Dehumidification device and control method thereof

Abstract

The invention discloses a dehumidification device and a control method thereof, the dehumidification device comprises an air flow path, an air supply flow path and an air exhaust flow path of the air flow path intersect, the two ends of the air supply flow path are provided with an air inlet and an air supply outlet, and the two ends of the air exhaust flow path are provided with an air return outlet and an air exhaust outlet; the heat exchange core body is arranged in an intersection area of the air supply flow path and the air exhaust flow path; the refrigerant circulating flow path comprises a compressor, a first air supply coil pipe, a second air supply coil pipe and an air return coil pipe which are connected with one another; wherein the first air supply coil pipe and the second air supply coil pipe are arranged on the upstream side of the air supply opening, and the air return coil pipe is arranged in the exhaust flow path and located on the downstream side of the air return opening and the upstream side of the heat exchange core body. Due to the arrangement of the dehumidification device and the air return coil pipe, active heat pump heat recovery is taken as a main part in a heating mode, passive total heat exchange heat recovery is taken as an auxiliary part, sufficient heat recovery of the heat pump is guaranteed, stable heat supply operation is achieved, and the heat pump system is suitable for being operated under the severe cold working condition.

Description

Technical Field

[0001] The present invention relates to the technical field of dehumidification and ventilation, and in particular to a dehumidification device and a control method thereof. Background Art

[0002] Exhaust air energy recovery technology has become an important approach to building energy conservation. Common exhaust air heat recovery technologies include heat exchangers (sensible or total heat) and heat pumps. The former is particularly effective when there is a significant difference in indoor and outdoor temperature and humidity. It transfers heat and moisture through the temperature and humidity differential between indoor and outdoor, reducing the heat and moisture load introduced by fresh air. The latter, relying on a vapor compression heat pump cycle, can achieve greater dehumidification capacity.

[0003] The prior art proposes a fresh air dehumidification system that combines two heat recovery technologies. The main air treatment process is that the fresh air first passes through the heat exchange core to exchange heat and moisture with the exhaust air, then passes through the heat pump system for deep dehumidification and reheating, and finally is sent into the room. Its main disadvantage is that all the condensation heat of the heat pump dehumidification is brought into the room by the fresh air, increasing the indoor heat load. If the dehumidification capacity is large, the condenser requires a larger heat exchange capacity, which will lead to problems such as too high supply air temperature and too high condensation temperature. The indoor exhaust air only undergoes one heat and moisture exchange with the outdoor fresh air in the heat exchange core, and the heat recovery of the indoor exhaust air is insufficient. The prior art also proposes a temperature and humidity dual-control heat pump fresh air dehumidifier with deep full heat recovery. By adding a heat exchanger in the exhaust duct, deep heat recovery of the exhaust air is achieved. At the same time, by connecting the heat exchangers in parallel, the supply air temperature is controlled, avoiding the problem of too high supply air temperature when the dehumidification capacity is large. However, there is no detailed distinction between the operating conditions throughout the year. For example, in the extremely cold winter environment (-10℃ or lower inlet air), the low-temperature fresh air can only be heated to a limited temperature after passing through the heat exchange core and exchanging heat with the indoor return air. In theory, it does not exceed the return air temperature, which is usually below 20℃. At the same time, after the return air heat is transferred to the fresh air, its own temperature drops to about 0℃, which can no longer support the heat pump to carry out further heat recovery. Otherwise, the evaporation temperature of the heat pump will be as low as about -15℃, resulting in frequent frosting, inability to provide stable heat supply, and affecting the reliable operation of the equipment. Summary of the Invention

[0004] In order to solve the above problems, the present invention provides a dehumidification device and a control method thereof, wherein the dehumidification device is suitable for operating under severe cold conditions.

[0005] The dehumidification device proposed by the present invention comprises:

[0006] An air flow path, comprising an air supply flow path and an air exhaust flow path, wherein the air supply flow path and the air exhaust flow path intersect with each other, an air inlet and an air supply vent are provided at both ends of the air supply flow path, and a return air vent and an air exhaust vent are provided at both ends of the air exhaust flow path;

[0007] a heat exchange core, arranged at the intersection of the air supply flow path and the air exhaust flow path;

[0008] A refrigerant circulation circuit includes a compressor, a first air supply coil, a second air supply coil, and a return air coil connected to each other;

[0009] The first supply air coil and the second supply air coil are arranged on the upstream side of the supply air outlet, and the return air coil is arranged in the exhaust air flow path and is located on the downstream side of the return air outlet and the upstream side of the heat exchange core.

[0010] In some optional embodiments, the refrigerant circulation flow path further includes: an exhaust coil; the exhaust coil is arranged on the upstream side of the exhaust vent and is located on the downstream side of the heat exchange core.

[0011] In some optional embodiments, the refrigerant circulation flow path further includes a resistance element, and the resistance element is disposed on the connecting flow path between the return air coil and the exhaust air coil.

[0012] In some optional embodiments, the refrigerant circulation flow path also includes a first one-way valve and a second one-way valve; the first one-way valve is arranged on the connecting flow path between the first supply air coil and the second supply air coil; a bypass branch is arranged between the first supply air coil and the return air coil, and the second one-way valve is arranged on the bypass branch.

[0013] In some optional embodiments, when the first one-way valve is turned on and the second one-way valve is turned off, the refrigerant flows from the second supply air coil into the first supply air coil; when the second one-way valve is turned on and the first one-way valve is turned off, the refrigerant flows from the first supply air coil into the return air coil.

[0014] In some optional embodiments, it also includes: a first bypass damper, which is arranged between the air inlet section of the supply air flow path and the exhaust section of the exhaust air flow path, and the first bypass damper can be adjusted to switch between an open state and a closed state. When the first bypass damper is in an open state, the air inlet and the exhaust outlet are connected; a second bypass damper, which is arranged between the return air section of the exhaust air flow path and the supply air section of the supply air flow path, and the second bypass damper can be adjusted to switch between an open state and a closed state. When the second bypass damper is in an open state, the supply air outlet and the return air outlet are connected.

[0015] In some optional embodiments, the first bypass damper is in an open state, and the second bypass damper is in a closed state. Part of the air entering from the air inlet is discharged to the air supply outlet through the air supply path, and the other part is discharged to the air exhaust outlet through the first bypass damper.

[0016] In some optional embodiments, it also includes: an intake air sensor, arranged on the downstream side of the air inlet, for detecting the temperature and humidity of the intake air; and / or a return air sensor, arranged on the downstream side of the return air outlet, for detecting the temperature, humidity and carbon dioxide concentration of the return air.

[0017] The control method of the dehumidification device proposed by the present invention includes:

[0018] Obtaining a measured humidity value of the return air of the dehumidification device;

[0019] Based on the comparison result of the measured humidity value and the preset humidity value, the rotation speed of the compressor included in the dehumidification device is adjusted.

[0020] In some optional embodiments, when the measured humidity value is higher than a preset humidity value, the compressor speed is increased; when the measured humidity value is not higher than the preset humidity value, the compressor speed is reduced.

[0021] In some optional embodiments, it also includes: obtaining the suction port superheat value of the compressor; and adjusting the opening of the throttling device in the refrigerant circulation flow path of the dehumidification device based on the comparison result of the suction port superheat value and the preset superheat value.

[0022] In some optional embodiments, when the superheat value of the air intake port is higher than a preset superheat value, the opening of the throttling device is increased; when the superheat value of the air intake port is not higher than the preset superheat value, the opening of the throttling device is reduced.

[0023] In some optional embodiments, the method further includes: obtaining a carbon dioxide concentration value of the return air of the dehumidification device; and adjusting a rotation speed of an air supply fan of the dehumidification device based on a comparison result of the carbon dioxide concentration value and a preset concentration value.

[0024] In some optional embodiments, when the carbon dioxide concentration value is higher than a preset concentration value, the speed of the air supply fan is increased; when the carbon dioxide concentration value is not higher than the preset concentration value, the speed of the air supply fan is reduced.

[0025] In some optional embodiments, the method further includes adjusting the exhaust fan and the supply fan included in the dehumidification device so that the exhaust volume of the exhaust fan is 80% to 90% of the supply volume of the supply fan.

[0026] In some optional embodiments, the method further includes: obtaining a measured temperature value of the supply air of the dehumidification device; and adjusting the rotation speed of the compressor based on a comparison result between the measured temperature value and a preset temperature value.

[0027] In some optional embodiments, the method further includes: determining an operating mode of the dehumidification device; and adjusting the speed of the supply fan and / or exhaust fan of the dehumidification device based on the operating mode to meet set conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 Schematic diagram of the structure of a dehumidification device according to an embodiment of the present invention;

[0029] Figure 2 Schematic diagram of the working principle of the dehumidification device in the first dehumidification mode according to an embodiment of the present invention;

[0030] Figure 3 Schematic diagram of the connection relationship of the refrigerant circulation flow path of the dehumidification device in the first dehumidification mode according to an embodiment of the present invention;

[0031] Figure 4 Schematic diagram of the working principle of the dehumidification device according to an embodiment of the present invention in the second dehumidification mode (hot and wet working condition);

[0032] Figure 5 Schematic diagram of the working principle of the dehumidification device according to an embodiment of the present invention in the first heating mode (severe cold conditions);

[0033] Figure 6 Schematic diagram of the connection relationship of the refrigerant circulation flow path of the dehumidification device according to an embodiment of the present invention in the first heating mode (severe cold conditions);

[0034] Figure 7 This is a schematic diagram of the working principle of the dehumidification device in the second heating mode according to an embodiment of the present invention;

[0035] Figure 8 Schematic diagram of the working principle of the dehumidification device in the internal circulation mode according to an embodiment of the present invention;

[0036] Figure 9 Schematic diagram of the working principle of the dehumidification device in heat exchange mode according to an embodiment of the present invention;

[0037] Figure 10 Schematic diagram of the working principle of the dehumidification device in ventilation mode according to an embodiment of the present invention.

[0038] Reference numerals

[0039] Compressor 1, four-way reversing valve 2, exhaust air coil 3, second supply air coil 4, first supply air coil 5, return air coil 6, first one-way valve 7, second one-way valve 8, throttling device 9, first bypass damper 10, air inlet 11, supply air inlet 12, return air inlet 13, exhaust air inlet 14, exhaust fan 15, supply air fan 16, second bypass damper 17, return air sensor 18, intake air sensor 19, intake air filter 20, return air filter 21, supply air filter 22, electric control cabinet 23, heat exchange core 24, resistance element 25. DETAILED DESCRIPTION

[0040] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present disclosure without making any creative efforts shall fall within the scope of protection of the present disclosure.

[0041] The following orientations or positional relationships are intended solely for the purpose of facilitating the description of the present disclosure and simplifying the description. They are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation, and are therefore not to be construed as limiting the present disclosure. Specifically, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

[0042] In the description of this disclosure, it should be noted that, unless otherwise specified or limited, the terms "connected" and "connection" should be understood broadly. For example, they can refer to mechanical or electrical connections, direct connections, or indirect connections through an intermediary. Those skilled in the art will understand the specific meanings of these terms in this disclosure based on the specific circumstances.

[0043] Figure 1 Schematic diagram of the structure of a dehumidification device according to an embodiment of the present invention.

[0044] like Figure 1As shown, the dehumidification device in this embodiment includes an air flow path, a heat exchange core 24 and a refrigerant circulation flow path, the air flow path includes a supply air flow path and an exhaust air flow path, the supply air flow path and the exhaust air flow path intersect, and an air inlet 11 and an air supply air outlet 12 are provided at both ends of the supply air flow path, and a return air outlet 13 and an exhaust air outlet 14 are provided at both ends of the exhaust air flow path; the heat exchange core 24 is provided at the intersection area of ​​the supply air flow path and the exhaust air flow path; the refrigerant circulation flow path includes a connected compressor 1, a first supply air coil 5, a second supply air coil 4 and a return air coil 6; wherein, the first supply air coil 5 and the second supply air coil 4 are provided on the upstream side of the supply air outlet 12, and the return air coil 6 is provided in the exhaust air flow path, and is located on the downstream side of the return air outlet and the upstream side of the heat exchange core 24.

[0045] Specifically, the dehumidification device includes a housing having a first side and a second side opposite each other. The first side of the housing is provided with an air inlet 11 and an air outlet 14, and the second side of the housing is provided with a return air outlet 13 and an air supply outlet 12. The air inlet 11 and the air supply outlet 12 are arranged diagonally, and the return air outlet 13 and the air outlet 14 are arranged diagonally, forming an air supply flow path and an air exhaust flow path within the housing.

[0046] The heat exchange core 24 is located at the intersection of the supply air flow path and the exhaust air flow path. The heat exchange core 24 has a first surface opposite the air inlet 11, a second surface opposite the air supply vent 12, a third surface opposite the return air vent 13, and a fourth surface. An air inlet filter 20 can be provided on the first surface to filter the incoming air, a supply air filter 22 can be provided on the second surface to filter the supply air, and a return air filter 21 can be provided on the third surface to filter the return air. The air inlet filter 20, the supply air filter 22, and the return air filter 21 can be the same filter, or different filters, or one or two of the filters can be an activated carbon filter, a formaldehyde filter, or a PM2.5 high-efficiency filter.

[0047] The compressor 1, four-way reversing valve 2, first supply air coil 5, second supply air coil 4, return air coil 6, and exhaust air coil 3 are arranged circumferentially around the heat exchange core 24. The first supply air coil 5 and second supply air coil 4 face the second surface of the heat exchange core 24, and are spaced apart from each other. The first supply air coil 5 and second supply air coil 4 are located upstream of the supply air outlet 12. In this embodiment, the heat exchange core 24 is a rectangular parallelepiped. In other embodiments, the heat exchange core 24 may be a hexagon. When the heat exchange core 24 is a hexagon, the first supply air coil 5 and second supply air coil 4 are not completely opposite to the second surface of the heat exchange core 24. The return air coil 6 faces the third surface of the heat exchange core 24, and the exhaust air coil 3 faces the fourth surface of the heat exchange core 24. The exhaust air coil 3 is located upstream of the exhaust outlet 14 and downstream of the heat exchange core 24. Four-way reversing valve 2 has ports E, C, S, and D. Port E communicates with the first supply air coil 5, port C communicates with the exhaust air coil 3, port S communicates with the intake port of compressor 1, and port D communicates with the exhaust port of compressor 1. Compressor 1, four-way reversing valve 2, first supply air coil 5, second supply air coil 4, return air coil 6, and exhaust air coil 3 are connected to form a refrigerant circulation path.

[0048] The housing also houses a supply fan 16 and an exhaust fan 15. The supply fan 16 is positioned near the air inlet 11, while the exhaust fan 15 is positioned near the return air outlet 13. Both the supply fan 16 and the exhaust fan 15 are preferably variable-frequency fans with adjustable speeds. An electrical control cabinet 23 is also located within the housing, mounted near the housing. In other embodiments, for greater energy efficiency and efficiency, the supply fan 16 can be positioned upstream of the supply air outlet 12, while the exhaust fan 15 can be positioned upstream of the exhaust air outlet 14.

[0049] The following describes the dehumidification mode of the dehumidifier under the condition of a small indoor and outdoor temperature difference in summer. In this mode, the air supplied to the room is entirely composed of outdoor fresh air. After being filtered, the outdoor fresh air exchanges heat and moisture with the return air that has undergone initial heat recovery by the heat pump, and the temperature and humidity are reduced. After deep dehumidification and reheating treatment by the heat pump, it is then sent into the room. This mode is suitable for working conditions with a small indoor and outdoor temperature difference in summer.

[0050] The working status of each component of the dehumidification device is that the supply fan 16 and the exhaust fan 15 are turned on, the E port and the S port of the four-way reversing valve 2 are connected, so that the first supply air coil 5 and the intake port of the compressor 1 are connected, the D port and the C port of the four-way reversing valve 2 are connected, so that the exhaust port of the compressor 1 and the exhaust coil 3 are connected, and the exhaust coil 3, the return air coil 6, the second supply air coil 4 and the first supply air coil 5 are connected in sequence.

[0051] The air flow path state is as follows: outdoor fresh air is introduced from the air inlet 11, and driven by the supply fan 16, it flows through the air inlet filter 20 in sequence to be purified, flows through the heat exchange core 24 to exchange heat and moisture with the return air, flows through the supply air filter 22 to be deeply purified, flows through the first supply air coil 5 for deep cooling and dehumidification, flows through the second supply air coil 4 for reheating, and then flows into the room from the supply air inlet 12. Indoor return air is introduced from the return air inlet 13, and driven by the exhaust fan 15, first flows through the return air coil 6 to increase the temperature to achieve preliminary heat recovery of the indoor cold air, and then flows through the return air filter 21 and the heat exchange core 24 in sequence to exchange moisture with the fresh air. At this time, the fluid temperatures on both sides are similar, but the moisture content is still quite different. The return air can still be used to remove some of the moisture in the fresh air, flows through the exhaust coil 3 to remove some of the condensation heat, and finally is discharged to the outside through the exhaust air inlet 14.

[0052] The refrigerant circulation path is as follows: the refrigerant evaporates in the first supply air coil 5, absorbs heat, and transforms into low-pressure vapor. It then flows through the four-way reversing valve 2 and enters the compressor 1, where it is compressed into high-temperature, high-pressure refrigerant gas. It is then discharged from the exhaust port of the compressor 1. It then flows through the four-way reversing valve 2 and enters the exhaust air coil 3, where it initially dissipates heat to the exhaust air. It then flows through the return air coil 6 and dissipates heat to the return air. Finally, it condenses in the second supply air coil 4, reheating the low-temperature supply air after deep dehumidification. The refrigerant flowing out of the second supply air coil 4 is throttled by the throttling device 9, converted into a low-temperature, low-pressure two-phase refrigerant, and flows into the first supply air coil 5, continuing the above cycle.

[0053] In dehumidification mode, the return air coil 6 and exhaust coil 3 fully recover heat from the indoor exhaust air. In addition to the conventional exhaust coil 3, the return air coil 6 increases the heat exchange area on the condensing side, helping to lower the condensing temperature and improve the heat pump system's circulation performance. The heat exchange core 24 and the heat pump system work well together, allowing the sensible heat of the return air to be used for heat pump heat recovery while still maintaining a lower moisture content than the fresh air. This achieves preliminary dehumidification of the fresh air during the full heat exchange process, reducing the heat pump system's moisture load.

[0054] The following describes the heating mode of the dehumidification device under a low-temperature and severe cold working condition in winter. The temperature under the low-temperature and severe cold working condition is, for example, below -10°C.

[0055] The working status of each component of the dehumidification device is that the supply fan 16 and the exhaust fan 15 are turned on, the C port and the S port of the four-way reversing valve 2 are connected, so that the exhaust coil 3 and the suction port of the compressor 1 are connected, the D port and the E port of the four-way reversing valve 2 are connected, so that the exhaust port of the compressor 1 and the first supply air coil 5 are connected, and the first supply air coil 5, the return air coil 6 and the exhaust coil 3 are connected in sequence.

[0056] The air flow path is as follows: outdoor fresh air is introduced from the air inlet 11, driven by the supply fan 16, and flows through the air inlet filter 20 for preliminary purification. It then flows through the heat exchange core 24 to exchange heat and moisture with the return air. It then flows through the supply air filter 22 for deep purification. After flowing through the first supply air coil 5 and being heated, it enters the room through the supply air inlet 12. Indoor return air is introduced from the return air inlet 13, and driven by the exhaust fan 15, it flows through the return air coil 6 for cooling to achieve preliminary heat recovery. After being filtered and purified by the return air filter 21, it enters the heat exchange core 24 to exchange heat and moisture with the fresh air for further heat recovery, and is finally discharged to the outside through the exhaust air inlet 14. The temperature of the air flowing through the exhaust coil 3 is similar to that of the refrigerant in the exhaust coil 3, and almost no heat exchange occurs between the two.

[0057] The refrigerant circulation flow state is that the refrigerant evaporates and absorbs heat in the return air coil 6 and is transformed into low-pressure steam, flows through the four-way reversing valve 2 and enters the compressor 1, is compressed into high-temperature and high-pressure refrigerant gas, and then flows through the four-way reversing valve 2 and enters the first supply air coil 5. The high-temperature and high-pressure refrigerant gas condenses and dissipates heat in the first supply air coil 5, heating the fresh air flowing through, and the high-temperature and high-pressure refrigerant gas is transformed into a low-temperature and high-pressure refrigerant liquid. After being throttled by the throttling device 9, the low-temperature and high-pressure refrigerant is transformed into a low-temperature and low-pressure two-phase refrigerant and flows into the return air coil 6, continuing the above-mentioned cycle process.

[0058] The return air coil 6 serving as an evaporator is located before the heat exchange core 24 on the exhaust air flow path. The return air coil 6 is used to realize active heat recovery of the indoor return air waste heat, and the heat exchange core 24 is used to realize passive heat recovery of the remaining part. Active heat recovery is mainly used to increase its priority to ensure sufficient heat recovery space for the heat pump system. The return air coil 6 will not frost and can achieve a stable supply air temperature, which can reach 30°C or higher.

[0059] Traditional dehumidification systems combine active heat pump heat recovery with passive full heat exchange heat recovery. Full heat exchange is the primary method, supplemented by heat pump heat recovery. For example, in heating mode, full heat exchange completes the initial heat transfer from return air to fresh air, and then the heat pump extracts the remaining heat from the return air to further heat the fresh air. This approach is not suitable for extremely cold operating conditions, as the return air temperature after full heat exchange is too low, making it difficult for the heat pump to operate stably.

[0060] The dehumidification device disclosed in the present invention is provided with a return air coil 6 on the downstream side of the return air outlet 13, and the heat exchanger acting as an evaporator in the winter heating mode is moved in the air flow path to before the heat exchange core 24, thereby ensuring sufficient heat recovery of the heat pump without affecting the operation of the heat exchange core 24. There is no risk of frost for both, and stable heating operation can be achieved.

[0061] In heating mode, the return air coil 6, acting as the evaporator, is located before the heat exchange core 24 in the air flow path. Active heat recovery from the indoor return air is performed by the return air coil 6, while the remaining heat is recovered passively by the heat exchange core 24. Prioritizing active heat recovery ensures sufficient heat recovery space in the heat pump system and prevents frost from forming on the return air coil 6, acting as the evaporator.

[0062] In the dehumidification mode and heating mode, in addition to the conventional exhaust coil 3, the return air coil 6 increases the heat exchange area on the condensation side or the evaporation side, which is beneficial to lowering the condensation temperature or raising the evaporation temperature, thereby improving the circulation performance of the heat pump system.

[0063] In this embodiment, the heat exchange core 24 is located at the intersection of the supply air flow path and the exhaust air flow path, the return air coil 6 is located between the heat exchange core 24 and the return air outlet 13, and the first supply air coil 5 and the second supply air coil 4 are located between the heat exchange core 24 and the supply air outlet 12. This structure increases the heat exchange area on the condensation side or the evaporation side, which is beneficial to improving the circulation performance of the heat pump system. The setting of the return air coil 6 makes the active heat pump heat recovery the main method in the heating mode, supplemented by the passive full heat exchange heat recovery, to ensure sufficient heat recovery of the heat pump, achieve stable heating operation, and is suitable for operation under severe cold conditions.

[0064] like Figure 1 As shown, in the embodiment of the present disclosure, the refrigerant circulation flow path further includes a resistance element 25 , and the resistance element 25 is provided on the connecting flow path between the return air coil 6 and the exhaust air coil 3 .

[0065] Specifically, a resistance element 25 is installed in the connecting pipe between the return air coil 6 and the exhaust air coil 3. In heating mode, resistance element 25 is used to control the refrigerant temperature in the exhaust air coil 3 so that it is close to the temperature of the air flowing through it, thereby virtually eliminating heat exchange and ensuring safe operation of the system. Resistance element 25 can be a throttling device or an expansion valve.

[0066] In heating mode, there's a temperature difference between the refrigerant's evaporation phase transition temperature in the return air coil 6 and the air temperature at the outlet of the heat exchange core 24. The evaporation phase transition temperature in the return air coil 6 corresponds to the temperature of the refrigerant flowing into the exhaust air coil 3, while the air temperature at the outlet of the heat exchange core 24 corresponds to the temperature of the air flowing through the exhaust air coil 3. If the evaporation phase transition temperature in the return air coil 6 is lower than the air temperature at the outlet of the heat exchange core 24, the refrigerant will continue to absorb heat from the outlet of the heat exchange core 24, causing frost on the exhaust air coil 3. If the evaporation phase transition temperature in the return air coil 6 is higher than the air temperature at the outlet of the heat exchange core 24, the refrigerant will release heat to the outlet of the heat exchange core 24, causing the refrigerant on the inlet of the compressor 1 to reverse to a saturated or even two-phase state, risking liquid entrainment and wet compression. When the temperature of the refrigerant flowing into the exhaust duct approaches the temperature of the air flowing through it, the resistance element 25 is closed.

[0067] In this embodiment, by adjusting the opening of the resistance element 25, the refrigerant evaporation phase change temperature in the return air coil 6 and the air temperature on the outlet side of the heat exchange core 24 in the heating mode are close or the difference between the two is maintained within a preset range, thereby ensuring reliable operation of the system.

[0068] like Figure 1 As shown, in the embodiment of the present disclosure, the refrigerant circulation flow path also includes a first one-way valve 7 and a second one-way valve 8; the first one-way valve 7 is arranged on the connecting flow path between the first supply air coil 5 and the second supply air coil 4; a bypass branch is provided between the first supply air coil 5 and the return air coil 6, and the second one-way valve 8 is provided on the bypass branch.

[0069] Specifically, the first one-way valve 7 and the throttling device 9 are arranged on the connecting flow path between the first supply air coil 5 and the second supply air coil 4, a bypass path is provided between the first supply air coil 5 and the return air coil 6, and the second one-way valve 8 is provided on the bypass branch.

[0070] In dehumidification mode, first check valve 7 is open, second check valve 8 is closed, and throttling device 9 adjusts its opening as needed. In the refrigerant circulation path, the air outlet of compressor 1, exhaust coil 3, return coil 6, second supply coil 4, first check valve 7, throttling device 9, first supply coil 5, four-way reversing valve 2, and the air inlet of compressor 1 are sequentially connected.

[0071] In heating mode, first check valve 7 is closed, second check valve 8 is open, and throttling device 9 adjusts its opening as needed. The refrigerant circulation path connects the compressor 1's outlet, first supply air coil 5, throttling device 9, second check valve 8, return air coil 6, exhaust air coil 3, four-way reversing valve 2, and compressor 1's inlet in sequence.

[0072] In this embodiment, by providing the first one-way valve 7 and the second one-way valve 8, the circulation flow path of the refrigerant can be conveniently switched between the dehumidification mode and the heating mode, thereby ensuring the reliable operation of the system.

[0073] like Figure 1 As shown, in an embodiment of the present disclosure, the dehumidification device also includes a first bypass damper 10 and a second bypass damper 17. The first bypass damper 10 is arranged between the air inlet section of the supply air flow path and the exhaust section of the exhaust air flow path. The first bypass damper 10 can be adjusted to switch between an open state and a closed state. When the first bypass damper 10 is in an open state, the air inlet 11 and the exhaust air outlet 14 are connected; the second bypass damper 17 is arranged between the return air section of the exhaust air flow path and the supply air section of the supply air flow path. The second bypass damper 17 can be adjusted to switch between an open state and a closed state. When the second bypass damper 17 is in an open state, the supply air outlet 12 and the return air outlet 13 are connected.

[0074] Specifically, a first bypass damper 10 is provided between the air inlet section of the supply air flow path and the exhaust section of the exhaust air flow path, and a second bypass damper 17 is provided between the return air section of the exhaust air flow path and the supply air section of the supply air flow path.

[0075] In dehumidification mode, for high-temperature and high-humidity summer conditions, first bypass damper 10 is open, second bypass damper 17 is closed, and air inlet 11 is connected to exhaust vent 14. Air entering through air inlet 11 is partially discharged through the supply air path to supply vent 12, while another portion flows through first bypass damper 10 to the upstream side of exhaust coil 3. There, it mixes with the return air and removes more condensation heat from exhaust coil 3.

[0076] In heating mode, for winter heating conditions above 0°C, the first bypass damper 10 is open, the second bypass damper 17 is closed, and the air inlet 11 is connected to the air outlet 14. Part of the air entering from the air inlet 11 is discharged through the supply air flow path to the supply air outlet 12, while part of the air flows through the first bypass damper 10 and is discharged upstream of the exhaust coil 3. There, it mixes with the return air and removes more condensation heat from the exhaust coil 3.

[0077] In internal circulation mode, to address conditions such as the rainy season, when outdoor air is extremely humid and polluted, making it difficult to introduce fresh air, the first and second bypass dampers 10 and 17 are opened. Indoor air is introduced through the return air vent 13 and, driven by the exhaust fan 15, flows through the second bypass damper 17. It is then cooled and dehumidified by the first supply air coil 5 and reheated by the second supply air coil 4 before being returned to the room through the supply air vent 12. Outdoor air is introduced through the air inlet 11, flows through the first bypass damper 10, and then passes through the exhaust coil 3 to remove excess condensation heat before being discharged to the outdoors through the exhaust vent 14. In actual operation, due to the greater resistance to flow through the heat exchange core 24, most of the return air will bypass the second bypass damper 17 directly, and similarly, most of the intake air will bypass the first bypass damper 10. Consequently, a small amount of the two air streams will pass through the heat exchange core 24 for heat exchange, meaning that a small amount of fresh air can still be introduced in this mode.

[0078] Furthermore, an air path switching plate can be set on the upstream side of the heat exchange core 24, that is, when the air path switching plate is switched to the upstream side of the heat exchange core 24, the air entering from the return air inlet 13 and the air entering from the air inlet 11 cannot enter the heat exchange core 24.

[0079] In heating mode and dehumidification mode, the first bypass damper 10 is opened, allowing additional air to flow through the exhaust coil 3, which can enhance the heat exchange between the exhaust coil 3 and the air flowing through it. In the two modes, the evaporation temperature is increased and the condensation temperature is reduced, which is beneficial to improving the energy efficiency of the heat pump cycle, or improving the heating or dehumidification capacity at the same power consumption.

[0080] In internal circulation mode, the first bypass damper 10 is opened, bypassing a small amount of incoming air to remove excess condensation heat from the heat pump system. Otherwise, in the high-power mode with a large dehumidification capacity, the heat pump system's condensation temperature is likely to exceed the limit, and the indoor air supply temperature is too high, affecting user comfort. The first bypass damper 10 and the second bypass damper 17 are opened simultaneously, and in conjunction with the heat pump system, an internal circulation mode can be achieved. This can be used to cope with situations where it is not appropriate to introduce fresh air, such as during the rainy season when outdoor humidity is high or outdoor air pollution is severe. It can also achieve rapid indoor dehumidification under conditions where the indoor humidity load is particularly high, such as during the return of the south wind.

[0081] Furthermore, the dehumidifier is also provided with a bypass vent, which can be located at the bottom of the heat exchange core 24, or a damper for closing or opening the bypass vent can be provided downstream of the air inlet. When the damper opens the bypass vent, air enters through the bypass vent and is discharged to the supply vent 12 along the air duct connecting the bypass vent and the supply vent 12. In ventilation mode, only filtered fresh air is allowed to be introduced, achieving an effect similar to mechanical bypass, which helps reduce operating energy consumption.

[0082] like Figure 1As shown, in an embodiment of the present disclosure, the dehumidification device also includes an intake air sensor 19 and / or a return air sensor 18. The intake air sensor 19 is arranged on the downstream side of the air inlet 11 to detect the temperature and humidity of the intake air; the return air sensor 18 is arranged on the downstream side of the return air outlet 13 to detect the temperature, humidity and carbon dioxide concentration of the return air.

[0083] Specifically, the intake air sensor 19 is used to detect the temperature and humidity of the intake air, and the return air sensor 18 is used to detect the temperature and humidity of the return air. According to the temperature and humidity of the intake air and the temperature and humidity of the return air, the operating parameters of the compressor 1, the supply fan 16 and the exhaust fan 15 are adjusted to ensure the reliable operation of the dehumidification device.

[0084] like Figure 1 As shown, the structure of the dehumidification device, the air flow path and the refrigerant circulation flow path are described below using a specific embodiment.

[0085] The dehumidification device includes a housing, with an air inlet 11 and an exhaust vent 14 disposed on a first side of the housing, and a return air vent 13 and a supply air vent 12 disposed on a second side of the housing. The air inlet 11 and the supply air vent 12 are arranged diagonally, while the return air vent 13 and the exhaust vent 14 are arranged diagonally. Supply and exhaust air paths are formed within the housing. A first bypass damper 10 is disposed between the inlet section of the supply air path and the exhaust section of the exhaust air path. The inlet section of the supply air path is located upstream of the heat exchange core 24 in the supply air path; the exhaust section of the exhaust air path is located downstream of the heat exchange core 24 in the exhaust air path. A second bypass damper 17 is arranged between the return air section of the exhaust air flow path and the supply air section of the supply air flow path. The return air section of the exhaust air flow path is the flow path on the upstream side of the heat exchange core 24 in the exhaust air flow path; the supply air section of the supply air flow path is the flow path on the downstream side of the heat exchange core 24 in the supply air flow path.

[0086] The heat exchange core 24 is located at the intersection of the supply and exhaust air paths. It has a first surface facing the air inlet 11, a second surface facing the air supply 12, a third surface facing the return air vent 13, and a fourth surface. The first surface is equipped with an inlet air filter 20, the second surface is equipped with a supply air filter 22, and the third surface is equipped with a return air filter 21. The supply fan 16 is located near the air inlet 11, and the exhaust fan 15 is located near the return air vent 13. The dehumidifier also has a bypass vent.

[0087] The compressor 1, four-way reversing valve 2, first supply air coil 5, second supply air coil 4, return air coil 6, and exhaust air coil 3 are arranged circumferentially around the heat exchange core 24. The first supply air coil 5 and second supply air coil 4 face the second surface of the heat exchange core 24, and are spaced apart from each other. The return air coil 6 faces the third surface of the heat exchange core 24, and the exhaust air coil 3 faces the fourth surface of the heat exchange core 24. The four-way reversing valve 2 has ports E, C, S, and D. Port E is connected to the first supply air coil 5, port C is connected to the exhaust air coil 3, port S is connected to the intake port of the compressor 1, and port D is connected to the exhaust port of the compressor 1.

[0088] A first check valve 7 and a throttling device 9 are installed on the flow path connecting the first supply air coil 5 and the second supply air coil 4. A bypass path is provided between the first supply air coil 5 and the return air coil 6, with a second check valve 8 installed on the bypass branch. A resistance element 25 is installed on the pipeline connecting the return air coil 6 and the exhaust air coil 3.

[0089] The air inlet section of the air supply path is provided with an air inlet sensor 19 for detecting the temperature and humidity of the inlet air. The return air section of the exhaust path is provided with a return air sensor 18 for detecting parameters such as the temperature, humidity, and carbon dioxide concentration of the return air.

[0090] By switching the operating states of various components in the air flow path and refrigerant circulation flow path, the dehumidifier can operate in the first dehumidification mode, the second dehumidification mode (hot and humid conditions), the first heating mode (severe cold conditions), the second heating mode, the internal circulation mode, the heat exchange mode, and the ventilation mode. The first dehumidification mode is suitable for summer conditions with a small temperature difference between indoor and outdoor, while the second dehumidification mode (hot and humid conditions) is suitable for summer conditions with high temperature and high humidity. The first heating mode (severe cold conditions) is suitable for winter conditions with low and severe temperatures, such as conditions with an ambient temperature below -10°C, while the second heating mode is suitable for winter conditions with an ambient temperature above 0°C. The internal circulation mode is suitable for conditions such as the rainy season when the outdoor air is extremely humid and the outdoor air is severely polluted, where the introduction of fresh air is not suitable. The heat exchange mode is suitable for low-temperature environments in transitional seasons, such as ambient temperatures of 14-16°C. The ventilation mode is suitable for conditions in transitional seasons, where outdoor fresh air is suitable for direct indoor flow.

[0091] The following describes in detail the working status of each component in each mode, the air flow path status, the refrigerant circulation flow path status, the control method during the operation of the dehumidification device, and the beneficial effects.

[0092] Figure 2 Schematic diagram of the working principle of the dehumidification device in the first dehumidification mode according to an embodiment of the present invention; Figure 3 Schematic diagram of the connection relationship of the refrigerant circulation flow path of the dehumidification device in the first dehumidification mode according to an embodiment of the present invention.

[0093] First dehumidification mode

[0094] In this mode, the air supplied to the room is entirely composed of outdoor fresh air. The outdoor fresh air enters the shell through the air inlet 11, and after being filtered, it undergoes heat and moisture exchange with the return air that has undergone preliminary heat recovery by the return air coil 6. The temperature and humidity are both reduced, and then the air is sent into the room after deep dehumidification by the first supply air coil 5 and reheating treatment by the second supply air coil 4. It is suitable for working conditions with a small temperature difference between indoor and outdoor in summer.

[0095] The dehumidification system components are operating as follows: supply fan 16 and exhaust fan 15 are on, first bypass damper 10 and second bypass damper 17 are closed, and the bypass vent is closed. Ports E and S of four-way reversing valve 2 are connected, allowing communication between the first supply air coil 5 and the intake port of compressor 1. Ports D and C of four-way reversing valve 2 are connected, allowing communication between the exhaust port of compressor 1 and the exhaust air coil 3. First check valve 7 is in the on state, second check valve 8 is in the off state, throttling device 9 is adjusted in opening as needed, and resistance element 25 is inactive.

[0096] The air flow path state is that outdoor fresh air is introduced from the air inlet 11, and under the drive of the supply air fan 16, it flows through the air inlet filter 20 in turn to be purified, flows through the heat exchange core 24 to exchange heat and moisture with the return air entering from the return air outlet 13, flows through the supply air filter 22 to be deeply purified, flows through the first supply air coil 5 for deep cooling and dehumidification, flows through the second supply air coil 4 for reheating, and is sent into the room from the supply air outlet 12. The indoor return air is introduced from the return air vent 13, and driven by the exhaust fan 15, it first flows through the return air coil 6 to heat up and realize the preliminary heat recovery of the indoor cold air, and then flows through the return air air filter 21 and the heat exchange core 24 in turn to exchange moisture with the fresh air introduced from the air inlet 11. At this time, the temperature of the fresh air and the return air are similar, but the moisture content is still quite different. The return air can still be used to remove some of the moisture in the fresh air, flow through the exhaust coil 3 to take away some of the condensation heat, and finally be discharged to the outside from the exhaust vent 14.

[0097] The refrigerant circulation path is as follows: the refrigerant evaporates in the first supply air coil 5, absorbs heat, and transforms into low-pressure vapor. It then flows through the four-way reversing valve 2 and enters the compressor 1, where it is compressed into high-temperature, high-pressure refrigerant gas. It is then discharged from the exhaust port of the compressor 1. It then flows through the four-way reversing valve 2 and enters the exhaust air coil 3, where it initially dissipates heat to the exhaust air. It then flows through the return air coil 6 and dissipates heat to the return air. Finally, it condenses in the second supply air coil 4, reheating the low-temperature supply air after deep dehumidification. The refrigerant flowing out of the second supply air coil 4 is throttled by the throttling device 9, converted into a low-temperature, low-pressure two-phase refrigerant, and flows into the first supply air coil 5, continuing the above cycle.

[0098] The control method in the first dehumidification mode adjusts the dehumidification capacity by changing the speed of compressor 1. Return air sensor 18 detects the humidity of the indoor return air, obtains the actual humidity value of the return air, and adjusts the speed of compressor 1 based on the comparison result between the measured humidity value and the preset humidity value. If the measured humidity value is higher than the preset humidity value, the speed of compressor 1 is increased; if the measured humidity value is lower than the preset humidity value, the speed of compressor 1 is reduced.

[0099] The bypass vents are closed, allowing the fresh air entering from the air inlet 11 to flow through the heat exchange core 24 and perform moisture exchange with the return air.

[0100] The superheat at the intake port of compressor 1 is controlled by throttling device 9. The intake port superheat value of compressor 1 is obtained. Based on the comparison result between the intake port superheat value and the preset superheat value, the opening of throttling device 9 in the refrigerant circulation flow path is adjusted. If the intake port superheat value is higher than the preset superheat value, the opening of throttling device 9 is increased; if the intake port superheat value is not higher than the preset superheat value, the opening of throttling device 9 is decreased.

[0101] The indoor air quality is regulated by the supply fan 16. The return air sensor 18 detects the indoor carbon dioxide concentration and obtains the indoor carbon dioxide concentration value. The speed of the supply fan 16 is adjusted based on the comparison between the carbon dioxide concentration value and the preset concentration value. If the carbon dioxide concentration value is higher than the preset concentration value, the speed of the supply fan 16 is increased to increase the fresh air volume; if the carbon dioxide concentration value is lower than the preset concentration value, the speed of the supply fan 16 is reduced.

[0102] The exhaust fan 15 is linked with the supply fan 16 to adjust the rotation speed of the supply fan 16 and the rotation speed of the exhaust fan 15, so as to always maintain the exhaust volume of the exhaust fan 15 at 80% to 90% of the supply volume of the supply fan 16 to control the positive indoor pressure of the room.

[0103] The beneficial effect of the first dehumidification mode is that the return air coil 6 and exhaust air coil 3 achieve sufficient heat recovery from the indoor exhaust air. In addition to the conventional exhaust air coil 3, the return air coil 6 increases the heat exchange area on the condensing side, which helps to reduce the condensing temperature and improve the circulation performance of the heat pump system. The heat exchange core 24 and the heat pump system achieve excellent coordination. The sensible heat of the return air is used for heat recovery in the heat pump, while still maintaining a lower moisture content than the fresh air. This achieves preliminary dehumidification of the fresh air during the full heat exchange process, reducing the moisture load of the heat pump system.

[0104] Figure 4 Schematic diagram of the working principle of the dehumidification device of an embodiment of the present invention in the second dehumidification mode (hot and wet working condition).

[0105] Second dehumidification mode (hot and humid conditions)

[0106] In this mode, the air supplied to the room is entirely composed of outdoor fresh air. The first bypass damper 10 is opened, so that the air inlet 11 is connected to the return air outlet 13. Part of the air entering from the air inlet 11 is discharged to the supply air outlet 12 through the supply air path, and part of the air is diverted to flow through the first bypass damper 10 and directly bypass to the upstream side of the exhaust coil 3. After mixing with the return air on the upstream side, it flows through the exhaust coil 3 and is discharged from the exhaust outlet 14. It is suitable for high temperature and high humidity working conditions in summer.

[0107] The working status of each component of the dehumidification device is that the first bypass damper 10 is in the open state, and the working status of other components is the same as that of the first dehumidification mode, which will not be repeated here.

[0108] The air flow state is that compared with the first dehumidification mode, more fresh air is introduced. In addition to the part of the air entering from the air inlet 11 that is sent to the room, a part of the air is diverted to flow through the first bypass damper 10 and directly bypass the upstream side of the exhaust coil 3. After mixing with the return air on the upstream side, it takes away more condensation heat of the exhaust coil 3 together.

[0109] The refrigerant circulation flow path state in the second dehumidification mode is the same as the refrigerant circulation flow path state in the first dehumidification mode.

[0110] The control method in the second dehumidification mode is to adjust the dehumidification capacity by adjusting the speed of compressor 1, control the superheat of the air intake of compressor 1 by adjusting the opening of throttling device 9, and adjust the speed of supply fan 16 to adjust the indoor air quality. The exhaust fan 15 and supply fan 16 are linked together, and the control method is the same as in the first dehumidification mode. In addition, compared with the first dehumidification mode, the speed of supply fan 16 is increased to drive more fresh air into the air inlet 11.

[0111] The beneficial effect of the second dehumidification mode is that by opening the first bypass damper 10, or increasing the speed of the supply air fan 16, or simultaneously opening the first bypass damper 10 and increasing the speed of the supply air fan 16, a larger air volume is allowed to flow through the exhaust coil 3, thereby accelerating heat dissipation to achieve a larger dehumidification capacity and higher dehumidification energy efficiency.

[0112] Figure 5 Schematic diagram of the working principle of the dehumidification device according to an embodiment of the present invention in the first heating mode (severe cold conditions); Figure 6 Schematic diagram of the connection relationship of the refrigerant circulation flow path of the dehumidification device according to an embodiment of the present invention in the first heating mode (severe cold working conditions).

[0113] First heating mode (severe cold conditions)

[0114] In this mode, the air supplied to the room is entirely composed of outdoor fresh air. After being filtered, the outdoor fresh air undergoes heat exchange with the air in the exhaust air path in the supply air path, and its temperature rises. It is then heated by the first air supply coil 5 and sent into the room. It is suitable for low temperature and severe cold conditions in winter, such as conditions where the ambient temperature is below -10°C.

[0115] The dehumidification system components operate as follows: supply fan 16 and exhaust fan 15 are on, first and second bypass dampers 10 and 17 are closed, and the bypass vent is closed. Ports C and S of four-way reversing valve 2 are connected, allowing the exhaust coil 3 to communicate with the intake port of compressor 1. Ports D and E of four-way reversing valve 2 are connected, allowing the exhaust port of compressor 1 to communicate with the first supply coil 5. First check valve 7 is closed, second check valve 8 is open, throttling device 9 is adjusted as needed, and resistance element 25 is adjusted as needed.

[0116] The air flow path is as follows: outdoor fresh air is introduced from the air inlet 11, driven by the supply fan 16, and then flows through the air inlet filter 20 for preliminary purification. It then flows through the heat exchange core 24 to exchange heat and moisture with the return air. It then flows through the supply air filter 22 for deep purification. After flowing through the first supply air coil 5 and being heated, it is then delivered to the room through the supply air inlet 12. Indoor return air is introduced from the return air inlet 13, and driven by the exhaust fan 15, it then flows through the return air coil 6 for cooling and preliminary heat recovery. After being filtered and purified by the return air filter 21, it enters the heat exchange core 24 to exchange heat and moisture with the fresh air for further heat recovery, and is finally discharged to the outside through the exhaust air inlet 14. The temperature of the air flowing through the exhaust coil 3 is similar to that of the refrigerant in the exhaust coil 3, and almost no heat exchange occurs between the two.

[0117] The refrigerant circulation flow state is that the refrigerant evaporates and absorbs heat in the return air coil 6 and is transformed into low-pressure steam, flows through the four-way reversing valve 2 and enters the compressor 1, is compressed into high-temperature and high-pressure refrigerant gas, and then flows through the four-way reversing valve 2 and enters the first supply air coil 5. The high-temperature and high-pressure refrigerant gas condenses and dissipates heat in the first supply air coil 5, heating the fresh air flowing through, and the high-temperature and high-pressure refrigerant gas is transformed into a low-temperature and high-pressure refrigerant liquid. After being throttled by the throttling device 9, the low-temperature and high-pressure refrigerant is transformed into a low-temperature and low-pressure two-phase refrigerant and flows into the return air coil 6, continuing the above-mentioned cycle process.

[0118] The control method in the first heating mode adjusts the heating capacity by adjusting the speed of compressor 1. The supply air sensor detects the temperature of the indoor supply air, obtains the actual temperature value of the supply air, and adjusts the speed of compressor 1 based on the comparison result between the measured temperature value and the preset temperature value. If the measured temperature value is higher than the preset temperature value, the speed of compressor 1 is increased; if the measured temperature value is lower than the preset temperature value, the speed of compressor 1 is reduced.

[0119] The superheat at the intake port of compressor 1 is controlled by adjusting the opening of throttling device 9. The intake port superheat value of compressor 1 is obtained, and the opening of throttling device 9 is adjusted based on the comparison result between the intake port superheat value and the preset superheat value. If the intake port superheat value is higher than the preset superheat value, the opening of throttling device 9 is increased; if the intake port superheat value is not higher than the preset superheat value, the opening of throttling device 9 is decreased.

[0120] Indoor air quality is adjusted by adjusting the speed of the supply fan 16. The return air sensor 18 detects the carbon dioxide concentration of the indoor return air, obtains the carbon dioxide concentration of the return air, and adjusts the speed of the supply fan 16 based on the comparison result of the carbon dioxide concentration with the preset concentration value. If the carbon dioxide concentration value is higher than the preset concentration value, the speed of the supply fan 16 is increased to increase the fresh air volume; if the carbon dioxide concentration value is lower than the preset concentration value, the speed of the supply fan 16 is reduced.

[0121] The exhaust fan 15 is linked with the supply fan 16 to adjust the rotation speed of the supply fan 16 and the rotation speed of the exhaust fan 15, so as to always maintain the exhaust volume of the exhaust fan 15 at 80% to 90% of the supply volume of the supply fan 16 to control the positive indoor pressure of the room.

[0122] By adjusting the resistance element 25 , the temperature of the refrigerant in the exhaust coil 3 is made close to the temperature of the air flowing through the exhaust coil 3 .

[0123] The beneficial effect in the first heating mode is that the return air coil 6 serving as the evaporator is located before the heat exchange core 24 on the exhaust air flow path. The return air coil 6 is used to realize active heat recovery of the indoor return air waste heat, and the heat exchange core 24 is used to realize passive heat recovery of the remaining part. Active heat recovery is mainly used to increase its priority, ensuring sufficient heat recovery space for the heat pump system. The return air coil 6 will not frost and can achieve a stable supply air temperature, which can reach 30°C or higher.

[0124] A resistance element 25 is installed in the connecting pipe between the return air coil 6 and the exhaust air coil 3. This resistance element 25 is used to regulate the refrigerant temperature in the exhaust air coil 3. There is a temperature difference between the refrigerant's evaporation phase transition temperature in the return air coil 6 and the air temperature at the outlet of the heat exchange core 24. If the refrigerant's evaporation phase transition temperature in the return air coil 6 is lower than the air temperature at the outlet of the heat exchange core 24, the refrigerant will continue to absorb heat from the outlet of the heat exchange core 24, causing frost on the exhaust air coil 3. If the refrigerant's evaporation phase transition temperature in the return air coil 6 is higher than the air temperature at the outlet of the heat exchange core 24, the refrigerant will release heat to the outlet of the heat exchange core 24, causing the refrigerant on the inlet of the compressor 1 to reverse to a saturated or even two-phase state, risking liquid inhalation and wet compression. By adjusting the opening of the resistance element 25, the refrigerant's evaporation phase transition temperature in the return air coil 6 and the air temperature at the outlet of the heat exchange core 24 are kept close, or the difference between the two is maintained within a preset range, ensuring reliable system operation.

[0125] Figure 7 Schematic diagram of the working principle of the dehumidification device in the second heating mode according to an embodiment of the present invention.

[0126] Second heating mode

[0127] In this mode, the air supplied to the room is entirely composed of outdoor fresh air. The first bypass damper 10 is opened, so that the air inlet 11 is connected to the return air outlet 13. Part of the air entering from the air inlet 11 is discharged to the supply air outlet 12 through the supply air path, and part of the air is diverted to flow through the first bypass damper 10 and directly bypass to the upstream side of the exhaust coil 3. After being mixed with the return air on the upstream side, it is discharged from the exhaust vent 14. It is suitable for heating conditions above 0°C in winter.

[0128] The working status of each component of the dehumidification device is that the first bypass damper 10 is in the open state, the resistance element 25 is in the closed state, and the working status of the remaining components is the same as that of the first heating mode, which will not be repeated here.

[0129] The airflow path is as follows: outdoor fresh air is drawn in through the air inlet 11 and, driven by the supply fan 16, flows through the inlet air filter 20 for preliminary purification, then flows through the heat exchange core 24 to exchange heat and moisture with the return air, then flows through the supply air filter 22 for further purification, then flows through the first supply air coil 5 for heating, before being delivered to the room through the supply air inlet 12. Indoor return air is drawn in through the return air inlet 13 and, driven by the exhaust fan 15, flows through the return air coil 6 for preliminary heat recovery. After being filtered and purified by the return air filter 21, it flows through the heat exchange core 24 and the exhaust coil 3 for further heat recovery, before finally being discharged to the outside through the exhaust air inlet 14. In addition to the portion of air entering the room from the air inlet 11, a portion is diverted and flows through the first bypass damper 10 directly to the upstream side of the exhaust coil 3. There, it mixes with the return air and removes more condensation heat from the exhaust coil 3.

[0130] The refrigerant circulation flow state is that the refrigerant evaporates and absorbs heat in the return air coil 6 and the exhaust air coil 3 to be transformed into low-pressure steam, flows through the four-way reversing valve 2 and enters the compressor 1, is compressed into high-temperature and high-pressure refrigerant gas, then flows through the four-way reversing valve 2, enters the first supply air coil 5 to condense and dissipate heat, heats the fresh air flowing through, and then is throttled by the throttling device 9, transformed into a low-temperature and low-pressure two-phase refrigerant and flows into the return air coil 6, continuing the above cycle process.

[0131] The control method in the second heating mode is to adjust the heating capacity by adjusting the speed of compressor 1, control the superheat at the compressor 1's intake port by adjusting the opening of throttling device 9, and adjust the speed of supply fan 16 to adjust the indoor air quality. The exhaust fan 15 and supply fan 16 are linked together, and the control method is the same as in the first heating mode. In addition, compared to the first heating mode, the speed of supply fan 16 is increased to drive more fresh air into the air inlet 11.

[0132] The beneficial effect of the second heating mode is that it mainly uses the active heat recovery of the heat pump, supplemented by the passive heat recovery of a small amount of heat exchange core 24, so that the operation is stable and the heating effect is guaranteed; by opening the first bypass damper 10 and increasing the speed of the supply air fan 16, a larger air volume is allowed to flow through the exhaust coil 3, thereby increasing the evaporation temperature of the heat pump system and increasing the cycle energy efficiency.

[0133] Figure 8 Schematic diagram of the working principle of the dehumidification device in the internal circulation mode according to an embodiment of the present invention.

[0134] Internal circulation mode

[0135] In this mode, the air supplied to the room is all internally circulated return air. The return air entering the shell from the return air vent 13 is cooled and dehumidified by the first supply air coil 5 and reheated by the second supply air coil 4 before being sent into the room from the supply air vent 12. This mode is suitable for working conditions where it is not suitable to introduce fresh air, such as extreme humidity outdoors during the rainy season and severe outdoor air pollution.

[0136] The dehumidification system components are operating as follows: supply fan 16 and exhaust fan 15 are on, first bypass damper 10 and second bypass damper 17 are open, and the bypass vent is closed. Ports E and S of four-way reversing valve 2 are connected, allowing communication between the first supply air coil 5 and the intake port of compressor 1. Ports D and C of four-way reversing valve 2 are connected, allowing communication between the exhaust port of compressor 1 and the exhaust air coil 3. First check valve 7 is in the on state, second check valve 8 is in the off state, throttling device 9 is adjusted in opening as needed, and resistance element 25 is inactive.

[0137] The air flow path state is that the indoor return air is introduced from the return air vent 13, and driven by the exhaust fan 15, flows through the second bypass damper 17, passes through the first supply air coil 5 for cooling and dehumidification, and then passes through the second supply air coil 4 for reheating, and is then sent back to the room from the supply air vent 12. Outdoor air is introduced from the air inlet 11, flows through the first bypass damper 10, and then flows through the exhaust coil 3 to remove excess condensation heat, and is discharged to the outside through the exhaust vent 14. In actual operation, due to the greater resistance to flow through the heat exchange core 24, most of the return air will directly bypass the second bypass damper 17, and similarly, most of the intake air will bypass the first bypass damper 10; accordingly, a small amount of the two air streams will pass through the heat exchange core 24 for heat exchange, which is equivalent to still being able to introduce a small amount of fresh air in this mode.

[0138] The refrigerant circulation flow state is that the refrigerant evaporates and absorbs heat in the first air supply coil 5 and is transformed into low-pressure steam, flows through the four-way reversing valve 2 and enters the compressor 1, is compressed into high-temperature and high-pressure refrigerant gas, and then is discharged from the exhaust port of the compressor 1, and then flows through the four-way reversing valve 2 and enters the exhaust coil 3 to condense and release heat, and then flows through the return air coil 6. At this time, there is almost no air flowing through the return air coil 6, which is equivalent to flowing through a section of copper pipe, and then flows into the second air supply coil 4 to continue condensing and releasing heat to be transformed into a refrigerant supercooled liquid, and then flows through the first one-way valve 7, is throttled by the throttling device 9, and is transformed into a low-temperature and low-pressure two-phase refrigerant and returns to the first air supply coil 5, continuing the above-mentioned cycle process.

[0139] The control method in the internal circulation mode is to control the superheat of the refrigerant at the suction port of the compressor 1 by adjusting the opening of the throttling device 9, and control the indoor return air humidity by adjusting the frequency of the compressor 1. The supply fan 16 and the exhaust fan 15 adjust the speed as needed. When the demand for indoor dehumidification is large, the speed can be increased to increase the air volume.

[0140] The beneficial effect of internal circulation mode is that the first bypass damper 10 is opened, bypassing a small amount of incoming air to remove excess condensation heat from the heat pump system. Otherwise, in the high-power mode with high dehumidification capacity, the heat pump system's condensation temperature is likely to exceed the limit, and the indoor air supply temperature is too high, affecting user comfort. The second bypass damper 17 is opened, fully dehumidifying the return air and delivering it directly indoors. In conjunction with the heat pump system, this can be used to cope with high outdoor humidity during the rainy season or severe outdoor air pollution, where the introduction of fresh air is unsuitable. It can also achieve rapid dehumidification during the high indoor humidity stage during the initial startup of the equipment.

[0141] Figure 9 Schematic diagram of the working principle of the dehumidification device in heat exchange mode according to an embodiment of the present invention.

[0142] Hot swap mode

[0143] In this mode, the air supplied to the room is entirely composed of outdoor fresh air. The outdoor fresh air enters from the air inlet 11, is filtered, and undergoes heat exchange with the indoor air entering from the return air outlet 13 in the heat exchange core 24, and is then sent to the room from the air supply outlet 12. It is suitable for low-temperature operating conditions in transition seasons, for example, an ambient temperature of 14 to 16°C.

[0144] The working status of each component of the dehumidification device is that the heat pump system is closed, the refrigerant circulation flow path is not opened, the supply fan 16 and the exhaust fan 15 are turned on, the first bypass damper 10 and the second bypass damper 17 are closed, and the bypass vent is closed.

[0145] The air flow path is as follows: outdoor fresh air is introduced from the air inlet 11, driven by the air supply fan 16, flows through the air inlet filter 20 for preliminary purification, flows through the heat exchange core 24 to exchange heat and moisture with the return air, flows through the air supply filter 22 for deep purification, and is then delivered into the room through the air supply vent 12. Indoor return air is introduced from the return air vent 13, driven by the exhaust fan 15, flows through the return air filter 21 for filtration and purification, flows through the heat exchange core 24 to exchange heat and moisture with the fresh air, and is then discharged to the outside through the exhaust vent 14.

[0146] The control method in the heat exchange mode is to adjust the indoor air quality by adjusting the speed of the supply fan 16. The return air sensor 18 detects the carbon dioxide concentration in the room. If the carbon dioxide concentration is higher than the preset concentration, the speed of the supply fan 16 is increased to increase the fresh air volume; if the carbon dioxide concentration is not higher than the preset concentration, the speed of the supply fan 16 is reduced.

[0147] The exhaust fan 15 and the supply fan 16 are linked to maintain the exhaust air volume at 80% to 90% of the intake air volume at all times to control the positive indoor pressure of the room.

[0148] The beneficial effect of the heat exchange mode is that the heat exchange core 24 operates independently. When the outdoor humidity is not high and the temperature is low, the return air is used to heat the fresh air and then send it into the room. This mode achieves high efficiency and quietness, which is conducive to improving user experience.

[0149] Figure 10 Schematic diagram of the working principle of the dehumidification device in ventilation mode according to an embodiment of the present invention.

[0150] Ventilation mode

[0151] In this mode, the air supplied to the room is entirely composed of outdoor fresh air, which enters from the air inlet 11 and is sent to the room from the air supply vent 12 after being filtered. It is suitable for working conditions in transition seasons, that is, outdoor fresh air is suitable for directly entering the room.

[0152] The working status of each component of the dehumidification device is that the heat pump system is closed, the refrigerant circulation path is not opened, the supply fan 16 is opened, the exhaust fan 15 is closed, the first bypass damper 10 and the second bypass damper 17 are closed, and the bypass vent is opened.

[0153] The air flow path state is that outdoor fresh air is introduced from the air inlet 11, and under the drive of the air supply fan 16, it flows through the air inlet filter 20 in sequence to be initially purified, flows through the bypass vent of the heat exchange core 24, flows through the air supply air filter 22 to be deeply purified, and then is sent into the room from the air supply vent 12.

[0154] The control method in the ventilation mode is to adjust the indoor air quality by adjusting the speed of the supply fan 16. The return air sensor 18 detects the carbon dioxide concentration in the room. If the carbon dioxide concentration is higher than the preset concentration, the speed of the supply fan 16 is increased to increase the fresh air volume; if the carbon dioxide concentration is not higher than the preset concentration, the speed of the supply fan 16 is reduced.

[0155] The beneficial effect in the ventilation mode is that only the air supply fan 16 is operated, allowing fresh air to be introduced after being filtered, achieving an effect similar to mechanical bypass, which is beneficial to reducing operating energy consumption.

[0156] In summary, the dehumidification device disclosed herein has the following beneficial effects.

[0157] The return air coil 6 is provided in the return air section of the exhaust air flow path, which broadens the range of operating conditions of the dehumidification device. In the first heating mode (severe cold conditions), the return air coil 6, which serves as an evaporator, is located before the heat exchange core 24 on the air flow path. The return air coil 6 is used to complete the active heat recovery of the indoor return air waste heat, and the heat exchange core 24 is used to realize the passive heat recovery of the remaining part. Active heat recovery is given priority and its priority is increased, which ensures sufficient heat recovery space for the heat pump system. The return air coil 6, which serves as an evaporator, will not frost, and can eventually achieve a stable supply air temperature of 30°C or higher. In the second dehumidification mode (hot and humid conditions) and the second heating mode, in addition to the conventional exhaust coil 3, the return air coil 6 is provided to increase the heat exchange area on the condensation side or the evaporation side, which is conducive to lowering the condensation temperature or raising the evaporation temperature, thereby improving the circulation performance and capacity of the heat pump system.

[0158] A resistance element 25 is provided on the connecting pipe between the return air coil 6 and the exhaust air coil 3. The resistance element 25 is used to regulate the temperature of the refrigerant in the exhaust air coil 3. By adjusting the opening of the resistance element 25, the temperature of the refrigerant in the exhaust air coil 3 and the temperature of the air flowing through the exhaust air coil 3 are made close or the difference between the two is maintained within a preset range, and almost no heat exchange occurs between the two, thereby ensuring reliable operation of the system.

[0159] A first bypass damper 10 is provided between the air inlet section of the air supply path and the air outlet section of the air exhaust path. In the second heating mode and the second dehumidification mode (heat and humidity working conditions), the first bypass damper 10 is opened to allow additional air to flow through the exhaust coil 3, which can enhance the heat exchange between the exhaust coil 3 and the air flowing through it. In the two modes, the evaporation temperature is increased and the condensation temperature is decreased, respectively, which is beneficial to improving the energy efficiency of the heat pump cycle, or improving the heating or dehumidification capacity at the same power consumption. In the internal circulation mode, the first bypass damper 10 is opened to bypass a small amount of the air intake to take away the additional condensation heat of the heat pump system. Otherwise, in the strong mode with a large dehumidification amount, the condensation temperature of the heat pump system is likely to exceed the limit, and the air supply temperature to the room is too high, affecting the comfort of the user.

[0160] A second bypass damper 17 is provided between the return air section of the exhaust air path and the supply air section of the supply air path. When the first bypass damper 10 and the second bypass damper 17 are opened, an internal circulation mode can be realized in conjunction with the heat pump system. This can cope with situations where it is not suitable to introduce fresh air, such as high outdoor humidity or serious outdoor air pollution during the rainy season. It can also realize rapid indoor dehumidification under conditions where the indoor humidity load is particularly high, such as the return of the south wind.

[0161] The dehumidifier is equipped with a bypass vent. Opening the bypass vent can significantly reduce the amount of fresh air passing through the heat exchange core 24, thus shielding the heat exchange core 24. In ventilation mode, only filtered fresh air is allowed to be introduced, achieving an effect similar to mechanical bypass, which helps reduce operating energy consumption.

[0162] The heat exchange core 24 can operate independently. When the outdoor humidity is not high and the temperature is low, the return air is used to heat the fresh air and then send it into the room. This mode achieves high efficiency and quietness, which is conducive to improving user experience.

[0163] The dehumidification device can operate in multiple modes. Through the reasonable arrangement of the heat exchanger of the heat pump system combined with the heat exchange core 24, it can realize the operation of multiple working conditions in a large temperature zone. In summer, it is divided into the first dehumidification mode and the second dehumidification mode (hot and humid working conditions) according to the ambient temperature; in winter, it is divided into the first heating mode (severe cold working conditions) and the second heating mode according to the ambient temperature; in the transition season, it is divided into heat exchange mode and ventilation mode according to the ambient temperature and humidity. In order to cope with some extreme special working conditions, it also has an internal circulation mode. By switching the working states of each component in the air flow path and the refrigerant circulation flow path, a variety of operating modes can be realized, and detailed distinction and adaptation of the working conditions throughout the year are achieved. It is applicable to the large temperature zone of -15 to 45°C. The appropriate working conditions can be matched as needed to realize the year-round operation of the dehumidification device under multiple working conditions in a large temperature zone.

[0164] The above embodiments do not fully display all the components of the refrigerant cycle and the air duct. During implementation, common refrigeration accessories such as high-pressure liquid storage tanks, gas-liquid separators, oil separators, filters, dryers, etc. are set in the refrigerant circuit, and air treatment accessories such as silencers, humidifiers, heaters, and sterilization devices are set in the air duct. Different air supply nozzles and return air grilles are selected, the position of the fan is changed, or heat exchangers, fans and air valves are added without departing from the spirit of the technical solution of the present invention. These cannot be regarded as substantial improvements to the present invention and should fall within the scope of protection of the present invention.

[0165] So far, the embodiments of the present invention have been described in detail with reference to the accompanying drawings. Based on the above description, those skilled in the art should have a clear understanding of the present invention.

[0166] It should be noted that any implementations not shown or described in the drawings or the main text of the specification are known to those skilled in the art and are not described in detail. Furthermore, the above definitions of the various components are not limited to the specific structures and shapes described in the embodiments, and can be easily modified or replaced by those skilled in the art.

[0167] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above are only specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A dehumidification device, characterized in that: include: An air flow path, comprising an air supply flow path and an air exhaust flow path, wherein the air supply flow path and the air exhaust flow path intersect with each other, an air inlet and an air supply vent are provided at both ends of the air supply flow path, and a return air vent and an air exhaust vent are provided at both ends of the air exhaust flow path; a heat exchange core, arranged at the intersection of the air supply flow path and the air exhaust flow path; A refrigerant circulation circuit includes a compressor, a first air supply coil, a second air supply coil, and a return air coil connected to each other; The first supply air coil and the second supply air coil are arranged on the upstream side of the supply air outlet, and the return air coil is arranged in the exhaust air flow path and is located on the downstream side of the return air outlet and the upstream side of the heat exchange core.

2. The dehumidification device according to claim 1, characterized in that The refrigerant circulation flow path further includes: an exhaust coil; The exhaust coil is arranged on the upstream side of the exhaust vent and is located on the downstream side of the heat exchange core.

3. The dehumidification device according to claim 2, characterized in that: The refrigerant circulation flow path further includes a resistance element, and the resistance element is provided on the connection flow path between the return air coil and the exhaust air coil.

4. The dehumidification device according to claim 2, characterized in that: The refrigerant circulation circuit further includes a first one-way valve and a second one-way valve; The first one-way valve is provided on the connecting flow path between the first air supply coil and the second air supply coil; A bypass branch is provided between the first supply air coil and the return air coil, and the second one-way valve is provided on the bypass branch.

5. The dehumidification device according to claim 4, characterized in that: When the first one-way valve is turned on and the second one-way valve is turned off, the refrigerant flows from the second air supply coil into the first air supply coil; When the second one-way valve is turned on and the first one-way valve is turned off, the refrigerant flows from the first supply air coil into the return air coil.

6. The dehumidification device according to claim 1, characterized in that: Also includes: a first bypass damper, disposed between an air inlet section of the air supply flow path and an air outlet section of the air outlet flow path, the first bypass damper being adjustable to switch between an open state and a closed state; when the first bypass damper is in the open state, the air inlet and the air outlet are in communication; The second bypass damper is arranged between the return air section of the exhaust air flow path and the supply air section of the supply air flow path. The second bypass damper can be adjusted to switch between an open state and a closed state. When the second bypass damper is in an open state, the supply air outlet and the return air outlet are connected.

7. The dehumidification device according to claim 6, characterized in that: When the first bypass damper is in an open state and the second bypass damper is in a closed state, part of the air entering from the air inlet is discharged to the air supply outlet through the air supply path, and the other part is discharged to the air exhaust outlet through the first bypass damper.

8. The dehumidification device according to claim 1, characterized in that Also includes: an intake air sensor, disposed on the downstream side of the air inlet, for detecting the temperature and humidity of the intake air; and / or, The return air sensor is arranged at the downstream side of the return air outlet and is used to detect the temperature, humidity and carbon dioxide concentration of the return air.

9. A method for controlling a dehumidification device, characterized in that: include: Obtaining a measured humidity value of return air of the dehumidification device according to claims 1 to 8; Based on the comparison result of the measured humidity value and the preset humidity value, the rotation speed of the compressor included in the dehumidification device is adjusted.

10. The control method of the dehumidification device according to claim 9, characterized in that: When the measured humidity value is higher than the preset humidity value, increasing the speed of the compressor; When the measured humidity value is not higher than the preset humidity value, the compressor speed is reduced.

11. The control method of the dehumidification device according to claim 9, characterized in that: Also includes: Obtaining a superheat value of the suction port of the compressor; Based on the comparison result of the air intake superheat value and the preset superheat value, the opening of the throttling device in the refrigerant circulation flow path of the dehumidification device is adjusted.

12. The control method of the dehumidification device according to claim 11, characterized in that: When the superheat value of the air intake port is higher than a preset superheat value, increasing the opening of the throttling device; When the superheat value of the air intake port is not higher than the preset superheat value, the opening of the throttling device is reduced.

13. The control method of the dehumidification device according to claim 9, characterized in that: Also includes: Obtaining a carbon dioxide concentration value of the return air of the dehumidification device; Based on the comparison result of the carbon dioxide concentration value and the preset concentration value, the speed of the air supply fan of the dehumidification device is adjusted.

14. The control method of the dehumidification device according to claim 13, characterized in that: When the carbon dioxide concentration value is higher than a preset concentration value, increasing the speed of the air supply fan; When the carbon dioxide concentration value is not higher than the preset concentration value, the rotation speed of the air supply fan is reduced.

15. The control method of the dehumidification device according to claim 14, characterized in that: Also includes: The exhaust fan and the supply fan included in the dehumidification device are adjusted so that the exhaust volume of the exhaust fan is 80% to 90% of the supply volume of the supply fan.

16. The control method of the dehumidification device according to claim 9, characterized in that: Also includes: Obtaining a measured temperature value of the supply air of the dehumidification device; Based on the comparison result of the measured temperature value and the preset temperature value, the speed of the compressor is adjusted.

17. The control method of the dehumidification device according to claim 9, characterized in that: Also includes: determining an operating mode of the dehumidification device; Based on the operating mode, the speed of the supply fan and / or the exhaust fan of the dehumidification device is adjusted to meet the set conditions.

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