Outdoor-air-treating air conditioner

Abstract

To provide an outside air processing air conditioner capable of reducing leakage from a return air side to a supply air side even when an air volume to a rotary type total heat exchanger is increased or decreased.SOLUTION: The outdoor-air treating air conditioner (1) includes an outdoor-air fan (3) disposed on an outdoor side of the rotary total heat exchanger (10) and configured to adjust an air volume of outdoor air, an exhaust fan (7) disposed on the outdoor side of the rotary total heat exchanger (10) and configured to adjust an air volume of exhaust air, an air-volume detection unit (31) configured to detect an air volume to the rotary total heat exchanger (10), and a control unit (21) configured to control a rotation speed of a driving rotor according to the air volume detected by the air-volume detection unit (31).SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an outdoor air processing air conditioner that can reduce leakage of small particles such as viruses from the return air side to the supply air side even when the air volume to a rotary total enthalpy heat exchanger is increased or decreased. [Background technology]

[0002] Outdoor air conditioning units are primarily designed for ventilation, reducing the indoor air conditioning load (outdoor air load) associated with introducing outdoor air while also regulating temperature, humidity, and cleanliness. Outdoor air load is a major factor in air conditioning load, but the use of a total heat exchanger (TEAT) can reduce this load. A TEAT recovers heat from exhaust air to supply air, and one type of TEAT is the rotary type. Rotary type TEATs are regenerative heat exchangers that recover heat from exhaust air to supply air through the rotation of a rotor, which is designed to absorb moisture. When exhaust air passes through approximately half of the circular rotor, the heat (temperature and humidity) from the exhaust air accumulates in the rotor, and as the rotor rotates, the heat- and humidity-accumulated rotor enters the supply air passage, releasing the accumulated heat and humidity into the supply air.

[0003] Patent Document 1 describes a rotary total heat exchanger, and discloses that the rotation speed of the rotor is controlled to control the indoor dew point temperature. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 2018-71944 Summary of the Invention [Problem to be solved by the invention]

[0005] In outdoor air processing air conditioners that use a rotary type total heat exchanger, a leak occurs in which part of the return air passes through the rotary type total heat exchanger and moves to the supply air side. To reduce this leakage, fans are installed on both the exhaust side and the outdoor air side of the rotary type total heat exchanger, and a purge sector is also installed on the rotary type total heat exchanger to further reduce leakage.

[0006] However, even with these leak reduction measures in place, measurements of the leak rate using fluorescent powder on an actual unit revealed that the amount of leakage increases significantly when the airflow rate is reduced for energy-saving operation. This leakage is a major problem in hospitals and other facilities where infection risk must be reduced.

[0007] The present invention has been made in consideration of the above, and aims to provide an outdoor air processing air conditioner that can reduce leakage from the return air side to the supply air side even when the air volume to the rotary total heat exchanger is increased or decreased. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems and achieve the object, the present invention provides an outdoor air processing air conditioner that performs total heat exchange between exhaust air and supply air using a rotary total heat exchanger, and is characterized by comprising an outdoor air fan that is arranged on the outdoor side of the rotary total heat exchanger and adjusts the volume of outdoor air, an exhaust fan that is arranged on the outdoor side of the rotary total heat exchanger and adjusts the volume of exhaust air, an air volume detection unit that detects the volume of air entering the rotary total heat exchanger, and a control unit that controls the rotation speed of the drive rotor of the rotor of the rotary total heat exchanger in accordance with the air volume detected by the air volume detection unit.

[0009] In the present invention, the control unit reduces the rotation speed of the drive rotor when the air volume decreases.

[0010] In the above invention, the control unit controls the rotation speed of the drive rotor in accordance with the total thermal efficiency of the rotary total heat exchanger.

[0011] Furthermore, in the above invention, the present invention is characterized in that the control unit controls the rotation of the rotor at a drive rotor rotation speed such that the ratio of the drive rotor rotation speed to the maximum rotor rotation speed of the rotor of the rotary total heat exchanger is close to the air volume ratio of the detected air volume of the air volume detection unit to the maximum air volume to the rotary total heat exchanger.

[0012] Furthermore, in the present invention, the air volume detection unit detects the air speed on the return air side of the rotary total enthalpy heat exchanger as the air volume. [Effects of the Invention]

[0013] According to the present invention, even when the air volume to the rotary total enthalpy heat exchanger is increased or decreased, leakage from the return air side to the supply air side can be reduced. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a schematic diagram showing the overall configuration of an outside air processing air conditioner according to this embodiment. [Figure 2] FIG. 2 is a partially cutaway perspective view showing the configuration of a rotary type total heat exchanger used in an outdoor air processing air conditioner. [Figure 3] FIG. 3 is a diagram showing the relationship between wind speed, total heat efficiency of a rotary total heat exchanger, and rotor rotation speed. [Figure 4] FIG. 4 is a diagram showing the relationship between wind speed, return air leakage rate, and rotor rotation speed. [Figure 5] FIG. 5 is a graph showing the relationship between wind speed and leak rate when the rotor rotation speed is set to a constant 16 rpm, depending on whether the purge sector 16 is present or not. [Figure 6] FIG. 6 is an example of a control method for the rotor rotation speed control unit, and is a flowchart showing a procedure for controlling the rotation speed of the drive rotor by the control unit 21 using the rotation speed ratio and the air volume ratio. [Figure 7] FIG. 7 is a graph showing the results of reducing the leak rate by reducing the drive rotor rotation speed in response to a reduction in air volume, with and without a purge sector. [Figure 8] FIG. 8 is a diagram showing the relationship between the leak rate and the overall thermal efficiency when the air volume is changed for each rotation speed of the drive rotor. [Figure 9] FIG. 9 is a flowchart showing a procedure for controlling the rotational speed of the drive rotor by the control unit, as an example of control that reflects the leak rate. [Figure 10] FIG. 10 is a diagram showing an example of control of the rotation speed of the drive rotor relative to the wind speed. DETAILED DESCRIPTION OF THE INVENTION

[0015] Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

[0016] <Overall structure> FIG. 1 is a schematic diagram showing the overall configuration of an outdoor air processing air conditioner 1 according to this embodiment. FIG. 2 is a partially cutaway perspective view showing the configuration of a rotary total heat exchanger 10 used in the outdoor air processing air conditioner 1. As shown in FIG. 1, the outdoor air processing air conditioner 1 is provided with an exhaust flow path L1 that exhausts return air from indoors to the outdoors via the rotary total heat exchanger 10, and an outdoor air flow path L2 that draws in outdoor air from the outdoors and supplies it indoors. The rotary total heat exchanger 10 performs total heat exchange, exchanging the heat and humidity of the exhaust air (return air) with the heat and humidity of the outdoor air (supply air). The rotary total heat exchanger 10 recovers indoor heat that would otherwise be wasted during exhaust and returns it to the outdoor air that has been drawn in, supplying it indoors.

[0017] An exhaust fan 7 is provided on the exhaust side of the rotary total heat exchanger 10 to adjust the flow rate of the exhaust flow path L1.

[0018] A filter 2 and an outdoor air fan 3 are sequentially arranged in the outdoor air flow path L2 on the outdoor air side of the rotary total heat exchanger 10. The filter 2 filters particles in the outdoor air. The outdoor air fan 3 adjusts the flow rate of the outdoor air flow path L2. A cooling coil 4a, a heating coil 4b, and a humidifier 5 are sequentially arranged on the intake air side of the rotary total heat exchanger 10. Chilled water or the like flows through the cooling coil 4a, cooling the air on the coil surface. Hot water or the like flows through the heating coil 4b, heating the air on the coil surface. The humidifier 5 humidifies the air that has passed through the cooling coil 4a and heating coil 4b, and sends it out as intake air indoors.

[0019] The control device 20 controls the fan rotation speeds of the exhaust fan 7 and the outdoor air fan 3 to adjust the airflow rates in the exhaust flow path L1 and the outdoor air flow path L2, and also controls the rotation speed of the rotor of the rotary total heat exchanger 10. In this embodiment, the control device 20 controls the drive rotor rotation speed so that the rotation speed ratio of the drive rotor rotation speed to the maximum rotor rotation speed of the rotary total heat exchanger 10 approaches the airflow rate ratio of the current airflow rate to the maximum airflow rate to the rotary total heat exchanger 10.

[0020] <Rotary type total heat exchanger> 2, the rotary total heat exchanger 10 includes a casing 11 inside which a rotor 12, a rotary motor 14, and a drive belt 15 are provided. The casing 11 has a substantially rectangular parallelepiped shape and has circular openings on each of two opposing faces. The two openings are partitioned by a separator 17 into an area E1 for the exhaust air flow path L1 and an area E2 for the outside air flow path L2.

[0021] The rotor 12 is disk-shaped and is rotatably supported in the casing 11 by bearings 13, with the central axis of the disk as the axis of rotation and the disk surface and opening parallel to each other. The rotor 12 has a heat exchange element with a honeycomb structure or corrugated structure that is air permeable in the direction of the rotation axis.

[0022] Rotary motor 14 rotates at a predetermined rotation speed in accordance with a drive signal issued by control device 20. A drive belt 15 is wound around rotor 12, and the rotational force generated by rotary motor 14 is transmitted to rotor 12 via drive belt 15, causing rotor 12 to rotate in the direction of arrow W at the desired drive rotor rotation speed.

[0023] A purge sector 16 is provided near where the rotor 12 transitions from region E1 to region E2. The purge sector 16 receives a portion of the outside air flowing into the rotor 12 and returns it to the exhaust side, thereby reducing the leakage F (see FIG. 1) of return air near the purge sector 16 returning to the intake side.

[0024] Here, focusing on a portion of the rotor 12 of the rotary total heat exchanger 10, the rotor 12 rotates in the direction of arrow W by a rotary motor 14 and a drive belt 15, and the air circulates through zones E1 and E2 separated by a separator 17. Indoor air is taken in as return air from zone E1, an opening facing the indoors. After a portion of the total heat (temperature, humidity) of the return air taken in from zone E1 is recovered (stored) by the rotor 12, the return air is discharged outdoors as exhaust air from zone E1, an opening facing the outdoors. Meanwhile, outdoor air is taken in as outside air from zone E2, an opening facing the outdoors. After the outside air taken in from zone E2 receives the total heat (temperature, humidity) recovered (stored) from the return air from the rotor 12, it is introduced indoors as supply air from zone E2, an opening facing the indoors.

[0025] In this way, the rotary total heat exchanger 10 exchanges the total heat (temperature, humidity) of the return air with the total heat (temperature, humidity) of the outside air to produce the total heat (temperature, humidity) of the supply air. The efficiency of the exchange of total heat (temperature, humidity) between the return air and the outside air increases as the rotation speed of the rotor 12 increases, and decreases as the rotation speed of the rotor 12 decreases.

[0026] <Wind speed, total thermal efficiency, rotor rotation speed and leak rate> Fig. 3 is a diagram showing the relationship between wind speed, the total thermal efficiency of the rotary total heat exchanger 10, and the rotor rotation speed. Fig. 4 is a diagram showing the relationship between wind speed, the return air leakage rate, and the rotor rotation speed. Note that the wind speed in this embodiment is substantially the same as the air volume.

[0027] As shown in Figure 3, the total thermal efficiency of the rotary total heat exchanger 10 increases as the rotor rotation speed increases, and decreases as the wind speed increases. Note that the ventilation volume can be increased as the wind speed increases.

[0028] For example, when the wind speed is 3.5 m / s, increasing the rotor rotation speed above 16 rpm makes it possible to raise the total thermal efficiency to 70% or higher (total thermal efficiency L11), while decreasing the rotor rotation speed below 16 rpm makes the total thermal efficiency fall below 70% (total thermal efficiency L11). Also, when the rotor rotation speed is 16 rpm, the total thermal efficiency can be increased by lowering the wind speed, for example, by increasing the wind speed from 3.5 m / s to 1.75 m / s. In other words, the total thermal efficiency can be improved as the rotor rotation speed increases and the wind speed decreases. Note that the total thermal efficiency L12 indicates a total thermal efficiency of 74%.

[0029] On the other hand, as shown in Figure 4, the leak rate increases as the wind speed decreases. The leak rate also increases as the rotor rotation speed increases. For example, when the rotor rotation speed is 16 rpm, the leak rate is higher at a wind speed of 1.05 m / s than at a wind speed of 3.5 m / s. Furthermore, at a wind speed of 1.05 m / s, the leak rate is higher when the rotor rotation speed is 16 rpm than at 6 rpm, and the leak rate increases as the rotor rotation speed increases.

[0030] This is thought to be because when the wind speed is slow, the time it takes for the air to pass through the rotor of the rotary total heat exchanger 10 is slow, and the rotor rotates with the air from the exhaust side remaining in the rotor, causing it to move to the intake side.

[0031] This is especially likely to occur when the rotor is rotating fast, and even if a purge sector is installed, the remaining air will rotate to the intake side before passing through the rotor. Therefore, by slowing down the rotor rotation speed in line with the slower wind speed, the air can be made to rotate to the intake side after passing through the rotor, thereby suppressing leakage.

[0032] FIG. 5 shows the relationship between wind speed and leak rate when the rotor rotation speed is fixed at 16 rpm, with and without the purge sector 16. The right side of FIG. 5 shows the relationship between wind speed and leak rate when the purge sector 16 is provided, and the change in leak rate with changes in wind speed when the rotor rotation speed in FIG. 4 is 16 rpm is shown in a bar graph. On the other hand, the left side of FIG. 5 shows the relationship between wind speed and leak rate when the purge sector 16 is not provided. As with the right side of FIG. 5, the leak rate increases with increasing wind speed, but the magnitude of the increase is greater than when the purge sector 16 is provided. Therefore, it can be seen that providing the purge sector significantly contributes to reducing the leak rate.

[0033] In this way, if the rotor rotation speed is kept constant and the wind speed is reduced to save energy, the leak rate increases. This tendency is the same regardless of whether or not there is a purge sector 16. Therefore, in this embodiment, when the wind speed is reduced to save energy, the rotor rotation speed is also reduced, thereby reducing the leak rate.

[0034] <Control function> Returning to FIG. 1, the control device 20 has a control unit 21, a setting unit 22, and a memory unit 23. The control unit 21 is a control unit that controls the entire control device 20, and has a fan airflow setting control unit 30, an airflow detection unit 31, and a rotor rotation speed control unit 32. The control unit 21 stores programs corresponding to these functional units in a storage device such as a nonvolatile memory or a magnetic disk device, and loads these programs into memory and executes them on a CPU to execute the corresponding processes. The setting unit 22 is an input interface for setting and inputting various information, and the set information is held as setting information D in the memory unit 23.

[0035] The fan airflow rate setting control unit 30 controls the fan rotation speeds of the outdoor air fan 3 and the exhaust fan 7 to achieve a predetermined airflow rate. The airflow rate detection unit 31 detects the airflow rate to the rotary total heat exchanger 10. The fan airflow rate setting control unit 30 adjusts the airflow rates of the outdoor air fan 3 and the exhaust fan 7 by changing the inverter frequency of the inverter that operates the outdoor air fan 3 and the exhaust fan 7. The airflow rate detection unit 31 expresses the change in the inverter frequency of the outdoor air fan 3 and the exhaust fan 7 as a ratio and estimates the change in wind speed. For example, in the Kanto region, an inverter frequency of 50 Hz is the standard operation, and this standard operation results in a wind speed of 3.5 m / s. With an inverter frequency of 25 Hz (50 Hz x 50%), the wind speed is estimated to be 1.75 m / s (50%), and with an inverter frequency of 20 Hz (50 Hz x 40%), the wind speed is estimated to be 1.4 m / s (40%). The wind speeds measured by the anemometers 3a and 7a of the outdoor air fan 3 and the exhaust fan 7 may be directly measured as equivalent to the air volume to the rotary total heat exchanger 10. The air volume detection unit 31 essentially detects the wind speed on the return air side of the rotary total heat exchanger 10.

[0036] The rotor rotation speed control unit 32 controls the rotor rotation speed when the rotary total heat exchanger 10 is driven, depending on the air volume detected by the air volume detection unit 31. The rotor rotation speed control unit 32 increases the rotor rotation speed when the air volume detected by the air volume detection unit 31 increases. The rotor rotation speed control unit 32 decreases the rotor rotation speed when the air volume detected by the air volume detection unit 31 decreases. Setting information, which contains a table of the relationship between air speed, rotor rotation speed, and leak rate as shown in FIGS. 3 and 4 , may be stored in advance in the storage unit 23, and the rotor rotation control unit 31 may control the rotor rotation speed based on this setting information. The drive rotor rotation speed may also be controlled so that the ratio of the drive rotor rotation speed to the maximum rotor rotation speed of the rotary total heat exchanger 10 approaches the ratio of the air volume detected by the air volume detection unit 31 to the maximum air volume flowing into the rotary total heat exchanger.

[0037] Even if the air volume is reduced by energy-saving operation, the control of the rotor rotation speed control unit 32 reduces the drive rotor rotation speed to a value that corresponds to the reduction in air volume, thereby preventing an increase in the leakage rate.

[0038] <Modification of rotor rotation speed control procedure> FIG. 6 is a flowchart showing an example of a control method of the rotor rotation speed control unit 32, and is a procedure for controlling the drive rotor rotation speed by the control unit 21 using the rotation speed ratio and the air volume ratio. As shown in FIG. 6, the air volume detection unit 31 detects the current air volume as air speed A (step S101). Thereafter, the rotor rotation speed control unit 32 calculates the drive rotor rotation speed B at which the air volume ratio RA = the rotation speed ratio RB, setting the air volume ratio RA = the drive rotor rotation speed B / the maximum rotor rotation speed Bmax, and performs control to rotate the rotor 12 at a drive rotor rotation speed close to the drive rotor rotation speed B (step S102), thereby terminating this process. The above process is repeated at predetermined time intervals.

[0039] <Specific leak rate reduction> Specifically, when the maximum air volume is 3.5 m / s (100% operation), the maximum rotor rotation speed is 16 rpm (100% operation). When operating at 50% for energy saving operation, the air volume is 1.75 m / s and the drive motor rotation speed is 8 rpm; when operating at 40% the air volume is 1.4 m / s and the drive motor rotation speed is 6.4 rpm; and when operating at 30% the air volume is 1.05 m / s and the drive motor rotation speed is 4.8 rpm.

[0040] Figure 7 is a graph showing the results of reducing the leak rate by reducing the drive rotor rotation speed corresponding to the reduction in air volume, with and without the purge sector 16. As shown on the left side of Figure 7, when the purge sector 16 is installed, even when the operation rate is changed from 100% to 50%, the leak rate drops from 0.32% to 0.08%, maintaining a low leak rate. Even when the operation rate is changed to 40%, the leak rate remains low at 0.05%, maintaining a low leak rate. Furthermore, even when the operation rate is changed to 30%, the leak rate remains low at 0.06%.

[0041] Therefore, by reducing the rotational speed of the drive rotor in response to a reduction in the air volume, the leakage rate can be improved more effectively than when the rotational speed of the drive rotor is kept constant.

[0042] The right side of Figure 7 shows the change in the leak rate when the purge sector 16 is not installed. By reducing the drive rotor rotation speed in response to the reduction in air volume, a similar improvement trend to that when the purge sector 16 is installed can be obtained.

[0043] <Application example reflecting leak rate> Figure 8 shows the relationship between the leak rate and the overall thermal efficiency when the airflow rate is changed for each drive rotor rotation speed. Figure 8 also shows the leak rate for each combination of airflow rate and drive rotor rotation speed, the combination of airflow rate and drive rotor rotation speed that achieves an overall thermal efficiency of 70% or more, and the combination of airflow rate and drive rotor rotation speed that achieves an overall thermal efficiency of 74% or more. Note that 100% airflow rate is 3.5 m / s, 50% airflow rate is 1.75 m / s, 40% airflow rate is 1.4 m / s, and 30% airflow rate is 1.05 m / s. Also, 100% drive rotor rotation speed is 16 rpm, 80% drive rotor rotation speed is 12.8 rpm, 60% drive rotor rotation speed is 9.6 rpm, and 40% drive rotor rotation speed is 6.4 rpm.

[0044] As shown in Figure 8, the leak rate can be reduced by controlling the drive rotor rotation speed in response to increases or decreases in airflow, just as in the embodiment. However, depending on the combination of airflow and drive rotor rotation speed, the desired total thermal efficiency cannot be achieved. For example, if the desired total thermal efficiency is set to 70% or higher, the combination of 100% airflow (3.5 m / s) and 60% drive rotor rotation speed (9.6 rpm) and the combination of 100% airflow (3.5 m / s) and 40% drive rotor rotation speed (6.4 rpm) do not satisfy the desired total thermal efficiency. Similarly, if the desired total thermal efficiency is set to 74% or higher, the combination of 100% airflow (3.5 m / s) and 80% drive rotor rotation speed (12.8 rpm) and the combination of 50% airflow (1.75 m / s) and 40% drive rotor rotation speed (6.4 rpm) also do not satisfy the desired total thermal efficiency.

[0045] Therefore, in this application example, when a total thermal efficiency instruction that sets the total thermal efficiency of the rotary total heat exchanger 10 to be equal to or greater than the set total thermal efficiency and an air volume instruction indicating a set air volume or set air volume range corresponding to energy-saving operation are set, a drive rotor rotation speed is set in advance that satisfies the total thermal efficiency equal to or greater than the set total thermal efficiency and has a rotation speed ratio close to the air volume ratio for the air volume instruction, and the control unit 21 controls the rotation of the rotor 12 at this preset drive rotor rotation speed. The above total thermal efficiency instruction and air volume instruction are set via the setting unit 22, and the set contents are stored as setting information D in the memory unit 23. Note that the set total thermal efficiency is variable, but it may also be set in advance to a predetermined total thermal efficiency.

[0046] 9 is a flowchart showing a procedure for controlling the rotation speed of the drive rotor by the control unit 21, as an example of control that reflects the leak rate. In this example, a total thermal efficiency of 70% or more and a total thermal efficiency of 74% or more can be set as the total thermal efficiency instruction. The operation modes include a strong operation mode, a medium-weak operation mode, a medium operation mode, and a weak operation mode. In the strong operation mode, the wind speed is 100%, in the medium-weak operation mode, the wind speed is 30 to 50% (when the total thermal efficiency is 70% or more), in the medium operation mode, the wind speed is 50% (when the total thermal efficiency is 74% or more), and in the weak operation mode, the wind speed is 30 to 40% (when the total thermal efficiency is 74% or more).

[0047] 9, the control unit 21 first determines whether the set total thermal efficiency is 70% or more, or 74% or more (step S301). If the set total thermal efficiency is 70% or more (step S301: 70% or more), it further determines whether the operation mode is the high operation mode or the medium / low operation mode (step S302).

[0048] If the operation mode is the strong operation mode (step S302: strong operation mode), the drive rotor rotation speed is controlled by a combination of wind speed = 100% and drive rotor rotation speed = 100% (step S303), and this process ends.On the other hand, if the operation mode is the medium-weak operation mode (step S302: medium-weak operation mode), the drive rotor rotation speed is controlled by a combination of wind speed = 30-50% and drive rotor rotation speed = 80% (step S304), and this process ends.

[0049] On the other hand, if the set total thermal efficiency is 74% or more (step S301: 74% or more), it is further determined whether the operation mode is the strong operation mode, the medium operation mode, or the weak operation mode (step S305).

[0050] If the operation mode is the strong operation mode (step S305: strong operation mode), the process proceeds to step S303, where the drive rotor rotation speed is controlled to a combination of 100% wind speed and 100% drive rotor rotation speed, and the process ends. On the other hand, if the operation mode is the medium operation mode (step S305: medium operation mode), the drive rotor rotation speed is controlled to a combination of 50% wind speed and 60% drive rotor rotation speed (step S306), and the process ends. Also, if the operation mode is the weak operation mode (step S305: weak operation mode), the drive rotor rotation speed is controlled to a combination of 30-40% wind speed and 40% drive rotor rotation speed (step S307), and the process ends.

[0051] With the above configuration, even when the airflow rate to the rotary total heat exchanger is increased or decreased, a predetermined total thermal efficiency can be maintained and leakage from the return air side to the supply air side can be reduced. The combination of air speed and drive rotor rotation speed in each operating mode is selected so that, when the leakage rate is approximately the same, the total thermal efficiency condition is satisfied and the drive rotor rotation speed is increased to increase the total thermal efficiency. Furthermore, when there is a range of airflow rates, the leakage rate is approximately the same for all airflow rates, and a higher drive rotor rotation speed is selected from among the drive rotor rotation speeds that satisfy the total thermal efficiency condition to increase the total thermal efficiency. In these operating modes, a single drive rotor rotation speed is preset, allowing for simplified control.

[0052] Furthermore, when the leak rate exceeds a predetermined value, i.e., when the wind speed falls below a predetermined value, the drive rotor rotation speed may be controlled. For example, as shown in Figure 10, by reducing the drive rotor rotation speed when the wind speed falls below 45%, the heat exchange rate can be maintained at 60% or higher even if the wind speed is changed. In this case, the leak rate also becomes 1% or less.

[0053] In this embodiment and its modifications, the rotation of the rotor is controlled so that the drive rotor rotation speed is variably controlled and increases or decreases in accordance with increases or decreases in the air volume. Therefore, even if the air volume to the rotary total heat exchanger is increased or decreased due to energy conservation, the total heat efficiency can be maintained and leakage from the return air side to the supply air side can be significantly reduced. As a result, it is possible to realize an outdoor air processing air conditioner using a rotary total heat exchanger that can achieve both infection control and energy conservation, even in hospital facilities where infection risk reduction is necessary.

[0054] In addition, in this embodiment and its variants, by providing a purge sector 16, the purge sector 16 receives a portion of the outside air flowing into the rotor 12 and generates a flow that returns it to the exhaust side, thereby reducing leakage of return air back to the intake side.

[0055] In the above embodiment, the combination of airflow rate and drive rotor rotation speed is discrete, but it may be changed continuously. In other words, it is sufficient if the drive rotor rotation speed increases or decreases in the same way as the airflow rate increases or decreases.

[0056] Furthermore, the configurations illustrated in the above embodiments and modifications are merely functional schematics and do not necessarily have to be physically configured as shown. In other words, the distribution and integration of each device and component is not limited to that illustrated, and all or part of them can be functionally or physically distributed and integrated in any unit depending on various usage situations, etc. [Explanation of symbols]

[0057] 1. Outdoor air processing air conditioner 2. Filters 3. Outdoor air fan 3a,7a Anemometer 4a Cooling coil 4b Heating coil 5 Humidifier 7. Exhaust fan 10 Rotary type total heat exchanger 11 Casing 12 rotors 13 Bearings 14 Rotation Motor 15 Drive belt 16 Purge Sectors 17 Separator 20 Control device 21 Control section 22 Setting section 23 Memory section 30 Fan airflow setting control section 31 Air volume detection unit 32 Rotor speed control unit A Wind speed Amax Maximum wind speed B Drive rotor rotation speed Bmax Maximum rotor speed D. Setting Information E1,E2 area F Leak L1 exhaust passage L2 Outside air flow path L11, L12 Total thermal efficiency RA air volume ratio RB rotation speed ratio W Arrow

Claims

1. An outdoor air processing air conditioner that performs total heat exchange between exhaust air and intake air using a rotary type total heat exchanger, an outdoor air fan disposed on the outdoor side of the rotary total heat exchanger to adjust the volume of outdoor air; an exhaust fan disposed on the outdoor side of the rotary total heat exchanger to adjust the volume of exhaust air; an air volume detection unit that detects the air volume to the rotary total heat exchanger; a control unit that controls a rotation speed of a drive rotor of the rotary total heat exchanger in accordance with the air volume detected by the air volume detection unit; An outdoor air processing air conditioner comprising:

2. The outdoor air processing air conditioner according to claim 1 , wherein the control unit reduces the rotation speed of the drive rotor when the air volume decreases.

3. 2. The outdoor air processing air conditioner according to claim 1, wherein the control unit controls the rotation speed of the drive rotor in accordance with the total thermal efficiency of the rotary total heat exchanger.

4. The control unit controls the rotation of the rotor at a drive rotor rotation speed such that the ratio of the drive rotor rotation speed to the maximum rotor rotation speed of the rotor of the rotary total heat exchanger is close to the ratio of the air volume detected by the air volume detection unit to the maximum air volume to the rotary total heat exchanger.

5. 5. The outdoor air processing air conditioner according to claim 4, wherein the control unit controls the rotation of the rotor at a rotation speed of the drive rotor such that the rotation speed ratio becomes the air volume ratio.

6. 6. The outdoor air processing air conditioner according to claim 1, wherein the air volume detection unit detects the air speed on the return air side of the rotary type total enthalpy heat exchanger as the air volume.

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