Energy-saving defrosting fresh air system, control method and device thereof and storage medium

Abstract

This invention discloses an energy-saving defrosting fresh air system and its control method, device, and storage medium. The control method of the fresh air system includes: controlling the fresh air system to operate in a first working mode, in which the preheating device is working; detecting environmental parameters in the exhaust side duct, and determining the environmental state of the heat exchanger based on the detection results of the environmental parameters; if the heat exchanger is in a frosting environment, controlling the preheating device to work, reducing the speed of the intake fan, and controlling the opening of the third air path. In the embodiment provided by the invention, based on the conventional use of the preheating device to defrost the heat exchanger, a portion of the indoor airflow is drawn back into the room using the third pipe to enhance the defrosting effect, while maintaining the introduction of fresh air. This reduces the fresh air volume while maintaining stable indoor air pressure, avoiding negative indoor pressure, ensuring the fresh air effect while achieving efficient and energy-saving defrosting.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, specifically to an energy-saving defrosting fresh air system and its control method, device, and storage medium. Background Technology

[0002] As consumers' demands for air quality increase, fresh air systems are gradually becoming more common in homes and public environments. Current fresh air systems utilize heat exchangers to exchange heat when there is a large temperature difference between indoors and outdoors, thus maintaining a constant indoor temperature and saving energy.

[0003] In low-temperature environments, heat exchangers may experience frost formation. Current technology uses preheating devices to preheat the exhaust air for defrosting. However, when the outdoor ambient temperature is extremely low, preheating alone is insufficient to defrost the heat exchanger. This forces the fresh air system to stop operating while waiting for the heat exchanger to defrost, making sustained operation impossible in extremely low-temperature environments. Summary of the Invention

[0004] Therefore, the present invention aims to provide a fresh air system capable of rapid energy-saving defrosting and long-lasting operation, as well as its control method, device and storage medium.

[0005] To solve the above-mentioned technical problems, the present invention provides a control method for a fresh air system. The fresh air system includes a fresh air unit and an air duct assembly. The fresh air unit forms an air inlet side duct and an air outlet side duct connecting the indoor and outdoor environments. An air inlet fan is provided in the air inlet side duct, and an exhaust fan and a preheating device are provided in the exhaust side duct. The fresh air unit also includes heat exchangers disposed in the air inlet side duct and the exhaust side duct. The air duct assembly includes a first air duct connecting the air inlet side duct and the outdoor environment, a second air duct connecting the exhaust side duct and the outdoor environment, and a third air duct connecting the exhaust side duct and the indoor environment.

[0006] The control method for the fresh air system includes:

[0007] The fresh air system is controlled to operate in a first working mode. In the first working mode, the preheating device is working, the air intake fan and the air exhaust fan are rotating at normal speed, the first air passage and the second air passage are open, and the third air passage is closed.

[0008] Detect the environmental parameters inside the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters;

[0009] If the heat exchanger is in a frosty environment, the fresh air system is controlled to operate in the second working mode. In the second working mode, the preheating device is controlled to work, the air intake fan rotates at a low speed lower than the normal speed, the exhaust fan rotates at the normal speed, and the first air path, the second air path and the third air path are controlled to open.

[0010] In one embodiment, after the steps of controlling the fresh air system to operate in a second working mode if the heat exchanger is in a frosting environment, controlling the preheating device to operate in the second working mode, the intake fan rotating at a low speed lower than the normal speed, the exhaust fan rotating at the normal speed, and controlling the opening of the first air path, the second air path, and the third air path, the method further includes:

[0011] Detect the environmental parameters inside the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters;

[0012] If the heat exchanger is in a frosting environment, the fresh air system is controlled to continue operating in the second working mode.

[0013] In one embodiment, after the steps of controlling the fresh air system to operate in a second working mode if the heat exchanger is in a frosting environment, controlling the preheating device to operate in the second working mode, the intake fan rotating at a low speed lower than the normal speed, the exhaust fan rotating at the normal speed, and controlling the opening of the first air path, the second air path, and the third air path, the method further includes:

[0014] Detect the environmental parameters inside the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters;

[0015] If the heat exchanger is in a non-frost environment, the fresh air system is controlled to operate in normal working mode. In normal working mode, the preheating device is controlled to stop working, the air intake fan and the air exhaust fan rotate at normal speed, and the first air path and the second air path are controlled to open, while the third air path is closed.

[0016] In one embodiment, after the steps of controlling the fresh air system to operate in a second working mode if the heat exchanger is in a frosting environment, controlling the preheating device to operate in the second working mode, the intake fan rotating at a low speed lower than the normal speed, the exhaust fan rotating at the normal speed, and controlling the opening of the first air path, the second air path, and the third air path, the method further includes:

[0017] Detect the environmental parameters inside the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters;

[0018] If the heat exchanger is in a frosting environment, the fresh air system is controlled to operate in the third working mode. In the third working mode, the preheating device is controlled to work, the air intake fan stops rotating, the exhaust fan rotates at normal speed, and the first air path and the second air path are controlled to close, while the third air path is opened.

[0019] In one embodiment, if the heat exchanger is in a frosting environment, the fresh air system is controlled to operate in a third working mode. In this third working mode, the preheating device is controlled to operate, the intake fan stops rotating, the exhaust fan rotates at normal speed, and the first and second air paths are controlled to close, while the third air path is opened. Following this step, the system further includes:

[0020] Detect the environmental parameters inside the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters;

[0021] If the heat exchanger is in a non-frost environment, the fresh air system is controlled to operate in normal working mode. In normal working mode, the preheating device is controlled to stop working, the air intake fan and the air exhaust fan rotate at normal speed, and the first air path and the second air path are controlled to open, while the third air path is closed.

[0022] Alternatively, if the heat exchanger is in a frosting environment, the fresh air system is controlled to operate in a third working mode. In this third working mode, the preheating device is controlled to operate, the intake fan stops rotating, the exhaust fan rotates at normal speed, and the first and second air passages are controlled to close, followed by the step of opening the third air passage:

[0023] Detect the environmental parameters inside the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters;

[0024] If the heat exchanger is in a frosting environment or a waiting-to-frost environment, the fresh air system is controlled to continue operating in the third working mode.

[0025] In one embodiment, before the step of controlling the fresh air system to operate in a first working mode, in which the preheating device operates, the intake fan and the exhaust fan rotate at normal speed, the first air passage and the second air passage are opened, and the third air passage is closed, the following steps are included:

[0026] The fresh air system is controlled to operate in normal working mode. In normal working mode, the preheating device is controlled to stop working, the air intake fan and the air exhaust fan rotate at normal speed, and the first air passage and the second air passage are controlled to open, while the third air passage is closed.

[0027] Detect the environmental parameters inside the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters;

[0028] If the heat exchanger is in a frosting environment or a frosting environment, the fresh air system is controlled to switch to the first working mode.

[0029] In one embodiment, the environmental parameters include the temperature and humidity values ​​of the exhaust-side duct, and the step of detecting the environmental parameters within the exhaust-side duct and determining the environmental state of the heat exchanger based on the detection results of the environmental parameters includes:

[0030] A first temperature threshold and a second temperature threshold are determined based on the humidity value;

[0031] When the temperature value is less than or equal to the first temperature threshold, it is determined that the heat exchanger is in a frosting environment;

[0032] When the temperature value is greater than the first temperature threshold and less than the second temperature threshold, it is determined that the heat exchanger is in a frosting environment.

[0033] When the temperature value is greater than or equal to the second temperature threshold, it is determined that the heat exchanger is in a non-frost environment.

[0034] To solve the above-mentioned technical problems, the present invention provides a control device, including a memory, a processor, and a control program for a fresh air system stored in the memory and executable on the processor. The control program for the fresh air system is configured to implement the steps of the control method for the energy-saving defrosting fresh air system as described above.

[0035] To solve the above-mentioned technical problems, the present invention provides an energy-saving defrosting fresh air system, comprising:

[0036] The fresh air unit comprises an intake duct and an exhaust duct connecting the indoor and outdoor areas respectively. The fresh air unit also includes an intake fan located in the intake duct, an exhaust fan located in the exhaust duct, a heat exchanger, and a preheating device. The heat exchanger has a heat absorption end and a heat release end. The heat absorption end is located in the exhaust duct, and the heat release end is located in the intake duct. The preheating device is located in the exhaust duct and upstream of the heat absorption end.

[0037] The air duct assembly includes a first air duct connecting the air inlet side duct to the outside, a second air duct connecting the air outlet side duct to the outside, and a third air duct connecting the air outlet side duct to the interior.

[0038] A valve assembly for controlling the on / off state of the first air passage, the second air passage, and the third air passage; and,

[0039] As described above, the control device is electrically connected to the air intake fan, the exhaust fan, the preheating device, and the valve assembly.

[0040] To solve the above-mentioned technical problems, the present invention provides a storage medium storing a control program for a fresh air system. When the control program for the fresh air system is executed by a processor, it implements the steps of the energy-saving defrosting control method for the fresh air system as described above.

[0041] The technical solution provided by this invention has the following advantages:

[0042] The control method for the energy-saving defrosting fresh air system provided by this invention includes: controlling the fresh air system to operate in a first working mode, during which the preheating device operates; detecting environmental parameters in the exhaust side duct, and determining the environmental state of the heat exchanger based on the detection results of the environmental parameters; if the heat exchanger is in a frosting environment, controlling the fresh air system to operate in a second working mode, in which the preheating device is controlled to operate, the speed of the intake fan is reduced, and the third air path is controlled to open. In the embodiment provided by the invention, based on the conventional use of the preheating device to defrost the heat exchanger, a portion of the indoor airflow is drawn back into the room using the third pipe to enhance the defrosting effect, while maintaining the introduction of fresh air. This reduces the fresh air volume while maintaining stable indoor air pressure, avoiding negative indoor pressure, ensuring the fresh air effect while achieving efficient and energy-saving defrosting. Attached Figure Description

[0043] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0044] Figure 1 A schematic diagram of the structural layout of an embodiment of the energy-saving defrosting fresh air system provided by the present invention;

[0045] Figure 2 for Figure 1 A schematic diagram of the airflow direction of the fresh air system in normal working mode or first working mode;

[0046] Figure 3 for Figure 1 A schematic diagram of the airflow direction of the fresh air system in the second working mode;

[0047] Figure 4 for Figure 1 A schematic diagram of the airflow direction of the fresh air system in its third operating mode;

[0048] Figure 5 for Figure 1 A schematic diagram of the internal structure of a centrally located air distribution box, wherein the fourth valve body is in the first valve position;

[0049] Figure 6 for Figure 5 A schematic diagram of the internal structure of the center-distribution air box, in which the fourth valve body is in the second valve position;

[0050] Figure 7 A schematic diagram of the structure of an embodiment of the control device provided by the present invention;

[0051] Figure 8 A schematic diagram of the first embodiment of the control method for the energy-saving defrosting fresh air system provided by the present invention;

[0052] Figure 9 A schematic diagram of a second embodiment of the control method for the energy-saving defrosting fresh air system provided by the present invention;

[0053] Figure 10 A schematic diagram of the third embodiment of the control method for the energy-saving defrosting fresh air system provided by the present invention.

[0054] Explanation of reference numerals in the attached figures:

[0055] 1000-Fresh air system; 1001-Indoor; 1002-Outdoor; 100-Fresh air unit; 10-Casing; 11-Inlet side air duct; 12-Exhaust side air duct; 20-Heat exchanger; 21-Heat absorption end; 22-Heat release end; 31-Inlet fan; 32-Exhaust fan; 40-Preheating device; 50-Filter device; 200-Air distribution box; 201-Air inlet; 202-First air outlet; 203-Second air outlet; 204-Air distribution chamber; 210-First air path; 220-Second air path; 230-Third air path; 301-First valve body; 302-Second valve body; 303-Third valve body; 304-Fourth valve body; Control device-2000; Processor-2001; Memory-2002. Detailed Implementation

[0056] The technical solution of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The present invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise specified, the embodiments and features in the embodiments of the present invention can be combined with each other.

[0057] It should be noted that the terms "first," "second," etc., in the specification, claims, and drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0058] In this invention, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not intended to limit this invention.

[0059] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the various embodiments of the present invention will be described in detail below with reference to the accompanying drawings. However, those skilled in the art will understand that many technical details are presented in the embodiments of the present invention to facilitate a better understanding of the invention. However, the technical solutions claimed in the present invention can be implemented even without these technical details and various variations and modifications based on the following embodiments. The division of the following embodiments is for ease of description and should not constitute any limitation on the specific implementation of the present invention. The various embodiments can be combined with and referenced by each other without contradiction.

[0060] This invention provides an energy-saving defrosting fresh air system 1000, such as... Figures 1 to 4 As shown, the fresh air system 1000 includes a fresh air unit 100, air duct components, and valve components. The fresh air unit 100 includes a housing 10, an intake fan 31, and an exhaust fan 32. An intake-side air duct 11 and an exhaust-side air duct 12, respectively connecting the indoor unit 1001 and the outdoor unit 1002, are formed within the housing 10. The intake fan 31 is located in the intake-side air duct 11 and drives outdoor fresh air to flow into the indoor unit via the intake-side air duct 11. The exhaust fan 32 is located in the exhaust-side air duct 12 and drives indoor stale air to flow outward via the exhaust-side air duct 12. The intake fan 31 and the exhaust fan 32 can be of various types, such as centrifugal fans, axial fans, and cross-flow fans.

[0061] The air duct assembly includes a first air duct 210, a second air duct 220, and a third air duct 230. One end of the first air duct 210 connects to the air inlet of the air inlet-side duct 11, and the other end connects to the outside. One end of the second air duct 220 connects to the air outlet of the exhaust-side duct 12, and the other end connects to the outside. One end of the third air duct 230 connects to the air outlet of the exhaust-side duct 12, and the other end connects to the indoor environment. A valve assembly is used to control the on / off state of the first air duct 210, the second air duct 220, and the third air duct 230. Its specific form is not limited; for example, it can be a solenoid valve, a throttle valve, etc., installed within the air duct, as long as it can control the on / off state of the first air duct 210, the second air duct 220, and the third air duct 230.

[0062] In the preferred embodiment, please continue reading Figure 4 The fresh air unit 100 also includes a heat exchanger 20, which has a heat absorption end 21 and a heat release end 22. The heat absorption end 21 is located in the exhaust side duct 12, and the heat release end 22 is located in the intake side duct 11. The function of the heat exchanger 20 is to use the heat of the indoor stale air to preheat the outdoor fresh air, thereby reducing the energy consumption of the fresh air system 1000 and improving the stability of the indoor temperature. When the outdoor temperature is low, the outdoor fresh air enters the fresh air unit 100 through the first air duct 210 and flows into the room 1001 through the heat release end 22. At this time, the heat absorption end 21 absorbs the heat of the indoor stale air and transfers it to the outdoor fresh air through the heat release end 22, thereby raising the temperature of the outdoor fresh air.

[0063] Furthermore, such as Figure 1 As shown, the fresh air unit 100 also includes a preheating device 40, which is located in the exhaust-side duct 12 and upstream of the heat absorption end 21. The preheating device 40 is used to heat the stale air flowing through the exhaust-side duct 12. The function of the preheating device 40 is to prevent the heat exchanger 20 from frosting or freezing in low-temperature environments such as winter. When the outdoor temperature is low, water vapor in the exhaust-side duct 12 may condense into frost or ice upon contact with the heat absorption end 21, thus affecting the efficiency and lifespan of the heat exchanger 20. To avoid this, the preheating device 40 can be controlled by a controller to heat the stale air flowing through the exhaust-side duct 12 when needed, raising the temperature of the stale air and reducing the possibility of water vapor condensing into frost or ice.

[0064] In one embodiment, the valve assembly can be specifically configured as follows, such as... Figure 1As shown, the valve assembly includes a first valve body 301 located in the first air passage 210, a second valve body 302 located in the second air passage 220, and a third valve body 303 located in the third air passage 230. The first valve body 301, second valve body 302, and third valve body 303 can all be controlled to open or close via a controller to adjust the flow of the corresponding air passages. When the indoor and outdoor temperature difference is small, the third valve body 303 can be closed, disconnecting the third air passage 230. At this time, the fresh air system 1000 is in normal operating mode or the first operating mode. In normal operating mode, such as... Figure 2 As shown, both the intake fan 31 and the exhaust fan 32 are operating normally. Outdoor fresh air enters the fresh air unit 100 through the first air duct 210 and flows into the room 1001 through the intake side air duct 11. Indoor stale air enters the fresh air unit 100 through the exhaust side air duct 12 and flows into the outside 1002 through the second air duct 220. In the first operating mode, the preheating device 40 starts working, and the indoor airflow is preheated before being blown onto the heat exchanger to prevent it from frosting.

[0065] Please see Figure 3 and Figure 4 The dashed arrows in the diagram represent the direction of airflow. Please continue reading. Figure 3 , Figure 3 The fresh air system is in its second operating mode. While the first air duct 210 and the second air duct 220 are circulating normally, the third air duct 230 is also circulating. At this time, the airflow of the intake fan 31 can be relatively reduced, while the airflow of the exhaust fan 32 can be relatively increased. If the third air duct 230 is not connected, negative pressure will occur indoors. By connecting the third air duct 230, part of the exhaust airflow flows to the outside 1002 via the second air duct 220, while the other part of the indoor airflow returns to the inside 1001 via the third air duct 230. It is understood that the air outlet of the indoor duct in the inside 1001 should be kept at an appropriate distance from the air outlet of the third air duct 230 to avoid airflow short-circuiting and affecting the fresh air effect. In this embodiment, the indoor temperature is kept relatively constant while avoiding negative pressure indoors. Please continue reading... Figure 4 , Figure 4 The fresh air system is in its third operating mode. In this mode, the first and second air ducts 210 and 220 are closed, with only the third air duct 230 open, allowing airflow to return only through the third air duct 230. At this time, the preheating device 40 is also operating. When only the third air duct 230 is open, the high-temperature indoor air can be preheated by the preheating device 40 to continuously heat the heat exchanger 20, enabling rapid defrosting and allowing the fresh air system 1000 to operate continuously.

[0066] In another embodiment of the fresh air system 1000 provided by the present invention, such as Figure 5 and Figure 6As shown, the fresh air system 1000 also includes a distribution box 200, which has an air inlet 201, a first air outlet 202, and a second air outlet 203. The air inlet 201 is connected to the air outlet of the exhaust side duct 12, the first air outlet 202 is connected to the air inlet of the second air passage 220, and the second air outlet 203 is connected to the air inlet of the third air passage 230. A distribution chamber 204 is formed within the distribution box 200, connecting the air inlet 201, the first air outlet 202, and the second air outlet 203. The valve assembly includes a first valve body 301 disposed in the first air passage 210 and a fourth valve body 304 disposed within the distribution box 200. The fourth valve body 304 is movably disposed in the distribution chamber 204, having a first valve position that blocks the first air outlet 202 and opens the second air outlet 203; and a second valve position that blocks the second air outlet 203 and opens the first air outlet 202. In this embodiment, the installation of the air distribution box 200, combined with the installation of the fourth valve body, is simple and easy to modify the existing air duct system in the fresh air system 1000, requiring minimal engineering work.

[0067] In a preferred embodiment, the air distribution box 200 has a first box plate and a second box plate arranged intersecting each other. A first air outlet 202 is opened on the first box plate, and a second air outlet 203 is opened on the second box plate. A fourth valve body 304 is rotatably connected to the inner wall of the air distribution chamber 204 to have a rotational stroke between a first valve position and a second valve position. Figure 5 As shown, when the fresh air system 1000 is in normal operating mode or the first operating mode, the fourth valve body 304 can be in the second valve position. At this time, both the intake fan 31 and the exhaust fan 32 are working normally. Outdoor fresh air enters the fresh air unit 100 through the first air passage 210 and flows to the room 1001 through the intake side air duct 11. Indoor stale air enters the fresh air unit 100 through the exhaust side air duct 12 and flows to the outside 1002 through the air inlet 201 and the first air outlet 202 of the air distribution box 200, and flows to the room 1001 through the air inlet 201 and the second air outlet 203 of the air distribution box 200. When the fresh air system 1000 is in the second operating mode or the third operating mode with the third air passage 230 open, please refer to [the relevant documentation]. Figure 6 When the fourth valve body 304 is in the first valve position, some of the indoor stale air returns to the room 1001 through the second air outlet 203 of the air distribution box 200 and the third air passage 230. At the same time, some outdoor fresh air enters the exhaust side air passage 12 through the first air outlet 202 of the air distribution box 200, mixes with the indoor stale air, and flows to the outside 1002.

[0068] Please see Figure 7 The present invention also provides a control device 2000, which can be modularly configured and universally compatible with various specifications of fresh air unit 100; or, the control device can be installed in a fresh air unit 100 of a specific specification.

[0069] In practical applications, the control device is electrically connected to the intake fan 31, the exhaust fan 32, the preheating device 40, and the valve assembly, respectively. The control device includes a control unit, which includes a memory 2002, a processor 2001, and a control program for the energy-saving defrosting fresh air system stored in the memory and capable of running on the processor. The control program for the fresh air system is configured to implement the steps of the control method for the fresh air system described in the following embodiments.

[0070] The memory 2002 and processor 2001 are connected via a bus. This bus can include any number of interconnecting buses and bridges, connecting various circuits of one or more processors 2001 and memory 2002. The bus can also connect various other circuits, such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. A bus interface provides an interface between the bus and the transceiver. The transceiver can be a single element or multiple elements, such as multiple receivers and transmitters, providing a unit for communicating with various other devices over a transmission medium. Data processed by processor 2001 is transmitted over a wireless medium via an antenna, which further receives data and transmits it to processor 2001.

[0071] Processor 2001 is responsible for managing the bus and general processing, and can also provide various functions, including timing, peripheral interfaces, voltage regulation, power management, and other control functions. Memory 2002 can be used to store data used by processor 2001 during operation.

[0072] Based on the above, the implementation details of the control method of the fresh air system in the first embodiment of the present invention will be described below. The following implementation details are provided for ease of understanding only and are not necessary for implementing this solution.

[0073] Please see Figure 8 The control method for the fresh air system includes:

[0074] Step S1: Control the fresh air system to operate in a first working mode. In the first working mode, the preheating device is working, the air intake fan and the air exhaust fan are rotating at normal speed, the first air passage and the second air passage are open, and the third air passage is closed.

[0075] In this step, the fresh air volume of the fresh air system is the same as in normal operating mode. Both the intake and exhaust fans operate normally, introducing airflow into the room through the first air duct and exhausting airflow to the outside through the second air duct. It is understandable that when the outdoor temperature is low, water vapor in the exhaust side duct may condense into frost or ice upon contact with the heat exchanger's absorber end, affecting the heat exchanger's efficiency and lifespan. To avoid this, in this step, the preheating device is controlled to heat the stale air flowing through the heat exchanger when needed, increasing its temperature and reducing the likelihood of water vapor condensation into frost or ice. The specific heating method of the preheating device is not limited; for example, it can use light heating, electric heating wire heating, graphene heating, etc.

[0076] Step S2: Detect the environmental parameters in the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters.

[0077] In this step, the environmental parameters within the exhaust-side duct are not acquired in real-time, but rather within a preset time period prior to the current time. For example, the average value of the environmental parameter within that preset time period can be obtained. This preset time period can be set by the manufacturer. This is because when the operating mode of the fresh air system changes, the environmental parameters may fluctuate drastically, failing to accurately reflect whether the heat exchanger within the exhaust-side duct is in a state of potential or actual frosting. Furthermore, whenever the fresh air system switches operating modes, it needs to operate in that mode for a period of time before any change in the environment within the exhaust-side duct occurs. By acquiring environmental parameters within a preset time period prior to the current time, the impact of the current operating mode on the environment within the exhaust-side duct can be accurately reflected.

[0078] It should be noted that the environmental parameters may only include the temperature value within the exhaust-side duct, or they may include multiple parameters related to the environment within the exhaust-side duct, including the temperature value. Based on these environmental parameters, it can be determined whether there is a risk of frost formation on the heat exchanger within the exhaust-side duct. It is understood that the temperature at which frost may form on the heat exchanger varies depending on the humidity level; for example, the higher the humidity, the higher the temperature at which frost may form. Therefore, in a preferred embodiment, the environmental parameters include both the temperature and humidity values ​​within the exhaust-side duct. Specifically, these temperature and humidity values ​​can be obtained by installing a temperature sensor, a humidity sensor, or a temperature and humidity sensor within the exhaust-side duct.

[0079] In this step, the environmental state of the heat exchanger includes a non-frost environment, a pre-frost environment, and a frosty environment. The risk of frosting on the heat exchanger increases progressively under these three environments. The specific meanings of these three environments are described below.

[0080] In a preferred embodiment, step S2 may include:

[0081] The step involves determining a first temperature threshold and a second temperature threshold based on the humidity value.

[0082] In this step, a first temperature threshold and a second temperature threshold corresponding to the currently acquired humidity value can be obtained through preset frosting temperature and humidity function relationships within the program. The first temperature threshold is less than the second temperature threshold. Under this humidity environment, the first and second temperature thresholds indicate that when the current temperature value is less than or equal to the first temperature threshold, the heat exchanger is in a frosting environment where it can frost; if the temperature value does not rise, the heat exchanger will frost. When the current temperature value is greater than the first temperature threshold but less than the second temperature threshold, the heat exchanger is considered not in a frosting environment, but there is a risk of it frostning soon. In this case, the heat exchanger is in a waiting-to-frost environment; if the temperature value rises, the heat exchanger will not frost, or the frost will not increase. If the temperature drops below the first temperature threshold, the heat exchanger will frost. When the current temperature is greater than or equal to the second temperature threshold, the heat exchanger in the exhaust side duct is considered to have virtually no risk of frosting in this environment, i.e., the heat exchanger is in a non-frost environment.

[0083] Specifically, after the previous step, the specific methods for determining the environmental state of the heat exchanger may include the following.

[0084] The step involves determining that the heat exchanger is in a frosting environment when the temperature value is less than or equal to the first temperature threshold. That is, after this step, if the operating mode of the heat exchange system is not adjusted, the heat exchanger may quickly frost in this environment, and its frosting condition will not improve.

[0085] The step involves determining that the heat exchanger is in a frosting environment when the temperature value is greater than the first temperature threshold and less than the second temperature threshold. That is, after this step, if the operating mode of the heat exchange system is not adjusted, the heat exchanger will not continue to frost in this environment. Alternatively, even if it has already frostted, without adjusting the operating mode, the temperature value in the exhaust side duct may continue to rise, improving the frosting condition of the heat exchanger, or the temperature value in the exhaust side duct may decrease until it is less than or equal to the first temperature threshold.

[0086] The step involves determining that the heat exchanger is in a non-frost environment when the temperature value is greater than or equal to the second temperature threshold. That is, after this step, the risk of frost formation on the heat exchanger is generally very low. Even if it continues to operate in the current mode, it will take a period of time for the temperature value in the exhaust duct to gradually decrease before the heat exchanger becomes susceptible to frost formation.

[0087] Step S3: If the heat exchanger is in a frosting environment, control the fresh air system to operate in the second working mode. In the second working mode, control the preheating device to work, the air intake fan to rotate at a low speed lower than the normal speed, the exhaust fan to rotate at the normal speed, and control the first air path, the second air path and the third air path to open.

[0088] In this step, if the heat exchanger temperature continues to drop despite preheating by the preheating device, potentially leading to frosting, the intake fan speed is reduced to a low level below normal, while the preheating device continues operating and the third air duct is activated. Specifically, the reduced intake fan speed decreases the fresh air volume, resulting in less outdoor air being introduced than exhausted air, thus raising the indoor air temperature. Furthermore, while the first and second air ducts operate normally, the third air duct also circulates, reintroducing some exhaust air into the room to prevent negative pressure, improving ventilation and maintaining a constant indoor temperature with higher energy efficiency. Specifically, by connecting the third air duct, part of the exhaust air flows to the outside via the second air duct, while another part of the indoor air returns to the room via the third air duct. Simultaneously, the preheating device is also operating, and the activation of the third air duct increases the preheated airflow to the heat exchanger, accelerating defrosting or raising the heat exchanger temperature. The fresh air system can operate continuously while enhancing defrosting, achieving energy-efficient defrosting.

[0089] In this embodiment, based on the conventional use of a preheating device to defrost the heat exchanger, a third pipeline is used to draw part of the indoor airflow back into the room to enhance the defrosting effect. At the same time, the fresh air intake is maintained, and the indoor air pressure is kept stable while reducing the fresh air volume, avoiding indoor negative pressure. This ensures the fresh air effect and achieves efficient and energy-saving defrosting.

[0090] Based on the first embodiment described above, the present invention also proposes a second embodiment of the fresh air system control method. Please refer to [link to embodiment]. Figure 9 In the second embodiment, after step S3, the following steps are included:

[0091] Step S21: Detect the environmental parameters in the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters.

[0092] The specific implementation method of this step is the same as that of step S2, as detailed above, and will not be repeated here.

[0093] Step S41: If the heat exchanger is in a frosting environment, control the fresh air system to continue operating in the second working mode.

[0094] In this step, the specific control method of the fresh air system in the second working mode is as described in step S3 above. At this time, in the second working mode, within the preset time period before the current time, the temperature value in the exhaust side duct has increased compared to the first working mode. This indicates that in this working mode, when the external environment remains unchanged, the heat exchanger will not continue to frost, but there is still a risk of frost formation. However, the risk of frost formation in the environment where the heat exchanger is located gradually decreases. Therefore, the fresh air system is controlled to continue operating in the current second working mode to ensure continuous fresh air exchange and simultaneously drive the temperature in the exhaust side duct to continue to rise, thus saving energy and defrosting while ensuring a certain amount of fresh air.

[0095] After step S21, the method may further include:

[0096] Step S42: If the heat exchanger is in a non-frost environment, control the fresh air system to operate in normal working mode. In the normal working mode, control the preheating device to stop working, the air intake fan and the air exhaust fan to rotate at normal speed, and control the first air path and the second air path to open, and the third air path to close.

[0097] After the fresh air system has operated in the second working mode for a preset period of time, the temperature in the exhaust side duct has risen to a point where the heat exchanger is essentially free of frost risk. In this step, the fresh air system is switched from the second working mode to the normal working mode, i.e., operating in the most conventional manner. The intake fan drives outdoor airflow into the room through the first air duct, and the exhaust fan drives indoor airflow out through the second air duct. The fresh air volume and exhaust volume are approximately the same, or the fresh air volume is greater than the exhaust volume, ensuring fresh indoor air and good air quality. Thus, in this embodiment, once the heat exchanger is free of frost risk, the fresh air system is controlled to return to normal working mode, avoiding excessive operation of the preheating device, saving energy during defrosting, and ensuring good fresh air effect, thereby improving indoor air quality.

[0098] After step S21, the method may further include:

[0099] Step S43: If the heat exchanger is in a frosting environment, control the fresh air system to operate in the third working mode. In the third working mode, control the preheating device to work, stop the air intake fan from rotating, rotate the exhaust fan at normal speed, and control the first air path and the second air path to close, while the third air path to open.

[0100] In this step, after the fresh air system operates in the second working mode for a preset period of time, the temperature in the exhaust side duct has continued to drop to an even lower temperature, indicating that the current working mode is insufficient to raise the heat exchanger temperature and achieve a defrosting effect, or to remove the heat exchanger from the risk of frosting. At this time, the fresh air system is switched from the second working mode to the third working mode, which enhances defrosting. In this working mode, compared to the second working mode, the intake fan stops rotating, and the first and second air ducts are closed. The third intake air duct is opened, and the exhaust side fan continuously blows indoor air through the preheating device to the heat exchanger before returning to the room. At this time, both the indoor temperature and the temperature of the heat exchanger will continue to rise, thereby achieving the purpose of efficient defrosting.

[0101] In this embodiment, the indoor airflow is continuously heated and blown onto the heat exchanger through the third air path to achieve high-speed and high-intensity defrosting. Although the fresh air system does not continue to introduce fresh air in the third working mode, the defrosting speed is fast. After defrosting, it can return to the normal working mode to continue introducing fresh air. The time when the fresh air system stops introducing fresh air due to the defrosting of the heat exchanger is shorter than that of the conventional method of only setting a preheating device, thereby achieving efficient and energy-saving defrosting, while reducing the adverse effects of defrosting on the operation of the fresh air unit and ensuring the fresh air exchange effect.

[0102] Based on the second embodiment described above, the present invention also proposes a third embodiment of the fresh air system control method, please refer to [link to embodiment]. Figure 10 In the third embodiment, after step S43, the following is included:

[0103] Step S22: Detect the environmental parameters in the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters.

[0104] The specific implementation method of this step is the same as that of step S2, as detailed above, and will not be repeated here.

[0105] Step S51: If the heat exchanger is in a non-frost environment, control the fresh air system to operate in normal working mode. In normal working mode, control the preheating device to stop working, the intake fan and the exhaust fan to rotate at normal speed, and control the first air path and the second air path to open, while the third air path to close. In this step, the operation of the fresh air system in normal working mode is the same as described in step S42 above, and will not be repeated here. In this embodiment, although the fresh air system does not continue to introduce fresh air in the third working mode, the defrosting speed is fast. After defrosting, it can return to the normal working mode to continue introducing fresh air. The time when the fresh air system stops introducing fresh air due to heat exchanger defrosting is shorter than the conventional method of only setting a preheating device, thereby achieving efficient and energy-saving defrosting, while reducing the adverse effects of defrosting on the operation of the fresh air unit and ensuring the fresh air exchange effect.

[0106] After step S22, the method may further include:

[0107] Step S52: If the heat exchanger is in a frosting environment or a waiting-to-frost environment, control the fresh air system to continue operating in the third working mode.

[0108] In this step, the operation of the fresh air system in the third working mode is the same as described in step S43 above, and will not be repeated here.

[0109] In this embodiment, the fresh air system continuously monitors the changes in environmental parameters in the exhaust side duct in the third working mode, and determines whether to return to the normal working mode based on the environmental parameters. After the heat exchanger is free from the risk of frost, the system promptly controls the operation of the intake fan to introduce as much fresh air as possible to ensure indoor air quality.

[0110] Based on the above embodiments, the present invention also proposes a fourth embodiment of the fresh air system control method. In the fourth embodiment, after step S2, the method may further include:

[0111] If the heat exchanger is in a non-frost environment, control the fresh air system to operate in normal working mode.

[0112] In this step, the operation of the fresh air system in the normal working mode is the same as described in step S42 above, and will not be repeated here. In this embodiment, in the first working mode, the fresh air system continuously monitors the changes in environmental parameters in the exhaust side duct, and determines whether to return to the normal working mode based on the environmental parameters. After the heat exchanger is free from the risk of frost formation, it promptly controls the operation of the intake fan to introduce as much fresh air as possible to ensure indoor air quality.

[0113] Alternatively, after step S2, the following may also be included:

[0114] If the heat exchanger is in a frosting environment, the control air system continues to operate in the first working mode.

[0115] In this step, the operation of the fresh air system in the first working mode is as described in step S1 above, and will not be repeated here.

[0116] In this embodiment, in the first working mode of the fresh air system, the temperature value in the exhaust side duct has increased compared to the normal working mode within a preset time period before the current time. This indicates that in this first working mode, when the external environment remains unchanged, the heat exchanger will not continue to frost, but there is still a risk of frost formation. However, the risk of frost formation in the environment where the heat exchanger is located gradually decreases. Therefore, the fresh air system is controlled to continue operating in the current first working mode to ensure continuous fresh air exchange and simultaneously drive the temperature in the exhaust side duct to continue to rise, achieving energy-saving defrosting while ensuring a certain amount of fresh air volume.

[0117] Based on the above embodiments, the present invention also proposes a fifth embodiment of the fresh air system control method, wherein, before step S1, the method includes:

[0118] The steps include controlling the fresh air system to operate in normal working mode, in which the preheating device is stopped, the intake fan and the exhaust fan rotate at normal speed, and the first air passage and the second air passage are opened, while the third air passage is closed.

[0119] In this step, when the fresh air system is powered on and starts running for the first time, the system will automatically enter normal operating mode to introduce fresh outdoor air and improve indoor air quality.

[0120] The steps include detecting environmental parameters within the exhaust side duct and determining the environmental state of the heat exchanger based on the detection results of the environmental parameters.

[0121] The specific implementation method of this step is the same as that of step S2, as detailed above, and will not be repeated here.

[0122] If the heat exchanger is in a frosting environment or a frosting environment, the fresh air system is controlled to switch to the first working mode.

[0123] In this step, the operation of the fresh air system in the first working mode is as described in step S1 above, and will not be repeated here.

[0124] In this embodiment, when the fresh air system is in normal working mode, within a preset time period before the current time, the temperature value in the exhaust side duct is in a range that makes the heat exchanger prone to frost or has already frostted. At this time, the fresh air system is controlled to enter the first working mode, and the preheating device is turned on to preheat the airflow blowing into the heat exchanger room, thereby reducing the risk of frost formation on the heat exchanger.

[0125] Obviously, the embodiments described above are merely some, not all, embodiments of the present invention. Based on the embodiments of the present invention, those skilled in the art can make other variations or modifications without creative effort, and all such variations or modifications should fall within the scope of protection of the present invention.

Claims

1. A control method for an energy-saving defrosting fresh air system, characterized in that, The fresh air system includes a fresh air unit and an air duct assembly. The fresh air unit forms an air inlet side duct and an air outlet side duct that connect the indoor and outdoor environments. An air inlet fan is installed in the air inlet side duct, and an exhaust fan and a preheating device are installed in the air outlet side duct. The fresh air unit also includes heat exchangers installed in the air inlet side duct and the air outlet side duct. The air duct assembly includes a first air duct connecting the air inlet side duct and the outdoor environment, a second air duct connecting the exhaust side duct and the outdoor environment, and a third air duct connecting the exhaust side duct and the indoor environment. The control method for the fresh air system includes: The fresh air system is controlled to operate in a first working mode. In the first working mode, the preheating device is working, the air intake fan and the air exhaust fan are rotating at normal speed, the first air passage and the second air passage are open, and the third air passage is closed. Detect the environmental parameters in the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters; If the heat exchanger is in a frosting environment, the fresh air system is controlled to operate in the second working mode. In the second working mode, the preheating device is controlled to work, the air intake fan rotates at a low speed lower than the normal speed, the exhaust fan rotates at the normal speed, and the first air path, the second air path and the third air path are controlled to open, so that the third air path draws part of the indoor airflow back into the room, enhances the defrosting effect, and maintains the introduction of fresh air. After the fresh air system has been running in the second working mode for a preset period of time, the environmental parameters in the exhaust side duct are detected, and the environmental state of the heat exchanger is determined based on the detection results of the environmental parameters. If the heat exchanger is in a frosting environment, control the fresh air system to operate in the third working mode. In the third working mode, control the preheating device to work, the air intake fan to stop rotating, the exhaust fan to rotate at normal speed, and control the first air path and the second air path to close, while the third air path to open. If the heat exchanger is in a frosting environment, the fresh air system is controlled to continue operating in the second working mode; If the heat exchanger is in a non-frost environment, the fresh air system is controlled to operate in normal working mode. In normal working mode, the preheating device is controlled to stop working, the air intake fan and the air exhaust fan rotate at normal speed, and the first air path and the second air path are controlled to open, while the third air path is closed.

2. The control method for the energy-saving defrosting fresh air system as described in claim 1, characterized in that, If the heat exchanger is in a frosting environment, the fresh air system is controlled to operate in a third working mode. In the third working mode, the preheating device is controlled to operate, the intake fan stops rotating, the exhaust fan rotates at normal speed, and the first and second air passages are controlled to close, while the third air passage is opened. Following this step, the system includes: Detect the environmental parameters in the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters; If the heat exchanger is in a non-frost environment, the fresh air system is controlled to operate in normal working mode. In normal working mode, the preheating device is controlled to stop working, the air intake fan and the air exhaust fan rotate at normal speed, and the first air path and the second air path are controlled to open, while the third air path is closed. If the heat exchanger is in a frosting environment or a waiting-to-frost environment, the fresh air system is controlled to continue operating in the third working mode.

3. The control method for the energy-saving defrosting fresh air system as described in claim 1, characterized in that, The step of controlling the fresh air system to operate in a first working mode, in which the preheating device operates, the intake fan and the exhaust fan rotate at normal speed, the first air passage and the second air passage are opened, and the third air passage is closed, includes: The fresh air system is controlled to operate in normal working mode. In normal working mode, the preheating device is controlled to stop working, the air intake fan and the air exhaust fan rotate at normal speed, and the first air passage and the second air passage are controlled to open, while the third air passage is closed. Detect the environmental parameters in the exhaust side duct, and determine the environmental state of the heat exchanger based on the detection results of the environmental parameters; If the heat exchanger is in a frosting environment or a frosting environment, the fresh air system is controlled to switch to the first working mode.

4. The control method for the energy-saving defrosting fresh air system as described in any one of claims 1 to 3, characterized in that, The environmental parameters include the temperature and humidity values ​​of the exhaust-side duct. The step of detecting the environmental parameters within the exhaust-side duct and determining the environmental state of the heat exchanger based on the detection results includes: A first temperature threshold and a second temperature threshold are determined based on the humidity value; When the temperature value is less than or equal to the first temperature threshold, it is determined that the heat exchanger is in a frosting environment; When the temperature value is greater than the first temperature threshold and less than the second temperature threshold, it is determined that the heat exchanger is in a frosting environment. When the temperature value is greater than or equal to the second temperature threshold, it is determined that the heat exchanger is in a non-frost environment.

5. A control device, characterized in that, The system includes a memory, a processor, and a control program for a fresh air system stored in the memory and executable on the processor, the control program being configured to implement the steps of the control method for the energy-saving defrosting fresh air system as described in any one of claims 1 to 4.

6. An energy-saving defrosting fresh air system, characterized in that, include: The fresh air unit comprises an intake duct and an exhaust duct connecting the indoor and outdoor areas respectively. The fresh air unit also includes an intake fan located in the intake duct, an exhaust fan located in the exhaust duct, a heat exchanger, and a preheating device. The heat exchanger has a heat absorption end and a heat release end. The heat absorption end is located in the exhaust duct, and the heat release end is located in the intake duct. The preheating device is located in the exhaust duct and upstream of the heat absorption end. The air duct assembly includes a first air duct connecting the air inlet side duct to the outside, a second air duct connecting the air outlet side duct to the outside, and a third air duct connecting the air outlet side duct to the interior. A valve assembly for controlling the on / off state of the first air passage, the second air passage, and the third air passage; and, The control device as described in claim 5 is electrically connected to the air intake fan, the air exhaust fan, the preheating device, and the valve assembly.

7. A storage medium, characterized in that, The storage medium stores a control program for the fresh air system, which, when executed by a processor, implements the steps of the energy-saving defrosting control method for the fresh air system as described in any one of claims 1 to 4.

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