaust H
Is provided.

The heat exchanger 23 exchanges heat between the supply air K passing through the air supply passage 21 and the exhaust H passing through the exhaust passage 22. A filter 26 (see FIG. 5) for filtering the supply air K and the exhaust H is provided in a portion facing the upstream side. The heat exchange ventilator 2 is provided with a bypass path 27 that guides the exhaust H to the outside O without passing through the heat exchanger 23 and performs only ventilation, as indicated by a dashed line arrow in FIG. . This bypass path 27 is connected to the heat exchanger 2 of the exhaust path 22.
It branches off from the portion of the damper 28 provided on the upstream side of 3 and is connected to the exhaust path 22 on the downstream side of the heat exchanger 23 without passing through the heat exchanger 23. Above damper 28
Is switched from the position shown by the solid line in the figure to the position shown by the two-dot chain line by the operation control means 4 (see FIG. 3), and guides the exhaust H to the bypass path 27 and the heat exchanger 23. Reference numeral 29 in the drawing denotes a driving means for switching the damper 28.

FIG. 3 is a block diagram showing the operation control means 4. The indoor temperature detector 4 detects the indoor temperature Tr.
1, an outside air temperature detector 42 for detecting an outside air temperature To,
A controller 43 for controlling the switching of the damper 28;
1, 42 are connected. The controller 43
Is connected to a monitor line 44 for monitoring an operation mode signal of the air conditioner 1 and an indoor set temperature signal, and a temperature detected by each of the detectors 41 and 42;
The damper 28 is automatically controlled by an output signal from the controller 43 based on the operation mode signal and the set temperature signal of the air conditioner 1 monitored by the monitor line 44. In the drawings, reference numeral 45 denotes an operation switch of the air conditioner 1, and reference numeral 46 denotes an operation switch of the heat exchange ventilator 2.

FIG. 1 is a flow chart showing the control operation of the heat exchange ventilator 2 by the operation control means 4. First, when an operation mode signal of the air conditioner 1 is input (step S1), in steps S2, S3, and S4, a blowing operation, a cooling operation, and a heating operation are determined in accordance with the operation mode signal, respectively. In the case of the blowing operation (Step S2), the heat exchange ventilation is performed in the heat exchange ventilator 2 (Step S5).

In the cooling operation (step S
3) In step S6, it is determined whether or not the set temperature Ts set in the air conditioner 1 is higher than the outside air temperature To detected by the outside air temperature detector 42, and the set temperature Ts is higher than the outside air temperature To. Is higher than the room temperature Tr detected by the room temperature detector 41 in step S7.
Is in an intermediate range between the outside air temperature To and the set temperature Ts.
If the heat exchange ventilation of No. 5 is performed and it is not in the intermediate region, the outside air temperature To is set to a predetermined portion along the air supply path 21 of the heat exchange ventilator 1, for example, the outer wall of the air supply duct D2 in step S8. It is determined whether the temperature is higher or lower than a temperature Ta (hereinafter, referred to as a dew-condensation suppression temperature Ta) at which the occurrence of dew condensation can be suppressed.
If the temperature is higher than the dew condensation suppression temperature Ta, step S10
Is performed, and when the temperature is lower than the dew condensation suppression temperature Ta, the heat exchange ventilation in step S5 is performed. Here, the dew condensation suppression temperature Ta is, for example, 80% humidity.
Is selected in consideration of some safety in addition to the dew point in the above, and it is usually selected in the range of 5 ° C. to 10 ° C., as described later, although it varies depending on the climate, use conditions, and the like.

Further, if the outside air temperature To is higher than the set temperature Ts in step S6, step S6 is executed.
In step 9, it is determined whether or not the outside air temperature To is higher than the room temperature Tr. If the temperature is high, the heat exchange ventilation in step S5 is performed. If the temperature is low, the normal ventilation in step S10 is performed. On the other hand, in the case of the heating operation (step S4), it is determined in step S11 whether or not the outside air temperature To is higher than the set temperature Ts. If it is higher, in step S12, the indoor temperature Tr is changed to the outside air temperature To and the set temperature Ts. It is determined whether or not it is in the middle area, and if it is in the middle area, the heat exchange ventilation in step S5 is performed. If it is not in the middle area, normal ventilation in step S10 is performed.
Further, when the outside air temperature To is lower than the set temperature Ts in the above step S11, it is determined in a step S13 whether or not the room temperature Tr is higher than the outside air temperature To. When it is higher, the heat exchange ventilation in the above step S5 is performed. When it is low, normal ventilation in step S10 is performed.

The above mode switching mode will be described in more detail with reference to Table 1. In Table 1, cooling A and heating A
Indicates the state of use in a general room, cooling B and heating B
Indicates a use state in an office or the like where many OA devices are provided. In Table 1, To indicates the outside air temperature detected by the outside air temperature detector 42, Ts indicates the set temperature set on the air conditioner 1 side, and Tr1 to Tr3 indicate the indoor temperature state.

[0022]

[Table 1]

In Table 1, (1) When the indoor temperature Tr is in the temperature state indicated by Tr1 in the cooling A, that is, when the indoor temperature Tr> the outside air temperature To> the set temperature Ts, the bypass path 27 is passed through the damper 28. Opening and performing ordinary ventilation cools the outside air to assist the operation of the air conditioner 1 and achieve energy saving. (2) When the indoor temperature Tr is in the temperature state indicated by Tr2 in the cooling A, that is, when the outside air temperature To> the indoor temperature Tr> the set temperature Ts, the bypass path 27 is closed by the damper 28 to perform heat exchange ventilation. By doing so, the outside air introduced into the room is cooled by the heat exchanger 23 to achieve energy saving. (3) When the room temperature Tr is in the temperature state indicated by Tr3 in the cooling A, that is, when the outside air temperature To> the set temperature Ts> the room temperature Tr, the bypass path 27 is closed by the damper 28 to perform heat exchange ventilation. By doing so, comfort is obtained by eliminating the feeling of drafts due to outside air, and energy saving is achieved. (4) When the room temperature Tr is in the temperature state indicated by Tr1 in the cooling B, that is, when the room temperature Tr> the set temperature Ts> the outside air temperature To, ordinary ventilation is performed to achieve energy saving. ing. (5) When the indoor temperature Tr is in the temperature state indicated by Tr2 in the cooling B, that is, when the set temperature Ts> the indoor temperature Tr> the outside air temperature To, the heat exchange ventilation is performed to sacrifice some energy characteristics. In addition, the draft feeling due to the direct introduction of the outside air into the room is suppressed, the comfort is enhanced, and the room temperature Tr is prevented from further lowering from the set temperature Ts. That is, the problem (1) is solved. (6) When the indoor temperature Tr is in the temperature state indicated by Tr3 in the cooling B, that is, when the set temperature Ts> the outside air temperature To> the indoor temperature Tr, normal ventilation is performed to bring the indoor temperature Tr closer to the set temperature quickly. As a result, comfort is enhanced and energy saving is achieved. That is, the problem (2) is solved.

Further, when the outside air temperature To is lower than the dew condensation suppressing temperature Ta, heat exchange ventilation is performed to suppress the occurrence of dew condensation on a predetermined portion along the air supply path 21, ie, the duct D2. (7) When the room temperature Tr is in the temperature state indicated by Tr1 in the heating A, that is, when the room temperature Tr> the set temperature Ts> the outside air temperature To, heat exchange ventilation is performed to warm the outside air and introduce it into the room. Thus, comfort is obtained by eliminating the feeling of draft in the cold wind, and energy saving is achieved. (8) In the heating A, when the indoor temperature Tr is in the temperature state indicated by Tr2, that is, when the set temperature Ts> the indoor temperature Tr> the outside air temperature To, heat exchange ventilation is performed to warm the outside air and introduce the room into the room. By doing so, it is possible to suppress the feeling of draft of the cool wind, enhance comfort, and achieve energy saving. (9) When the room temperature Tr in the heating A is in the temperature state indicated by Tr3, that is, when the set temperature Ts> the outside air temperature To> the room temperature Tr, the normal condition ventilation is performed, and the operation of the air conditioner 1 by the outside air is performed. To help save energy. (10) When the room temperature Tr is in the temperature state indicated by Tr1 in the heating B, that is, when the room temperature Tr> the outside air temperature To> the set temperature Ts, the normal ventilation is performed to set the room temperature Tr to the set temperature T.
s is approached quickly. That is, the problem (3) is solved. (11) When the room temperature Tr in the heating B is in the temperature state indicated by Tr2, that is, when the outside air temperature To> the room temperature Tr> the set temperature Ts, the heat exchange ventilation is performed to set the room temperature Tr to the set temperature Ts. To get closer to That is,
The problem (4) is solved. (12) When the room temperature Tr is in the temperature state indicated by Tr3 in the heating B, that is, when the outside air temperature To> the set temperature Ts> the room temperature Tr, the normal air is ventilated and the operation of the air conditioner 1 by the outside air is performed. To help save energy.

The above dew condensation suppression temperature Ta is based on whether or not dew condensation occurs in the duct D2 and the like downstream of the heat exchanger 23 when the supply air K is introduced into the room R without exchanging heat. It is a defined temperature, and as described above, 10
It is practically sufficient to select a temperature in the range of 5 ° C. to 5 ° C. The dew condensation suppression temperature Ta is calculated, for example, by calculating the surface temperature Tw of the duct D2. At the calculated surface temperature Tw, it is determined whether or not dew condensation occurs under the condition of 80% humidity in the humid air i shown in FIG. -Determined by comparing and using an x-ray diagram. More specifically, first, a heat insulating material (thickness: 20 mm, heat conductivity: 0.035 Kca) made of polyurethane foam is provided in the duct D2 of the heat exchange ventilator 2.
1 / m · h · deg, the room temperature Tr is 2
When the outside air temperature To is 0 ° C., 5 ° C., and 10 ° C. at 0 ° C., the temperature Tw on the surface of the duct D2 is calculated by the equation (1).
Calculated based on

Tw = (λ · To + t · α · Tr) ÷ (t · α + λ) (1) where λ is the thermal conductivity of the heat insulating material, t is the thickness of the heat insulating material, and α is the surface of the duct. Thermal conductivity (7 Kcal / m
² h · deg). From Expression (1), 16 ° C. is calculated as the surface temperature Tw of the duct D2 when the outside air temperature To is 0 ° C., and 17 ° C. is calculated as the surface temperature Tw of the duct D2 when the outside air temperature To is 5 ° C. Outside air temperature To is 1
18 ° C. is calculated as the surface temperature Tw of the duct D2 at 0 ° C. And from the humid air ix diagram of FIG.
It can be seen that when the surface temperature Tw is 16 ° C., dew forms at a humidity of 80% or more. Further, it can be seen that when the surface temperature Tw is 17 ° C., dew condensation does not occur at a humidity of 80% or less. Further, when the surface temperature Tw of the duct is 18 ° C., the humidity 80
It can be seen that no condensation occurs at less than 10%. Therefore, in the cooling operation in winter, if the heat exchange ventilation is generally performed when the outside air temperature To is lower than 5 ° C. to 10 ° C., the supply air K is warmed by the exhaust H, so that dew condensation occurs on the surface of the duct D2. It can be seen that this can be suppressed.

On the other hand, if the supply air temperature in the heat exchange ventilation is Ti, the thermal efficiency q is 70%, and the outside air temperature To is 5 ° C., the supply air temperature Ti = 15.5 ° C. is calculated from the equation (2). . (To−Ti) ÷ (To−Tr) = thermal efficiency q (2) Therefore, the indoor temperature Tr−the supply air temperature Ti = 20−1
5.5 = 4.5 deg, and the unpleasant sensation such as the draft sensation in the cold wind is reduced.

In the above embodiment, the dew condensation suppressing temperature Ta is selected on the basis of the dew point in the duct D2. What is necessary is just to select based on a dew point.

[0029]

As described above, according to the air conditioner system of the present invention, when the outside air temperature To is lower than the temperature Ta at which dew condensation cannot be suppressed in the air conditioner in the cooling operation mode, heat exchange ventilation is performed. Since the air supply is warmed and introduced into the room by performing the mode, it is possible to suppress the occurrence of dew condensation at a predetermined portion along the air supply path downstream of the heat exchanger. Therefore, damage to the OA equipment or the like due to condensation during the cooling operation in winter can be suppressed with a simple configuration. Further, even when a heat insulating material is stuck to prevent dew condensation, the thickness can be reduced, which is economical.

[Brief description of the drawings]

FIG. 1 is a flowchart showing a control mode by an operation control unit.

FIG. 2 is a schematic diagram showing an air conditioning system of the present invention.

FIG. 3 is a block diagram showing an electrical configuration.

FIG. 4 is a schematic plan view showing the internal configuration of the heat exchange ventilator.

FIG. 5 is a schematic view showing the internal configuration of the heat exchange ventilator as viewed from a side.

FIG. 6 is a humid air ix diagram.

FIG. 7 is a side view showing the internal configuration of the heat exchange ventilator.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 air conditioner 2 heat exchange ventilator 4 operation control means H exhaust K air supply 21 air supply path

Claims (1)

(57) [Claims] 1. An air conditioner (1) for cooling and heating, heat exchange ventilation for exchanging heat between indoor exhaust air (H) and outdoor air supply (K), and ventilation without heat exchange. Based on the heat exchange ventilator (2) that selectively performs normal ventilation, and the indoor set temperature Ts and operation mode information of the air conditioner (1), and the outside air temperature To and the indoor temperature Tr,
Operation control means for switching between the above heat exchange ventilation and ordinary ventilation
(4) In the air conditioning system including (4), the operation control means (4) is configured such that, in the cooling operation mode, the outside air temperature To exceeds the temperature Ta at which dew condensation can be suppressed in a predetermined portion along the air supply path (21). And a mode setting unit that sets the heat exchange ventilation device to the heat exchange ventilation mode when the determination unit determines that the temperature is lower than the temperature Ta at which dew condensation can be suppressed. An air conditioning system characterized by the above.