Outside air treatment air conditioner

Abstract

To provide an outdoor air-conditioner which saves energy, saves space, and reduces costs.SOLUTION: An outdoor air-conditioner has an exhaust passage exhausting circulated air from an indoor space and an air-supply passage for supplying outside air into an indoor space, and disposes a total heat exchanger at a front stage and a desiccant rotor at a subsequent stage across the exhaust passage and the air-supply passage in order of passage of the outside air on the air-supply passage side. In the total heat exchanger, total heat exchange is performed between the circulated air from indoors and the outside air. In the desiccant rotor, latent heat exchange is performed between the circulated air and the outside air that were total heat exchanged. In the air-supply passage, an air blower on the air-supply passage side is disposed between the total heat exchanger and the desiccant rotor. There is provided a heat pump circuit which exchanges heat between the outside air on the air-supply passage side passing the total heat exchanger and the exhaust air on the exhaust passage side passing the desiccant rotor. The equipment is simplified, needs no outdoor unit, and is of a unit split type, so that it can reduce the total cost of the equipment, can reduce site construction cost after installation of the equipment, and can shorten a construction period.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[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 flows, without using a total heat exchanger or an external heat source for regeneration. [Background technology]

[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 describes 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 has 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 has 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 has 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 is low-cost because it does not require an outdoor unit. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2020-12602 Summary of the Invention [Problem to be solved by the invention]

[0005] The outdoor air-conditioning unit described in Patent Document 1 uses return air from indoors to reduce initial and running costs. However, there is a demand for more efficient, space-saving, and cost-effective devices that are more energy-efficient and can 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, which acts 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 makes it easy for leakage from the exhaust duct side to the supply air duct side. This raises concerns that odors contained in the return air from indoors may transfer to the supply air, and reducing leakage 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, but this can lead to a problem of insufficient heat exchange capacity when the load is high. 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 EA 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 acts 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 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). [Means for solving the problem]

[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. [Effects of the Invention]

[0011] The outdoor air-conditioning unit of the present invention, configured as described above, can provide all cooling and heating functions using only a heat pump system, 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 has excellent 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. [Brief explanation of the drawings]

[0014] [Figure 1] FIG. 1 is a flow diagram of the outdoor air conditioning unit of Patent Document 1. [Figure 2] FIG. 2 is a flow diagram of the outdoor air conditioning unit of the present invention. [Figure 3] FIG. 3 is a diagram showing the unit structure of the outdoor air-conditioning unit of the present invention. [Figure 4] FIG. 4 is a flow diagram showing a comparative example in which the humidifier 11 is provided on the air intake path side instead of the exhaust path side in the outdoor air-conditioning unit of Patent Document 1. [Figure 5] 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. [Figure 6] FIG. 6 shows the test results for Example 4 using a test machine for outdoor air-conditioning units according to the present invention. [Figure 7]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. DETAILED DESCRIPTION OF THE INVENTION

[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 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 exchanges total heat between the return air from the indoor space and the outdoor air, and the desiccant rotor 6 exchanges latent heat 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 on the outlet side of the total heat exchange rotor 3 and on the inlet side of the desiccant rotor 6, and an exhaust path-side heat exchanger 14 is provided on the exhaust path B side, on the outlet side of the desiccant rotor 6. The system is configured with 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) Reference numeral 3 denotes a total heat exchange rotor, which is made by corrugating a sheet such as aluminum foil into a rotor shape and is loaded with an adsorbent material such as silica gel or ion exchange resin that adsorbs 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) Desiccant rotor 6 is a rotor-shaped desiccant rotor made of a porous inorganic fiber sheet, such as glass fiber, corrugated to absorb moisture. It supports an adsorbent, such as silica gel, zeolite, or 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 that compresses the refrigerant, and an expansion valve (not shown) that controls the expansion of the refrigerant. The 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 released / absorbed by the exhaust-side heat exchanger 14. The intake-side heat exchanger 5 and the exhaust-side heat exchanger 14 function as evaporators or condensers, respectively, 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. It directly draws in outside air to stabilize the heat pump circuit. An air volume control device 25, such as a volume damper (VD: volume damper, MD: motor damper), a variable air volume control device (VAV: variable air volume control device), or a constant air volume control device (CAV: constant air volume control device), allows outside air (OA) to be directly drawn into the exhaust air EA via the bypass path D. In summer, to ensure the heat dissipation capacity of the heat pump, the bypass path D automatically draws outside air directly into the exhaust path B, ensuring sufficient heat exchange capacity. This eliminates the need to send a portion of the outside air drawn in as supply air via 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 would 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 regeneration heat source, raising the regeneration inlet temperature and improving the dehumidification performance of the desiccant rotor. However, the present invention takes a different approach than this conventional approach, placing the exhaust path heat exchanger 14 on the exhaust path B side and on the outlet side of the desiccant rotor 6, thereby eliminating the need for a regeneration heat source for the desiccant rotor 6. This allows the heat pump's heat balance to be adjusted by the amount of outside air taken in from bypass path D, thereby prioritizing the effect of increasing the cooling effect of the intake air path heat exchanger 5 in summer.

[0022] (humidifier) In the outdoor air-conditioning unit 23 described in Patent Document 1, a humidifier 11 is installed on the exhaust path side and is configured to humidify when the indoor space becomes too dry, such as in winter, but the humidifying effect is enhanced by directly humidifying the supply air SA. Therefore, in this embodiment, a 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 air supply path-side blower 8 is located on the outlet side of the desiccant rotor 6, creating a negative pressure on the air supply path, resulting in an overall pressure balance that favors leakage from the exhaust path to the air supply path. Leakage, particularly on the indoor side of the desiccant rotor 6, is likely to occur; that is, return air RA from the indoors in the exhaust path is likely to leak into the supply air SA in the air supply path. 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 indoors to the supply air SA. Therefore, in the present invention, the air supply path-side blower 8 is located on the outlet side of the total heat exchange rotor 3 in the air supply path 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 air supply path C to the exhaust path 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 located before the exhaust path-side heat exchanger 14. In Patent Document 1, it is located at the outlet of the total heat exchange rotor 3 on the exhaust path side, while in the present invention, it is located at the outlet of the desiccant rotor 6 on the exhaust path B side. In the present invention, pressure loss due to the air flowing around the inlet path (B' described below) that passes from the outlet of the total heat exchange rotor 3 to the inlet of the desiccant rotor 6 on exhaust path B has a significant impact on the power consumption of the exhaust path-side blower 13. However, by locating 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 path C side flows into the return air RA on the exhaust path B side, thereby reducing odor transfer. Furthermore, by locating the supply path-side blower 8 between the total heat exchange rotor 3 and the desiccant rotor 6, the temperature of the air after passing through the blower 8 increases slightly, but as described below, it becomes possible to divide the system into two rotor units and a heat pump / blower unit.

[0025] (Outdoor air conditioning 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, heat exchanger 5 on the air intake path that constitutes the heat pump circuit, heat exchanger 14 on the air exhaust path, compressor 16, humidifier 11, blower 8 on the air intake path, blower 13 on the air exhaust path, and air filters 2, 10, 28. Based on this device configuration, the unit is divided into three units: total heat exchanger unit 31, heat pump / blower unit 32, and 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. It also has 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 also 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 and an air filter 28, has a bypass passage F and an air volume regulator 27 below the desiccant rotor 6, and is provided with 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 and installed separately as shown in Figure 3(b) 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. When space is limited, such as when upgrading existing equipment to the outdoor air-conditioning unit of the present invention, the units can be separated and installed separately. 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 exiting the total heat exchange rotor 3 in the exhaust path B is introduced into the desiccant rotor 6 through the top of the unit (path B'). By incorporating this path B' within the unit, the overall height of the system increases, but the installation can be simplified by reducing the amount of ductwork required at the customer's site. The 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 (paths E and F) and airflow control devices 26 and 27 on the intake path C side within the unit can reduce the amount of bypass ductwork required at the customer's site. Furthermore, by making the bypass paths E and F removable, 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 installation based on customer specifications, eliminating the need for the humidifier unit 34 or adding it later.

[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 arranged upside down. Furthermore, for example, the air intake passage fan 8 may be included in the total heat unit 31, or the air exhaust passage fan 13 may be included in the desiccant unit 33. The unit division unit may be further reduced, for example, to form 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 exchange 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 status of the components according to the outdoor temperature and humidity. Table 1 shows the ON / OFF status of each component in these three modes. In Table 1, ON for air volume control devices 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 space temperature is primarily adjusted by the indoor air-conditioning unit (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"). Below, operation and performance calculation examples for summer, mid-season, and winter are described as Examples 1, 2, and 3, respectively.

[0032] [Table 1]

[0033] (Summer operation: Cooling mode) The cooling and dehumidifying operation in summer will now be explained. In the air supply path C, outside air OA is sent through an air filter 2 to the total heat exchange rotor 3 by the air supply path side blower 8, which functions as a processing 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 heat-exchanged outside air OA is sent to the heat exchanger 5 on the air supply path, which functions as the evaporator of the heat pump circuit, and cooled. The air that passes through the heat exchanger 5 on the air supply path is sent to the desiccant rotor 6, where it is dehumidified, and then passes through the air filter 28 and is supplied to the indoor space as supply air SA.

[0034] In 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 outdoor 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 functions 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, outdoor air is automatically taken directly into exhaust path B via 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. [Example]

[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 5000 m 3 / h, return air RA volume 4000m 3 The calculation was made as / h.

[0036] The flow of the comparative example (FIG. 4) described below is compared with that of Comparative Example 1 in summer (FIG. 5). 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, and has the effect of raising the temperature of the air 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 temperature at the regeneration inlet side of the desiccant rotor 6 is 32.1°C in Example 1 and 26.0°C in Comparative Example 1, so that Example 1 has a higher regeneration inlet temperature, effectively utilizing the total heat exchange effect of the high-temperature 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, but 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 during intermediate seasons: Fan mode) The following describes the fan operation during the intermediate season. 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 make up the heat pump circuit, are stopped. Therefore, power consumption in the fan mode is solely for the fans. In addition, 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. 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. Bypassing air through bypass paths E and F results in lower pressure loss than when passing through the rotor, thereby reducing power consumption of the air supply path fan 8. [Example]

[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 fan operation is performed, the temperature of the air after passing through 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, making it possible to reduce the power consumption of fan 8 on the air supply path side.

[0040] (Winter operation: Heating mode) The heating and humidification 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, which serves 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 heat-exchanged outside air OA is sent to the heat exchanger 5, which serves as the condenser of the heat pump circuit, and heated. The air that passes 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 to the total heat exchange rotor 3 by a blower 13 on the exhaust path side that functions as a regenerative fan. The return air RA undergoes total heat exchange with outside air OA in the total heat exchange rotor 3, and is cooled and dehumidified. 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 that functions as an evaporator of the heat pump circuit, and is then exhausted to the outside of the device as exhaust air EA. [Example]

[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, because 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 outdoor 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) in Example 3 when humidified only by the total heat exchange rotor 3, and 5.3 g / kg (DA) in Comparative Example 3 when humidified by both the total heat exchange rotor 3 and the desiccant rotor 6 (humidification by the total heat exchange rotor 3 is 2.2 g / kg (DA), and humidification by the desiccant rotor 6 is 3.1 g / kg (DA)). Although the humidification amount in Example 3 is less than that in Comparative Example 3, a sufficient humidification effect can be obtained with 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 through the bypass passage F, so that the 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, humidification is performed through the desiccant rotor, so 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 only necessary to raise the temperature by the intake air passage heat exchanger 5 to approach 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. [Example]

[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 φ1100 mm. The test results are shown in Figure 6.

[0046] Figure 6(a) shows the test results when operation was switched 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, 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 than 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 a stable supply of 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, 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 reduction. 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, although 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 circuit, 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, if the adjustment cycle exceeds capacity, the base system compressor is activated, 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, rather than being limited to two heat pump circuits, one for base and one for 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 its 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 be provided with 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 similarly, 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. In Figure 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 in which 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, in comparison 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 examples: cooling mode in summer, ventilation mode in intermediate seasons, and heating mode in winter.

[0052] [Table 2] Comparative Example 1

[0053] During cooling and dehumidification operation (cooling mode) in summer, outdoor air (OA) is sent through an air filter 2 to the total heat exchange rotor 3 by a blower 8, which functions 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 a heat exchanger 5 on the supply air path, which serves as the evaporator of the heat pump circuit, where it is cooled. The 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). The return air (RA) from the indoor space is sent to the desiccant rotor 6 by a blower 13, which functions 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 system 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 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, the power consumption is only for the fans. The outside air OA passes through the intake air passage, 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. The return air RA from the indoor space passes through the exhaust passage, 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 through an air filter 2 to a total heat exchange rotor 3 by a blower 8, which functions 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 a heat exchanger 5 on the air supply path, which functions as a condenser for the heat pump circuit, where it is 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, which functions as a regenerative fan, where it is 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 the 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 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. [Industrial Applicability]

[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 and have production processes or production environments that require the intake of outside air, such as in food processing, pharmaceutical manufacturing, and the automotive industry.

[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 are poor in 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 many options open.

[0059] Because the outdoor air-conditioning unit of the present invention uses a total heat exchanger, desiccant rotor, and heat pump, it has higher initial costs (CAPEX) and tends to be larger than other outdoor air-conditioning units. However, its running costs (OPEX), including power consumption and other chilled water and steam usage, are significantly reduced, making it the lowest among outdoor air-conditioning units. For example, when calculated under the same conditions, compared to an air-conditioning unit using chilled water and steam as a heat source, the CAPEX is 1.88 times higher, but 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 unit 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 it. Furthermore, the amount of carbon dioxide emitted by the outdoor air-conditioning unit of the present invention is the lowest of all outdoor air-conditioning units, at only 0.41 times that of an air-conditioning unit that uses chilled water and steam as its heat source. Because the air-conditioning unit 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 offers 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 decarbonized society. [Explanation of symbols]

[0060] 1, 12, 15, 25, 26, 27 Air volume adjustment device 2, 10, 28 Air Filter 3 Total heat exchange rotor 4, 7 Gear motor 5. Heat exchanger on the air supply side 6 Desiccant Rotor 8 Air supply side blower 9 Indoor space 11 Humidifier 13 Exhaust road side blower 14 Exhaust road side heat exchanger 16 Compressor 17, 18, 19 Temperature sensors 20 Dew point sensor 21 Temperature controller 22 Dew point control device 23 Outside conditioning machine 31 Total heat exchanger unit 32 Heat pump / blower unit 33 Desiccant rotor unit 34 Humidifier unit 35 Fresh air intake to air supply passage 36 Return air intake to exhaust duct 37 Exhaust port 38 Outside air intake to bypass route D 39 Air intake to indoor space A, D, E, F bypass routes B Exhaust passage B' introduction path C Air supply path

Claims

1. 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 a total heat exchanger is disposed in the front stage and a desiccant rotor is disposed in the rear stage, straddling the exhaust passage and the air supply passage, in the order that the outside air passes through on the air supply passage side; the total heat exchanger exchanges total heat between the return air from the indoor space and the outside air, and the desiccant rotor exchanges latent heat between the return air that has been subjected to total heat exchange and the outside air; and a blower is disposed on the air supply passage side between the total heat exchanger and the desiccant rotor in the air supply passage.

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

3. 2. The 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. 2. The outdoor air processing air conditioner of claim 1, wherein an air intake path heat exchanger is provided on the outlet side of the total heat exchanger, on the inlet side of the desiccant rotor, and an exhaust path heat exchanger is provided on the exhaust path side, on the outlet side of the desiccant rotor, and the air intake path heat exchanger, the exhaust path heat exchanger, and a heat pump circuit having a compressor, the heat pump circuit exchanging heat between the outdoor air on the air intake path side that has passed through the total heat exchanger and the exhaust air on the exhaust path side that has passed through the desiccant rotor.

5. 5. The outdoor air processing air conditioner according to claim 1, wherein the desiccant rotor is a passive desiccant rotor that does not require a regenerative heat source.

6. 5. The outdoor air processing air conditioner according to claim 1, wherein 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. 5. The outdoor air processing air conditioner according to claim 1, wherein a bypass path is provided in the air supply path to bypass the inlet side and the outlet side of the total heat exchanger and / or the desiccant rotor, respectively.

8. 5. 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. 5. The outdoor air processing air conditioner according to 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. 10. The outdoor air processing air conditioner according to claim 1, further comprising a humidifier or a humidifier unit in the air supply passage on the outlet side of the desiccant rotor.

Images