Fresh air dehumidifier and its control method

Abstract

This application discloses a fresh air dehumidifier, comprising: a first adsorption unit and a second adsorption unit; a first main heat exchanger and a second main heat exchanger, wherein one of them serves as the main evaporator and the other as the main condenser; a first auxiliary heat exchanger located on the air outlet side of the first adsorption unit, serving as an auxiliary evaporator or an auxiliary condenser; a second auxiliary heat exchanger located on the air outlet side of the second adsorption unit, serving as an auxiliary evaporator or an auxiliary condenser; and a controller, configured to connect the first main heat exchanger, the second main heat exchanger, and the auxiliary evaporator in a cooling dehumidification mode when the supply air temperature is higher than the set temperature, provided that the absolute value of the indoor and outdoor air temperature difference is not less than a first preset temperature tolerance value; and in a heating humidification mode when the supply air temperature is lower than the set temperature. This fresh air dehumidifier can improve system energy efficiency.

Description

Technical Field

[0001] This application relates to the field of air treatment technology, and in particular to a fresh air dehumidifier and its control method. Background Technology

[0002] Fresh air dehumidifiers are mainly used to introduce conditioned fresh air into a room. They typically have two air ducts: one for exhaust and the other for supply. During summer dehumidification, fresh air is cooled by the evaporator, and the moisture it carries is adsorbed onto the absorbent material, thus dehumidifying the fresh air. Under certain conditions, the air ducts are switched, and the evaporator becomes a condenser. Indoor return air is heated by the condenser, which then dries out the moisture inside the absorbent material and carries it away. During winter humidification, the principle is reversed: indoor return air is cooled by the evaporator, and the moisture it carries is adsorbed onto the absorbent material for storage. Under certain conditions, the air ducts are switched, and the evaporator becomes a condenser. Fresh air is heated by the condenser, which dries out the moisture on the absorbent material and sends it into the room, thus humidifying the fresh air.

[0003] Outdoor air temperature changes after passing through the adsorption material, which reduces system energy efficiency. Summary of the Invention

[0004] This application provides a fresh air dehumidifier that can improve system energy efficiency and ensure that the heat and humidity load of fresh air is within a comfortable range.

[0005] In one aspect of this application, a fresh air dehumidifier includes: a first adsorption unit and a second adsorption unit, each having a moisture adsorbent, wherein one of the first adsorption unit and the second adsorption unit is used to adsorb moisture, and the other is used to regenerate the adsorbent; an airflow switching device for switching the air flowing through the first adsorption unit and the air flowing through the second adsorption unit; and a refrigerant circuit including: a compressor, an electronic expansion valve, a four-way valve, a heat exchanger, and a valve switch; the valve switch is used to control the connection or disconnection of the heat exchanger in the refrigerant circuit.

[0006] The heat exchanger includes: a first main heat exchanger located on the windward side of the first adsorption unit; a second main heat exchanger located on the windward side of the second adsorption unit, wherein when one of the second main heat exchanger and the first main heat exchanger functions as the main evaporator, the other functions as the main condenser; a first auxiliary heat exchanger located on the air outlet side of the first adsorption unit, wherein when the first auxiliary heat exchanger functions as the auxiliary evaporator, the first main heat exchanger functions as the main evaporator, and when the first auxiliary heat exchanger functions as the auxiliary condenser, the first main heat exchanger functions as the main condenser; and a second auxiliary heat exchanger located on the air outlet side of the second adsorption unit, wherein when one of the second auxiliary heat exchanger and the first auxiliary heat exchanger functions as the auxiliary evaporator, the other functions as the auxiliary condenser.

[0007] It also includes: an outdoor temperature and humidity detection device for detecting the temperature and humidity of outdoor air; an indoor temperature and humidity detection device for detecting the temperature and humidity of indoor air; and an outdoor supply air temperature and humidity detection device for detecting the temperature and humidity of fresh air supply.

[0008] The fresh air dehumidifier can operate in at least one of the following modes: cooling dehumidification mode and heating humidification mode;

[0009] The controller of the fresh air dehumidifier is used to ensure that the absolute value of the temperature difference between indoor and outdoor air is not less than a first preset temperature tolerance value.

[0010] In the cooling and dehumidification mode, when the supply air temperature is higher than the set temperature, the first main heat exchanger, the second main heat exchanger and the auxiliary evaporator are connected.

[0011] In heating and humidification mode, when the supply air temperature is lower than the set temperature, the first main heat exchanger, the second main heat exchanger, and the auxiliary condenser are connected.

[0012] In some embodiments, the heat exchange area of ​​the first auxiliary heat exchanger is smaller than that of the first main heat exchanger, and the heat exchange area of ​​the second auxiliary heat exchanger is smaller than that of the second main heat exchanger.

[0013] The controller is used to control the on / off state of the heat exchangers when the absolute value of the temperature difference between indoor and outdoor air is less than the first preset temperature tolerance value: connecting the first auxiliary heat exchanger and the second auxiliary heat exchanger, and disconnecting the first main heat exchanger and the second main heat exchanger.

[0014] In some embodiments, the controller is configured to: control the compressor to reduce its frequency when the absolute value of the indoor and outdoor air temperature difference is less than a first preset temperature tolerance value.

[0015] In some embodiments, the controller is configured to: compare the supply air temperature with the set temperature after the control step of switching the heat exchanger on and off.

[0016] In cooling and dehumidification mode, when the supply air temperature is higher than the set temperature, the opening of the electronic expansion valve is reduced; when the supply air temperature is lower than the set temperature, the opening of the electronic expansion valve is increased.

[0017] In heating and humidification mode, when the supply air temperature is higher than the set temperature, the opening of the electronic expansion valve is increased; when the supply air temperature is lower than the set temperature, the opening of the electronic expansion valve is decreased.

[0018] In some embodiments, the controller is configured to: in cooling and dehumidifying mode, when the supply air temperature is equal to the set temperature, determine whether the exhaust air temperature is less than the preset value for heat recovery; if not, then connect the auxiliary condenser.

[0019] In some embodiments, the controller is configured to: when the supply air temperature is equal to the set temperature, determine whether the supply air humidity is equal to the set humidity; if not, adjust the frequency of the compressor.

[0020] If the supply air humidity is still not equal to the set humidity after adjusting the compressor frequency, then adjust the opening of the electronic expansion valve.

[0021] If the supply air humidity is still not equal to the set humidity after adjusting the opening of the electronic expansion valve, then adjust the air volume.

[0022] In some embodiments, the controller is configured to: in air conditioning mode, when the absolute value of the indoor and outdoor air temperature difference is not greater than a second preset temperature tolerance value, connect the first auxiliary heat exchanger and the second auxiliary heat exchanger, and disconnect the first main heat exchanger and the second main heat exchanger.

[0023] When the absolute value of the temperature difference between indoor and outdoor air is greater than the third preset temperature tolerance value, the first main heat exchanger, the second main heat exchanger, the first auxiliary heat exchanger, and the second auxiliary heat exchanger are all connected.

[0024] When the absolute value of the temperature difference between indoor and outdoor air is greater than the second preset temperature tolerance value but not greater than the third preset temperature tolerance value, the first main heat exchanger and the second main heat exchanger are connected, and the first auxiliary heat exchanger and the second auxiliary heat exchanger are disconnected.

[0025] In some embodiments, the controller is configured to: in automatic mode, when the set humidity is between the outdoor air humidity and the indoor air humidity and the absolute value of the difference between the indoor and outdoor air humidity is less than a preset humidity tolerance value, and the set temperature is between the outdoor air temperature and the indoor air temperature and the absolute value of the difference between the indoor and outdoor air temperatures is less than a first preset temperature tolerance value, operate a full heat exchange mode.

[0026] When the set humidity is between the outdoor air humidity and the indoor air humidity, and the absolute value of the difference between the indoor and outdoor air humidity is less than the preset humidity tolerance value, and the set temperature is not between the outdoor air temperature and the indoor air temperature, the air conditioning mode is activated.

[0027] When the set humidity is not between the outdoor and indoor air humidity, the humidity adjustment mode will be activated.

[0028] In some embodiments, when the set temperature is between the outdoor air temperature and the indoor air temperature and the absolute value of the difference between the indoor and outdoor air temperatures is less than the first preset temperature tolerance value, and the indoor and outdoor air humidity is greater than the set humidity, the cooling and dehumidification mode is operated.

[0029] When the set temperature is between the outdoor air temperature and the indoor air temperature, and the absolute value of the temperature difference between the indoor and outdoor air is less than the first preset temperature tolerance value, and the indoor and outdoor air humidity is less than the set humidity, the heating and humidification mode is activated.

[0030] Another aspect of this application provides a control method for a fresh air dehumidifier, the fresh air dehumidifier comprising: a first adsorption unit and a second adsorption unit having a moisture adsorbent, one of the first adsorption unit and the second adsorption unit being used to adsorb moisture, and the other being used to regenerate the adsorbent; and an air switching device for switching the air flowing through the first adsorption unit and the air flowing through the second adsorption unit.

[0031] The refrigerant circuit includes: a compressor, an electronic expansion valve, and a four-way valve; and a main heat exchanger located on the windward side of the first adsorption unit.

[0032] The second main heat exchanger is located on the windward side of the second adsorption unit. When one of the second main heat exchanger and the first main heat exchanger functions as the main evaporator, the other functions as the main condenser. The first auxiliary heat exchanger is located on the air outlet side of the first adsorption unit. When the first auxiliary heat exchanger functions as the auxiliary evaporator, the first main heat exchanger functions as the main evaporator; when the first auxiliary heat exchanger functions as the auxiliary condenser, the first main heat exchanger functions as the main condenser. The second auxiliary heat exchanger is located on the air outlet side of the second adsorption unit. When one of the second auxiliary heat exchanger and the first auxiliary heat exchanger functions as the auxiliary evaporator, the other functions as the auxiliary condenser.

[0033] The fresh air dehumidifier can operate in at least one of the following modes: cooling dehumidification mode and heating humidification mode;

[0034] The control method includes: acquiring the indoor and outdoor air temperatures and the supply air temperature of the fresh air; in the cooling and dehumidification mode, when the supply air temperature is higher than the set temperature, connecting the first main heat exchanger, the second main heat exchanger, and the auxiliary evaporator; and in the heating and humidification mode, when the supply air temperature is lower than the set temperature, connecting the first main heat exchanger, the second main heat exchanger, and the auxiliary condenser. Attached Figure Description

[0035] Figure 1 A schematic diagram of a fresh air dehumidifier according to some embodiments is shown;

[0036] Figure 2 It shows Figure 1 A sectional view along the XX direction;

[0037] Figure 3 It shows Figure 1 Cross-sectional views of two states in the YY direction;

[0038] Figure 4 A schematic diagram of the refrigerant circuit of a fresh air dehumidifier according to some embodiments is shown;

[0039] Figure 5 A schematic diagram of a fresh air dehumidifier according to some other embodiments is shown;

[0040] Figure 6 A schematic diagram of the refrigerant circuit of a fresh air dehumidifier according to some other embodiments is shown;

[0041] Figure 7 A control block diagram of a fresh air dehumidifier according to some embodiments is shown;

[0042] Figure 8 A flowchart of a fresh air dehumidifier in air conditioning mode according to some embodiments is shown;

[0043] Figure 9 A flowchart of a fresh air dehumidifier in dehumidification mode according to some embodiments is shown;

[0044] Figure 10 A flowchart of a fresh air dehumidifier in automatic mode according to some embodiments is shown;

[0045] Figure 11 A flowchart of the fresh air dehumidifier in air conditioning mode according to some other embodiments is shown;

[0046] Figure 12 A flowchart of the fresh air dehumidifier in cooling and dehumidification mode according to some other embodiments is shown;

[0047] Figure 13 A flowchart of a fresh air dehumidifier in heating and humidification mode according to some other embodiments is shown. Detailed Implementation

[0048] To make the objectives and implementation methods of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the exemplary embodiments described are only some embodiments of this application, and not all embodiments.

[0049] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0050] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0051] Reference Figures 1 to 3 The fresh air dehumidifier according to the embodiments of this application includes a housing 100.

[0052] The casing 100 is equipped with a fresh air inlet OA, a fresh air supply outlet SA, a return air inlet RA, and a return air exhaust outlet EA. The fresh air inlet OA and the return air exhaust outlet EA are both connected to the outside, while the fresh air supply outlet SA and the return air inlet RA are both connected to the inside.

[0053] An air handling chamber is provided inside the housing 100, which is used to dehumidify or humidify fresh air.

[0054] The air handling chamber includes a first air handling chamber 121 and a second air handling chamber 122. The first air handling chamber is equipped with a first main heat exchanger 13 and a first adsorption unit 310, and the second air handling chamber 122 is equipped with a second main heat exchanger 14 and a second adsorption unit 320. The first main heat exchanger 13 is located in front of the first adsorption unit 310, and the second main heat exchanger 14 is located in front of the second adsorption unit 320.

[0055] It should be noted that "front" and "back" are relative concepts with reference to the direction of air flow. The place where the air flows first is the front, and the place where it flows last is the back. That is, the air in the first air handling chamber 121 flows through the first main heat exchanger 13 and the first adsorption unit 310 in sequence, and the air in the second air handling chamber 122 flows through the second main heat exchanger 14 and the second adsorption unit 320 in sequence.

[0056] The materials of the first adsorption unit 310 and the second adsorption unit 320 can be MOF polymers, silica gel, etc.

[0057] The air handling chamber is located in the middle of the housing 100. Ventilation switching devices are provided at the front and rear ends of the air handling chamber. These devices can switch between a first state and a second state. In the first state, the first air handling chamber 121 is connected to the fresh air inlet OA and the fresh air outlet SA, and the second air handling chamber 122 is connected to the return air inlet RA and the return air exhaust outlet EA. In the second state, the first air handling chamber 121 is connected to the return air inlet RA and the return air exhaust outlet EA, and the second air handling chamber 122 is connected to the fresh air inlet OA and the fresh air outlet SA.

[0058] It should be noted that the ventilation switching device is applicable to existing technology and will not be described in detail here.

[0059] Specifically, the ventilation switching device includes a front ventilation switching device 410 located at the front end and a rear ventilation switching device 420 located at the rear end.

[0060] The fresh air dehumidifier also includes a supply fan 210 and an exhaust fan 220. The supply fan 210 corresponds to the fresh air supply outlet SA setting, and the exhaust fan 220 corresponds to the return air exhaust outlet EA setting.

[0061] In the first state of the fresh air dehumidifier, under the action of the supply fan 210, outdoor air enters through the fresh air inlet OA, passes through the first main heat exchanger 13 and the first adsorption unit 310 in the first air handling chamber 121, and is finally delivered to the room through the fresh air outlet SA; under the action of the exhaust fan 220, indoor air enters through the return air inlet RA, passes through the second main heat exchanger 14 and the second adsorption unit 320 in the second air handling chamber 122, and is finally discharged to the outside through the return air outlet EA.

[0062] In the second state of the fresh air dehumidifier, under the action of the supply fan 210, outdoor air enters through the fresh air inlet OA, passes through the second main heat exchanger 14 and the second adsorption unit 320 in the second air handling chamber 122, and is finally delivered to the room through the fresh air supply outlet SA; under the action of the exhaust fan 220, indoor air enters through the return air inlet RA, passes through the first main heat exchanger 13 and the first adsorption unit 310 in the first air handling chamber 121, and is finally discharged to the outside through the return air exhaust outlet EA.

[0063] In some embodiments, the housing 100 also includes a heat recovery processing chamber 110. A total heat exchanger 500 is disposed within the heat recovery processing chamber 110 for exchanging heat between outdoor air and indoor air.

[0064] Specific reference Figure 2 The heat recovery processing chamber 110 is divided into four regions surrounding the total heat exchanger 500: a fresh air inlet zone 111 and a return air inlet zone 113 located at the front of the total heat exchanger 500, and a fresh air heat exchange zone 112 and a return air heat exchange zone 114 located at the rear of the total heat exchanger 500. The fresh air inlet OA is located on the side wall of the fresh air inlet zone 111, and the return air inlet RA is located on the side wall of the return air inlet zone 113.

[0065] Outdoor air enters the fresh air intake zone 111 through the fresh air inlet OA, and flows to the fresh air heat exchange zone 112 after passing through the total heat exchanger 500; indoor air enters the return air intake zone 113 through the return air inlet RA, and flows to the return air heat exchange zone 114 after passing through the total heat exchanger 500.

[0066] The heat recovery chamber 110 is located in front of the air handling chamber.

[0067] In the first state of the front ventilation switching device 410, the first air handling chamber 121 is connected to the fresh air heat exchange zone 112, and the second air handling chamber 122 is connected to the return air heat exchange zone 114; in the second state of the front ventilation switching device 410, the first air handling chamber 121 is connected to the return air heat exchange zone 114, and the second air handling chamber 122 is connected to the fresh air heat exchange zone 112.

[0068] Reference Figure 1 and Figure 4 In addition to the first main heat exchanger 13 and the second main heat exchanger 14, the refrigerant circuit also includes a compressor 11, a four-way valve 12 and an electronic expansion valve 15.

[0069] The exhaust port of compressor 11 is connected to the first port of four-way valve 12. The third port of four-way valve 12 is connected in series with gas-liquid separator 16 and then connected to the suction port of compressor 11. The second port of four-way valve 12 is connected in series with second main heat exchanger 14, electronic expansion valve 15 and first main heat exchanger 13 and then connected to the fourth port of four-way valve 12.

[0070] According to an embodiment of this application, the housing 100 is further provided with a compressor chamber 130 and an electrical chamber 140 on the front side of the heat recovery processing chamber 110. The compressor 11, the four-way valve 12 and the gas-liquid separator 16 are disposed in the compressor chamber 130, and the electrical control box of the fresh air dehumidifier is disposed in the electrical chamber 140.

[0071] In other embodiments, refer to Figure 5 The air handling chamber is divided into a compressor chamber 130. The electrical control box is connected to the outer wall of the housing 100, which makes the fresh air dehumidifier more compact and smaller in size.

[0072] Continue to refer to Figure 4 The compressor 11 compresses the refrigerant; one of the first main heat exchanger 13 and the second main heat exchanger 14 performs heat exchange between indoor air and refrigerant, and the other performs heat exchange between outdoor air and refrigerant; the four-way valve 12 selectively guides the refrigerant compressed by the compressor 11 to the first main heat exchanger 13 or the second main heat exchanger 14 according to heating or cooling; the electronic expansion valve 15 reduces the pressure of the refrigerant; and the pressure separator 16 prevents unevaporated refrigerant from flowing to the compressor 11.

[0073] The four-way valve 12 can be switched to either the first state or the second state. In the first state, the exhaust port of the compressor 11 is connected to the second main heat exchanger 14, and the suction port of the compressor 11 is connected to the first main heat exchanger 13. That is, in the first state, the second main heat exchanger 14 functions as a condenser, and the first main heat exchanger 13 functions as an evaporator.

[0074] The first main heat exchanger 13 acts as an evaporator to regulate the air temperature at the adsorption end of the first adsorption unit 310. The first adsorption unit 310 absorbs water through the adsorption action of the adsorbent within it, thereby drying the air in the first air handling chamber 121. The second main heat exchanger 14 acts as a condenser to regulate the temperature at the regeneration end of the second adsorption unit 320. The second adsorption unit 320 causes water to evaporate from the adsorbent through the regeneration action of the adsorbent, thereby humidifying the air in the second air handling chamber 122.

[0075] In the second state of the four-way valve, the discharge port of compressor 11 is connected to the first main heat exchanger 13, and the suction port of compressor 11 is connected to the second main heat exchanger 14. That is, in the second state, the first main heat exchanger 13 functions as a condenser, and the second main heat exchanger 14 functions as an evaporator.

[0076] The second main heat exchanger 14 acts as an evaporator to regulate the air temperature at the adsorption end of the second adsorption unit 320. The second adsorption unit 320 absorbs water through the adsorption action of the adsorbent within it, thereby drying the air in the second air handling chamber 122. The first main heat exchanger 13 acts as a condenser to regulate the temperature at the regeneration end of the first adsorption unit 310. The first adsorption unit 310 causes water to evaporate from the adsorbent through the regeneration action of the adsorbent, thereby humidifying the air in the first air handling chamber 121.

[0077] The four-way valve 12 and the ventilation switching device periodically switch between the first and second states. Therefore, whenever the four-way valve 12 and the ventilation switching device switch, the functions of the first main heat exchanger 13 and the second main heat exchanger 14 are switched, the functions of the first adsorption unit 121 and the second adsorption unit 320 are switched, and the air in the first air treatment chamber 121 and the air in the second air treatment chamber 122 are switched. Thus, water absorption and discharge are repeated.

[0078] The air handling chamber is also equipped with a first auxiliary heat exchanger 17 and a second auxiliary heat exchanger 18. The first auxiliary heat exchanger 17 is located behind the first adsorption unit 310, that is, the first main heat exchanger 13 and the first auxiliary heat exchanger 17 are located on the front and rear sides of the first adsorption unit 310, respectively. The second auxiliary heat exchanger 18 is located behind the second adsorption unit 320, that is, the second main heat exchanger 14 and the second auxiliary heat exchanger 18 are located on the front and rear sides of the second adsorption unit 320, respectively.

[0079] In the refrigerant circuit, the first auxiliary heat exchanger 17 is connected in parallel across the two ends of the first main heat exchanger 13, and the second auxiliary heat exchanger 18 is connected in parallel across the two ends of the second main heat exchanger 14.

[0080] For ease of description, this application refers to the first main heat exchanger 13 and the second main heat exchanger 14 as the main evaporator and the one as the condenser as the main condenser; and to the first auxiliary heat exchanger 17 and the second auxiliary heat exchanger 18 as the auxiliary evaporator and the one as the condenser as the auxiliary condenser.

[0081] In some embodiments, the refrigerant circuit further includes a valve switch for controlling the on / off state of the heat exchanger in the refrigerant circuit.

[0082] Specifically, the valve switch may include a first auxiliary valve switch 171 and a second auxiliary valve switch 181. The valve switch may be a solenoid valve.

[0083] The first auxiliary valve switch 171 is connected in series in the branch where the first auxiliary heat exchanger 17 is located. When the first auxiliary valve switch 171 is connected, the branch where the first auxiliary heat exchanger 17 is located is connected, that is, the first auxiliary heat exchanger 17 is connected in the refrigerant circuit; when the first auxiliary valve switch 171 is disconnected, the branch where the first auxiliary heat exchanger 17 is located is not connected, that is, the first auxiliary heat exchanger 17 is not connected in the refrigerant circuit.

[0084] The second auxiliary valve switch 181 is connected in series in the branch where the second auxiliary heat exchanger 18 is located. When the second auxiliary valve switch 181 is closed, the branch where the second auxiliary heat exchanger 18 is located is connected, that is, the second auxiliary heat exchanger 18 is connected in the refrigerant circuit. When the second auxiliary valve switch 181 is open, the branch where the second auxiliary heat exchanger 18 is located is not connected, that is, the second auxiliary heat exchanger 18 is not connected in the refrigerant circuit.

[0085] The following describes the working modes of the fresh air dehumidifier.

[0086] The fresh air dehumidifier can operate in total heat exchange mode, air conditioning cooling / heating mode, and cooling dehumidification / heating humidification mode.

[0087] [Total Heat Exchange Mode]

[0088] This mode is mainly used when the indoor and outdoor temperatures and humidity are not much different, and the outdoor temperature and humidity are in the comfort zone.

[0089] In this mode, the refrigerant circuit stops, the adsorption unit does not function, only the total heat exchanger 500 functions, the ventilation switching device switches from the initial state to the given state, and the fresh air dehumidifier supplies outdoor air to the room and exhausts indoor air to the outside.

[0090] The ventilation switching device is initially in a half-open state, and the given state can be, for example, the first state.

[0091] [Air Conditioner Cooling Mode]

[0092] This mode is mainly used when the outdoor temperature is higher than the indoor temperature and the indoor latent heat load is not large.

[0093] In this mode, the ventilation switching device is in a given state, such as the first state, where the refrigerant circuit is running, the fresh air dehumidifier cools the outdoor air and supplies it to the room, and heats the indoor air and discharges it to the outside.

[0094] In the refrigerant circuit, the four-way valve is in a given state, such as the first state, with the first auxiliary valve switch 171 and the second auxiliary valve switch 181 open. The compressor 11 compresses the refrigerant to a high pressure, and as the refrigerant is compressed, its pressure and temperature increase. The compressed refrigerant is guided to the second main heat exchanger 14 through the four-way valve 12, where it is condensed. Simultaneously, heat exchange occurs between the refrigerant and the indoor air in the second air handling chamber. The refrigerant pressure is reduced through the electronic expansion valve 15, and its temperature decreases. The depressurized liquid refrigerant is evaporated through the first main heat exchanger 14, and heat exchange occurs between the refrigerant and the outdoor air in the first air handling chamber during evaporation. The second main heat exchanger 14 acts as the main condenser, heating the indoor air in the second air handling chamber, while the first main heat exchanger 14 acts as the main evaporator, cooling the outdoor air in the first air handling chamber.

[0095] [Air Conditioner Heating Mode]

[0096] This mode is mainly used when the outdoor temperature is lower than the indoor temperature and the indoor latent heat load is not large.

[0097] In this mode, the ventilation switching device is in a given state, such as the first state, the refrigerant circuit is running, the fresh air dehumidifier heats the outdoor air and supplies it to the room, and cools the indoor air and exhausts it to the outside.

[0098] In the refrigerant circuit, the four-way valve is in a different state than during cooling, for example, in a second state. The first auxiliary valve switch 171 and the second auxiliary valve switch 181 are open, and the compressor 11 compresses the refrigerant to high pressure. As the refrigerant is compressed, its pressure and temperature increase. The compressed refrigerant is guided to the first main heat exchanger 13 through the four-way valve 12, where it is condensed. Simultaneously, heat exchange occurs between the refrigerant and the outdoor air in the first air handling chamber. The refrigerant pressure is reduced through the electronic expansion valve 15, and its temperature decreases. The reduced-pressure liquid refrigerant is evaporated through the second main heat exchanger 14, and heat exchange occurs between the refrigerant and the indoor air in the second air handling chamber during evaporation. The second main heat exchanger 14 acts as the main evaporator, cooling the indoor air in the second air handling chamber, while the first main heat exchanger 14 acts as the main condenser, heating the outdoor air in the first air handling chamber.

[0099] [Cooling and Dehumidifying Mode]

[0100] This mode is mainly used in situations where there is a high temperature and humidity difference and refrigeration and dehumidification are required.

[0101] In this mode, the total heat exchanger 500, refrigerant circuit, and adsorption unit all function, thus accompanied by the periodic switching of the four-way valve 12 and the ventilation switching device:

[0102] In the first half of a single cycle, the four-way valve 12 and the ventilation switching device are in the first state. The first main heat exchanger 13 acts as the main evaporator to cool the outdoor air, and the first adsorption unit 310 absorbs moisture to dehumidify the outdoor air. The cooled and dehumidified outdoor air is then supplied to the indoor air. The second main heat exchanger 14 acts as the main condenser to heat the indoor air. When the high-temperature air passes through the second adsorption unit 320, the water-containing adsorbent in the second adsorption unit 320 is regenerated. Thus, the water contained in the adsorbent is transferred to the indoor air, and the indoor air is discharged to the outside.

[0103] In the latter half of a single cycle, the four-way valve 12 and the ventilation switching device are in the second state. The second main heat exchanger 14 acts as the main evaporator to cool the outdoor air, and the second adsorption unit 320 absorbs moisture to dehumidify the outdoor air. The cooled and dehumidified outdoor air is then supplied to the indoor air. The first main heat exchanger 13 acts as the main condenser to heat the indoor air. When the high-temperature air passes through the first adsorption unit 310, the water-containing adsorbent in the first adsorption unit 310 is regenerated. Thus, the water contained in the adsorbent is transferred to the indoor air, and the indoor air is discharged to the outside.

[0104] In this mode, the heat exchanger has three working modes depending on different environmental conditions. In the first mode, both the first auxiliary valve switch 171 and the second auxiliary valve switch 181 are open, the first auxiliary heat exchanger 17 and the second auxiliary heat exchanger 18 do not work, and only the first main heat exchanger 13 and the second main heat exchanger 14 work. The refrigerant circuit is the same as the air conditioning cooling mode in the first half of a single cycle and the same as the air conditioning heating mode in the second half of a single cycle.

[0105] The second configuration involves the operation of the first main heat exchanger 13 and the second main heat exchanger 14, as well as the operation of the auxiliary evaporator located in the outdoor air flow path. The auxiliary evaporator can be used to regulate the supply air temperature. In the first half of a single cycle, the refrigerant circuit operates as follows: compressor 11 → four-way valve 12 → second main heat exchanger 14 → electronic expansion valve 15 → first auxiliary heat exchanger 17 and first main heat exchanger 13 → gas-liquid separator 16 → compressor 11. In the second half of a single cycle, the refrigerant circuit operates as follows: compressor 11 → four-way valve 12 → first main heat exchanger 13 → electronic expansion valve 15 → second auxiliary heat exchanger 18 and second main heat exchanger 14 → gas-liquid separator 16 → compressor 11.

[0106] The third configuration involves the operation of the first main heat exchanger 13, the second main heat exchanger 14, and the auxiliary condenser located in the indoor air flow path. The auxiliary condenser can be used to recover heat from the indoor air. In the first half of a single refrigerant cycle, the refrigerant circuit operates as follows: compressor 11 → four-way valve 12 → second main heat exchanger 14 and second auxiliary heat exchanger 18 → electronic expansion valve 15 → first main heat exchanger 13 → gas-liquid separator 16 → compressor 11. In the second half of a single refrigerant cycle, the refrigerant circuit operates as follows: compressor 11 → four-way valve 12 → first main heat exchanger 13 and first auxiliary heat exchanger 17 → electronic expansion valve 15 → second main heat exchanger 14 → gas-liquid separator 16 → compressor 11.

[0107] [Heating and Humidification Mode]

[0108] This mode is mainly used in situations where there is a high temperature and humidity difference and heating and humidification are required.

[0109] In this mode, the total heat exchanger 500, refrigerant circuit, and adsorption unit all function, which is accompanied by the periodic switching of the four-way valve 12 and the ventilation switching device: in the first half of a single cycle, the four-way valve 12 is in the second state and the ventilation switching device is in the first state; in the second half of a single cycle, the four-way valve 12 is in the first state and the ventilation switching device is in the second state.

[0110] The main condenser heats the outdoor air, while the adsorption unit in the outdoor airflow path regenerates the water-containing adsorbent. This process introduces water from the adsorbent into the outdoor air, which is then supplied to the indoor unit. The main evaporator cools the indoor air, and the adsorption unit in the indoor airflow path absorbs moisture from the indoor air, thus removing water from the indoor air and expelling it outdoors. The water absorbed from the indoor air becomes the water used to humidify the outdoor air.

[0111] In this mode, the heat exchanger has two operating modes depending on different environmental conditions:

[0112] The first configuration: both the first auxiliary valve switch 171 and the second auxiliary valve switch 181 are open, the first auxiliary heat exchanger 17 and the second auxiliary heat exchanger 18 are not in operation, and only the first main heat exchanger 13 and the second main heat exchanger 14 are in operation; the refrigerant circuit is the same as the air conditioning heating mode in the first half of a single cycle, and the same as the air conditioning cooling mode in the second half of a single cycle.

[0113] The second configuration involves the operation of the first main heat exchanger 13, the second main heat exchanger 14, and the auxiliary condenser located in the outdoor airflow path. The auxiliary condenser can be used to regulate the supply air temperature. In the first half of a single cycle, the refrigerant circuit operates as follows: compressor 11 → four-way valve 12 → first main heat exchanger 13 and first auxiliary heat exchanger 17 → electronic expansion valve 15 → second main heat exchanger 14 → gas-liquid separator 16 → compressor 11. In the second half of a single cycle, the refrigerant circuit operates as follows: compressor 11 → four-way valve 12 → second main heat exchanger 14 and second auxiliary heat exchanger 18 → electronic expansion valve 15 → first main heat exchanger 13 → gas-liquid separator 16 → compressor 11.

[0114] Generally, the temperature difference between indoors and outdoors is not significant in spring and autumn, making it relatively comfortable; however, the temperature difference is greater in summer and winter. Therefore, total heat exchange mode is mostly used in spring and autumn, introducing fresh air into the room through a fresh air dehumidifier to improve indoor air quality.

[0115] Air conditioning cooling and cooling dehumidification modes are mostly used in summer. The difference between the two is that in air conditioning cooling mode, when the ambient humidity is comfortable, the fresh air dehumidifier only controls the operation based on the temperature; in cooling dehumidification mode, when the ambient humidity is uncomfortable, the fresh air dehumidifier controls the operation based on both the temperature and humidity.

[0116] Similarly, air conditioner heating and heating-humidification modes are mostly used in winter. The difference between the two is that in air conditioner heating mode, the ambient humidity is comfortable, and the fresh air dehumidifier only controls the operation based on temperature; in heating-humidification mode, the ambient humidity is uncomfortable, and the fresh air dehumidifier controls the operation based on both temperature and humidity.

[0117] The following text will describe the signal flow between the components contained in the fresh air dehumidifier.

[0118] Reference Figure 7 The fresh air dehumidifier includes a controller 600, a memory 610, an input unit 620, an outdoor temperature and humidity detection device 630, an indoor temperature and humidity detection device 640, and an indoor exhaust air temperature detection device 650.

[0119] The controller 600 is used to control the operation of the compressor 11, four-way valve 12, electronic expansion valve 15, valve switch, ventilation switching device, blower 210 and exhaust fan 220 according to different working modes.

[0120] The memory 610 is used to store programs and data related to the operation of the fresh air dehumidifier.

[0121] The input unit 620 is used to receive operation commands from the user regarding the fresh air dehumidifier.

[0122] The outdoor temperature and humidity detection device 630 is used to detect the outdoor air temperature Toa and humidity doa. The outdoor temperature and humidity detection device 630 can be installed at the fresh air inlet OA.

[0123] The indoor temperature and humidity detection device 640 is used to detect the indoor air temperature Toa and humidity doa, while the outdoor temperature and humidity detection device 630 can be installed at the return air inlet RA.

[0124] The outdoor air supply temperature and humidity detection device 650 is used to detect the temperature Tsa and humidity dsa of the outdoor air supply. The outdoor air supply temperature and humidity detection device 650 can be installed at the fresh air supply outlet SA.

[0125] The indoor exhaust air temperature detection device 660 is used to detect the temperature of the indoor exhaust air Tea. The outdoor exhaust air temperature detection device 660 can be installed at the return air exhaust vent EA.

[0126] The following details the steps for controlling a fresh air dehumidifier.

[0127] When the fresh air dehumidifier is started, the supply fan 210 and exhaust fan 220 are controlled to start at the preset default fan speed.

[0128] [Total Heat Exchange Mode]

[0129] Upon receiving the user's input of the total heat exchange mode, the compressor is kept off, and the ventilation switching device is in the first state.

[0130] [Air Conditioner Cooling Mode]

[0131] Reference Figure 8Upon receiving the user's input of the air conditioning cooling mode and set temperature Tset, the compressor is started, the first auxiliary valve switch 171 and the second auxiliary switch 181 are in the open state, and the four-way valve and ventilation switching device operate in the first state.

[0132] The steps for temperature adjustment are as follows: Compare the supply air temperature Tsa with the user-set temperature Tset. If they are equal, no change is required.

[0133] If Tsa > Tset, it indicates that the supply air temperature is higher than the user's desired temperature, requiring enhanced cooling. In this case, the compressor frequency is increased. The compressor frequency can be increased according to a first preset increment, for example, 3Hz. Increasing the compressor frequency improves the cooling effect, thus lowering the supply air temperature Tsa. After increasing the frequency, after a first preset time, Tsa and Tset are compared again. If Tsa is still greater than Tset, the opening of the electronic expansion valve 15 is reduced. Reducing the opening of the electronic expansion valve 15 lowers the evaporation temperature, thereby lowering the supply air temperature Tsa. After reducing the opening, after another first preset time, Tsa and Tset are compared again. If Tsa is still greater than Tset, the cycle returns to controlling the compressor frequency increase.

[0134] In other embodiments, when Tsa > Tset, the opening degree of the electronic expansion valve 15 can also be reduced directly.

[0135] If Tsa < Tset, it means the supply air temperature is lower than the user's desired temperature. The fresh air dehumidifier can reduce its cooling capacity, so the compressor frequency is controlled to decrease. The compressor can decrease its frequency according to the first preset reduction, for example, the first preset reduction is 3Hz. The compressor frequency reduction can reduce the cooling effect, causing the supply air temperature Tsa to rise. After the frequency reduction, after the first preset time, Tsa and Tset are compared again. If Tsa is still less than Tset, the opening of the electronic expansion valve 15 is increased. The increased opening of the electronic expansion valve 15 can increase the evaporation temperature, thereby increasing the supply air temperature Tsa. After the opening is increased, after the first preset time, Tsa and Tset are compared again. If Tsa is still less than Tset, the cycle of controlling the compressor frequency reduction continues.

[0136] [Air Conditioner Heating Mode]

[0137] When the fresh air dehumidifier starts, it controls the supply fan 210 and exhaust fan 220 to start at the preset default fan speed. Upon receiving the user's input of the air conditioning heating mode and set temperature Tset, it controls the compressor to start at the default frequency. The first auxiliary valve switch 171 and the second auxiliary switch 181 are in the open state, the four-way valve operates in the second state, and the ventilation switching device operates in the first state.

[0138] Temperature adjustment steps: Compare the supply air temperature Tsa with the user-set temperature Tset. If they are equal, no change is required.

[0139] If Tsa > Tset, it indicates that the supply air temperature is higher than the user's desired temperature. The fresh air dehumidifier can reduce its heating capacity, thus controlling the compressor to reduce its frequency. The compressor can reduce its frequency according to the first preset reduction. Reducing the compressor frequency can decrease the heating effect, causing the supply air temperature Tsa to decrease. After reducing the frequency, after the first preset time, Tsa and Tset are compared again. If Tsa is still greater than Tset, the opening of the electronic expansion valve 15 is increased. Increasing the opening of the electronic expansion valve 15 can reduce the condensing temperature, thereby reducing the supply air temperature Tsa. After increasing the opening, after the first preset time, Tsa and Tset are compared again. If Tsa is still greater than Tset, the cycle returns to controlling the compressor to reduce its frequency.

[0140] If Tsa < Tset, it indicates that the supply air temperature is lower than the user's desired temperature. The fresh air dehumidifier can increase its heating capacity, so the compressor frequency is increased. The compressor frequency can be increased according to the first preset increment. Increasing the compressor frequency can improve the heating effect, causing the supply air temperature Tsa to rise. After increasing the frequency, after the first preset time, Tsa and Tset are compared again. If Tsa is still less than Tset, the opening of the electronic expansion valve 15 is reduced. Reducing the opening of the electronic expansion valve 15 can increase the condensing temperature, thereby increasing the supply air temperature Tsa. After the opening is reduced, after the first preset time, Tsa and Tset are compared again. If Tsa is still less than Tset, the cycle of controlling the compressor frequency increase continues.

[0141] In some embodiments, the air conditioning cooling mode and the air conditioning heating mode can be combined into an air conditioning mode. When using the fresh air dehumidifier, the user can directly select the air conditioning mode, and then the fresh air dehumidifier will automatically determine whether to switch to cooling or heating.

[0142] Users can select the air conditioning mode when they perceive that the indoor air humidity does not need to be adjusted and they wish to adjust the fresh air temperature.

[0143] When the fresh air dehumidifier starts, it controls the supply fan 210 and exhaust fan 220 to start at the preset default fan speed. Upon receiving the air conditioning mode and set temperature Tset input by the user, it controls the compressor to start at the default frequency. The first auxiliary valve switch 171 and the second auxiliary switch 181 are in the off state.

[0144] The steps for determining whether to enter cooling or heating mode are as follows: The set temperature Tset is compared with the indoor and outdoor temperatures. When the set temperature is less than the indoor air temperature Tra and less than the outdoor air temperature Toa, i.e., Tset < min(Toa, Tra), the air conditioner automatically enters the cooling mode and controls the four-way valve and ventilation switching device to operate in the first state. When the set temperature is greater than the indoor air temperature Tra and greater than the outdoor air temperature Toa, i.e., Tset > max(Toa, Tra), the air conditioner automatically enters the heating mode and controls the four-way valve to operate in the second state, while the ventilation switching device operates in the first state.

[0145] [Cooling and Dehumidifying Mode]

[0146] Reference Figure 9 When the fresh air dehumidifier starts, it controls the supply fan 210 and exhaust fan 220 to start at the preset default fan speed. It receives the cooling and dehumidification mode input by the user and the user's set temperature Tset and set humidity dset, and controls the compressor to start at the default frequency. The first auxiliary valve switch 171 and the second auxiliary switch 181 remain in the default open state. The four-way valve and ventilation switching device first operate in the first state, and then switch states according to the preset cycle.

[0147] The steps for temperature adjustment are as follows: Compare the supply air temperature Tsa with the user-set temperature Tset.

[0148] If Tsa > Tset, it means that the supply air temperature is higher than the user's expected temperature and the cooling needs to be strengthened. In this case, reduce the opening of the electronic expansion valve 15 to connect the auxiliary switch controlling the auxiliary evaporator.

[0149] The opening of the electronic expansion valve 15 is reduced, which can lower the evaporation temperature and thus lower the supply air temperature Tsa. After the opening is reduced, Tsa and Tset are compared again after a second preset time. If Tsa is still greater than Tset, the opening of the electronic expansion valve 15 is further reduced.

[0150] When the four-way valve 12 is in the first state, the first auxiliary valve switch 171 is connected, connecting the first auxiliary heat exchanger 17 in the refrigerant circuit, whereby the first auxiliary heat exchanger 17 acts as an auxiliary evaporator. When the four-way valve 12 is in the second state, the second auxiliary valve switch 181 is connected, connecting the second auxiliary heat exchanger 17 in the refrigerant circuit, whereby the second auxiliary heat exchanger 18 acts as an auxiliary evaporator. After the outdoor air passes through the adsorption unit to absorb moisture, its temperature will rise slightly. Then, after passing through the auxiliary evaporator, the outdoor air supply temperature Tsa can be reduced, thereby further reducing Tsa.

[0151] The states of the first auxiliary valve switch 171 and the second auxiliary valve switch 181 correspond to the states of the four-way valve. That is, the first state of the four-way valve 12 corresponds to the first auxiliary valve switch 171 being connected and the second auxiliary valve switch 181 being disconnected; the second state of the four-way valve 12 corresponds to the second auxiliary valve switch 181 being connected and the first auxiliary valve switch 171 being disconnected.

[0152] According to an embodiment of this application, when the supply air temperature Tsa needs to be reduced, connecting the auxiliary evaporator in the refrigerant circuit can accelerate the reduction of the supply air temperature Tsa, so as to meet the requirements of the supply air temperature as soon as possible and improve the unit's energy efficiency.

[0153] In addition, since the on / off state of the heat exchanger will not change in the subsequent humidity adjustment steps, the auxiliary condenser does not work here because it diverts some refrigerant, which weakens the regeneration heat of the main condenser. Keeping the auxiliary condenser off and not working allows all the refrigerant to flow through the main condenser, thereby improving the regeneration effect of the main condenser. The adsorbent can absorb moisture better, improving the dehumidification effect.

[0154] If Tsa < Tset, it indicates that the supply air temperature is lower than the user's desired temperature. The fresh air dehumidifier can reduce its cooling capacity, so the opening of the electronic expansion valve 15 is increased, while the first auxiliary valve switch 171 and the second auxiliary valve switch 181 remain open. Increasing the opening of the electronic expansion valve 15 can raise the evaporation temperature, thereby increasing the supply air temperature Tsa. After the opening is increased, after a first preset time, Tsa and Tset are compared again. If Tsa is still less than Tset, the opening of the electronic expansion valve 15 is further increased.

[0155] If Tsa = Tset, then proceed to the step of determining the indoor exhaust air temperature Tea: determine whether Tea is less than the preset value for heat recovery. If yes, then the valve controlling the auxiliary condenser is opened; if not, then the valve controlling the auxiliary condenser is opened, thus connecting the auxiliary condenser in the refrigerant circuit. The connection of the auxiliary condenser enables heat recovery, prevents the condenser temperature from becoming too high, and reduces excessive heat discharge to the outside.

[0156] After determining the indoor exhaust temperature Tea, proceed to the humidity adjustment step: compare the supply air humidity dsa with the set humidity dset;

[0157] If dsa = dset, then no changes need to be made to the compressor, electronic expansion valve, and fan.

[0158] If dsa > dset, it indicates that the supply air humidity dsa is relatively high, requiring enhanced dehumidification. In this case, the compressor frequency is increased, with the compressor increasing its frequency according to a second preset increment, for example, 5Hz. Increasing the compressor frequency improves dehumidification, reducing the supply air humidity dsa. After increasing the frequency, after a second preset time, dsa and dset are compared again. If dsa is still greater than dset, the opening of the electronic expansion valve 15 is reduced. After the opening is reduced, after another second preset time, dsa and dset are compared again. If dsa is still greater than dset, the speed of the supply and exhaust fans is reduced, resulting in a decrease in airflow. For example, after the fan speed is reduced, the airflow decreases by 3% each time. After the airflow decreases, after another second preset time, dsa and dset are compared again. If dsa is still greater than dset, the cycle returns to the compressor frequency increase step.

[0159] If dsa < dset, it indicates that the supply air humidity dsa is relatively low, and the dehumidification capacity can be reduced. In this case, the compressor frequency is controlled to decrease. The compressor can decrease the frequency according to the second preset reduction, for example, the second preset reduction is 5Hz. After the frequency decreases, after the second preset time, dsa and dset are compared again. If dsa is still less than dset, the opening of the electronic expansion valve 15 is increased. After the opening is increased, after the second preset time, dsa and dset are compared again. If dsa is still less than dset, the speed of the supply fan and exhaust fan is increased, so that the air volume increases. For example, after the fan speed is increased, the air volume increases by 3% each time. After the air volume increases, after the second preset time, dsa and dset are compared again. If dsa is still less than dset, the cycle returns to the step of compressor frequency reduction.

[0160] According to embodiments of this application, adjusting the compressor frequency, adjusting the opening of the electronic expansion valve, and adjusting the fan airflow all have progressively smaller effects on the supply air humidity dsa. In other words, adjusting the compressor frequency can cause a significant change in the supply air humidity dsa, adjusting the opening of the electronic expansion valve can cause a smaller change, and adjusting the fan airflow can cause the smallest change. Adjusting the supply air humidity dsa in the order of compressor frequency, electronic expansion valve opening, and fan airflow can improve the speed of supply air humidity dsa adjustment while avoiding energy waste caused by over-adjustment.

[0161] [Heating and Humidification Mode]

[0162] When the fresh air humidifier is started, the supply fan 210 and exhaust fan 220 are controlled to start at the preset default fan speed. The heating and humidification mode input by the user and the user's set temperature Tset and set humidity dset are received. The compressor is controlled to start at the default frequency. The first auxiliary valve switch 171 and the second auxiliary switch 181 are kept in the default open state. The four-way valve first operates in the second state, and the ventilation switching device first operates in the first state. Then, the four-way valve and the ventilation switching device switch states according to the preset cycle.

[0163] The steps to enter temperature adjustment are: compare the supply air temperature Tsa with the user-set temperature Tset;

[0164] If Tsa > Tset, it means the supply air temperature is higher than the user's desired temperature. The heating capacity can be reduced by increasing the opening of the electronic expansion valve 15, thus lowering the supply air temperature Tsa. After the opening is increased, after a second preset time, Tsa and Tset are compared again. If Tsa is still greater than Tset, the opening of the electronic expansion valve 15 is further increased.

[0165] If Tsa < Tset, it means that the supply air temperature is lower than the user's expected temperature. The fresh air dehumidifier can accelerate heating. Therefore, reduce the opening of the electronic expansion valve 15 and control the valve switch of the auxiliary condenser to connect so that the auxiliary condenser is connected in the refrigerant circuit.

[0166] The opening of the electronic expansion valve 15 decreases, causing the supply air temperature Tsa to increase. After the opening decreases, Tsa and Tset are compared again after a second preset time. If Tsa is still less than Tset, the opening of the electronic expansion valve 15 is further reduced.

[0167] The operation of the auxiliary condenser extends the heat exchange path and time of the outdoor air, increases the rate at which the supply air temperature rises, and enables the supply air temperature to quickly meet the requirements.

[0168] If Tsa = Tset, then proceed to the humidity adjustment step: compare the supply air humidity dsa with the set humidity dset.

[0169] If dsa = dset, then no changes need to be made to the compressor, electronic expansion valve, and fan.

[0170] If dsa > dset, it indicates that the supply air humidity dsa is relatively high, and the humidification intensity can be reduced. The compressor frequency is then controlled to decrease, and the compressor can reduce its frequency according to the second preset reduction, for example, 5Hz. The compressor frequency reduction lowers the supply air humidity dsa. After the frequency reduction, after a second preset time, dsa and dset are compared again. If dsa is still greater than dset, the opening of the electronic expansion valve 15 is increased. After the opening is increased, after another second preset time, dsa and dset are compared again. If dsa is still greater than dset, the speed of the supply and exhaust fans is increased, increasing the airflow. For example, after the fan speed is increased, the airflow increases by 3% each time. After the airflow increases, after another second preset time, dsa and dset are compared again. If dsa is still greater than dset, the cycle returns to the compressor frequency reduction step.

[0171] If dsa < dset, it indicates that the supply air humidity dsa is relatively low, and the humidification intensity can be increased. In this case, the compressor frequency is controlled to increase. The compressor can increase the frequency according to the second preset increment, for example, the second preset increment is 5Hz. After the frequency is increased, after the second preset time, dsa and dset are compared again. If dsa is still less than dset, the opening of the electronic expansion valve 15 is reduced. After the opening is reduced, after the second preset time, dsa and dset are compared again. If dsa is still less than dset, the speed of the supply fan and exhaust fan is reduced, so that the air volume is reduced. For example, after the fan speed is reduced, the air volume is reduced by 3% each time. After the air volume is reduced, after the second preset time, dsa and dset are compared again. If dsa is still less than dset, the cycle returns to the step of increasing the compressor frequency.

[0172] In some embodiments of this application, cooling dehumidification and heating humidification modes can be combined into a humidity adjustment mode. When the user selects the humidity adjustment mode, the fresh air dehumidifier can automatically determine whether to enter cooling dehumidification or heating humidification based on the temperature and humidity.

[0173] Specifically, after entering the humidity control mode, the following steps are taken to determine whether to perform cooling dehumidification or heating humidification:

[0174] When the set temperature Tset is lower than the indoor and outdoor air temperatures, or...

[0175] When the set temperature Tset is between the indoor and outdoor air temperatures and the absolute value of the indoor and outdoor air temperature difference is less than the first preset temperature tolerance value ΔT1, and the set humidity dset is less than the indoor and outdoor air humidity, the cooling and dehumidification mode is entered.

[0176] In other words, the cooling and dehumidification mode will be activated when any of the following conditions are met:

[0177] Condition 1: Tset < min(Toa, Tra);

[0178] Condition 2: Tset∈[min(Toa, Tra), max(Toa, Tra)]&|Toa-Tra|<ΔT1&dset<min(doa, dra).

[0179] When the set temperature Tset is greater than the indoor and outdoor air temperatures, or...

[0180] When the set temperature Tset is between the indoor and outdoor air temperatures and the absolute value of the indoor and outdoor air temperature difference is less than the first preset temperature tolerance value ΔT1, and the set humidity dset is greater than the indoor and outdoor air humidity, the heating and humidification mode is entered.

[0181] In other words, the heating and humidification mode will be activated when any of the following conditions are met:

[0182] Condition 1: Tset > max(Toa, Tra);

[0183] Condition 2: Tset∈[min(Toa, Tra), max(Toa, Tra)]&|Toa-Tra|<ΔT1&dset>max(doa, dra).

[0184] In this application, if the set temperature Tset is lower than the indoor and outdoor air temperature, it indicates that the ambient temperature is relatively high, and cooling and dehumidification are performed; if the set temperature Tset is higher than the indoor and outdoor air temperature, it indicates that the ambient temperature is relatively low, and heating and humidification are performed; if the indoor and outdoor temperature difference is not large, and the set temperature is within the range of the indoor and outdoor temperature difference, it indicates that the ambient temperature is relatively comfortable. In this case, the working mode is determined based on the humidity: if the set humidity dset is lower than the indoor and outdoor air humidity, it indicates that the ambient humidity is relatively high, and cooling and dehumidification are performed; if the set humidity dset is higher than the indoor and outdoor air humidity, it indicates that the ambient humidity is relatively low, and heating and humidification are performed.

[0185] In some embodiments of this application, reference is made to Figure 10 The fresh air dehumidifier has an automatic mode. When the user selects the automatic mode, the fresh air dehumidifier can automatically determine the working mode to enter based on the temperature and humidity.

[0186] Specifically, after entering automatic mode, when the set humidity dset is between the indoor and outdoor air humidity and the absolute value of the indoor and outdoor humidity difference is less than the preset humidity tolerance value Δd, and the set temperature Tset is between the indoor and outdoor air temperatures and the absolute value of the indoor and outdoor temperature difference is less than the first preset temperature tolerance value ΔT1, then the total heat exchange mode is entered.

[0187] In other words, dset∈[min(doa,dra),max(doa,dra)]&|doa-dra|<Δd&Tset∈[min(Toa,Tra),max(Toa,Tra)]&|Toa-Tra|<ΔT1. Under these conditions, it indicates that the temperature and humidity of the environment are relatively comfortable, and there is no need to adjust the temperature and humidity.

[0188] When the set humidity dset is between the indoor and outdoor humidity, and the absolute value of the difference between the indoor and outdoor humidity is less than the preset humidity tolerance value, and the set temperature Tset is not between the indoor and outdoor temperatures, the air conditioning mode is activated.

[0189] In other words, dset∈[min(doa,dra),max(doa,dra)]&|doa-dra|<Δd&[Tset<[min(Toa,Tra)|Tset>max(Toa,Tra)], under this condition, it means that the ambient humidity is relatively comfortable, and only the temperature needs to be adjusted to enter air conditioning mode.

[0190] Specifically, when dset∈[min(doa,dra),max(doa,dra)]&|doa-dra|<Δd&Tset<[min(Toa,Tra), the system enters the air conditioning cooling mode within the air conditioning mode; when dset∈[min(doa,dra),max(doa,dra)]&|doa-dra|<Δd&Tset>[max(Toa,Tra), the system enters the air conditioning heating mode within the air conditioning mode.

[0191] When the set humidity dset is less than the indoor and outdoor air humidity or greater than the indoor and outdoor air humidity, i.e. dset < min(doa, dra) | dset > max(doa, dra), the humidity adjustment mode is entered.

[0192] This application also provides another embodiment, in which reference is made to... Figure 6 In the refrigerant circuit, the branch containing the first main heat exchanger 13 is connected in series with the first main valve switch 131, and the branch containing the second main heat exchanger 14 is connected in series with the second main valve switch 141.

[0193] When the first main valve switch 131 is closed, the first main heat exchanger 13 is connected in the refrigerant circuit; when the first main valve switch 131 is open, the first main heat exchanger 13 is not connected in the refrigerant circuit. When the second main valve switch 141 is closed, the second main heat exchanger 14 is connected in the refrigerant circuit; when the second main valve switch 141 is open, the second main heat exchanger 14 is not connected in the refrigerant circuit.

[0194] Therefore, the fresh air dehumidifier can make the first main heat exchanger 13 work or not work by controlling the state of the first main valve switch 131, and can make the second main heat exchanger 14 work or not work by controlling the state of the second main valve switch 141.

[0195] The following describes the differences between the control of the fresh air dehumidifier in this embodiment and the above embodiments:

[0196] [Air Conditioning Mode]

[0197] Reference Figure 11 When the user inputs the air conditioning mode or the fresh air dehumidifier automatically enters the air conditioning mode, the supply fan and exhaust fan start at the default fan speed, the compressor starts, and the first main valve switch 141 and the second main valve switch 142 are connected, entering the on / off control steps of the heat exchanger: it is determined whether the absolute value of the indoor and outdoor temperature difference is greater than the second temperature tolerance value ΔT2, that is, it is determined that |Toa-Tra|>ΔT2. If not, it means that the indoor and outdoor temperature difference is relatively small and the sensible heat load is relatively low, so the first main valve switch 141 and the second main valve switch 142 are disconnected, the first auxiliary valve switch 171 and the second auxiliary valve switch 181 are connected, the auxiliary heat exchanger works, and the main heat exchanger does not work.

[0198] Since the sensible heat load in the environment is relatively low, and the heat exchange area of ​​the auxiliary heat exchanger is smaller than that of the main heat exchanger, only the auxiliary heat exchanger is working, which can operate at low load and avoid energy waste compared to the operation of the main heat exchanger.

[0199] Specifically, in the direction of airflow, the thickness of the auxiliary heat exchanger is smaller than that of the main heat exchanger, and the path of air through the auxiliary heat exchanger is shorter than that through the main heat exchanger.

[0200] If |Toa-Tra|>ΔT2 is true, then continue to determine whether the absolute value of the indoor and outdoor temperature difference is greater than the third temperature tolerance value ΔT3, i.e. |Toa-Tra|>ΔT3. If not, then keep the first main valve switch 141 and the second main valve switch 142 connected, and the first auxiliary valve switch 171 and the second auxiliary valve switch 181 disconnected. If yes, then the first main valve switch 141, the second main valve switch 142, the first auxiliary valve switch 171, and the second auxiliary valve switch 181 connected.

[0201] In this embodiment, when ΔT3 > ΔT2 and ΔT2 < |Toa-Tra| < ΔT3, the main valve is switched on and the auxiliary valve is switched off. That is to say, under this temperature condition, the heat load is in the middle, and the requirements can be met by adjusting the temperature by the main heat exchanger. If only the auxiliary heat exchanger works, it will take a long time to meet the temperature conditions.

[0202] When |Toa-Tra|>ΔT3, both the main valve switch and the auxiliary valve switch are connected. Under this temperature condition, the heat load is relatively large, and both the main heat exchanger and the auxiliary heat exchanger are working. This allows the air to pass through the heat exchanger for the longest time and along the longest path, thus enabling rapid temperature regulation.

[0203] For example, ΔT1 = 6℃, ΔT2 = 10℃, and ΔT3 = 15℃. When the temperature difference between indoors and outdoors is less than 6℃, the temperature is relatively suitable; when the temperature difference between indoors and outdoors is between 6℃ and 10℃, the heat load is relatively low; when the temperature difference between indoors and outdoors is between 10℃ and 15℃, the heat load is not too large; and when the temperature difference between indoors and outdoors is greater than 15℃, the heat load is relatively large.

[0204] Compared to the previous embodiment, where the main heat exchanger operates regardless of the heat load, this embodiment allows the auxiliary heat exchanger to operate at a low load during low heat loads, thus avoiding energy waste. During high heat loads, the simultaneous operation of the main and auxiliary heat exchangers improves the speed of temperature regulation. Therefore, the regulation in this embodiment is more precise, achieving both energy saving and rapid regulation.

[0205] After the on / off control steps of the heat exchanger are completed, the cooling / heating determination steps are then performed.

[0206] In some embodiments, if the user inputs an air conditioning cooling mode when starting the fresh air dehumidifier, the on / off control steps of the heat exchanger are performed in the air conditioning cooling mode; if the user inputs an air conditioning heating mode when starting the fresh air dehumidifier, the on / off control steps of the heat exchanger are performed in the air conditioning heating mode.

[0207] [Humidity Adjustment Mode]

[0208] Reference Figure 12 and Figure 13 After the fresh air dehumidifier enters the dehumidification mode, before proceeding with the temperature adjustment step, it determines whether the absolute value of the difference between the indoor and outdoor temperatures is less than the first preset temperature tolerance ΔT1. If not, it proceeds with the temperature adjustment step.

[0209] If so, that is, |Toa-Tra|<ΔT1, it means that the indoor and outdoor temperature difference is not large and the heat load is relatively small. Then the compressor frequency is reduced, which causes the first main valve switch 131 and the second main valve switch 141 to be disconnected, and the first auxiliary valve switch 171 and the second auxiliary valve switch 181 to be connected.

[0210] With a relatively small heat load, the compressor can achieve temperature regulation by operating at low frequency, thus avoiding energy waste during high-frequency operation. With only the auxiliary heat exchanger operating at low load, energy can be saved, and the problem of low utilization efficiency of the main heat exchanger, which may lead to excessive superheating of the suction gas, can be avoided.

[0211] After the steps of disconnecting the first main valve switch 131 and the second main valve switch 141, and connecting the first auxiliary valve switch 171 and the second auxiliary valve switch 181, compare the supply air temperature Tsa with the set temperature Tset:

[0212] If Tsa = Tset, then proceed to the humidity adjustment step.

[0213] In cooling and dehumidification mode, if Tsa > Tset, the opening of the electronic expansion valve is reduced; if Tsa < Tset, the opening of the electronic expansion valve is increased.

[0214] In heating and humidification mode, if Tsa > Tset, the opening of the electronic expansion valve is increased; if Tsa < Tset, the opening of the electronic expansion valve is decreased.

[0215] In this application, the heat absorption and release of the adsorption unit can be utilized by the auxiliary heat exchanger behind it, thereby improving the unit's energy efficiency.

[0216] In this application, in the humidity control mode, when the ambient heat load is relatively small and the ambient temperature is close to the comfort zone, only the auxiliary heat exchanger operates at a low load, which can save energy and avoid the problem of low utilization efficiency of the main heat exchanger, which may lead to excessive superheating of the intake air.

[0217] In this application, in air conditioning mode, when the ambient heat load is relatively small, only the auxiliary heat exchanger operates; when the heat load is moderate, the main heat exchanger operates; and when the heat load is large, both the main heat exchanger and the auxiliary heat exchanger operate simultaneously. This achieves rapid temperature regulation while avoiding energy waste.

[0218] In this application, in the cooling and dehumidification mode, when the exhaust temperature meets the preset value, the operation of the auxiliary condenser can achieve the purpose of recovering indoor air heat.

[0219] In this application, the fresh air dehumidifier is subdivided according to environmental conditions and various working modes are set accordingly, which can improve system energy efficiency and ensure that the fresh air heat and humidity load is within the comfort range.

[0220] In this application, the fresh air dehumidifier has an air conditioning mode that controls only the temperature when the humidity is comfortable, and a dehumidification mode that controls both the temperature and humidity, which is more energy-efficient while ensuring the comfort of the fresh air heat and humidity load.

[0221] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0222] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the described embodiments and various different variations of embodiments suitable for specific use considerations.

Claims

1. A fresh air dehumidifier, characterized in that, include: The first adsorption unit and the second adsorption unit have a moisture adsorbent, one of the first adsorption unit and the second adsorption unit is used to adsorb moisture, and the other is used to regenerate the adsorbent. The ventilation switching device switches between the air flowing in the first adsorption unit and the air flowing in the second adsorption unit. The refrigerant circuit includes: a compressor, an electronic expansion valve, a four-way valve, a heat exchanger, and a valve switch; the valve switch is used to control the connection or disconnection of the heat exchanger in the refrigerant circuit. The heat exchanger includes: The first main heat exchanger is located on the windward side of the first adsorption unit; The second main heat exchanger is located on the windward side of the second adsorption unit. When one of the second main heat exchanger and the first main heat exchanger serves as the main evaporator, the other serves as the main condenser. The first auxiliary heat exchanger is located on the air outlet side of the first adsorption unit. When the first auxiliary heat exchanger acts as an auxiliary evaporator, the first main heat exchanger acts as the main evaporator. When the first auxiliary heat exchanger acts as an auxiliary condenser, the first main heat exchanger acts as the main condenser. The second auxiliary heat exchanger is located on the air outlet side of the second adsorption unit. When one of the second auxiliary heat exchanger and the first auxiliary heat exchanger serves as an auxiliary evaporator, the other serves as an auxiliary condenser. The fresh air dehumidifier also includes: Outdoor temperature and humidity detection device, used to detect the temperature and humidity of outdoor air; Indoor temperature and humidity detection device, used to detect the temperature and humidity of indoor air; Outdoor air supply temperature and humidity detection device, used to detect the temperature and humidity of fresh air supply; The fresh air dehumidifier can operate in at least one of the following modes: cooling dehumidification mode and heating humidification mode; The controller of the fresh air dehumidifier is used to: ensure that the absolute value of the temperature difference between indoor and outdoor air is not less than a first preset temperature tolerance value. In the cooling and dehumidification mode, when the supply air temperature is higher than the set temperature, the first main heat exchanger, the second main heat exchanger and the auxiliary evaporator are connected. In heating and humidification mode, when the supply air temperature is lower than the set temperature, the first main heat exchanger, the second main heat exchanger, and the auxiliary condenser are connected.

2. The fresh air dehumidifier according to claim 1, characterized in that, The heat exchange area of ​​the first auxiliary heat exchanger is smaller than that of the first main heat exchanger, and the heat exchange area of ​​the second auxiliary heat exchanger is smaller than that of the second main heat exchanger. The controller is used to: control the on / off of the heat exchangers when the absolute value of the indoor and outdoor air temperature difference is less than the first preset temperature tolerance value: connect the first auxiliary heat exchanger and the second auxiliary heat exchanger, and disconnect the first main heat exchanger and the second main heat exchanger.

3. The fresh air dehumidifier according to claim 2, characterized in that, The controller is used for: When the absolute value of the temperature difference between indoor and outdoor air is less than the first preset temperature tolerance value, the compressor frequency is reduced.

4. The fresh air dehumidifier according to claim 2, characterized in that, The controller is used for: After the heat exchanger on / off control steps, compare the supply air temperature with the set temperature: In cooling and dehumidification mode, when the supply air temperature is higher than the set temperature, the opening of the electronic expansion valve is reduced; when the supply air temperature is lower than the set temperature, the opening of the electronic expansion valve is increased. In heating and humidification mode, when the supply air temperature is higher than the set temperature, the opening of the electronic expansion valve is increased; when the supply air temperature is lower than the set temperature, the opening of the electronic expansion valve is decreased.

5. The fresh air dehumidifier according to claim 1, characterized in that, The controller is used for: In cooling and dehumidification mode, when the supply air temperature is equal to the set temperature, it checks whether the exhaust air temperature is less than the preset value of heat recovery. If not, it connects the auxiliary condenser.

6. The fresh air dehumidifier according to claim 1, characterized in that, The controller is used for: When the supply air temperature equals the set temperature, check whether the supply air humidity equals the set humidity. If not, adjust the compressor frequency. If the supply air humidity is still not equal to the set humidity after adjusting the compressor frequency, then adjust the opening of the electronic expansion valve. If the supply air humidity is still not equal to the set humidity after adjusting the opening of the electronic expansion valve, then adjust the supply air volume.

7. The fresh air dehumidifier according to claim 1, characterized in that, The controller is used for: In air conditioning mode, when the absolute value of the temperature difference between indoor and outdoor air is not greater than the second preset temperature tolerance value, the first auxiliary heat exchanger and the second auxiliary heat exchanger are connected, and the first main heat exchanger and the second main heat exchanger are disconnected. When the absolute value of the temperature difference between indoor and outdoor air is greater than the third preset temperature tolerance value, the first main heat exchanger, the second main heat exchanger, the first auxiliary heat exchanger, and the second auxiliary heat exchanger are all connected. When the absolute value of the temperature difference between indoor and outdoor air is greater than the second preset temperature tolerance value but not greater than the third preset temperature tolerance value, the first main heat exchanger and the second main heat exchanger are connected, and the first auxiliary heat exchanger and the second auxiliary heat exchanger are disconnected.

8. The fresh air dehumidifier according to claim 1, characterized in that, The controller is used for: In automatic mode, when the set humidity is within the closed range formed by outdoor air humidity and indoor air humidity and the absolute value of the difference between indoor and outdoor air humidity is less than the preset humidity tolerance value, and the set temperature is within the closed range formed by outdoor air temperature and indoor air temperature and the absolute value of the difference between indoor and outdoor air temperature is less than the first preset temperature tolerance value, the total heat exchange mode is run. When the set humidity is within the closed range formed by the outdoor air humidity and the indoor air humidity, and the absolute value of the difference between the indoor and outdoor air humidity is less than the preset humidity tolerance value, and the set temperature is not within the closed range formed by the outdoor air temperature and the indoor air temperature, the air conditioning mode is activated. When the set humidity is not within the closed range formed by the outdoor air humidity and the indoor air humidity, the humidity adjustment mode will be activated.

9. The fresh air dehumidifier according to claim 8, characterized in that, In the dehumidification mode, when the set temperature is within the closed range formed by the outdoor air temperature and the indoor air temperature, and the absolute value of the temperature difference between the indoor and outdoor air is less than the first preset temperature tolerance value, and the indoor and outdoor air humidity is greater than the set humidity, the cooling and dehumidification mode is activated. When the set temperature is within the closed range formed by the outdoor air temperature and the indoor air temperature, and the absolute value of the temperature difference between the indoor and outdoor air is less than the first preset temperature tolerance value, and the indoor and outdoor air humidity is less than the set humidity, the heating and humidification mode is activated.

10. A control method for a fresh air dehumidifier, characterized in that, The fresh air dehumidifier includes: The first adsorption unit and the second adsorption unit have a moisture adsorbent, one of the first adsorption unit and the second adsorption unit is used to adsorb moisture, and the other is used to regenerate the adsorbent. The ventilation switching device switches between the air flowing in the first adsorption unit and the air flowing in the second adsorption unit. The refrigerant circuit includes: a compressor, an electronic expansion valve, and a four-way valve; The first main heat exchanger is located on the windward side of the first adsorption unit; The second main heat exchanger is located on the windward side of the second adsorption unit. When one of the second main heat exchanger and the first main heat exchanger serves as the main evaporator, the other serves as the main condenser. The first auxiliary heat exchanger is located on the air outlet side of the first adsorption unit. When the first auxiliary heat exchanger acts as an auxiliary evaporator, the first main heat exchanger acts as the main evaporator. When the first auxiliary heat exchanger acts as an auxiliary condenser, the first main heat exchanger acts as the main condenser. The second auxiliary heat exchanger is located on the air outlet side of the second adsorption unit. When one of the second auxiliary heat exchanger and the first auxiliary heat exchanger serves as an auxiliary evaporator, the other serves as an auxiliary condenser. The fresh air dehumidifier can operate in at least one of the following modes: cooling dehumidification mode and heating humidification mode; The control method includes: Obtain indoor and outdoor air temperatures and fresh air supply temperature; Provided that the absolute value of the temperature difference between indoor and outdoor air is not less than the first preset temperature tolerance value: In the cooling and dehumidification mode, when the supply air temperature is higher than the set temperature, the first main heat exchanger, the second main heat exchanger and the auxiliary evaporator are connected. In heating and humidification mode, when the supply air temperature is lower than the set temperature, the first main heat exchanger, the second main heat exchanger, and the auxiliary condenser are connected.

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