Outside air treatment air conditioner

Abstract

[Problem] To provide an energy-saving, space-saving, and low-cost outside conditioner. [Solution] The present invention comprises an exhaust passage for exhausting return air from an indoor space to the outside and an air supply passage for supplying outside air to the indoor space, wherein: in the order in which the outside air passes on the air supply passage side, a total heat exchanger in an upstream stage and a desiccant rotor in a downstream stage are disposed so as to span the exhaust passage and the air supply passage; the total heat exchanger performs total heat exchange between the return air from inside a room and the outside air; the desiccant rotor performs latent heat exchange between the outside air and the return air which has undergone the total heat exchange; in the air supply passage, an air supply passage-side blower is disposed between the total heat exchanger and the desiccant rotor; and a heat pump circuit is provided for performing heat exchange between air supply passage-side outside air which has passed through the total heat exchanger and exhaust passage-side exhaust air which has passed through the desiccant rotor. By simplifying the apparatus, eliminating the need for an outdoor unit, and providing a split-unit type, it is possible to achieve reduction of the total cost of the apparatus and achieve reduction of on-site construction cost after the installation of the apparatus and shortening of a construction term.

Description

Outdoor air processing air conditioner

[0001] The present invention relates to an outdoor air processing air conditioner (hereinafter referred to as "outdoor air conditioner") that can adjust the temperature and humidity of outdoor air with little energy by using a passive desiccant rotor that uses the relative humidity difference between two or more air streams, without using a total heat exchanger or an external heat source for regeneration.

[0002] Outdoor air conditioning units used in office buildings and commercial buildings are used to adjust the temperature and humidity of the air supplied to indoor air conditioners, etc., based on the temperature and humidity of the outside air in order to control the temperature and humidity of the indoor air. By reducing the indoor humidity, the comfort of the indoor space improves even if the temperature remains the same.

[0003] For example, Patent Document 1 discloses an outdoor air conditioning unit that includes a total heat exchanger and a desiccant rotor. As shown in FIG. 1 , the outdoor air conditioning unit described in Patent Document 1 includes an exhaust passage for exhausting return air from an indoor space to the outside and an intake passage for supplying outdoor air to the indoor space. The intake passage includes a total heat exchanger at the front and a desiccant rotor at the rear, in the order in which the outdoor air passes through. The unit also includes a heat pump circuit that exchanges heat between the outdoor air that has been subjected to total heat exchange and the return air. The total heat exchanger exchanges total heat between the outdoor air on the intake passage and the return air on the exhaust passage that has passed through the desiccant rotor. The desiccant rotor exchanges latent heat between the outdoor air on the intake passage that has passed through the total heat exchanger and the return air on the exhaust passage from the indoor space. The desiccant rotor saves energy by eliminating the need for a regenerative heat source, and it also saves space and costs by eliminating the need for an outdoor unit.

[0004] Japanese Patent Application Laid-Open No. 2020-12602

[0005] The outdoor air-conditioning unit described in Patent Document 1 reduces initial and running costs by utilizing return air from indoors. However, there is a demand for a device with high energy-saving effects that pursues even higher performance, space savings, and cost reduction, and aims to achieve climate neutrality.

[0006] The outdoor air-conditioning unit described in Patent Document 1 uses ion exchange resin as an adsorbent in the desiccant rotor, which is said to prevent odor transfer from the return air to the supply air. However, because the blower 8 serving as a treatment fan is installed after the desiccant rotor, negative pressure is created on the supply air duct side, resulting in an overall pressure balance that is prone to leaks from the exhaust duct side to the supply air duct side. This raises concerns about odors contained in the return air from indoors transferring to the supply air, and reducing leaks from the return air duct side and odor transfer from the return air has been a challenge.

[0007] Furthermore, the bypass path A of the outdoor air-conditioning unit in Patent Document 1 is provided to stabilize the heat pump circuit and allows outside air to be sent directly to the exhaust path. In summer, to ensure the heat dissipation capacity of the heat pump, for example, one-third of the outside air taken into the intake air path is sent to the exhaust path through bypass path A. However, under heavy loads, the heat exchange capacity is insufficient. The blower 13 on the exhaust path serves both to blow exhaust air and to take in intake air. When adjusting the heat balance of the heat pump circuit based on the exhaust air temperature, the air volume regulator 15 controls the heat exchanger 14 in conjunction with the blower 13, requiring complex control.

[0008] Furthermore, Patent Document 1 does not mention operation during intermediate periods. During intermediate periods, the operation of the total heat exchange rotor 3 and the passive desiccant rotor 6 is stopped, and only air is blown. Because outside air passes through two rotors in the air intake duct, pressure loss increases, and the power consumption of the blower 8, which serves as a treatment fan, increases. In addition, the air volume on the air intake duct side is controlled only by the air volume regulator 1 and the blower 8 located in front of the total heat exchange rotor 3, and fine adjustment of the air volume, such as the air volume passing through each rotor, is not possible. For this reason, it is difficult to say that operation during intermediate periods has been taken into consideration.

[0009] In order to solve the above problems, the present invention aims to provide an outdoor air-conditioning unit that has a passive desiccant rotor that does not require a total heat exchanger or a regenerative heat source, that uses only a heat pump system for cooling and heating, and that is more space-saving and less expensive than the outdoor air-conditioning unit described in Patent Document 1 (see the comparative example described below).

[0010] In order to solve the above problems, the outdoor air-conditioning unit of the present invention has an exhaust passage that exhausts return air from the indoor space to the outside, and an intake passage that supplies outdoor air to the indoor space, and on the intake passage side, in the order that the outdoor air passes, a total heat exchanger is arranged in the front stage and a desiccant rotor is arranged in the back stage, straddling the exhaust passage and the intake passage, with the total heat exchanger exchanging total heat between the return air from the indoor space and the outdoor air, and the desiccant rotor exchanging latent heat between the return air that has been totally heat exchanged and the outdoor air, and a blower on the intake passage side is arranged between the total heat exchanger and the desiccant rotor in the intake passage, and is configured with a heat pump circuit that exchanges heat between the outdoor air on the intake passage side that has passed through the total heat exchanger and the exhaust air on the exhaust passage side that has passed through the desiccant rotor.

[0011] The outdoor air-conditioning unit of the present invention, configured as described above, can provide all cooling and heating functions using a heat pump alone, utilizing a total heat exchanger and desiccant rotor. Since all refrigerant components are built into the unit, an outdoor unit is not required, reducing the total cost of the system. On-site installation work, such as chilled / hot water piping, refrigerant piping, and external wiring, is not required, and no additional space is required for the outdoor unit, reducing construction costs and shortening construction time. This single package does not affect existing facilities, allowing for new installations or replacements for existing facilities. Furthermore, the desiccant rotor does not require a regenerative heat source, and total heat exchange between return air (RA) and outdoor air (OA) in a total heat exchanger enhances the humidification / dehumidification effect, resulting in energy savings and high performance. Furthermore, by supporting ion exchange resin as an adsorbent on the rotor and optimizing the placement of the blower, the migration of odors contained in the return air to the supply air can be further reduced.

[0012] The outdoor air-conditioning unit of the present invention is slimmer than the conventional outdoor air-conditioning unit of Patent Document 1, making it compact and space-saving. Furthermore, by adopting a split-unit structure, it is possible to select an installation method that suits the installation location, such as an integrated or split type, and it is flexible and excellent in transportability and installation workability. Furthermore, the symmetrical design allows for offset installation, which shortens lead time. Therefore, it can also be used for renovation work on existing equipment, which was difficult with the conventional outdoor air-conditioning unit of Patent Document 1 due to the incompatible unit size.

[0013] Furthermore, the outdoor air-conditioning unit of the present invention can automatically switch between the total heat exchanger, desiccant rotor, heat pump, bypass, etc. depending on the operating mode, and detects the temperature and humidity of the outdoor air and automatically controls it to meet the required indoor air intake conditions, allowing stable operation throughout the year and contributing to improved energy savings. In the outdoor air-conditioning unit of the present invention, dehumidification is performed using the desiccant rotor in the summer, which reduces the load on the cooling coil compared to cooling dehumidification using only the cooling coil. By providing a bypass path for the total heat exchanger and desiccant rotor on the intake air path side, power consumption can be reduced in intermediate seasons.

[0014] FIG. 1 is a flow diagram of the outdoor air-conditioning unit of Patent Document 1. FIG. 2 is a flow diagram of the outdoor air-conditioning unit of the present invention. FIG. 3 is a diagram showing the unit structure of the outdoor air-conditioning unit of the present invention. FIG. 4 is a flow diagram showing a comparative example in which the humidifier 11 is installed on the air intake side rather than the exhaust side in the outdoor air-conditioning unit of Patent Document 1. FIG. 5 is a diagram showing the performance of an example of the outdoor air-conditioning unit of the present invention and a comparative example. FIG. 6 is a test result for Example 4 using a test machine for the outdoor air-conditioning unit of the present invention. FIG. 7 is a diagram showing an example of the configuration of a heat pump circuit when the specifications of the outdoor air-conditioning unit of the present invention are a large air volume type.

[0015] The outdoor air-conditioning unit of the present invention has a device design and configuration that takes into consideration energy saving and size reduction of the equipment. An embodiment of the outdoor air-conditioning unit of the present invention will be described in detail below with reference to FIG.

[0016] The outdoor air-conditioning unit of the present invention has an exhaust path B that exhausts return air from an indoor space to the outside, and an intake path C that supplies outdoor air to the indoor space. Furthermore, in the order in which the outdoor air passes on the intake path C, a total heat exchange rotor 3 serving as a total heat exchanger is provided in the upstream stage, and a desiccant rotor 6 is provided in the downstream stage. The total heat exchange rotor 3 performs total heat exchange between the return air from the indoor space and the outdoor air, and the desiccant rotor 6 performs latent heat exchange between the return air that has been totally heat exchanged and the outdoor air. Furthermore, on the intake path C side, an intake path-side heat exchanger 5 is provided at the outlet side of the total heat exchange rotor 3 and the inlet side of the desiccant rotor 6, and on the exhaust path B side, an exhaust path-side heat exchanger 14 is provided at the outlet side of the desiccant rotor 6. The system is configured to include a heat pump circuit having a heat exchanger 5 on the intake air path side, a heat exchanger 14 on the exhaust air path side, and a compressor 16, and this heat pump circuit exchanges heat between the outside air that has passed through the total heat exchange rotor 3 on the intake air path C side and the exhaust air that has passed through the desiccant rotor 6 on the exhaust air path side.

[0017] (Total Heat Exchanger) 3 is a total heat exchange rotor, made of a corrugated sheet such as aluminum foil, which is shaped like a rotor and supports an adsorbent material such as silica gel or ion exchange resin to adsorb moisture. In this embodiment, ion exchange resin is used to prevent odor transfer between the return air and the supply air. The total heat exchange rotor 3 is arranged to rotate by a gear motor (not shown) across an exhaust path B, which exhausts return air RA from the indoor space (not shown) as exhaust air EA, and an air supply path C, which supplies outside air OA to the indoor space as supply air SA. A bypass path E bypasses the inlet and outlet sides of the total heat exchange rotor 3 in the air supply path C, and an air volume regulator 26 adjusts the volume of outside air OA passing through the bypass path E.

[0018] (Desiccant Rotor) Reference numeral 6 denotes the desiccant rotor, which is a corrugated rotor made of porous inorganic fibers such as glass fiber. It is loaded with moisture-absorbing adsorbents such as silica gel, zeolite, and ion exchange resin. In this embodiment, ion exchange resin is used to prevent odor transfer between the return air and the supply air. The desiccant rotor 6 is a passive desiccant rotor that does not require a regenerative heat source. The desiccant rotor 6 is arranged to rotate by a gear motor (not shown) across an exhaust path B, which exhausts return air RA from the indoor space as exhaust air EA, and an air supply path C, which supplies outside air OA to the indoor space as supply air SA. A bypass path F bypasses the inlet and outlet sides of the total heat exchange rotor 6 in the air supply path C, and an air volume regulator 27 adjusts the volume of air passing through the bypass path F.

[0019] (Heat Pump Circuit) The heat pump circuit includes an intake-side heat exchanger 5 (such as a heat exchange coil), an exhaust-side heat exchanger 14, a compressor 16 for compressing the refrigerant, and an expansion valve (not shown) for controlling the expansion of the refrigerant. The heat pump circuit performs heat exchange and expansion of the refrigerant, transferring heat from low-temperature to high-temperature areas. Heat exchange occurs between the outside air OA on the intake-side C side that has passed through the total heat exchange rotor 3 and the exhaust air EA on the exhaust-side B side that has passed through a desiccant dehumidifier. Specifically, the thermal energy cooled / heated by the intake-side heat exchanger 5 is radiated / absorbed by the exhaust-side heat exchanger 14. The intake-side heat exchanger 5 and the exhaust-side heat exchanger 14 each function as an evaporator or condenser depending on the conditions.

[0020] The bypass path D is located on the exhaust path B, on the outlet side of the desiccant rotor 6, before the heat exchanger 14 on the exhaust path side, and directly takes in outside air to stabilize the heat pump circuit. An air volume control device 25, such as an air volume control damper (VD: Volume Damper, MD: Motor Damper), a variable air volume control device (VAV: Variable Air Volume), or a constant air volume control device (CAV: Constant Air Volume), allows outside air (OA) to be directly taken into the exhaust air (EA) through the bypass path D. In summer, to ensure the heat dissipation capacity of the heat pump, the bypass path D automatically takes in outside air directly to the exhaust path B, ensuring sufficient heat exchange capacity. This eliminates the need to send a portion of the outside air taken in as supply air through the bypass path A from the supply air path to the exhaust path, as in Patent Document 1, resulting in excellent operability.

[0021] Those skilled in the art will understand that, as in U.S. Patent Application Publication No. 2017 / 0356661 (FIGS. 1 and 11), an exhaust path heat exchanger is placed on the inlet side of the desiccant rotor (exhaust path side) as a regenerative heat source, raising the regeneration inlet temperature and improving the dehumidification performance of the desiccant rotor. However, the present invention takes a different approach from this conventional wisdom, placing the exhaust path heat exchanger 14 on the exhaust path B side at the outlet side of the desiccant rotor 6, thereby eliminating the need for a regenerative heat source for the desiccant rotor 6. This allows the heat pump's heat balance to be adjusted depending on the amount of outside air taken in from the bypass path D, thereby prioritizing the effect of increasing the cooling effect of the intake air path heat exchanger 5 in the summer.

[0022] (Humidifier) ​​In the outdoor air-conditioning unit 23 described in Patent Document 1, the humidifier 11 is installed on the exhaust path side and is configured to humidify the indoor space when it becomes too dry, such as in winter. However, the humidifying effect is enhanced by directly humidifying the supply air SA. Therefore, in this embodiment, the humidifier 11, such as a drip permeation humidifier or a two-fluid humidifier, is installed on the supply air path side, at a position near the outlet of the desiccant rotor 6. Note that in the comparative example described below, a case will be described in which the humidifier 11 is installed on the supply air path side instead of the exhaust path side, as shown in Figure 4, in the outdoor air-conditioning unit 23 of Patent Document 1.

[0023] (Blower) In the outdoor air-conditioning unit 23 described in Patent Document 1, the blower 8 on the intake air passage is located on the outlet side of the desiccant rotor 6, creating a negative pressure on the intake air passage, resulting in an overall pressure balance that favors leakage from the exhaust air passage to the intake air passage. In particular, leakage on the indoor side of the desiccant rotor 6, i.e., return air RA from the indoor air in the exhaust passage is prone to leak into the supply air SA in the intake air passage, is likely. Therefore, even if ion exchange resin is used as the adsorbent for the desiccant rotor 6, there is a concern that odors may migrate from the return air RA from the indoor air to the supply air SA. Therefore, in the present invention, the intake air passage-side blower 8 is located on the outlet side of the total heat exchange rotor 3 in the intake air passage C, but on the inlet side of the desiccant rotor 6, i.e., between the total heat exchange rotor 3 and the desiccant rotor 6. This results in an overall pressure balance that favors leakage from the intake air passage C to the exhaust air passage B, effectively reducing odor migration from the return air RA to the supply air SA. If there is a concern about odor leakage from the exhaust path B side, it is advisable to provide a purge sector between the regeneration zone (exhaust path B side) and the treatment zone (air supply path C side) of the desiccant rotor 6.

[0024] In both Patent Document 1 and the present invention, the exhaust path-side blower 13 is provided before the exhaust path-side heat exchanger 14; in Patent Document 1, it is located at the exhaust path outlet of the total heat exchange rotor 3, while in the present invention, it is located at the outlet of the exhaust path B of the desiccant rotor 6. In the present invention, pressure loss due to the air flowing around the introduction path (B' described below) that passes air from the outlet of the total heat exchange rotor 3 to the inlet of the desiccant rotor 6 in exhaust path B has a significant impact on the power consumption of the exhaust path-side blower 13. However, by arranging the exhaust path-side blower 13 on the outlet side of the regeneration (exhaust path B side) of the desiccant rotor 6, a pressure balance is achieved in which the supply air SA on the supply air path C side flows into the return air RA on the exhaust path B side, which has the effect of reducing odor transfer. Furthermore, by placing the blower 8 on the air supply path side between the total heat exchange rotor 3 and the desiccant rotor 6, the temperature after passing through the blower 8 increases slightly, but as described below, it is possible to divide it into two rotor units and a heat pump / blower unit.

[0025] (Outdoor air-conditioning unit unit structure) As described above, the outdoor air-conditioning unit of the present invention is composed of the total heat exchange rotor 3, desiccant rotor 6, the heat exchanger 5 on the air intake path that constitutes the heat pump circuit, the heat exchanger 14 on the air exhaust path, the compressor 16, the humidifier 11, the blower 8 on the air intake path, the blower 13 on the air exhaust path, and the air filters 2, 10, 28. Due to this device configuration, the outdoor air-conditioning unit is divided into three units: a total heat exchanger unit 31, a heat pump / fan unit 32, and a desiccant rotor unit 33, as shown in Figure 3.

[0026] Figures 3(a) and (b) show the unit structure of the outdoor air-conditioning unit of the present invention and the equipment configuration of each unit, with arrows indicating the direction of air flow for reference. Figure 3(a) shows the case where the units are connected as a single unit, while Figure 3(b) shows an example where the units are installed separately. Figure 3(c) shows the appearance of each separated unit. The total heat exchanger unit 31 includes a total heat exchange rotor 3 and air filters 2 and 10. It has a bypass path E and an air volume regulator 26 below the total heat exchange rotor 3, an outside air intake 35 to the supply air path C, and a return air intake 36 to the exhaust air path B. The heat pump / fan unit 32 includes a blower 8 on the supply air path side, a blower 13 on the exhaust air path side, a heat exchanger 5 on the supply air path side, a heat exchanger 14 on the exhaust air path side, and a compressor 16, which constitute the heat pump circuit. It has an exhaust port 37 and an outside air intake 38 to the bypass path D, and incorporates an air volume regulator 25. The desiccant rotor unit 33 includes a desiccant rotor 6, an air filter 28, a bypass passage F and an air volume regulator 27 below the desiccant rotor 6, and an air intake port 39 to the indoor space.

[0027] Depending on the installation layout, each unit can be connected as an integrated unit as shown in Figure 3(a), or can be separated as shown in Figure 3(b) and installed separately by connecting the units with ducts. This separate unit structure allows for the selection of an installation method that suits the installation location, making it flexible and easy to transport and install. Separate units can also be installed when space is limited, such as when upgrading existing equipment to the outdoor air-conditioning unit of the present invention. By incorporating the heat pump circuit into the unit, on-site installation of refrigerant piping and wiring is unnecessary, shortening the construction period. Furthermore, the outdoor air-conditioning unit of the present invention has a symmetrical design, making it possible to accommodate offset installations, thereby shortening the lead time.

[0028] As shown in Figure 3(a), the return air RA that leaves the total heat exchange rotor 3 in the exhaust path B is introduced into the desiccant rotor 6 through the top of the unit (inlet path B'). By incorporating this inlet path B' within the unit, the overall height of the system increases, but the installation of a duct system can be reduced. The inlet path B' can be made removable, and depending on the installation environment, it can be replaced with a sandwich panel equipped with a duct flange, allowing for a duct system. Similarly, incorporating the rotor bypass paths (bypass paths E and F) and air volume control devices 26 and 27 on the intake air path C side within the unit can reduce the installation of a bypass duct at the customer's site. Furthermore, by making the bypass paths E and F removable, depending on the installation environment, it can be replaced with a sandwich panel equipped with a duct flange, allowing for a duct system. The humidifier unit 34, including the humidifier 11, can also be installed separately, allowing for optional elimination or retrofitting of the humidifier unit 34 depending on the customer's specifications.

[0029] The unit division structure and the components built into each unit are not limited to the above-described configuration and may be modified as needed. For example, in FIG. 3, the exhaust passage B is located at the top and the intake passage C is located at the bottom, but they may be reversed. Furthermore, for example, the air intake passage fan 8 may be included in the total heat unit 31, or the exhaust passage fan 13 may be included in the desiccant unit 33. The unit division unit may be further reduced, for example, to a unit with only a blower or a unit with only a heat pump. Snow protection hoods or the like may be provided at the air outlets and intakes as needed.

[0030] The outdoor air processing operation of the outdoor air-conditioning unit according to this embodiment, based on the above configuration, will now be described. During cooling and dehumidifying operation (cooling mode) in summer, the heat exchanger 5 on the air intake path operates as an evaporator to cool outdoor air, and the heat exchanger 14 on the exhaust path operates as a condenser. Additional dehumidification is also performed by the desiccant rotor 6. During intermediate seasons, the total heat exchanger rotor 3 and the desiccant rotor 6 are stopped, and outdoor air is passed through bypass paths E and F to perform fan operation (fan mode). During heating and humidifying operation (heating mode) in winter, the heat exchanger 5 on the air intake path operates as a condenser to heat outdoor air, and the heat exchanger 14 on the exhaust path operates as an evaporator. The desiccant rotor 6 is stopped, and outdoor air is supplied to the indoor space through bypass path F. Furthermore, humidification operation is performed by the humidifier 11 as needed. In this way, heat pump technology detects the temperature and humidity of the outside air and automatically controls it to meet the set air supply conditions by switching between three operating modes: cooling mode in summer, ventilation mode in the intermediate seasons, and heating mode in winter.In addition, by installing a total heat exchanger, it is possible to recover the energy of the return air discharged from the indoor space, reducing energy consumption and significantly reducing running costs.

[0031] The outdoor air conditioning unit of the present invention automatically switches between ventilation, cooling, and heating modes by controlling the ON / OFF of the components according to the outdoor temperature and humidity. The ON / OFF states of each component in these three modes are shown in Table 1. In Table 1, ON of the air volume regulators 26 and 27 represents the OPEN state, and OFF represents the CLOSE state. For example, a temperature and humidity sensor (THS) measures the temperature and humidity of the outdoor air (OA), supply air (SA), and return air (RA), and a control device (not shown) controls the components. The outdoor air conditioning unit of the present invention primarily adjusts the humidity of the supply air (SA), and the temperature of the supply air (SA) is adjusted as close as possible to the customer's indoor space specifications, but this is subject to change. The indoor air conditioning unit primarily adjusts the temperature of the indoor space (latent and sensible separation). This allows the indoor space to be maintained at, for example, 24±1°C and 50±5% RH (all temperatures hereafter are in "Celsius"). Examples of operation and performance calculations in summer, intermediate seasons, and winter will be described below as Examples 1, 2, and 3, respectively.

[0032]

[0033] (Summer Operation: Cooling Mode) The cooling and dehumidifying operation in summer will now be described. In the air supply path C, outside air OA is sent through an air filter 2 to the total heat exchange rotor 3 by an air supply path-side blower 8 serving as a treatment fan. The outside air OA undergoes total heat exchange with return air RA from the indoor space in the total heat exchange rotor 3, where it is dehumidified and cooled. The outside air OA that has undergone total heat exchange is sent to the air supply path-side heat exchanger 5 serving as the evaporator of the heat pump circuit and cooled. The air that has passed through the air supply path-side heat exchanger 5 is sent to the desiccant rotor 6 where it is dehumidified, and then passes through an air filter 28 and is supplied to the indoor space as supply air SA.

[0034] In the exhaust path B, return air RA from the indoor space is sent to the total heat exchange rotor 3 through an air filter 10 by the exhaust path-side blower 13, which functions as a regenerative fan. The return air RA undergoes total heat exchange with outside air OA in the total heat exchange rotor 3, where it is humidified and heated. The heat-exchanged return air RA is sent to the desiccant rotor 6, where it is humidified and cooled. The air that passes through the desiccant rotor 6 is sent to the exhaust path-side heat exchanger 14, which serves as the condenser of the heat pump circuit, and then exhausted outside the system as exhaust air EA. In summer, the cooling load of the supply air path-side heat exchanger 5 increases. Therefore, as needed, outside air is automatically introduced directly into the exhaust path B via the bypass path D. The heat dissipation rate of the exhaust path-side heat exchanger 14 is controlled based on the temperature of the exhaust air EA, stabilizing the heat balance of the heat pump circuit. The humidifier 11 is also stopped.

[0035] The state of air inside and outside the outdoor air-conditioning unit of the present invention in summer is shown in Figure 5. In the table of Figure 5, (1) to (9) indicate the state of air at positions (1) to (9) inside and outside the unit in Figure 2. The same applies to Examples 2 to 3 and Comparative Examples 1 to 3 (Figure 4). In Examples 1 to 3 and Comparative Examples 1 to 3, the air volume of the supply air SA was 5,000 m ３ / h, return air RA volume is 4000m ３ The calculation was made as / h.

[0036] The flow chart is compared with that of the comparative example (FIG. 4) described below and comparative example 1 (FIG. 5) in summer. In the comparative example, return air RA from the room is introduced into the desiccant rotor 6, whereas in the outdoor air-conditioning unit of the present invention, it is introduced into the total heat exchange rotor 3. This enhances the total heat exchange effect between the outdoor air OA and the return air RA in the total heat exchange rotor 3, thereby increasing the air temperature at the inlet side of the regeneration (exhaust path B side) in the desiccant rotor 6 compared to comparative example 1. The higher the regeneration temperature of the desiccant rotor, the greater the relative humidity difference, resulting in better dehumidification performance. The regeneration inlet temperature of the desiccant rotor 6 is 32.1°C in example 1 and 26.0°C in comparative example 1, so that example 1 can effectively utilize the total heat exchange effect of the hot outdoor air OA in summer. Therefore, the dehumidification amount (the difference in absolute humidity between air (3) and air (5)) is 1.7 g / kg (DA) in example 1, while it is only 0.8 g / kg (DA) in comparative example 1.

[0037] The temperature of the indoor space is adjusted to the target temperature of the required specifications of the indoor space by an existing indoor conditioning unit such as an air conditioner. The temperature of the supply air SA is 26.4°C in Example 1 and 20.5°C in Comparative Example 1, which is lower than the target temperature, and the temperature adjustment load of the indoor conditioning unit increases.

[0038] (Operation in Intermediate Season: Fan Mode) The fan operation during intermediate seasons will now be described. Only the fans 8 and 13 are operated, the air volume regulators 26 and 27 are open, and the other components are stopped. That is, the heat exchanger 5 on the air supply path, the heat exchanger 14 on the air exhaust path, the compressor 16, and the humidifier 11, which constitute the heat pump circuit, are stopped. Therefore, in fan mode, power consumption is solely for the fans. Furthermore, the total heat exchange rotor 3 and the desiccant rotor 6 are stopped, and on the air supply path C side, outside air OA is supplied to the room via the respective rotor bypass paths E and F as supply air SA. The bypass paths E and F are each equipped with air volume regulators 26 and 27, which allow the air volume in the air supply path C to be adjusted. By passing the air through the bypass paths E and F, pressure loss is lower than when passing through the rotor, thereby reducing power consumption of the air supply path fan 8.

[0039] The state of air inside and outside the outdoor air-conditioning unit of the present invention during the intermediate season is shown in Figure 5. Because only the fan operation is in operation, the temperature of the air after passing through the fans 8 and 13 rises by about 1°C. Compared to Comparative Example 2 described below, the performance is unchanged, but in Example 2, rotor bypass fan blowing on the air supply path C side reduces pressure loss, thereby reducing the power consumption of the fan 8 on the air supply path side.

[0040] (Winter Operation: Heating Mode) The heating and humidifying operation in winter will be described. In winter, the desiccant rotor 6 is stopped, air is introduced into the bypass path F on the air supply path C side, and the air volume of the supply air SA is adjusted by the air volume regulator 27. In the air supply path C, outside air OA is sent to the total heat exchange rotor 3 through the air filter 2 by the air supply path side blower 8 serving as a treatment fan. The outside air OA undergoes total heat exchange with return air RA from the indoor space in the total heat exchange rotor 3. The outside air OA that has undergone total heat exchange is sent to the heat exchanger 5 serving as a condenser of the heat pump circuit and heated. The air that has passed through the heat exchanger 5 on the air supply path side is supplied to the indoor space as supply air SA through the bypass path F of the desiccant rotor 6. If the air in the indoor space is too dry, the supply air SA is humidified by the humidifier 11 to adjust the humidity.

[0041] In the exhaust path B, return air RA from the indoor space is sent through an air filter 10 by a blower 13 on the exhaust path side as a regenerative fan to the total heat exchange rotor 3. The return air RA is cooled and dehumidified by total heat exchange with outside air OA in the total heat exchange rotor 3. The return air RA that has undergone total heat exchange passes through the desiccant rotor 6, which is stopped, and is sent to a heat exchanger 14 on the exhaust path side as an evaporator of the heat pump circuit, and is then discharged outside the device as exhaust air EA.

[0042] Figure 5 shows the air conditions inside and outside the outdoor air-conditioning unit of the present invention in winter. In Comparative Example 3, described below, both the total heat exchange rotor 3 and the desiccant rotor 6 are operated. Those skilled in the art would attempt to achieve a humidifying effect by heating air using the heat exchanger 5 on the air supply path and passing it through the desiccant rotor 6, as in Comparative Example 3. However, in the present invention, the desiccant rotor 6 is stopped and bypassed. Furthermore, since the return air RA from the room exchanges total heat with the outdoor air OA using the total heat exchange rotor 3, the outdoor air can be sufficiently humidified using only the total heat exchange rotor 3. Therefore, the supply air SA passes through the bypass path F, which bypasses the desiccant rotor 6, reducing pressure loss and reducing power consumption by the blower 8 on the air supply path. On the other hand, the heat exchanger 5 on the air supply path heats humid air, resulting in increased energy consumption compared to Comparative Example 3. The humidification amount of the outside air OA before passing through the humidifier 11 (the difference in absolute humidity between air (4) and air (1)) is 4.8 g / kg (DA) when humidified using only the total heat exchange rotor 3 in Example 3, and 5.3 g / kg (DA) when humidified using both the total heat exchange rotor 3 and the desiccant rotor 6 in Comparative Example 3 (humidification using the total heat exchange rotor 3 is 2.2 g / kg (DA), and humidification using the desiccant rotor 6 is 3.1 g / kg (DA)). While the humidification amount in Example 3 is less than that in Comparative Example 3, a sufficient humidification effect can be obtained using only the total heat exchange rotor 3. While Patent Document 1 claims that a regenerative heat source is not required, in winter, the heat exchanger 5 on the air intake path side is used as a condenser to heat the air, thereby achieving the humidifying effect of the desiccant rotor 6. However, in the present invention, the heat exchanger 5 on the air supply path side is used as a condenser to heat the air, but the air is supplied bypassing the desiccant rotor 6, so that a regenerative heat source for the desiccant rotor 6 is truly unnecessary.

[0043] In Example 3, when there is no humidifier 11 or when humidification is not performed, the air that has passed through the intake air passage heat exchanger 5 is supplied to the indoor space as intake air SA via the bypass passage F, so that the intake air can be supplied while maintaining the heating effect of the intake air passage heat exchanger 5 as a condenser. On the other hand, in Comparative Example 3, the air is humidified through the desiccant rotor, so that the humidifying effect is obtained but the temperature drops. Alternatively, when humidification is not performed, there is no temperature drop of the intake air SA due to the humidifier 11, so it is sufficient to simply raise the temperature of the intake air passage heat exchanger 5 to a level close to the indoor required conditions, thereby reducing energy consumption.

[0044] The operation of the outdoor air-conditioning unit of the present invention in summer, intermediate seasons, and winter has been described above. Note that although the cooling mode is used in summer, the fan mode in intermediate seasons, and the heating mode in winter, the operating mode is automatically switched depending on the temperature and humidity conditions of the outdoor air. For example, even in intermediate seasons, if the temperature and humidity of the outdoor air deviates from the set temperature and humidity range of the supply air, the operating mode may be switched from the fan mode to the cooling mode or the heating mode.

[0045] A test machine having the flow and device configuration of the outdoor air conditioner of the present invention shown in Figure 2 was manufactured, and tests were conducted in the ventilation mode in the intermediate season and the heating mode in the winter. ３ / h, and the diameters of the total heat exchange rotor 3 and the desiccant rotor 6 were both 1100 mm. The test results are shown in FIG.

[0046] Figure 6(a) shows the test results when switching operation from heating mode to fan mode. The set temperature of the supply air SA in fan mode was 20-26°C, and the set dew point was 7.5-13.5°C DP. The outside air temperature and humidity were detected, and as the outside air temperature rose, the operation was automatically switched from heating mode to fan mode, demonstrating a smooth transition. The supply air SA was supplied within the set temperature, humidity, and dew point conditions.

[0047] Figure 6(b) shows the results of continuous operation in heating mode on a different winter day from that shown in Figure 6(a). The set temperature of the supply air SA in heating mode was set to 28°C. As the outside air temperature changed, the supply air SA remained almost constant at around 28°C. This shows that it is possible to absorb outside air temperature fluctuations and achieve stable supply air relative to the set temperature.

[0048] Although the above describes an embodiment of the present invention in detail, the present invention is not limited to the above embodiment. Various modifications and variations are possible within the scope of the present invention as defined in the claims, and such modifications and variations are also within the scope of the present invention. For example, after the bypass paths E and F are branched into their respective bypass paths, an additional air volume regulator may be provided on the rotor inlet side of the air supply path C to regulate the volume of air passing through each rotor. When the air volume regulators 26 and 27 are open, the air flows into the bypass paths E and F, which have low pressure loss. This eliminates the need for an air volume regulator on the rotor inlet side as in this embodiment, leading to cost savings. Both bypass paths E and F may be provided, or only one may be provided. Furthermore, the order of the air filter 28 and the humidifier 11 may be reversed. Furthermore, while the total heat exchanger has been described as a rotary type total heat exchange rotor, it may be replaced with a stationary type. Furthermore, the customer requirements and supply air conditions of the supply air SA may be controlled and managed not only by temperature and humidity but also by dew point.

[0049] The outdoor air conditioning unit of the present invention may be controlled by a single heat pump circuit or by multiple circuits or equipment configurations. In cooling or heating mode, when the fan mode setting is approached, the load on the heat pump circuit is reduced (the heat pump circuit is OFF in fan mode). Controlling the heat pump circuit under such low loads has been a challenge. Therefore, in this invention, the heat pump circuit is divided into two systems, one as a base and the other as an adjustment, with inverter-controlled compressors. These two heat pump circuits are connected in series or parallel. When the outdoor air load is low and the heat pump circuit is under low load, the base system is stopped and only the adjustment system is operated. Furthermore, by using a hot gas bypass depending on the load situation, precise humidity control is possible. Meanwhile, when the outdoor air load is high in cooling / heating mode, the base system compressor is activated if the adjustment cycle exceeds capacity, and two heat pump circuits are used. Furthermore, when the outdoor air load is high, the enthalpy difference between the outdoor air and the set supply air conditions can be calculated, and the number of base compressors in operation can be determined depending on the magnitude of the load (if there are multiple compressors).In addition to the two-system heat pump circuit, base and adjustment, modularization and control using multiple components or heat pump circuits can improve the efficiency of the entire heat pump circuit system, establish a backup system, and extend the lifespan.

[0050] When the specifications of the outdoor air-conditioning unit of the present invention are a large air volume type, the heat pump circuit may have multiple heat exchangers 5, 14 and compressors 16 as condensers and / or evaporators, as shown in Figure 7(a), or may have multiple refrigerant circuits (heat pump circuits) as shown in Figure 7(b). For example, if the heat exchanger 5 on the air supply path side is the evaporator and the heat exchanger 14 on the air exhaust path side is the condenser in Figure 7(a), multiple evaporators 5 (5a, 5b, 5c) are arranged in parallel, and multiple condensers 14 (14a, 14b, 14c) and compressors 16 (16a, 16b, 16c, 16d) are also arranged in parallel (parallel circuits not shown) to form a single heat pump circuit. 7(b), one evaporator 5 (5a, 5b, 5c), one condenser 14 (14a, 14b, 14c), and one compressor 16 (16a, 16b, 16c) are installed in each heat pump circuit, and multiple heat pump circuits are maintained. However, this is not limited to this, and one or multiple evaporators, condensers, and compressors may be installed in one heat pump circuit and connected in parallel or series, as appropriate.

[0051] (Comparative Example) Figure 4 shows the outdoor air-conditioning unit (Figure 1) of Patent Document 1, where the humidifier 11 is installed on the air intake duct side rather than the exhaust duct side. Below, examples of operation and performance calculations in summer, intermediate seasons, and winter will be explained as Comparative Examples 1, 2, and 3, respectively, while comparing with Examples 1 to 3 of the outdoor air-conditioning unit (Figure 2) of the present invention. Figure 5 shows the air conditions inside and outside the outdoor air-conditioning units of Comparative Examples 1 to 3. Table 2 also shows the ON / OFF status of each component device in the three modes of the comparative example: cooling mode in summer, ventilation mode in intermediate seasons, and heating mode in winter.

[0052] Comparative Example 1

[0053] During cooling and dehumidification operation (cooling mode) in summer, outdoor air OA is sent to the total heat exchange rotor 3 through an air filter 2 by a blower 8 serving as a processing fan. The total heat exchange rotor 3 exchanges total heat with return air RA from the indoor space that has passed through a desiccant rotor 6. The outdoor air OA that has undergone total heat exchange is sent to a heat exchanger 5 on the supply air path, which serves as the evaporator of the heat pump circuit, where it is cooled. Air that has passed through the heat exchanger 5 on the supply air path is sent to the desiccant rotor 6, where it is dehumidified and supplied to the indoor space as supply air SA. Return air RA from the indoor space is sent to the desiccant rotor 6 by a blower 13 serving as a regenerative fan, where it is humidified and cooled. The return air RA that has passed through the desiccant rotor 6 is sent to the total heat exchange rotor 3, where it exchanges total heat with outdoor air OA. The air that has passed through the total heat exchange rotor 3 is sent to a heat exchanger 14 on the exhaust air path, which serves as the condenser of the heat pump circuit, and then exhausted to the outside of the device as exhaust air EA. In summer, in order to ensure the amount of heat dissipation from the heat pump, for example, one-third of the outside air OA introduced into the air supply path is taken into the bypass path A. Comparative Example 2

[0054] In the ventilation operation (ventilation mode) during the intermediate season, only the fans 8 and 13 are operated, and the other components are stopped. Therefore, power consumption is solely for the fans. Outside air OA passes through the intake air path, first through the total heat exchange rotor 3 and then through the desiccant rotor 6, and is supplied to the indoor space as intake air SA. Return air RA from the indoor space passes through the exhaust path, first through the desiccant rotor 6 and then through the total heat exchange rotor 3, and is exhausted as exhaust air EA. Comparative Example 3

[0055] During heating and humidification operation (heating mode) in winter, outdoor air OA is sent to the total heat exchange rotor 3 through an air filter 2 by a blower 8 serving as a processing fan. The total heat exchange rotor 3 exchanges total heat with return air RA that has passed through a desiccant rotor 6 from the indoor space. The outdoor air OA that has undergone total heat exchange is sent to the heat exchanger 5 on the air supply path, which serves as a condenser for the heat pump circuit, and heated. The air that has passed through the heat exchanger 5 on the air supply path is sent to the desiccant rotor 6, where it is humidified and supplied to the indoor space as supply air SA. If the air in the indoor space is too dry, it is humidified by a humidifier 11 to increase the humidity of the supply air SA. The return air RA from the indoor space is sent to the desiccant rotor 6 by a blower 13 serving as a regenerative fan and dehumidified. The return air RA that has passed through the desiccant rotor 6 is sent to the total heat exchange rotor 3, where it exchanges total heat with outdoor air OA. The air that has passed through the total heat exchange rotor 3 is sent to a heat exchanger 14 on the exhaust path side, which serves as an evaporator of the heat pump circuit, and is then exhausted to the outside of the device as exhaust air EA.

[0056] As can be seen from Figure 5, the COP (Coefficient of Performance) is the same for the outdoor air-conditioning units of the present invention (Examples 1 to 4) and the conventional outdoor air-conditioning units according to Patent Document 1 (Comparative Examples 1 to 3). On the other hand, the outdoor air-conditioning units of the present invention consume less power, particularly in summer and intermediate seasons, and are more energy-efficient. As such, the energy-saving properties of the outdoor air-conditioning units of the present invention have been improved, and a more compact, split-unit structure has been achieved through ingenious equipment configuration. The installation area has been reduced by 10% compared to the outdoor air-conditioning unit of Patent Document 1.

[0057] The air conditioner of the present invention can be used not only for general air conditioning applications in commercial facilities, hotels, office buildings, etc., but also in factories that require year-round air conditioning management, such as in food processing, pharmaceutical manufacturing, and the automotive industry, and that have production processes and production environments that require the intake of outside air.

[0058] Products used as outdoor air-conditioning units include AHUs (air handling units) or FCUs (fan coil units), AHUs (total heat units) equipped with total heat exchangers, general-purpose desiccant units, and two-rotor desiccant units like the one in this invention. Heat sources include hot and cold water systems and heat pump systems. However, typical outdoor air-conditioning units have poor energy efficiency, accounting for a high proportion of annual running costs, at approximately 30%. While some of these outdoor air-conditioning units offer improved performance, there are still few groundbreaking energy-saving devices, leaving users with limited options.

[0059] Because the outdoor air-conditioning unit of the present invention uses a total heat exchanger, desiccant rotor, and heat pump, its initial cost, or CAPEX (Capital Expenditure), is higher than other outdoor air-conditioning units, and its size tends to be larger. However, its running cost, or OPEX (Operating Expenditure), including power consumption and other chilled water and steam usage, can be significantly reduced, making it the lowest among outdoor air-conditioning units. For example, when calculated under the same conditions, compared to an AHU using chilled water and steam as a heat source, the CAPEX is 1.88 times higher, while the OPEX is only 0.32 times higher. According to calculations, the cost-effectiveness of the outdoor air-conditioning unit of the present invention reverses within three years of use, and the longer it is used, the more cost-effective it becomes. Furthermore, compared to a two-rotor desiccant with the same configuration (total heat exchanger + desiccant rotor + heat pump), the cost of the unit itself is lower, and it achieves energy and space savings. This is due to the simplified equipment, despite the complex flow of the outdoor air-conditioning unit of the present invention, and the fact that the unit is split and all components are incorporated within the unit. Furthermore, the amount of carbon dioxide emitted by the outdoor air-conditioning unit of the present invention is the lowest among various outdoor air-conditioning units, at only 0.41 times that of an AHU that uses chilled water and steam as a heat source. Because the air conditioner of the present invention is electrically driven using a heat pump, it can contribute to climate neutrality when combined with clean electricity. Thus, the outdoor air-conditioning unit of the present invention has particularly outstanding energy-saving and environmentally friendly features among outdoor air-conditioning units, making it possible to provide equipment that meets the social needs of the future as we strive for a carbon-free society.

[0060] 1, 12, 15, 25, 26, 27 Air volume regulator 2, 10, 28 Air filter 3 Total heat exchange rotor 4, 7 Gear motor 5 Heat exchanger on intake air path 6 Desiccant rotor 8 Blower on intake air path 9 Indoor space 11 Humidifier 13 Blower on exhaust air path 14 Heat exchanger on exhaust air path 16 Compressor 17, 18, 19 Temperature sensor 20 Dew point sensor 21 Temperature regulator 22 Dew point control device 23 Outdoor air conditioning unit 31 Total heat exchanger unit 32 Heat pump / blower unit 33 Desiccant rotor unit 34 Humidifier unit 35 Outside air intake port to intake air path 36 Return air intake port to exhaust air path 37 Exhaust air outlet 38 Outside air intake port to bypass path D 39 Air intake port to indoor space A, D, E, F: Bypass passage B: Exhaust passage B': Inlet passage C: Air supply passage

Claims

1. An outdoor air processing air conditioner having an exhaust passage for exhausting return air from an indoor space to the outside, and an air intake passage for supplying outdoor air to the indoor space, wherein a total heat exchanger is arranged in the front stage and a desiccant rotor is arranged in the rear stage, straddling the exhaust passage and the air intake passage, in the order that the outdoor air passes through on the air intake passage side, the total heat exchanger exchanges total heat between the return air from the indoor space and the outdoor air, the desiccant rotor exchanges latent heat between the return air that has been totally heat exchanged and the outdoor air, and a blower is arranged on the air intake passage side between the total heat exchanger and the desiccant rotor in the air intake passage.

2. The outdoor air processing air conditioner according to claim 1, wherein the total heat exchanger is a total heat exchange rotor.

3. An outdoor air processing air conditioner according to claim 1, wherein the total heat exchanger and / or the desiccant rotor carries an ion exchange resin as an adsorbent.

4. An outdoor air processing air conditioner as described in claim 1, characterized in that on the intake air path side, an intake air path side heat exchanger is provided at the outlet side of the total heat exchanger and at the inlet side of the desiccant rotor, and on the exhaust air path side, an exhaust air path side heat exchanger is provided at the outlet side of the desiccant rotor, and the air intake air path side heat exchanger, the exhaust air path side heat exchanger, and a heat pump circuit having a compressor are provided, and the heat pump circuit exchanges heat between the outdoor air on the intake air path side that has passed through the total heat exchanger and the exhaust air on the exhaust air path side that has passed through the desiccant rotor.

5. An outdoor air processing air conditioner according to any one of claims 1 to 4, characterized in that the desiccant rotor is a passive desiccant rotor that does not require a regenerative heat source.

6. An outdoor air processing air conditioner as described in any one of claims 1 to 4, characterized in that a bypass path is provided in the exhaust path on the outlet side of the desiccant rotor, in front of the heat exchanger on the exhaust path side, to directly take in outdoor air.

7. An outdoor air processing air conditioner as described in any one of claims 1 to 4, characterized in that in the air supply path, a bypass path is provided that bypasses the inlet side and outlet side of the total heat exchanger and / or the desiccant rotor, respectively.

8. An outdoor air processing air conditioner as described in claim 4, characterized in that it has three operating modes: cooling mode, ventilation mode, and heating mode, and the operating mode is automatically switched to achieve the set air supply conditions depending on the temperature and humidity conditions of the outdoor air, and in the cooling mode, the heat exchanger on the air supply path side is operated as an evaporator and the heat exchanger on the exhaust path side is operated as a condenser, and in the heating mode, the heat exchanger on the air supply path side is operated as a condenser and the heat exchanger on the exhaust path side is operated as an evaporator.

9. The outdoor air processing air conditioner of claim 4, characterized in that it is divided into three units: a total heat exchanger unit including the total heat exchanger; a heat pump / blower unit including the heat exchanger on the air intake path side, the heat exchanger on the air exhaust path side, the compressor, and the blower on the air intake path side that constitute the heat pump circuit; and a desiccant rotor unit including the desiccant rotor.

10. An outdoor air processing air conditioner as described in any one of claims 1 to 4 and claim 9, further comprising a humidifier or humidifier unit on the outlet side of the desiccant rotor in the air supply path.

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