AIR HANDLING UNIT WITH HEAT RECOVERY.

Abstract

A heat recovery air handling unit (1) comprises an external module (4) with an external inlet grille (23) and an external exhaust grille (24), an internal module (2) with a plate heat exchanger (5), with an internal inlet grille (21) and an internal exhaust grille (22), with a filter (16), with an exhaust duct inlet chamber (6), with an exhaust duct outlet chamber (7), with an inlet duct inlet chamber (8), with an inlet duct outlet chamber (9), and a partition (10) between the inlet and outlet chambers of the exhaust and inlet ducts, respectively, with fans (3) (11) forming countercurrents of air, wherein the fan (3) is located in the inlet chamber of the inlet duct (8), and the fan (11) is located in the outlet chamber of the exhaust duct (7), characterized in that it contains a condensate removal system, and the internal module (2) comprises a piece on the wall (2A) and a wall-mounted piece (2B), wherein the wall-mounted piece (2B) contains a module (20) with fans (3) (11) installed therein.

Description

AIR HANDLING UNIT WITH HEAT RECOVERY The utility model refers to ventilation equipment, specifically to heat recovery supply and exhaust ventilation systems, and can be used for installation in domestic and special use premises. The state of the art reveals various technical solutions, forms and constructions designed for the natural ventilation of both residential and commercial buildings. The drive to find optimal ventilation solutions stems from the goal of designing buildings that guarantee maximum energy efficiency. However, increasing a building's energy efficiency rating proportionally reduces its natural self-regulation of the indoor climate. In other words, in these buildings, due to the use of central heating, the operation of numerous appliances, and other modern technological factors, considerable dryness of the indoor air occurs. This, in turn, promotes the development of allergies and respiratory complications or conditions. In spring and summer, energy-efficient buildings do not remove excess moisture well, which hinders the natural circulation of air inside the premises and thus creates favorable conditions for the growth of mold and harmful microorganisms. The above statements have been known for a long time. Therefore, in many developed countries, medical institutions recommend frequent ventilation of facilities. Most countries implement regulations governing air exchange systems. Ventilation is primarily achieved by opening windows, allowing natural air circulation within buildings. However, ventilation solely through windows presents several drawbacks. In winter, an open window significantly cools the room due to its surface area, while in summer it causes overheating. Consequently, this leads to considerable energy consumption to maintain acceptable and comfortable working and living conditions. Therefore, ongoing efforts are being made to develop and improve ventilation systems. A known heat recovery air handling unit [UA Patent No. 146223 F24F7 / 00, F28F13 / 14, dated January 27, 2021] comprises a heat recovery unit with air ducts, a fan, and a heat exchanger, interconnected and mounted on the wall of a room between its outer and inner surfaces. Two concentric straight-through cylinders are installed in the opening between the outer and inner surfaces of the room, and a corrugated heat exchanger (in cross-section) is fixed between them on the outer surface of the inner cylinder. Additionally, external and internal fans are installed opposite each other on the inner surface of the cylinder. The system openings are equipped with corresponding outer and inner covers, the inner cover being provided with an air inlet grille and an inner air outlet slot with an air diffuser.The outer cover is further equipped with a condensate drainage opening that extends beyond the plane of the outer wall surface, an air inlet grille, and a corresponding grille for the exhaust of internal air. The disadvantages of this heat recovery air handling unit are its low heat exchange efficiency. When air passes over the heat exchange surface of the corrugated heat exchanger, the cutouts in the heat exchanger channels reduce the heat exchange area. The low air exchange performance results from unbalanced airflow within the system. Furthermore, a disadvantage is its lack of resistance to wind loads. Since the exterior module is of an open type, it does not protect the exhaust duct from the wind, leading to a risk of the unit freezing in sub-zero temperatures. Since it is structurally impossible to install full-fledged heaters and filter elements, and the power supply is located in the room module, no additional heating is provided by the heat recovery unit. The heat exchanger design causes excessive condensation and can lead to the system freezing. A known heat recovery air handling unit [European Invention Application No. 23219860, dated December 22, 2023, F24F12 / 00; F24F7 / 08; F28D21 / 00; F28F9 / 02; dated August 21, 2024] is designed for installation on an external wall of a building. This system comprises an interior module and an adjacent heat exchange module, which consists of a corrugated cylindrical heat exchanger with multiple heat exchange air channels arranged along the heat exchanger's axis of symmetry. These air channels have identical cross-sections and are adjacent to each other, forming a continuous corrugated volume of heat exchange segments. A first and second separator are provided to separate and direct the exhaust and supply airflows in opposite directions within the heat exchange air ducts.The first and second separators are fixed to the heat exchanger at their two end surfaces and mounted along the heat exchanger's axis of symmetry. The first and second fans, whose housings are adjacent to the first and second separators respectively, are installed at the ends of the separators facing the opposite side of the heat exchanger. The axis of one fan is parallel, but not coaxial, to the axis of the other fan. The disadvantages of this heat recovery air handling unit are its low heat exchange efficiency and poor air exchange performance. The heat exchanger design can lead to excessive condensation, which may limit the system's use and operation, or insufficient condensate removal, which can cause the system to freeze up during cold weather. A well-known air handling unit with heat recovery [https: / / zehnder.com.ua / decentralized-ventilation / comfoair70], considered the closest analogue, contains an external module with external inlet and external exhaust grilles, an internal module with a plate heat exchanger, with internal inlet and internal exhaust grilles, with a filter, with an exhaust duct inlet chamber, with an exhaust duct outlet chamber, with an inlet duct inlet chamber, with an inlet duct outlet chamber, and a partition between the inlet and outlet chambers of the exhaust and inlet ducts, respectively, with fans forming countercurrents of air, with the fan located in the inlet chamber of the inlet duct, and the fan is located in the outlet chamber of the exhaust duct. The drawbacks of the closest analogue are as follows: - There is no condensate removal system, for example: a condensate collection tank, a pump to remove condensate from the system, or a channel to remove condensate from the system, which causes excessive condensate buildup and possible freezing of the system in countries with cold climates. - In the inlet chamber of the inlet duct there is no heater to preheat the air, which is necessary to prevent condensation. - in the outlet chamber of the inlet duct there is no heating element for post-heating the air, which is used to ensure a comfortable temperature of the inlet air in countries with cold climates; - there are no filters in the recessed piece in the wall of the interior module, resulting in contaminated air and insects entering the system and the installation; - complexity of the unit's design for maintenance during operation. The objective of the utility model is to create an air handling unit with heat recovery, in which: - a high level of air heat exchange efficiency is achieved by placing a counterflow or crossflow plate heat exchanger in the indoor module; - Thanks to the structural arrangement of the fans, a high level of air exchange performance is guaranteed. - The mixing of airflows is prevented by a partition placed in the inner module between the inlet and outlet chambers of the exhaust and intake ducts. - Maximum efficient heat transfer from the heater to preheat the air and the heater to post-heat it by their complete placement in the inlet chamber of the inlet duct and the outlet chamber of the inlet duct, respectively. - Excessive condensate buildup and the resulting freezing of the system in countries with cold climates is prevented by a condensate removal system, namely: a condensate collection tank and a channel to remove the condensate from the system, or a channel to remove the condensate from the system, or a pump to remove the condensate from the system, or a pump and a channel to remove the condensate from the system, or an evaporator. - The entry of contaminated air and insects into the system and facilities is prevented thanks to the presence of filters. - Maintenance of the unit during operation is improved due to the easy removal of the module with the fans, regulators, valve, and filter installed in it. The stated objective is achieved as follows. An air handling unit with heat recovery contains an external module with external supply and exhaust grilles, an internal module with a plate heat exchanger, with internal inlet and exhaust grilles, with a filter, with an exhaust duct inlet chamber, with an exhaust duct outlet chamber, with an inlet duct inlet chamber, with an inlet duct outlet chamber, and a partition between the inlet and outlet chambers of the exhaust and inlet ducts, respectively, with fans that form countercurrents of air, the first fan being located in the inlet chamber of the inlet duct, and the second fan being located in the outlet chamber of the exhaust duct.In which the system contains a condensate removal system, and the interior module consists of a piece on the wall and a piece embedded in the wall, wherein the piece embedded in the wall contains a module with fans installed in it. In one of the implementations to solve the problem, a module with the fans installed in the heat recovery air handling unit is removable. Another solution to the problem is that in the air handling unit with heat recovery, the module with the installed fans also contains a mechanical regulator and / or a gravity valve. In yet another implementation to solve the problem, a module with fans installed in the heat recovery air handling unit additionally contains at least one filter. The problem posed is also solved by the fact that in the air handling unit with heat recovery, the inlet chamber of the inlet duct contains a heater to preheat the air. In yet another solution to the problem, in the air handling unit with heat recovery, the outlet chamber of the inlet duct contains a heater to post-heat the air. The problem raised is also solved by the fact that in the air handling unit with heat recovery, the piece embedded in the wall of the interior module has an external thermal insulation casing. Furthermore, the problem posed is solved by the fact that in the air handling unit with heat recovery, the condensate removal system is the channel to remove the condensate from the system. Also, the problem raised is solved by the fact that in the air handling unit with heat recovery, the condensate removal system is the condensate collection tank and the channel to remove the condensate from the system. Another solution to the problem is that in the air handling unit with heat recovery, the condensate removal system is the pump to remove the condensate from the system. Yet another solution to the problem is that in the air handling unit with heat recovery, the condensate removal system is the pump and channel to remove the condensate from the system. As a further solution to the problem raised, in the air handling unit with heat recovery, the condensate removal system is the condensate collection tank with an ultrasonic evaporator. One of the solutions to the problem raised is that the air handling unit with heat recovery also has an air humidity sensor. Also, according to another embodiment, the problem posed is solved by the fact that, depending on the thickness of the wall, the length of the piece embedded in the wall of the interior module is regulated with the help of the external thermal insulation casing during installation. The proposed heat recovery air handling unit differs from the closest analogue in that it features: - an easily removable module with fans, regulators, valve and filter, which improves the maintenance of the unit during operation without disassembling the system itself. - a complete heater for preheating the air and a heater for post-heating the air, located in the inlet chamber of the inlet duct and in the outlet chamber of the inlet duct, whose presence ensures the most efficient heat transfer from them. - a condensate removal system, which prevents excessive condensate buildup and subsequent freezing of the system in countries with cold climates. - filters, which prevent contaminated air and insects from entering the system and facilities. As a result of using the proposed utility model, an air handling unit with heat recovery is created, which guarantees a high degree of heat exchange efficiency, a high degree of air exchange performance, and simplified maintenance of the unit during operation without disassembling the system itself. The essence of the utility model is explained by the figures, in which: Fig. 1 - General view of the air handling unit with heat recovery; Fig. 2 - Schematic representation of the air handling unit with heat recovery; Fig. 3 - Schematic representation of the air handling unit with heat recovery with additional constituent elements and the representation of the movement of hot and cold air; Fig. 4 - View of the air handling unit with heat recovery during system maintenance; Fig. 5 - View of the removable module from the other side. In Figs. 1-5, the following positions are marked: 1 - air handling unit with heat recovery 2 - interior module 2A - piece on the wall of the interior module 2 - piece embedded in the wall of the interior module 3, 11 - fans 4 - external module 5 - plate reclaimer 6 - exhaust duct inlet chamber 7 - exhaust duct outlet chamber 8 - inlet chamber of the inlet duct 9 - inlet duct outlet chamber 10 - partition 12 - mechanical regulator 13 - gravity valve 14 - air preheating element 15 - afterheating element 16, 28 - filter 17 - external thermal insulation casing 18 - channel for removing condensate 19 - condensate collection tank 20 - module 21 - internal inlet grille 22 - internal exhaust grille 23 - external inlet grille 24 - external exhaust grille 25 - ultrasonic evaporator 26 - condensate removal pump. The heat recovery air handling unit (1) consists of an indoor module (2) and an outdoor module (4). The indoor module (2) conventionally consists of the surface-mounted piece (2A) and the recessed piece (2B). The recessed piece (2B) of the indoor module (2) is surrounded by an external thermal insulation casing (17), which is used to reduce heat transfer to the surrounding structures (wall) and improve the noise cancellation characteristics of the system (see Fig. 1). In addition, the recessed piece (2B) of the indoor module (2) contains a module (20) with fans (3) (11), a mechanical regulator (12) and / or a gravity valve (13), and at least one filter (28) installed therein. The vertically mounted module (20) is removable and can be serviced from the front of the heat recovery air handling unit (1) after removing the service panel. As a result, routine maintenance on the heat recovery air handling unit (1) can be carried out from inside the room without disassembling the unit itself. The heat recovery air handling unit (1) includes a condensate removal system that can have different designs. For example, the condensate removal system is a condensate collection tank (19) and a channel (18) for removing condensate from the heat recovery air handling unit (1), or a channel (18) for removing condensate from the heat recovery air handling unit (1), or a pump (26) for removing condensate from the heat recovery air handling unit (1), or a pump (26) and a channel (18) for removing condensate from the heat recovery air handling unit (1), or a condensate collection tank (19) with an ultrasonic evaporator (25). The inlet chamber of the inlet duct (8) contains an air preheating element (14) for preheating the air. This air preheating element (14) is used to preheat the air to combat condensation. The outlet chamber of the inlet duct (9) contains a post-heating element (15) for post-heating the air. The post-heating element (15) is used to ensure a comfortable inlet air temperature in countries with cold climates. There is a filter (16) in the wall-mounted piece (2) of the indoor module (2), in the exhaust duct inlet chamber (6) directly in front of the plate heat exchanger (5). In the wall-mounted piece (2B) of the indoor module (2), there is a filter (28) located in the module (20), in the inlet chamber of the intake duct (8). These filters (16) and (28) are used to protect the counterflow or crossflow plate heat exchanger (5) and the radial fans (3) and (11) from the entry of contaminated air and insects into the units and the installation. The filters (16) and (28) may be treated with an antibacterial agent. The piece on the wall (2A) of the inner module (2) has an internal supply grille (21) and an internal exhaust grille (22), and the outer module (4) has an external inlet grille (23) and an external exhaust grille (24). Depending on the thickness of the wall, the length of the wall-mounted piece (2B) of the interior module (2) is regulated with the help of the external thermal insulation casing (17) during installation, by cutting a part of it from the street side with any cutting tool. In addition, the design of the heat recovery air handling unit is further equipped with an air humidity sensor (not shown in the figure), which can monitor the humidity of the supply and / or exhaust air, depending on the task. By plate recuperator (5) is meant a heat exchanger package (not shown in the figure) consisting of a certain number of thin profiled plates (not shown in the figure), which are arranged parallel to each other forming a solid package with separate airtight channels for the movement of two air streams towards each other. Fig. 2 and Fig. 3 schematically show the flow of hot air (dashed line) and the flow of cold air (solid line) through an air treatment unit with heat recovery (1). The heat recovery air handling unit (1) operates as follows. After the heat recovery air handling unit is switched on, the exhaust (11) and intake (3) fans are activated, initiating air exchange within the system. Used hot air from the facility enters the wall-mounted compartment (2A) of the indoor module (2) through the internal intake grille (22), flows through the exhaust duct inlet chamber (6), and enters the plate heat exchanger (5), where it heats the duct. Upon exiting the plate heat exchanger (5), the air enters the wall-mounted compartment (2B) of the indoor module (2), the exhaust duct outlet chamber (7), passes through the exhaust fan (11), then enters the outdoor module (4), and is discharged to the outside through the external exhaust grille (24). Simultaneously with the movement of warm air, cool fresh air is supplied. Cool air from outside enters the external inlet grille (23) and then passes through the recessed wall-mounted piece (2B) of the internal module (2), the inlet chamber of the inlet duct (8), the filter (28), and the inlet fan (3). It then enters the surface-mounted piece (2A) of the internal module (2), which houses the plate heat exchanger (5). Before entering the plate heat exchanger (5), the cool air is preheated by the air preheating element (14). Upon exiting the plate heat exchanger (5), the preheated cool air passes through the outlet chamber of the inlet duct (9), then through the internal inlet grille (21), and into the system.In countries with cold climates, the fresh but heated air leaving the plate recuperator (5), which enters the outlet chamber of the inlet duct (9), can be heated to a higher temperature by the afterheating element (15) to post-heat the air, and enters the installation by passing through the internal inlet grille (21). A partition (10) is placed between the inlet chamber of the intake duct (8) and the outlet chamber of the exhaust duct (7), as well as between the inlet chamber of the exhaust duct (6) and the outlet chamber of the intake duct (9), to prevent mixing of airflows. As a result of the operation of the heat recovery air handling unit, heat exchange occurs between the warm and cool air, while the airflows do not mix. Figure 2 schematically shows the air handling unit with heat recovery. Figure 3 schematically shows the air handling unit with heat recovery with additional components and a representation of the hot and cold air movement. Figure 4 schematically shows the air handling unit with heat recovery during system maintenance: removal or installation of a removable module. Figure 5 shows the other side of the removable module. The examples provided are for illustrative purposes only and do not limit the possible implementations of the utility model. The operation of the heat recovery air handling unit is carried out by means of a control panel located on the side panel of the system, via an infrared remote control, and via a mobile application on a Wi-Fi wireless network (not shown in the figures and not included within the scope of the patent claims). The air handling unit with heat recovery is designed with the possibility of easy disconnection of the ventilation duct from the piece embedded in the wall of the interior module, which contains an easily removable module with fans, mechanical regulator, gravity valve, and filter installed in it, simplifying its maintenance during repair or preventive service.

Claims

1. A heat recovery air handling unit (1) comprises an external module (4) with an external inlet grille (23) and an external exhaust grille (24), an internal module (2) with a plate heat exchanger (5), with an internal inlet grille (21) and an internal exhaust grille (22), with a filter (16), with an exhaust duct inlet chamber (6), with an exhaust duct outlet chamber (7), with an inlet duct inlet chamber (8), with an inlet duct outlet chamber (9), and a partition (10) between the inlet and outlet chambers of the exhaust and inlet ducts, respectively, with fans (3) (11) forming countercurrents of air, wherein the fan (3) is located in the inlet chamber of the inlet duct (8), and the fan (11) is located in the outlet chamber of the exhaust duct (7), characterized in that it contains a condensate removal system,and the interior module (2) comprises a surface-mounted piece (2A) and a recessed piece (2B), wherein the recessed piece (2B) contains a module (20) with fans (3) (11) installed therein.

2. An air handling unit with heat recovery according to claim 1, characterized in that the module (20) is removable.

3. An air handling unit with heat recovery according to claim 1, characterized in that the module (20) further contains a mechanical regulator (12) and / or a gravity valve (13).

4. An air handling unit with heat recovery according to claim 1, characterized in that the module (20) further contains at least one filter (28).

5. An air handling unit with heat recovery according to claim 1,characterized in that the inlet chamber of the inlet duct (8) contains a preheating element (14) for preheating the air.

6. An air handling unit with heat recovery according to claim 1, characterized in that the outlet chamber of the inlet duct (9) contains a post-heating element (15) for post-heating the air.

7. An air handling unit with heat recovery according to claim 1, characterized in that the recessed part (2B) of the inner module (2) has an external thermal insulation casing (17).

8. An air handling unit with heat recovery according to claim 1, characterized in that the condensate removal system is the channel (18) for removing condensate from the air handling unit with heat recovery (1).

9. An air handling unit with heat recovery according to claim 1,characterized in that the condensate removal system is the condensate collection tank (19) and the channel (18) for removing the condensate from the heat recovery air handling unit (1).

10. A heat recovery air handling unit according to claim 1, characterized in that the condensate removal system is the pump (26) for removing the condensate from the heat recovery air handling unit (1).

11. A heat recovery air handling unit according to claim 1, characterized in that the condensate removal system is the pump (26) and the channel (18) for removing the condensate from the heat recovery air handling unit (1).

12. A heat recovery air handling unit according to claim 1,characterized in that the condensate removal system is the condensate collection tank (19) with an ultrasonic evaporator (25).

13. An air handling unit with heat recovery according to claim 1, characterized in that it further contains an air humidity sensor.

14. An air handling unit with heat recovery according to claim 1, characterized in that the length of the wall-mounted part (2B) of the indoor module (2) is regulated by means of the external thermal insulation casing (17) during installation.