Fresh air machine circulation mode control method and device, fresh air machine and storage medium

Abstract

The application discloses a circulating mode control method and device of a fresh air machine, the fresh air machine, and a storage medium, wherein the fresh air channel of the fresh air machine is provided with a supply air valve, the exhaust air channel is provided with an exhaust air valve, and a bypass air valve is arranged between the fresh air channel and the exhaust air channel; the method obtains the air enthalpy value of the space where the fresh air machine is located and the current operation mode of the fresh air machine; and the states of the supply air valve, the exhaust air valve and / or the bypass air valve are adjusted according to the current operation mode and the air enthalpy value, so as to adjust the circulating mode of the fresh air machine. The circulating mode of the fresh air machine can be intelligently adjusted according to the current operation mode and the air enthalpy value, thereby improving the accuracy of the circulating mode control and the user experience.

Description

Technical Field

[0001] This invention relates to the field of fresh air system technology, and in particular to a method, device, fresh air system, and storage medium for controlling the circulation mode of a fresh air system. Background Technology

[0002] Fresh air systems generally have internal circulation mode and external circulation mode. In traditional circulation mode control, internal circulation mode is generally used for energy saving control and anti-condensation, while external circulation is generally used to refresh indoor air. When switching circulation modes, air parameters are not fully considered, and circulation mode control is based solely on experience. This results in low control accuracy and insufficient intelligence, making it impossible to truly achieve the goal of energy saving.

[0003] The above content is only used to help understand the technical solution of the present invention and does not represent an admission that the above content is prior art. Summary of the Invention

[0004] The main objective of this invention is to provide a method, device, fresh air unit, and storage medium for controlling the circulation mode of a fresh air unit, aiming to solve the technical problem of low accuracy in the existing fresh air unit circulation mode control.

[0005] To achieve the above objectives, the present invention provides a circulation mode control method for a fresh air unit, wherein the fresh air duct of the fresh air unit is provided with an air supply valve, the exhaust air duct is provided with an exhaust air valve, and a bypass ventilation valve is provided between the fresh air duct and the exhaust air duct.

[0006] The circulation mode control method of the fresh air unit includes:

[0007] Obtain the air enthalpy value of the space where the fresh air unit is located and the current operating mode of the fresh air unit; and,

[0008] The states of the supply air valve, the exhaust air valve, and / or the bypass ventilation valve are adjusted according to the current operating mode and the air enthalpy value to regulate the circulation mode of the fresh air unit.

[0009] Optionally, the air enthalpy value includes the indoor return air enthalpy value and the outdoor fresh air enthalpy value;

[0010] The step of adjusting the status of the supply air valve, the exhaust air valve, and / or the bypass ventilation valve according to the current operating mode and the air enthalpy value to regulate the circulation mode of the fresh air unit includes:

[0011] Obtain the first enthalpy difference between the outdoor fresh air enthalpy value and the indoor return air enthalpy value;

[0012] When the current operating mode is cooling mode and the first enthalpy difference is less than a first preset difference threshold, the supply air valve and the exhaust air valve are controlled to open, and the bypass ventilation valve is controlled to close, so that the fresh air unit operates in external circulation mode; and,

[0013] When the current operation is in heating mode and the first enthalpy difference is greater than or equal to the second preset difference threshold, the supply air valve and the exhaust air valve are controlled to open, and the bypass ventilation valve is controlled to close, so that the fresh air unit operates in external circulation mode.

[0014] Optionally, after obtaining the first enthalpy difference between the outdoor fresh air enthalpy value and the indoor return air enthalpy value, the method further includes:

[0015] When the current operating mode is cooling mode and the first enthalpy difference is greater than or equal to the first preset difference threshold, the air temperature and air humidity in the space where the indoor unit of the fresh air unit is located are obtained;

[0016] The temperature difference between the air temperature and the set temperature and the humidity difference between the air humidity and the set humidity are obtained;

[0017] When the temperature difference is less than or equal to a preset temperature threshold or the humidity difference is less than or equal to a preset humidity threshold, the supply air valve and the exhaust air valve are opened, and the bypass ventilation valve is closed, so that the fresh air unit operates in external circulation mode.

[0018] Optionally, after obtaining the temperature difference between the air temperature and the set temperature and the humidity difference between the air humidity and the set humidity, the method further includes:

[0019] Indoor air quality data is acquired when the temperature difference is greater than a preset temperature threshold and the humidity difference is greater than a preset humidity threshold.

[0020] When the indoor air quality data meets the preset standard, the bypass ventilation valve is opened to allow the fresh air unit to operate in internal circulation mode.

[0021] Optionally, after obtaining the first enthalpy difference between the outdoor fresh air enthalpy value and the indoor return air enthalpy value, the method further includes:

[0022] When the current operating mode is heating mode and the first enthalpy difference is less than the first preset difference threshold, the air temperature and air humidity in the space where the indoor unit of the fresh air unit is located are obtained;

[0023] The temperature difference between the air temperature and the set temperature and the humidity difference between the air humidity and the set humidity are obtained;

[0024] When the temperature difference is greater than a preset temperature threshold and the humidity difference is greater than a preset humidity threshold, the air quality data of the space where the indoor unit of the fresh air unit is located is obtained.

[0025] When the indoor air quality data meets the preset standard, the bypass ventilation valve is opened to allow the fresh air unit to operate in internal circulation mode.

[0026] Optionally, the fresh air unit includes a first heat exchange system and a second heat exchange system, the air enthalpy value includes the inlet air enthalpy value, the outlet air enthalpy value, the indoor return air enthalpy value and the outdoor fresh air enthalpy value, and the current operating mode includes a first current operating mode of the first heat exchange system and a second current operating mode of the second heat exchange system;

[0027] The step of adjusting the status of the supply air valve, the exhaust air valve, and / or the bypass ventilation valve according to the current operating mode and the air enthalpy value to regulate the circulation mode of the fresh air unit includes:

[0028] When the first current operating mode and the second current operating mode are inconsistent, or when both the first current operating mode and the second current operating mode are dehumidification and reheat modes, determine whether the outlet air enthalpy value is greater than the inlet air enthalpy value;

[0029] If so, when the outdoor fresh air enthalpy is greater than or equal to the indoor return air enthalpy, the supply air valve and the exhaust air valve are opened, and the bypass ventilation valve is closed, so that the fresh air unit operates in external circulation mode.

[0030] Optionally, after determining whether the outlet enthalpy is greater than the inlet enthalpy, the method further includes:

[0031] If not, when the outdoor fresh air enthalpy is less than or equal to the indoor return air enthalpy, the supply air valve and the exhaust air valve are opened, and the bypass ventilation valve is closed, so that the fresh air unit operates in external circulation mode.

[0032] In addition, to achieve the above objectives, the present invention also proposes a circulation mode control device for a fresh air unit, wherein the fresh air duct of the fresh air unit is provided with an air supply valve, the exhaust duct is provided with an exhaust valve, and a bypass ventilation valve is provided between the fresh air duct and the exhaust duct.

[0033] The circulation mode control device for the fresh air unit includes:

[0034] The acquisition module is used to acquire the air enthalpy value of the space where the fresh air unit is located and the current operating mode of the fresh air unit; and,

[0035] The adjustment module is used to adjust the status of the supply air valve, the exhaust air valve and / or the bypass ventilation valve according to the current operating mode and the air enthalpy value, so as to adjust the circulation mode of the fresh air unit.

[0036] Furthermore, to achieve the above objectives, the present invention also proposes a fresh air unit, the fresh air unit comprising: a memory, a processor, and a cyclic mode control program for the fresh air unit stored in the memory and executable on the processor, the cyclic mode control program for the fresh air unit being configured to implement the steps of the cyclic mode control method for the fresh air unit as described above.

[0037] In addition, to achieve the above objectives, the present invention also proposes a storage medium storing a circulation mode control program for a fresh air unit, wherein when the circulation mode control program for the fresh air unit is executed by a processor, the steps of the circulation mode control method for the fresh air unit as described above are implemented.

[0038] This invention acquires the air enthalpy value of the space where the fresh air unit is located and the current operating mode of the fresh air unit; based on the current operating mode and the air enthalpy value, it adjusts the state of the supply air valve, the exhaust air valve, and / or the bypass ventilation valve to regulate the circulation mode of the fresh air unit. This allows for intelligent adjustment of the fresh air unit's circulation mode using its current operating mode and air enthalpy value, improving the accuracy of circulation mode control while enhancing the user experience. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the structure of the fresh air unit in the hardware operating environment involved in the embodiments of the present invention;

[0040] Figure 2 This is a flowchart illustrating the first embodiment of the circulation mode control method for the fresh air unit of the present invention;

[0041] Figure 3 This is a schematic diagram of the structure of a fresh air unit in one embodiment of the fresh air unit circulation mode control method of the present invention;

[0042] Figure 4 This is a schematic diagram of another structure of the fresh air unit in one embodiment of the circulation mode control method of the fresh air unit of the present invention;

[0043] Figure 5 This is a flowchart illustrating the second embodiment of the circulation mode control method for the fresh air unit of the present invention;

[0044] Figure 6 This is a flowchart illustrating the third embodiment of the circulation mode control method for the fresh air unit of the present invention;

[0045] Figure 7 This is a structural block diagram of the first embodiment of the circulation mode control device for the fresh air unit of the present invention.

[0046] Explanation of reference numerals in the attached figures

[0047]

[0048]

[0049] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0050] It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the invention.

[0051] Reference Figure 1 , Figure 1 This is a schematic diagram of the structure of a fresh air unit in the hardware operating environment involved in the embodiments of the present invention.

[0052] like Figure 1 As shown, the fresh air unit may include: a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to enable communication between these components. The user interface 1003 may include a display screen or an input unit such as a keyboard; optionally, the user interface 1003 may also include a standard wired interface or a wireless interface. The network interface 1004 may optionally include a standard wired interface or a wireless interface (such as a Wireless-Fidelity (Wi-Fi) interface). The memory 1005 may be high-speed random access memory (RAM) or stable non-volatile memory (NVM), such as a disk storage device. Optionally, the memory 1005 may also be a storage device independent of the aforementioned processor 1001.

[0053] Those skilled in the art will understand that Figure 1 The structure shown does not constitute a limitation on the fresh air unit and may include more or fewer components than shown, or combine certain components, or have different component arrangements.

[0054] like Figure 1 As shown, the memory 1005, which serves as a storage medium, may include an operating system, a network communication module, a user interface module, and a cycle mode control program for the fresh air unit.

[0055] exist Figure 1In the fresh air unit shown, the network interface 1004 is mainly used for data communication with the network server; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the fresh air unit of the present invention can be set in the fresh air unit. The fresh air unit calls the cyclic mode control program of the fresh air unit stored in the memory 1005 through the processor 1001 and executes the cyclic mode control method of the fresh air unit provided in the embodiment of the present invention.

[0056] This invention provides a method for controlling the circulation mode of a fresh air system. The fresh air system has a supply air valve in its fresh air duct and an exhaust air valve in its exhaust air duct. A bypass ventilation valve is provided between the fresh air duct and the exhaust air duct. (Refer to...) Figure 2 , Figure 2 This is a flowchart illustrating the first embodiment of the circulation mode control method for the fresh air unit of the present invention.

[0057] In this embodiment, the fresh air unit's circulation mode control method includes the following steps:

[0058] Step S1: Obtain the air enthalpy value of the space where the fresh air unit is located and the current operating mode of the fresh air unit.

[0059] It should be noted that the executing entity in this embodiment can be a fresh air unit with data processing, network communication, and program execution functions, or an electronic device or a fresh air unit circulation mode control device capable of achieving the above functions. The following uses a fresh air unit circulation mode control device as an example to illustrate this embodiment and the subsequent embodiments.

[0060] This embodiment first proposes a new air ventilator structure, such as Figure 3 and Figure 4As shown. The fresh air unit 100 includes a housing and a first heat exchange system 10. An air supply duct 4 is provided within the housing. The first heat exchange system 10 includes a fresh air heat exchanger structure and a first switching device. The fresh air heat exchanger structure is located within the air supply duct 4 and has a refrigerant pipeline. The first switching device is connected to the fresh air heat exchanger structure and is used to switch the flow direction of the refrigerant within the fresh air heat exchanger structure. In different operating modes, the refrigerant of the first heat exchange system 10 first passes through the refrigerant pipeline located downstream of the air supply duct 4, and then through the refrigerant pipeline located upstream of the air supply duct 4. The air supply duct 4 refers to the channel through which the fresh air unit 100 delivers outdoor fresh air into the room, and the exhaust duct 5 refers to the channel through which the fresh air unit 100 exhausts indoor air to the outside. The fresh air heat exchanger is located in the first refrigerant flow path. The first heat exchange system 10 further includes a first compressor 11, a first heat exchange module 12, and a reversing device 3. The first compressor 11 is located in the first refrigerant flow path and has a first exhaust port and a first return port. The first heat exchange module 12 is located in the first refrigerant flow path and is connected to the first switching device. The first heat exchange module 12 includes a first outdoor heat exchanger 35 and a heat recovery heat exchanger 36 arranged in series. The heat recovery heat exchanger 36 is located in the exhaust duct 5. The first outdoor heat exchanger 35 is located outside the housing (main unit housing). The first compressor 11 is installed in the exhaust duct 5. The heat recovery heat exchanger 36 is installed inside or outside the housing (main unit housing). The heat recovery heat exchanger 36 is located inside the exhaust duct 5. After heat exchange occurs between the air in the exhaust duct 5 and the heat recovery heat exchanger 36, the air is discharged from the exhaust duct 5, thus enabling heat recovery of the air discharged from the exhaust duct 5. The reversing device 3 connects the first exhaust port, the first return port, the first heat exchange module 12, and the first switching device. The reversing device 3 is used to switch the refrigerant flow direction, so that the refrigerant first passes through the first heat exchange module 12 and then the first switching device, or so that the refrigerant first passes through the first switching device and then the first heat exchange module 12. To achieve the reheat dehumidification function of the fresh air unit 100, the fresh air heat exchanger structure includes a first fresh air heat exchanger 13 and a second fresh air heat exchanger 14 connected in series. The first fresh air heat exchanger 13 is located downstream of the air supply channel 4 relative to the second fresh air heat exchanger 14. The outlet 34 is connected to the first fresh air heat exchanger 13, and the inlet 33 is connected to the second fresh air heat exchanger 14. With this configuration, in the reheat dehumidification mode, the first fresh air heat exchanger 13 acts as an evaporator to cool the air, and the second fresh air heat exchanger 14 acts as a condenser to heat the air, thereby achieving reheat dehumidification of the air.To reduce the number of control components in the fresh air unit 100 and improve its stability, the first switching device has a first connecting port 31, a second connecting port 32, an inlet 33, and an outlet 34. The fresh air heat exchanger structure connects the outlet 34 and the inlet 33. The first switching device includes a first one-way valve 18, a second one-way valve 19, a third one-way valve 11, and a fourth one-way valve 2. The first one-way valve 18 is connected between the first connecting port 31 and the inlet 33, and is open in the direction from the inlet 33 to the first connecting port 31. The second one-way valve 19 is connected between the first connecting port 31 and the outlet 34. Between outlets 34, the second one-way valve 19 is open in the direction from the first connecting port 31 to the outlet 34; the third one-way valve 1 is connected between the inlet 33 and the second connecting port 32, and is open in the direction from the inlet 33 to the second connecting port 32; the fourth one-way valve 2 is connected between the outlet 34 and the second connecting port 32, and is open in the direction from the second connecting port 32 to the outlet 34. With this configuration, the first switching device is composed entirely of one-way valves. Compared with the four-way valve or two three-way valves, no control components are required, and the stability of the fresh air unit 100 is higher.

[0061] The fresh air heat exchanger structure includes a first fresh air heat exchanger 13 and a second fresh air heat exchanger 14 connected in series. The first fresh air heat exchanger 13 is located downstream of the air supply channel 4 relative to the second fresh air heat exchanger 14. The outlet 34 is connected to the first fresh air heat exchanger 13, and the inlet 33 is connected to the second fresh air heat exchanger 14. With this configuration, in the reheat dehumidification mode, the first fresh air heat exchanger 13 acts as an evaporator to cool the air, and the second fresh air heat exchanger 14 acts as a condenser to heat the air, thereby realizing the reheat dehumidification of the air.

[0062] The first heat exchange system 10 further includes a first throttling element 15 disposed on the first refrigerant flow path, the first throttling element 15 being located between the first heat exchange module 12 and the first switching device. The first heat exchange system 10 also includes a second throttling element 16 disposed in the flow path connected in series between the first fresh air heat exchanger 13 and the second fresh air heat exchanger 14, thereby enabling throttling of the refrigerant flowing out of the first fresh air heat exchanger 13.

[0063] Furthermore, the fresh air unit 100 also includes a second heat exchange system 20, on which a second refrigerant flow path is formed. The second heat exchange system 20 includes a second outdoor heat exchanger 21, a second compressor 27, a third fresh air heat exchanger 22, and a fourth fresh air heat exchanger 23 disposed in the second refrigerant flow path. The third fresh air heat exchanger 22 and the fourth fresh air heat exchanger 23 are both disposed in the air supply duct 4. At this time, the second outdoor heat exchanger 21 and the second compressor 27 can also be disposed in the exhaust duct 5, so that the fresh air unit 100 does not need an outdoor unit at all, saving space.

[0064] The second heat exchange system 20 further includes a second switching device for switching the connection of the second outdoor heat exchanger 21 to the third fresh air heat exchanger 22 or simultaneously to both the third fresh air heat exchanger 22 and the fourth fresh air heat exchanger 23. The second switching device includes a fourth throttling element 24 and a fifth one-way valve 25 (the fifth one-way valve 25 can be replaced by a solenoid valve). The fourth throttling element 24 is located in the second refrigerant flow path and is situated between the third fresh air heat exchanger 22 and the fourth fresh air heat exchanger 23. The fifth one-way valve 25 is connected in parallel with the third fresh air heat exchanger 22 and the fourth throttling element 24, and the conduction direction of the fifth one-way valve 25 is from the fourth fresh air heat exchanger 23 to the second outdoor heat exchanger 21.

[0065] This setup, with two heat exchange systems and two evaporators within the fresh air duct, results in two evaporation temperatures. The upstream evaporator has a higher temperature than the downstream one, enabling two-stage evaporative cooling. Compared to a single-stage evaporative cooling system, this significantly improves energy efficiency. Furthermore, the upstream heat exchange system can preheat or precool the air before it passes through the downstream system. This effectively lowers the outlet air temperature in cooling mode and raises it in heating mode. Alternatively, the upstream system can cool the air, while the downstream system heats it, achieving reheat dehumidification.

[0066] Because the first heat exchange system 10 and the second heat exchange system 20 coexist, it is often necessary to install two outdoor units for each system. This requires two separate outdoor unit locations, consuming too much space, and the installation workload is also significant. Therefore, the housing includes a main unit housing and an outdoor unit housing. The main unit housing contains the air supply duct 4 and the exhaust duct 5. The first heat exchange system 10 also includes a first compressor 11 and a first heat exchange module 12. The first heat exchange module 12 includes a first outdoor heat exchanger 35 and a heat recovery heat exchanger connected in series. The heat recovery heat exchanger is located within the exhaust duct 5. The fourth fresh air heat exchanger 23 is located within the air supply duct 4. The first compressor 11… The first outdoor heat exchanger 35, the second compressor 27, the second outdoor heat exchanger 21, and the outdoor fan 37 are all housed within the outdoor unit casing. The heat recovery heat exchanger 36 is housed within the exhaust duct 5, and the fourth fresh air heat exchanger 23 is housed within the supply air duct 4. By placing a portion of the outdoor unit components within the exhaust duct 5 and the remaining components within the outdoor unit casing, only one outdoor unit is needed to meet the requirements of both the first heat exchange system 10 and the second heat exchange system 20, reducing the space occupied by the outdoor unit and the workload of its installation.

[0067] Understandably, air enthalpy can be the total heat contained in the air. The air enthalpy of the space where the fresh air unit is located includes the air enthalpy of the space where the indoor unit is located or the air enthalpy at the indoor air outlet, and the air enthalpy of the space where the outdoor unit is located or the air enthalpy at the outdoor air inlet. The air enthalpy of the space where the indoor unit is located can be determined by obtaining the indoor temperature and humidity through temperature and humidity sensors located at the indoor unit's air outlet or indoors. Similarly, the air enthalpy of the space where the outdoor unit is located can be determined by obtaining the outdoor temperature and humidity through temperature and humidity sensors located at the outdoor unit or outdoor air inlet.

[0068] In this embodiment, before step S1, the fresh air unit is controlled to be in external circulation mode.

[0069] Step S2: Adjust the status of the supply air valve, the exhaust air valve, and / or the bypass ventilation valve according to the current operating mode and the air enthalpy value to regulate the circulation mode of the fresh air unit.

[0070] In this embodiment, the circulation mode of the fresh air unit is adjusted by regulating the opening or closing of the supply air valve, exhaust air valve, and / or bypass ventilation valve. The air valve consists of blades, a frame, and a stepper motor. The stepper motor drives the blades to rotate, thereby opening and closing the valve. The fresh air unit has two circulation modes: internal circulation and external circulation. In external circulation mode, the supply air valve and exhaust air valve are open, and the bypass ventilation valve is closed, isolating the fresh air passage and the exhaust air passage. In internal circulation mode, the bypass ventilation valve is open, and the supply air valve and exhaust air valve can be opened or closed. Some indoor return air is not exhausted to the outside but enters the fresh air passage through the bypass ventilation valve and then returns to the room.

[0071] In practice, the fresh air unit obtains indoor temperature and humidity through temperature and humidity sensors installed in the indoor unit, determines the indoor air enthalpy value based on the indoor temperature and humidity, obtains outdoor temperature and humidity through temperature and humidity sensors installed in the outdoor unit, determines the outdoor air enthalpy value based on the outdoor temperature and humidity, compares the outdoor air enthalpy value with the indoor air enthalpy value, and controls the opening or closing of the supply air valve, exhaust air valve and / or bypass ventilation valve according to the comparison result and the current operating mode to adjust the circulation mode of the fresh air unit.

[0072] Furthermore, in order to enable the fresh air unit to operate in a more energy-efficient circulation mode, the air enthalpy value includes the indoor return air enthalpy value and the outdoor fresh air enthalpy value. Step S2 includes:

[0073] Step S21: Obtain the first enthalpy difference between the outdoor fresh air enthalpy value and the indoor return air enthalpy value;

[0074] It is understandable that the outdoor fresh air enthalpy value can be the outdoor air enthalpy value, and the indoor return air enthalpy value can be the air enthalpy value at the return air vent of the fresh air unit, or the air enthalpy value inside the room; the first enthalpy difference can be the enthalpy difference obtained by subtracting the indoor return air enthalpy value from the outdoor fresh air enthalpy value.

[0075] Step S22: When the current operating mode is cooling mode and the first enthalpy difference is less than the first preset difference threshold, control the air supply valve and the exhaust valve to open, and control the bypass ventilation valve to close, so that the fresh air unit operates in external circulation mode;

[0076] It is understandable that the cooling mode essentially processes the air to reduce its enthalpy. The first preset difference threshold can be a pre-set value, such as a value approximately equal to 0, like -0.1, 0, or 0.2. When the first enthalpy difference is less than the first preset difference threshold, it means that the enthalpy of the outdoor fresh air is less than that of the indoor return air. At this time, the supply air valve and exhaust air valve are opened, and the bypass ventilation valve is closed, so that the fresh air unit operates in external circulation mode. This allows the low-enthalpy outdoor air to be sent into the room, reducing the energy consumption of the enthalpy reduction process and achieving energy saving while reducing the indoor air enthalpy.

[0077] Step S23: When the current operation is in heating mode and the first enthalpy difference is greater than or equal to the second preset difference threshold, control the air supply valve and the exhaust valve to open, and control the bypass ventilation valve to close, so that the fresh air unit operates in external circulation mode.

[0078] It is understandable that the heating mode essentially processes the control to increase the air enthalpy. The second preset difference threshold can be a pre-set value. It can be set to a value equal to the first preset difference threshold, or it can be set to a value approximately equal to 0, such as -0.07, 0, 0.11, etc. When the first enthalpy difference is greater than or equal to the second preset difference threshold, it means that the outdoor fresh air enthalpy is greater than the indoor return air enthalpy. At this time, the bypass ventilation valve is closed, and the fresh air unit operates in external circulation mode. This allows the high enthalpy outdoor air to be introduced into the room, reducing the energy consumption of enthalpy increase processing. This achieves energy saving while increasing the indoor air enthalpy.

[0079] In specific implementation, for example, if the first preset difference threshold and the second preset difference threshold are set to 0, then when the fresh air fan is running in cooling mode and the outdoor fresh air enthalpy is less than the indoor return air enthalpy, the fresh air fan is controlled to run in external circulation mode; when the fresh air fan is running in heating mode and the outdoor fresh air enthalpy is greater than the indoor return air enthalpy, the fresh air fan is also controlled to run in external circulation mode.

[0080] Furthermore, in order to quickly adjust the indoor temperature and humidity, after step S21, the method further includes: when the current operating mode is cooling mode and the first enthalpy difference is greater than or equal to the first preset difference threshold, obtaining the air temperature and air humidity in the space where the indoor unit of the fresh air unit is located; obtaining the temperature difference between the air temperature and the set temperature and the humidity difference between the air humidity and the set humidity; when the temperature difference is less than or equal to the preset temperature threshold or the humidity difference is less than or equal to the preset humidity threshold, controlling the air supply valve and the exhaust valve to open, and controlling the bypass ventilation valve to close, so that the fresh air unit operates in external circulation mode.

[0081] It is understandable that if the first enthalpy difference is greater than or equal to the first preset difference threshold, it means that the outdoor fresh air enthalpy is greater than the indoor return air enthalpy. At this time, it is necessary to further determine whether the indoor air temperature and air humidity are properly adjusted. The set temperature and set humidity can be the temperature and humidity set by the user. The temperature difference can be the temperature difference obtained by subtracting the set temperature from the air temperature. The humidity difference can be the humidity difference obtained by subtracting the set humidity from the air humidity. The preset temperature threshold and preset humidity threshold can be preset values. Both the preset temperature threshold and preset humidity threshold can be set to values ​​approximately equal to 0.

[0082] In specific implementation, for example, the preset temperature threshold, preset humidity threshold and first preset difference threshold are 0. When the fresh air unit is running in cooling mode and the outdoor fresh air enthalpy is greater than the indoor return air enthalpy, the indoor air temperature and air humidity are obtained. When the air temperature is less than or equal to the set temperature and / or the air humidity is less than or equal to the set humidity, the state of the air valve is controlled so that the fresh air unit operates in external circulation mode.

[0083] Furthermore, in order to ensure that the indoor air quality meets the preset standard when the fresh air unit is operating in internal circulation mode, thereby improving the user experience, after obtaining the temperature difference between the air temperature and the set temperature and the humidity difference between the air humidity and the set humidity, the method further includes: obtaining indoor air quality data when the temperature difference is greater than a preset temperature threshold and the humidity difference is greater than a preset humidity threshold; and controlling the bypass ventilation valve to open when the indoor air quality data meets the preset standard, so that the fresh air unit operates in internal circulation mode.

[0084] It is understandable that air quality data includes carbon dioxide concentration, formaldehyde concentration, and nitrogen dioxide concentration, etc.; the preset standard can be the standard data of the above air quality data, or it can be the standard set by the user.

[0085] It should be noted that in this embodiment, the indoor air temperature, air humidity and air quality data can be judged first, and then the circulation mode of the fresh air unit can be controlled according to the relationship between the outdoor fresh air enthalpy value and the indoor return air enthalpy value. That is, there is no order to the above steps.

[0086] This embodiment acquires the air enthalpy value of the space where the fresh air unit is located and the current operating mode of the fresh air unit; based on the current operating mode and the air enthalpy value, it adjusts the status of the supply air valve, the exhaust air valve, and / or the bypass ventilation valve to regulate the circulation mode of the fresh air unit. This allows for intelligent adjustment of the fresh air unit's circulation mode based on its current operating mode and the air enthalpy value, improving the accuracy of circulation mode control while enhancing the user experience.

[0087] refer to Figure 3 , Figure 3 This is a flowchart illustrating the second embodiment of the circulation mode control method for the fresh air unit of the present invention.

[0088] Based on the first embodiment described above, in this embodiment, after step S21, the method further includes:

[0089] Step S211: When the current operating mode is heating mode and the first enthalpy difference is less than the first preset difference threshold, obtain the air temperature and air humidity in the space where the indoor unit of the fresh air unit is located.

[0090] In practice, when the fresh air unit is running in heating mode, it is determined whether the first enthalpy difference is less than the first preset difference threshold. If so, the indoor air temperature and air humidity are obtained.

[0091] Step S212: Obtain the temperature difference between the air temperature and the set temperature and the humidity difference between the air humidity and the set humidity.

[0092] In this embodiment, the temperature difference is obtained by subtracting the set temperature from the air temperature, and the humidity difference is obtained by subtracting the set humidity from the air humidity.

[0093] Step S213: When the temperature difference is greater than a preset temperature threshold and the humidity difference is greater than a preset humidity threshold, obtain the air quality data of the space where the indoor unit of the fresh air unit is located;

[0094] Step S214: When the indoor air quality data meets the preset standard, control the bypass ventilation valve to open so that the fresh air unit operates in internal circulation mode.

[0095] In practice, when the fresh air unit is operating in heating mode and the outdoor fresh air enthalpy is less than the indoor return air enthalpy, the temperature difference between the indoor temperature and the set temperature and the humidity difference between the indoor humidity and the set humidity are calculated. If the temperature difference is greater than the preset temperature threshold and the humidity difference is greater than the preset humidity threshold, the indoor carbon dioxide concentration and formaldehyde concentration are obtained. If both the carbon dioxide concentration and formaldehyde concentration are less than the preset concentration, the bypass ventilation valve is opened to allow the fresh air unit to operate in internal circulation mode.

[0096] In this embodiment, when controlling the circulation mode of the fresh air unit, the outdoor fresh air enthalpy value, indoor return air enthalpy value, indoor air humidity, indoor air temperature, and indoor air quality data are comprehensively considered. This can take into account the fresh air demand, energy saving demand, and air treatment demand, thereby improving the accuracy of circulation mode control and enhancing the user experience.

[0097] refer to Figure 4 , Figure 4 This is a flowchart illustrating the third embodiment of the circulation mode control method for the fresh air unit of the present invention.

[0098] Based on the above embodiments, in this embodiment, the fresh air unit includes a first heat exchange system and a second heat exchange system, the air enthalpy value includes the inlet air enthalpy value, the outlet air enthalpy value, the indoor return air enthalpy value, and the outdoor fresh air enthalpy value, the current operating mode includes a first current operating mode of the first heat exchange system and a second current operating mode of the second heat exchange system, and step S2 further includes:

[0099] Step S20: When the first current operating mode and the second current operating mode are inconsistent, or when both the first current operating mode and the second current operating mode are dehumidification and reheat modes, determine whether the outlet air enthalpy value is greater than the inlet air enthalpy value.

[0100] It should be noted that if both the first current operating mode and the second current operating mode are heating modes, the control method of the circulation mode is the same as the control method when the current operating mode of the fresh air unit is heating mode in the above embodiment; if both the first current operating mode and the second current operating mode are cooling modes, the control method of the circulation mode is the same as the control method when the current operating mode of the fresh air unit is cooling mode in the above embodiment.

[0101] It is understandable that the first current operating mode includes cooling mode, heating mode, and dehumidification and reheat mode, and the second current operating mode also includes cooling mode, heating mode, and dehumidification and reheat mode; the first current operating mode and the second current operating mode are inconsistent, which may be that one is cooling mode and the other is heating mode; the outlet air enthalpy value can be the enthalpy value of the air at the indoor air outlet of the fresh air unit; the inlet air enthalpy value can be the enthalpy value of the air at the outdoor air inlet of the fresh air unit.

[0102] Step S30: If yes, when the outdoor fresh air enthalpy value is greater than or equal to the indoor return air enthalpy value, control the air supply valve and the exhaust valve to open, and control the bypass ventilation valve to close, so that the fresh air fan operates in external circulation mode.

[0103] It is understandable that if the outlet enthalpy is greater than the inlet enthalpy, it means that the overall effect of the fresh air unit is more inclined towards heating. In this case, if the outdoor fresh air enthalpy is greater than or equal to the indoor return air enthalpy, the fresh air unit will be controlled to operate in external circulation mode. When the overall effect of the fresh air unit is inclined towards heating, the control method of the circulation mode can refer to the control method of the fresh air unit when the current operating mode is heating mode in the above embodiment.

[0104] Furthermore, in order to improve the accuracy of the circulation mode control, after step S20, the method further includes: if not, when the outdoor fresh air enthalpy value is less than or equal to the indoor return air enthalpy value, controlling the supply air valve and the exhaust air valve to open, and controlling the bypass ventilation valve to close, so that the fresh air fan operates in the external circulation mode.

[0105] It is understandable that if the outlet enthalpy is less than or equal to the inlet enthalpy, it means that the overall effect of the fresh air unit is more inclined to cooling. In this case, if the outdoor fresh air enthalpy is less than or equal to the indoor return air enthalpy, the fresh air unit will be controlled to operate in external circulation mode. When the overall effect of the fresh air unit is more inclined to cooling, the control method of the circulation mode can refer to the control method of the fresh air unit when the current operating mode is cooling mode in the above embodiment.

[0106] In specific implementation, for example, the fresh air unit is a bidirectional flow fresh air dehumidifier, which includes two heat exchange systems. Each heat exchange system has a compressor, evaporator, condenser, reheater, four-way valve, and two expansion valves between each of the three heat exchangers. It also includes a wet film humidification system, which can realize the cooling, heating, dehumidification, and humidification of fresh air. If one heat exchange system operates in heating mode and the other operates in cooling mode, or if both heat exchange systems operate in dehumidification and reheating mode, then when the outlet air enthalpy is greater than the inlet air enthalpy, the overall effect of the fresh air unit is determined to be heating mode; when the outlet air enthalpy is less than or equal to the inlet air enthalpy, the overall effect of the fresh air unit is determined to be cooling mode. The control method of the circulation mode in cooling mode and heating mode can refer to the aforementioned embodiment, which will not be repeated here.

[0107] In this embodiment, when the operating modes of the two heat exchange systems are inconsistent, the overall operating mode of the fresh air unit is determined by the outlet air enthalpy and inlet air enthalpy, which determines whether it is a cooling mode or a heating mode. This allows for control of the circulation mode of the fresh air unit, improving the intelligence of the circulation mode control and enhancing the user experience.

[0108] Furthermore, this embodiment of the invention also proposes a storage medium storing a circulation mode control program for a fresh air unit. When the circulation mode control program for the fresh air unit is executed by a processor, it implements the steps of the circulation mode control method for the fresh air unit as described above.

[0109] Reference Figure 7 , Figure 7 This is a structural block diagram of the first embodiment of the circulation mode control device for the fresh air unit of the present invention. The fresh air duct of the fresh air unit is provided with an air supply valve, the exhaust duct is provided with an exhaust valve, and a bypass ventilation valve is provided between the fresh air duct and the exhaust duct.

[0110] like Figure 7 As shown, the air circulation mode control device for the fresh air unit proposed in this embodiment of the invention includes:

[0111] The acquisition module 10 is used to acquire the air enthalpy value of the space where the fresh air unit is located and the current operating mode of the fresh air unit.

[0112] It should be noted that the executing entity in this embodiment can be a fresh air unit with data processing, network communication, and program execution functions, or an electronic device or a fresh air unit circulation mode control device capable of achieving the above functions. The following uses a fresh air unit circulation mode control device as an example to illustrate this embodiment and the subsequent embodiments.

[0113] This embodiment first proposes a new air ventilator structure, such as Figure 3 and Figure 4As shown. The fresh air unit 100 includes a housing and a first heat exchange system 10. An air supply duct 4 is provided within the housing. The first heat exchange system 10 includes a fresh air heat exchanger structure and a first switching device. The fresh air heat exchanger structure is located within the air supply duct 4 and has a refrigerant pipeline. The first switching device is connected to the fresh air heat exchanger structure and is used to switch the flow direction of the refrigerant within the fresh air heat exchanger structure. In different operating modes, the refrigerant of the first heat exchange system 10 first passes through the refrigerant pipeline located downstream of the air supply duct 4, and then through the refrigerant pipeline located upstream of the air supply duct 4. The air supply duct 4 refers to the channel through which the fresh air unit 100 delivers outdoor fresh air into the room, and the exhaust duct 5 refers to the channel through which the fresh air unit 100 exhausts indoor air to the outside. The fresh air heat exchanger is located in the first refrigerant flow path. The first heat exchange system 10 further includes a first compressor 11, a first heat exchange module 12, and a reversing device 3. The first compressor 11 is located in the first refrigerant flow path and has a first exhaust port and a first return port. The first heat exchange module 12 is located in the first refrigerant flow path and is connected to the first switching device. The first heat exchange module 12 includes a first outdoor heat exchanger 35 and a heat recovery heat exchanger 36 arranged in series. The heat recovery heat exchanger 36 is located in the exhaust duct 5. The first outdoor heat exchanger 35 is located outside the housing (main unit housing). The first compressor 11 is installed in the exhaust duct. The heat recovery heat exchanger 36 is installed inside or outside the housing (main unit housing). The air in the exhaust duct 5 exchanges heat with the heat recovery heat exchanger 36 before being discharged from the exhaust duct 5, thus enabling heat recovery of the air discharged from the exhaust duct 5. The reversing device 3 connects to the first exhaust port, the first return port, the first heat exchange module 12, and the first switching device. The reversing device 3 is used to switch the refrigerant flow direction, so that the refrigerant first passes through the first heat exchange module 12 and then the first switching device, or so that the refrigerant first passes through the first switching device and then the first heat exchange module 12. To achieve the reheat dehumidification function of the fresh air unit 100, the fresh air heat exchanger structure includes a first fresh air heat exchanger 13 and a second fresh air heat exchanger 14 connected in series. The first fresh air heat exchanger 13 is located downstream of the air supply channel 4 relative to the second fresh air heat exchanger 14. The outlet 34 is connected to the first fresh air heat exchanger 13, and the inlet 33 is connected to the second fresh air heat exchanger 14. With this configuration, in the reheat dehumidification mode, the first fresh air heat exchanger 13 acts as an evaporator to cool the air, and the second fresh air heat exchanger 14 acts as a condenser to heat the air, thereby achieving reheat dehumidification of the air.To reduce the number of control components in the fresh air unit 100 and improve its stability, the first switching device has a first connecting port 31, a second connecting port 32, an inlet 33, and an outlet 34. The fresh air heat exchanger structure connects the outlet 34 and the inlet 33. The first switching device includes a first one-way valve 18, a second one-way valve 19, a third one-way valve 11, and a fourth one-way valve 2. The first one-way valve 18 is connected between the first connecting port 31 and the inlet 33, and is open in the direction from the inlet 33 to the first connecting port 31. The second one-way valve 19 is connected between the first connecting port 31 and the outlet 34. Between outlets 34, the second one-way valve 19 is open in the direction from the first connecting port 31 to the outlet 34; the third one-way valve 1 is connected between the inlet 33 and the second connecting port 32, and is open in the direction from the inlet 33 to the second connecting port 32; the fourth one-way valve 2 is connected between the outlet 34 and the second connecting port 32, and is open in the direction from the second connecting port 32 to the outlet 34. With this configuration, the first switching device is composed entirely of one-way valves. Compared with the four-way valve or two three-way valves, no control components are required, and the stability of the fresh air unit 100 is higher.

[0114] The fresh air heat exchanger structure includes a first fresh air heat exchanger 13 and a second fresh air heat exchanger 14 connected in series. The first fresh air heat exchanger 13 is located downstream of the air supply channel 4 relative to the second fresh air heat exchanger 14. The outlet 34 is connected to the first fresh air heat exchanger 13, and the inlet 33 is connected to the second fresh air heat exchanger 14. With this configuration, in the reheat dehumidification mode, the first fresh air heat exchanger 13 acts as an evaporator to cool the air, and the second fresh air heat exchanger 14 acts as a condenser to heat the air, thereby achieving reheat dehumidification of the air.

[0115] The first heat exchange system 10 further includes a first throttling element 15 disposed on the first refrigerant flow path, the first throttling element 15 being located between the first heat exchange module 12 and the first switching device. The first heat exchange system 10 also includes a second throttling element 16 disposed in the flow path connected in series between the first fresh air heat exchanger 13 and the second fresh air heat exchanger 14, thereby enabling throttling of the refrigerant flowing out of the first fresh air heat exchanger 13.

[0116] Furthermore, the fresh air unit 100 also includes a second heat exchange system 20, on which a second refrigerant flow path is formed. The second heat exchange system 20 includes a second outdoor heat exchanger 21, a second compressor 27, a third fresh air heat exchanger 22, and a fourth fresh air heat exchanger 23 disposed in the second refrigerant flow path. The third fresh air heat exchanger 22 and the fourth fresh air heat exchanger 23 are both disposed in the air supply duct 4. At this time, the second outdoor heat exchanger 21 and the second compressor 27 can also be disposed in the exhaust duct 5, so that the fresh air unit 100 does not need an outdoor unit at all, saving space.

[0117] The second heat exchange system 20 further includes a second switching device for switching the connection of the second outdoor heat exchanger 21 to the third fresh air heat exchanger 22 or simultaneously to both the third fresh air heat exchanger 22 and the fourth fresh air heat exchanger 23. The second switching device includes a fourth throttling element 24 and a fifth one-way valve 25 (the fifth one-way valve 25 can be replaced by a solenoid valve). The fourth throttling element 24 is located in the second refrigerant flow path and is situated between the third fresh air heat exchanger 22 and the fourth fresh air heat exchanger 23. The fifth one-way valve 25 is connected in parallel with the third fresh air heat exchanger 22 and the fourth throttling element 24, and the conduction direction of the fifth one-way valve 25 is from the fourth fresh air heat exchanger 23 to the second outdoor heat exchanger 21.

[0118] This setup, with two heat exchange systems and two evaporators within the fresh air duct, results in two evaporation temperatures. The upstream evaporator has a higher temperature than the downstream one, enabling two-stage evaporative cooling. Compared to a single-stage evaporative cooling system, this significantly improves energy efficiency. Furthermore, the upstream heat exchange system can preheat or precool the air before it passes through the downstream system. This effectively lowers the outlet air temperature in cooling mode and raises it in heating mode. Alternatively, the upstream system can cool the air, while the downstream system heats it, achieving reheat dehumidification.

[0119] Because the first heat exchange system 10 and the second heat exchange system 20 coexist, it is often necessary to install two outdoor units for each system. This requires two separate outdoor unit locations, consuming too much space, and the installation workload is also significant. Therefore, the housing includes a main unit housing and an outdoor unit housing. The main unit housing contains the air supply duct 4 and the exhaust duct 5. The first heat exchange system 10 also includes a first compressor 11 and a first heat exchange module 12. The first heat exchange module 12 includes a first outdoor heat exchanger 35 and a heat recovery heat exchanger connected in series. The heat recovery heat exchanger is located within the exhaust duct 5. The fourth fresh air heat exchanger 23 is located within the air supply duct 4. The first compressor 11… The first outdoor heat exchanger 35, the second compressor 27, the second outdoor heat exchanger 21, and the outdoor fan 37 are all housed within the outdoor unit casing. The heat recovery heat exchanger 36 is housed within the exhaust duct 5, and the fourth fresh air heat exchanger 23 is housed within the supply air duct 4. By placing a portion of the outdoor unit components within the exhaust duct 5 and the remaining components within the outdoor unit casing, only one outdoor unit is needed to meet the requirements of both the first heat exchange system 10 and the second heat exchange system 20, reducing the space occupied by the outdoor unit and the workload of its installation.

[0120] Understandably, air enthalpy can be the total heat contained in the air. The air enthalpy of the space where the fresh air unit is located includes the air enthalpy of the space where the indoor unit is located and the air enthalpy of the space where the outdoor unit is located. The air enthalpy of the space where the indoor unit is located can be determined by obtaining the indoor temperature and humidity through the temperature and humidity sensors installed on the indoor unit. The air enthalpy of the space where the outdoor unit is located can be determined by obtaining the outdoor temperature and humidity through the temperature and humidity sensors installed on the outdoor unit.

[0121] Adjustment module 20 is used to adjust the status of the supply air valve, the exhaust air valve, and / or the bypass ventilation valve according to the current operating mode and the air enthalpy value, so as to regulate the circulation mode of the fresh air unit.

[0122] In this embodiment, the circulation mode of the fresh air unit is adjusted by regulating the opening or closing of the supply air valve, exhaust air valve, and / or bypass ventilation valve. The air valve consists of blades, a frame, and a stepper motor. The stepper motor drives the blades to rotate, thereby opening and closing the valve. The fresh air unit has two circulation modes: internal circulation and external circulation. In external circulation mode, the supply air valve and exhaust air valve are open, and the bypass ventilation valve is closed, isolating the fresh air passage and the exhaust air passage. In internal circulation mode, the bypass ventilation valve is open, and the supply air valve and exhaust air valve can be opened or closed. Some indoor return air is not exhausted to the outside but enters the fresh air passage through the bypass ventilation valve and then returns to the room.

[0123] In practice, the fresh air unit obtains indoor temperature and humidity through temperature and humidity sensors installed in the indoor unit, determines the indoor air enthalpy value based on the indoor temperature and humidity, obtains outdoor temperature and humidity through temperature and humidity sensors installed in the outdoor unit, determines the outdoor air enthalpy value based on the outdoor temperature and humidity, compares the outdoor air enthalpy value with the indoor air enthalpy value, and controls the opening or closing of the supply air valve, exhaust air valve and / or bypass ventilation valve according to the comparison result and the current operating mode to adjust the circulation mode of the fresh air unit.

[0124] Furthermore, in order to enable the fresh air unit to operate in a more energy-efficient circulation mode, the air enthalpy value includes the indoor return air enthalpy value and the outdoor fresh air enthalpy value. The adjustment module 20 is also used to obtain a first enthalpy difference between the outdoor fresh air enthalpy value and the indoor return air enthalpy value.

[0125] It is understandable that the outdoor fresh air enthalpy value can be the outdoor air enthalpy value, and the indoor return air enthalpy value can be the air enthalpy value at the return air vent of the fresh air unit, or the air enthalpy value inside the room; the first enthalpy difference can be the enthalpy difference obtained by subtracting the indoor return air enthalpy value from the outdoor fresh air enthalpy value.

[0126] The adjustment module 20 is also used to control the air supply valve and the exhaust valve to open and control the bypass ventilation valve to close when the current operating mode is cooling mode and the first enthalpy difference is less than the first preset difference threshold, so that the fresh air unit can operate in external circulation mode.

[0127] It is understandable that the cooling mode essentially processes the air to reduce its enthalpy. The first preset difference threshold can be a pre-set value, such as a value approximately equal to 0, like -0.1, 0, or 0.2. When the first enthalpy difference is less than the first preset difference threshold, it means that the enthalpy of the outdoor fresh air is less than that of the indoor return air. At this time, the supply air valve and exhaust air valve are opened, and the bypass ventilation valve is closed, so that the fresh air unit operates in external circulation mode. This allows the low-enthalpy outdoor air to be sent into the room, reducing the energy consumption of the enthalpy reduction process and achieving energy saving while reducing the indoor air enthalpy.

[0128] The adjustment module 20 is further configured to control the air supply valve and the exhaust valve to open and control the bypass ventilation valve to close when the current operation is in heating mode and the first enthalpy difference is greater than or equal to the second preset difference threshold, so that the fresh air unit operates in external circulation mode.

[0129] It is understandable that the heating mode essentially processes the air to increase its enthalpy. The second preset difference threshold can be a pre-set value, which can be set to be equal to the first preset difference threshold, or it can be set to a value approximately equal to 0, such as -0.07, 0, 0.11, etc. When the first enthalpy difference is greater than or equal to the second preset difference threshold, it means that the outdoor fresh air enthalpy is greater than the indoor return air enthalpy. At this time, the bypass ventilation valve is closed, and the fresh air unit operates in external circulation mode. This allows the high enthalpy outdoor air to be introduced into the room, reducing the energy consumption of enthalpy enhancement processing and achieving energy saving while increasing the indoor air enthalpy.

[0130] In specific implementation, for example, if the first preset difference threshold and the second preset difference threshold are set to 0, then when the fresh air fan is running in cooling mode and the outdoor fresh air enthalpy is less than the indoor return air enthalpy, the fresh air fan is controlled to run in external circulation mode; when the fresh air fan is running in heating mode and the outdoor fresh air enthalpy is greater than the indoor return air enthalpy, the fresh air fan is also controlled to run in external circulation mode.

[0131] Furthermore, in order to quickly adjust the indoor temperature and humidity, the adjustment module 20 is also used to acquire the air temperature and air humidity in the space where the indoor unit of the fresh air unit is located when the current operating mode is cooling mode and the first enthalpy difference is greater than or equal to the first preset difference threshold; acquire the temperature difference between the air temperature and the set temperature and the humidity difference between the air humidity and the set humidity; and control the air supply valve and the exhaust valve to open and control the bypass ventilation valve to close when the temperature difference is less than or equal to the preset temperature threshold or the humidity difference is less than or equal to the preset humidity threshold, so that the fresh air unit operates in external circulation mode.

[0132] It is understandable that if the first enthalpy difference is greater than or equal to the first preset difference threshold, it means that the outdoor fresh air enthalpy is greater than the indoor return air enthalpy. At this time, it is necessary to further determine whether the indoor air temperature and air humidity are properly adjusted. The set temperature and set humidity can be the temperature and humidity set by the user. The temperature difference can be the temperature difference obtained by subtracting the set temperature from the air temperature. The humidity difference can be the humidity difference obtained by subtracting the set humidity from the air humidity. The preset temperature threshold and preset humidity threshold can be preset values. Both the preset temperature threshold and preset humidity threshold can be set to values ​​approximately equal to 0.

[0133] In specific implementation, for example, the preset temperature threshold, preset humidity threshold and first preset difference threshold are 0. When the fresh air unit is running in cooling mode and the outdoor fresh air enthalpy is greater than the indoor return air enthalpy, the indoor air temperature and air humidity are obtained. When the air temperature is less than or equal to the set temperature and / or the air humidity is less than or equal to the set humidity, the state of the air valve is controlled so that the fresh air unit operates in external circulation mode.

[0134] Furthermore, in order to ensure that the indoor air quality meets the preset standard when the fresh air unit is operating in internal circulation mode, thereby improving the user experience, the adjustment module 20 is also used to acquire indoor air quality data when the temperature difference is greater than a preset temperature threshold and the humidity difference is greater than a preset humidity threshold; and to control the bypass ventilation valve to open when the indoor air quality data meets the preset standard, so that the fresh air unit operates in internal circulation mode.

[0135] It is understandable that air quality data includes carbon dioxide concentration, formaldehyde concentration, and nitrogen dioxide concentration, etc.; the preset standard can be the standard data of the above air quality data, or it can be the standard set by the user.

[0136] It should be noted that in this embodiment, the indoor air temperature, air humidity and air quality data can be judged first, and then the circulation mode of the fresh air unit can be controlled according to the relationship between the outdoor fresh air enthalpy value and the indoor return air enthalpy value. That is, there is no order to the above steps.

[0137] This embodiment acquires the air enthalpy value of the space where the fresh air unit is located and the current operating mode of the fresh air unit; based on the current operating mode and the air enthalpy value, it adjusts the status of the supply air valve, the exhaust air valve, and / or the bypass ventilation valve to regulate the circulation mode of the fresh air unit. This allows for intelligent adjustment of the fresh air unit's circulation mode based on its current operating mode and the air enthalpy value, improving the accuracy of circulation mode control while enhancing the user experience.

[0138] Other embodiments or specific implementations of the circulation mode control device for the fresh air unit of the present invention can be referred to the above-described method embodiments, and will not be repeated here.

[0139] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0140] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0141] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as read-only memory / random access memory, magnetic disk, optical disk) and includes several instructions to cause a terminal fresh air unit (which may be a mobile phone, computer, server, fresh air unit, or network fresh air unit, etc.) to execute the methods described in the various embodiments of the present invention.

[0142] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A method for controlling the circulation mode of a fresh air unit, characterized in that, The fresh air duct of the fresh air unit is equipped with an air supply valve, the exhaust duct is equipped with an exhaust valve, and a bypass ventilation valve is installed between the fresh air duct and the exhaust duct. The circulation mode control method of the fresh air unit includes: Obtain the air enthalpy value of the space where the fresh air unit is located and the current operating mode of the fresh air unit; and, The states of the supply air valve, the exhaust air valve, and / or the bypass ventilation valve are adjusted according to the current operating mode and the air enthalpy value to regulate the circulation mode of the fresh air unit. The fresh air unit includes a first heat exchange system and a second heat exchange system. The air enthalpy value includes the inlet air enthalpy value, the outlet air enthalpy value, the indoor return air enthalpy value, and the outdoor fresh air enthalpy value. The current operating mode includes a first current operating mode of the first heat exchange system and a second current operating mode of the second heat exchange system. The step of adjusting the status of the supply air valve, the exhaust air valve, and / or the bypass ventilation valve according to the current operating mode and the air enthalpy value to regulate the circulation mode of the fresh air unit includes: The system obtains a first enthalpy difference between the outdoor fresh air enthalpy and the indoor return air enthalpy; when both the first current operating mode and the second current operating mode are in cooling mode and the first enthalpy difference is less than a first preset difference threshold, it controls the supply air valve and the exhaust air valve to open and controls the bypass ventilation valve to close, so that the fresh air unit operates in external circulation mode; when both the first current operating mode and the second current operating mode are in heating mode and the first enthalpy difference is greater than or equal to a second preset difference threshold, it controls the supply air valve and the exhaust air valve to open and controls the bypass ventilation valve to close, so that the fresh air unit operates in external circulation mode. When the first current operating mode and the second current operating mode are inconsistent, or when both the first current operating mode and the second current operating mode are dehumidification and reheat modes, it is determined whether the outlet air enthalpy is greater than the inlet air enthalpy; if so, when the outdoor fresh air enthalpy is greater than or equal to the indoor return air enthalpy, the supply air valve and the exhaust air valve are controlled to open, and the bypass ventilation valve is controlled to close, so that the fresh air unit operates in external circulation mode.

2. The method as described in claim 1, characterized in that, After obtaining the first enthalpy difference between the outdoor fresh air enthalpy value and the indoor return air enthalpy value, the method further includes: When the current operating mode is cooling mode and the first enthalpy difference is greater than or equal to the first preset difference threshold, the air temperature and air humidity in the space where the indoor unit of the fresh air unit is located are obtained; The temperature difference between the air temperature and the set temperature and the humidity difference between the air humidity and the set humidity are obtained; When the temperature difference is less than or equal to a preset temperature threshold or the humidity difference is less than or equal to a preset humidity threshold, the supply air valve and the exhaust air valve are opened, and the bypass ventilation valve is closed, so that the fresh air unit operates in external circulation mode.

3. The method as described in claim 2, characterized in that, After obtaining the temperature difference between the air temperature and the set temperature and the humidity difference between the air humidity and the set humidity, the method further includes: Indoor air quality data is acquired when the temperature difference is greater than a preset temperature threshold and the humidity difference is greater than a preset humidity threshold. When the indoor air quality data meets the preset standard, the bypass ventilation valve is opened to allow the fresh air unit to operate in internal circulation mode.

4. The method as described in claim 1, characterized in that, After obtaining the first enthalpy difference between the outdoor fresh air enthalpy value and the indoor return air enthalpy value, the method further includes: When the current operating mode is heating mode and the first enthalpy difference is less than the first preset difference threshold, the air temperature and air humidity in the space where the indoor unit of the fresh air unit is located are obtained; The temperature difference between the air temperature and the set temperature and the humidity difference between the air humidity and the set humidity are obtained; When the temperature difference is greater than a preset temperature threshold and the humidity difference is greater than a preset humidity threshold, the air quality data of the space where the indoor unit of the fresh air unit is located is obtained. When the indoor air quality data meets the preset standard, the bypass ventilation valve is opened to allow the fresh air unit to operate in internal circulation mode.

5. The method as described in claim 1, characterized in that, After determining whether the outlet enthalpy is greater than the inlet enthalpy, the method further includes: If not, when the outdoor fresh air enthalpy is less than or equal to the indoor return air enthalpy, the supply air valve and the exhaust air valve are opened, and the bypass ventilation valve is closed, so that the fresh air unit operates in external circulation mode.

6. A circulation mode control device for a fresh air unit, characterized in that, The fresh air duct of the fresh air unit is equipped with an air supply valve, the exhaust duct is equipped with an exhaust valve, and a bypass ventilation valve is installed between the fresh air duct and the exhaust duct. The circulation mode control device for the fresh air unit includes: The acquisition module is used to acquire the air enthalpy value of the space where the fresh air unit is located and the current operating mode of the fresh air unit; and, The adjustment module is used to adjust the status of the air supply valve, the exhaust valve and / or the bypass ventilation valve according to the current operating mode and the air enthalpy value, so as to adjust the circulation mode of the fresh air unit; The fresh air unit includes a first heat exchange system and a second heat exchange system. The air enthalpy value includes the inlet air enthalpy value, the outlet air enthalpy value, the indoor return air enthalpy value, and the outdoor fresh air enthalpy value. The current operating mode includes a first current operating mode of the first heat exchange system and a second current operating mode of the second heat exchange system. The adjustment module is further configured to obtain a first enthalpy difference between the outdoor fresh air enthalpy and the indoor return air enthalpy; when both the first current operating mode and the second current operating mode are cooling modes and the first enthalpy difference is less than a first preset difference threshold, the module controls the supply air valve and the exhaust air valve to open and controls the bypass ventilation valve to close, so that the fresh air unit operates in external circulation mode; when both the first current operating mode and the second current operating mode are heating modes and the first enthalpy difference is greater than or equal to a second preset difference threshold, the module controls the supply air valve and the exhaust air valve to open and controls the bypass ventilation valve to close, so that the fresh air unit operates in external circulation mode. The adjustment module is further configured to determine whether the outlet enthalpy is greater than the inlet enthalpy when the first current operating mode and the second current operating mode are inconsistent or both the first current operating mode and the second current operating mode are dehumidification and reheat modes; if so, when the outdoor fresh air enthalpy is greater than or equal to the indoor return air enthalpy, control the supply air valve and the exhaust air valve to open, and control the bypass ventilation valve to close, so that the fresh air unit operates in external circulation mode.

7. A fresh air ventilator, characterized in that, The fresh air unit includes: a memory, a processor, and a circulating mode control program for the fresh air unit stored in the memory and executable on the processor, the circulating mode control program for the fresh air unit being configured to implement the steps of the circulating mode control method for the fresh air unit as described in any one of claims 1 to 5.

8. A storage medium, characterized in that, The storage medium stores a circulation mode control program for the fresh air unit, which, when executed by a processor, implements the steps of the circulation mode control method for the fresh air unit as described in any one of claims 1 to 5.

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