Air conditioning unit and control method thereof

Abstract

The invention discloses an air conditioning unit and a control method thereof.The air conditioning unit comprises a fresh air channel, two stages of surface air coolers and an air return structure, the fresh air channel is provided with an air feeder, and the two stages of surface air coolers are the first-stage surface air cooler and the second-stage surface air cooler which are sequentially arranged in the fresh air channel in the air feeding direction; a liquid inlet of the first-stage surface air cooler and a liquid inlet of the second-stage surface air cooler are both connected with a liquid supply header pipe, a liquid outlet of the first-stage surface air cooler can be connected with a liquid inlet of the second-stage surface air cooler or a liquid return header pipe in a switching mode, and a liquid outlet of the second-stage surface air cooler is connected with the liquid return header pipe. The air return structure comprises a first-stage air return structure used for leading indoor return air into the air inlet side of the first-stage surface air cooler. The operation state of the surface air cooler and the air return state of the air return structure can be changed according to different use requirements of users, fresh air and return air are utilized at the same time, the effects of accurately controlling the indoor humidity and preventing excessive dehumidification are achieved, and the indoor comfort degree is remarkably improved.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning units, and in particular to an air conditioning unit capable of preventing excessive dehumidification and a control method thereof. Background Art

[0002] According to the data revealed by the China Building Energy Consumption Report, in 2020, the energy consumption of the entire construction process in my country accounted for 44.9% of the total national energy consumption, of which the energy consumption of building operation accounted for as high as 21.2%. Among the energy consumption of building operation, the energy consumption of air-conditioning systems is particularly prominent, accounting for more than 60%, and this proportion shows a continuous upward trend.

[0003] In the research and application of energy saving in air-conditioning systems, the medium-temperature water energy-saving system has attracted much attention because it can significantly improve the efficiency of the main unit. Specifically, by increasing the inlet temperature of the chilled water, such as from the commonly used 11°C to a higher temperature (for example, by 4°C), the main unit's additional temperature can be increased accordingly (such as by 3.5°C), thereby achieving an approximately 12% increase in the main unit's energy efficiency. However, this improvement measure also brings new problems: increasing the supply temperature of chilled water will cause the dehumidification capacity of commercial terminal units to drop significantly, affecting the user experience.

[0004] Traditional air-conditioning units usually lack the function of autonomously controlling indoor humidity. When users turn on the cooling and dehumidification mode of the air conditioner indoors, after a long period of operation, the user will often feel dry throat and discomfort due to excessive dehumidification caused by the cooling process. Compared with the indoor environment of the same temperature with higher humidity, users will feel less comfortable than the latter after a period of time at the same temperature. In order to alleviate this discomfort, users often need to manually adjust the air-conditioning temperature or turn off the air-conditioning to warm up, especially when sleeping at night. After turning on the air-conditioning and waking up in the morning, they often find that the indoor dehumidification is excessive, which seriously affects the comfort of the human body. These problems are all caused by excessive dehumidification of the air-conditioning system, which not only causes changes in the perceived temperature, but also causes discomfort to users. In order to cope with the situation of excessive dehumidification, the existing technology often requires the introduction of an additional humidification system, but this not only increases the complexity and cost of the unit, but also does not meet the energy-saving requirements.

[0005] Therefore, how to design an air-conditioning unit with a simple structure and the ability to flexibly match different usage requirements and a control method thereof is a technical problem that needs to be urgently solved in the industry. Summary of the invention

[0006] In order to solve the defects of existing air-conditioning units with single function and prone to over-dehumidification, the present invention proposes an air-conditioning unit and a control method thereof. The air-conditioning unit is designed with a two-stage surface cooler and a return air structure. The operating state of the surface cooler and the return air state of the return air structure can be changed according to different usage requirements of users, and fresh air and return air can be used at the same time to achieve the effect of accurately controlling indoor humidity and preventing over-dehumidification, thereby significantly improving indoor comfort.

[0007] The technical solution adopted by the present invention is to design an air-conditioning unit, including: a fresh air duct, a two-stage surface cooler and a return air structure. The fresh air duct is equipped with a blower. The two-stage surface cooler is a first-stage surface cooler and a second-stage surface cooler which are arranged in the fresh air duct in sequence along the air supply direction. The liquid inlet of the first-stage surface cooler and the liquid inlet of the second-stage surface cooler are both connected to the liquid supply main pipe. The liquid outlet of the first-stage surface cooler can be switched to connect to the liquid inlet of the second-stage surface cooler or the return liquid main pipe. The liquid outlet of the second-stage surface cooler is connected to the return liquid main pipe. The return air structure includes a first-stage return air structure for introducing indoor return air into the air inlet side of the first-stage surface cooler.

[0008] Furthermore, the return air structure also includes a secondary return air structure for introducing indoor return air into the air inlet side of the secondary surface cooler.

[0009] Furthermore, the first-level return air structure includes: a first-level return air inlet and a first-level return air fan, and the first-level return air inlet is located on the air inlet side of the first-level surface cooler; the second-level return air structure includes: a second-level return air inlet and a second-level return air fan, and the second-level return air inlet is located between the air outlet side of the first-level surface cooler and the air inlet side of the second-level surface cooler.

[0010] Furthermore, the liquid inlet of the primary cooler and the liquid inlet of the secondary cooler are both connected to the liquid supply main pipe through a control valve, and the control valve is used to adjust the liquid supply amount of the primary cooler and the secondary cooler.

[0011] Further, the air conditioning unit can operate in at least one of a fast dehumidification state, a cooling without dehumidification state, and a cooling and humidification state;

[0012] In the fast dehumidification state, the blower is turned off, the air inlet side of the first-stage surface cooler introduces indoor return air, and the liquid outlet of the first-stage surface cooler is connected to the liquid return main pipe;

[0013] In the cooling but not dehumidifying state, the blower is turned on, the air inlet side of the first-stage surface cooler does not introduce indoor return air, and the liquid outlet of the first-stage surface cooler is connected to the liquid inlet of the second-stage surface cooler;

[0014] In the cooling and humidifying state, the blower is turned on, the air inlet side of the first-stage surface cooler introduces indoor return air, and the liquid outlet of the first-stage surface cooler is connected to the liquid inlet of the second-stage surface cooler.

[0015] Furthermore, in the rapid dehumidification state, the liquid supply amount of the first-stage surface cooler and the second-stage surface cooler is the same; in the refrigeration without dehumidification state and the refrigeration humidification state, the liquid supply amount of the first-stage surface cooler is greater than that of the second-stage surface cooler.

[0016] Furthermore, the air inlet side of the two-stage surface cooler introduces indoor return air in the rapid dehumidification state, the cooling without dehumidification state, and the cooling and humidification state.

[0017] The present invention also provides a control method for an air conditioning unit, and the control method is applied to the above-mentioned air conditioning unit, comprising:

[0018] Detecting the actual humidity of the indoor environment and analyzing the actual humidity With user set humidity Humidity deviation

[0019] According to humidity deviation The size of the air conditioning unit is selected according to its operating status.

[0020] Further, selecting the operating state of the air conditioning unit according to the analysis result includes:

[0021] when When the air conditioner enters the rapid dehumidification state;

[0022] and / or when When the air conditioner enters the cooling but not dehumidifying state;

[0023] and / or when When the air conditioning unit enters the cooling and humidification state;

[0024] in, α1 and α2 are the set humidity values.

[0025] Furthermore, the control method also includes:

[0026] When the air conditioning unit enters the fast dehumidification state, according to the humidity deviation Control the return air volume of the return air structure;

[0027] And / or when the air conditioning unit enters the cooling but not dehumidifying state, the actual temperature of the indoor environment is detected and the temperature deviation ΔT between the actual temperature T1 and the user set temperature T2 is analyzed, and the return air volume of the return air structure is controlled according to the size of the temperature deviation ΔT;

[0028] And / or when the air conditioning unit enters the cooling and humidifying state, the return air structure is controlled to operate at a set mid-range return air volume.

[0029] Furthermore, according to the humidity deviation Controlling the return air volume of the return air structure includes:

[0030] when When the return air structure is running at the set low return air volume;

[0031] when When the return air structure operates at the set mid-range return air volume;

[0032] when When the return air structure is running at the set high return air volume;

[0033] Among them, α3 and α4 are set humidity values.

[0034] Further, controlling the return air volume of the return air structure according to the size of the temperature deviation ΔT includes:

[0035] When 0℃≤ΔT<β1, the return air structure operates at the set low return air volume;

[0036] When β1≤ΔT<β2, the return air structure operates at the set mid-range return air volume;

[0037] When β2≤ΔT, the return air structure operates at the set high return air volume;

[0038] Among them, ΔT=T1-T2, β1 and β2 are set temperature values.

[0039] Furthermore, controlling the return air volume of the return air structure according to the size of the temperature deviation ΔT also includes: when ΔT<0°C, turning off the air supply fan and the return air structure.

[0040] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0041] 1. Design of two-stage surface cooler and one-stage return air structure can change the operation state of the surface cooler and the return air state of the one-stage return air structure according to different user requirements, and use both fresh air and return air to achieve accurate control of indoor humidity, prevent excessive dehumidification, and significantly improve indoor comfort;

[0042] 2. Design a two-stage return air structure to introduce indoor return air into the air inlet side of the two-stage surface cooler. The temperature of the mixed gas is adjusted through the two-stage return air structure to avoid the supply air temperature being too low after the secondary cooling. In addition, the indoor return air is used to supplement the fresh air volume. There is no need to design an additional exhaust duct, which simplifies the air duct structure.

[0043] 3. The air conditioning unit can be switched to different operating states to perform indoor dehumidification, cooling without dehumidification, cooling and humidification, etc., especially the return water of the first-stage surface cooler can be recovered and combined with fresh air and return air to humidify the room. There is no need to add additional humidifiers and other devices, so that one machine can be used for multiple purposes;

[0044] 4. Autonomously adjust the operating status of the air-conditioning unit according to indoor environmental parameters, improve the accuracy of indoor humidity and / or indoor temperature control, so that the indoor environment is always maintained at a comfortable level and optimize the user experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The present invention is described in detail below with reference to the embodiments and accompanying drawings, wherein:

[0046] Figure 1 is a schematic diagram of a fresh air channel in a preferred embodiment of the present invention;

[0047] Figure 2 It is a schematic diagram of the pipeline connection of the two-stage surface cooler of the present invention;

[0048] Figure 3 It is a schematic diagram of liquid flow when the two-stage surface cooler of the present invention works independently;

[0049] Figure 4 It is a schematic diagram of liquid flow when the two-stage surface cooler of the present invention is connected and working;

[0050] Figure 5 Schematic diagram of air flow in the fresh air channel of the present invention in a rapid dehumidification state;

[0051] Figure 6 It is a schematic diagram of the air flow of the fresh air channel of the present invention in the cooling but not dehumidifying state;

[0052] Figure 7 It is a schematic diagram of the air flow of the fresh air channel of the present invention in the cooling and humidification state;

[0053] Figure 8 It is a flow chart of the control method of the present invention;

[0054] Description of the drawings: 1. Fresh air duct; 11. Air inlet; 12. Air outlet; 13. Primary return air vent; 14. Secondary return air vent; 2. Primary surface cooler; 3. Secondary surface cooler; 4. Primary return air fan; 5. Secondary return air fan; 6. Liquid supply main pipe; 7. Liquid return main pipe; 8. Control valve; 9. Switch valve. DETAILED DESCRIPTION

[0055] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0056] like Figure 1As shown, the air-conditioning unit proposed in the present invention includes: a fresh air duct 1, a primary surface cooler 2, a secondary surface cooler 3 and a return air structure. The air inlet 11 of the fresh air duct 1 is connected to the outdoors, and the air outlet 12 is connected to the indoors. The fresh air duct 1 is equipped with an air supply fan. When the air supply fan is turned on, the outdoor fresh air is driven to flow from the air inlet 11 of the fresh air duct 1 to the air outlet 12. The primary surface cooler 2 and the secondary surface cooler 3 are sequentially arranged in the fresh air duct 1 along the air supply direction. After the outdoor fresh air enters the fresh air duct 1, it first passes through the primary surface cooler 2, then passes through the secondary surface cooler 3, and then flows to the air outlet 12 of the fresh air duct 1.

[0057] The return air structure is used to introduce indoor return air into the fresh air duct 1. Specifically, the return air structure includes a first-level return air structure, which can introduce indoor return air into the air inlet side of the first-level surface cooler 2. Since the first-level surface cooler 2 is located upstream of the air supply of the second-level surface cooler 3, the indoor return air sent to the air inlet side of the first-level surface cooler 2 will continue to flow to the second-level surface cooler 3 after passing through the first-level surface cooler 2.

[0058] like Figures 2 to 4 As shown, the liquid inlet of the primary cooler 2 and the liquid inlet of the secondary cooler 3 are both connected to the liquid supply main pipe 6, and the liquid outlet of the primary cooler 2 and the liquid outlet of the secondary cooler 3 are both connected to the return liquid main pipe 7, but the liquid outlet of the primary cooler 2 can be switched to be connected to the liquid inlet of the secondary cooler 3, that is, the return water of the primary cooler 2 and the supply water of the liquid supply main pipe 6 are mixed and flow into the secondary cooler 3.

[0059] By designing a two-stage surface cooler and a one-stage return air structure, the present invention can change the operating state of the surface cooler and the return air state of the one-stage return air structure according to different user requirements, and utilize the return water, fresh air and indoor return air of the one-stage surface cooler 2 at the same time. By increasing the inlet water temperature of the two-stage surface cooler 3 and the gas temperature on the air inlet side of the one-stage surface cooler 2, the temperature and humidity of the air flow after being processed by the two-stage surface cooler can be adjusted, thereby achieving the effect of accurately controlling the indoor humidity and preventing excessive dehumidification, thereby significantly improving the indoor comfort.

[0060] like Figure 1 As shown, in a preferred embodiment of the present invention, the return air structure also includes: a secondary return air structure, which can introduce the indoor return air into the air inlet side of the secondary surface cooler 3. The indoor return air sent to the air inlet side of the secondary surface cooler 3 will not pass through the primary surface cooler 2. After passing through the secondary surface cooler 3, this part of the indoor return air will flow to the air outlet 12 of the fresh air duct 1.

[0061] In more detail, on the basis that the return air structure includes a primary return air structure and a secondary return air structure, the working state of the return air structure is divided into three cases:

[0062] The first type is that the primary return air structure is opened and the secondary return air structure is closed, and the indoor return air is introduced into the air inlet side of the primary surface cooler 2, and is sent to the room through the primary surface cooler 2 and the secondary surface cooler 3 in sequence;

[0063] The second type is that the primary return air structure is closed and the secondary return air structure is opened, the indoor return air is introduced into the air inlet side of the secondary surface cooler 3, and the indoor return air is sent to the room through the secondary surface cooler 3;

[0064] The third type, both the primary return air structure and the secondary return air structure are opened, and the indoor return air is introduced into the air inlet side of the primary surface cooler 2 and the air inlet side of the secondary surface cooler 3. The return air introduced into the air inlet side of the primary surface cooler 2 is successively sent to the room through the primary surface cooler 2 and the secondary surface cooler 3, and the return air introduced into the air inlet side of the secondary surface cooler 3 is sent to the room through the secondary surface cooler 3.

[0065] The advantage of this design is that the indoor return air is introduced into the air inlet side of the secondary surface cooler 3 through the secondary return air structure, and the indoor return air is used to adjust the gas temperature on the air inlet side of the secondary surface cooler 3 to avoid the supply air temperature being too low after the secondary cooling, and the indoor return air is used to supplement the fresh air volume, without the need to design an additional exhaust duct, simplifying the air duct structure.

[0066] like Figure 1 As shown, in some feasible embodiments of the present invention, the structures of the first-level return air structure and the second-level return air structure are similar, and each level of the return air structure is designed with a corresponding return air outlet. The return air outlet of the first-level return air structure is the first-level return air outlet 13, and the return air outlet of the second-level return air structure is the second-level return air outlet 14.

[0067] Specifically, the primary return air vent 13 and the secondary return air vent 14 are both provided on the fresh air passage 1, and the secondary return air vent 14 is located between the air outlet side of the primary cooler 2 and the air inlet side of the secondary cooler 3, and the indoor return air enters the fresh air passage 1 through the return air vent. In actual application, a baffle can be designed at the return air vent, and the movement of the baffle can be controlled to close or open the return air vent, which acts as an air valve. By designing the return air vent at different positions in the fresh air passage 1, the indoor return air can be accurately and reliably sent to the air inlet side of the corresponding cooler, and switching the switch state of the return air vent can flexibly adjust the mixing ratio of the return air and the fresh air, thereby ensuring that the air supply temperature and humidity meet the user's needs and improve the overall efficiency of the unit.

[0068] Each return air outlet is equipped with a return air fan with adjustable wind speed. The first-level return air fan 4 is arranged at the first-level return air outlet 13. When the first-level return air fan 4 is working, it drives the indoor return air to flow into the first-level return air outlet 13. The second-level return air fan 5 is arranged at the second-level return air outlet 14. When the second-level return air fan 5 is working, it drives the indoor return air to flow into the second-level return air outlet 14. The advantage of this design is that the wind speed of the return air can be flexibly adjusted according to actual needs to change the return air volume introduced into the first-level return air outlet 13 and the second-level return air outlet 14, and keep the temperature and humidity of the air supply stable, so as to better adapt to different indoor environments and load changes.

[0069] like Figures 2 to 4 As shown, in some feasible embodiments of the present invention, the liquid inlet of the primary cooler 2 and the liquid inlet of the secondary cooler 3 are both connected to the liquid supply main pipe 6 through the control valve 8, and the control valve 8 is used to adjust the liquid supply amount of the primary cooler 2 and the secondary cooler 3.

[0070] Specifically, in order to simplify the connection structure, the control valve 8 can adopt a three-way valve, the first end of the three-way valve is connected to the liquid supply main pipe 6, the second end is connected to the liquid inlet of the first-level surface cooler 2, and the third end is connected to the liquid inlet of the second-level surface cooler 3. When in use, the opening of the second end and the third end of the three-way valve is controlled to adjust the liquid supply amount of the first-level surface cooler 2 and the second-level surface cooler 3.

[0071] In addition, the liquid outlet of the first-stage cooler 2 is connected to the liquid inlet and the liquid return main pipe 7 of the second-stage cooler 3 through the switch valve 9. The switch valve 9 is used to switch the connection state of the liquid outlet of the first-stage cooler 2. When the switch valve 9 is in the first state, the liquid outlet of the first-stage cooler 2 and the liquid return main pipe 7 are connected, and the two-stage coolers are connected in parallel between the liquid supply main pipe 6 and the liquid return main pipe 7, and each works independently; when the switch valve 9 is in the second state, the liquid outlet of the first-stage cooler 2 and the liquid inlet of the second-stage cooler 3 are connected, and the liquid outlet of the first-stage cooler 2 and the liquid return main pipe 7 are blocked. The return water flowing out of the first-stage cooler 2 and the supply water of the liquid supply main pipe 6 are mixed and flow into the second-stage cooler 3, thereby increasing the inlet water temperature of the second-stage cooler 3.

[0072] This design ensures that each stage of the surface cooler receives the appropriate cooling medium (usually water) only when needed to perform different functions by precisely adjusting the liquid supply to the two-stage surface cooler to prevent excessive dehumidification.

[0073] Based on the pipe connection structure of the two-stage surface cooler and the one-stage return air structure, the air-conditioning unit can operate in at least one of the following states: rapid dehumidification state, cooling without dehumidification state, and cooling and humidification state. Each state is introduced in detail below.

[0074] In the rapid dehumidification state, the air supply fan is turned off, the air inlet side of the first-stage surface cooler 2 introduces indoor return air (the first-stage return air structure is open), and the liquid outlet of the first-stage surface cooler 2 is connected to the return liquid main pipe 7. The two-stage surface coolers perform cooling and dehumidification independently, and the indoor return air is sent back to the room after double dehumidification by the first-stage surface cooler 2 and the second-stage surface cooler 3, so that the actual humidity of the indoor environment drops rapidly, thereby achieving the effect of rapid dehumidification.

[0075] In the cooling but not dehumidifying state, the blower is turned on, the air inlet side of the first-stage cooler 2 does not introduce indoor return air (the first-stage return air structure is closed), and the liquid outlet of the first-stage cooler 2 is connected to the liquid inlet of the second-stage cooler 3. The high-temperature and high-humidity outdoor fresh air is cooled and dehumidified by the first-stage cooler 2 to become low-temperature and low-humidity gas, and the return water of the first-stage cooler 2 is mixed with the supply water of the liquid supply main pipe 6 and flows into the second-stage cooler 3, which increases the inlet water temperature of the second-stage cooler 3 and exceeds the dew point temperature of the mixed gas on the air inlet side of the second-stage cooler 3. Therefore, the mixed gas is only cooled but not dehumidified when passing through the second-stage cooler 3.

[0076] In the refrigeration and humidification state, the blower is turned on, and the air inlet side of the first-stage cooler 2 introduces indoor return air (the first-stage return air structure is open), and the liquid outlet of the first-stage cooler 2 is connected to the liquid inlet of the second-stage cooler 3. The high-temperature and high-humidity outdoor fresh air is first mixed with the indoor return air introduced from the air inlet side of the first-stage cooler 2, reducing the dry bulb temperature of the outdoor air and the dew point temperature of the mixed gas in this section, thereby greatly reducing the dehumidification effect of the first-stage cooler 2, so that the mixed gas flowing through the first-stage cooler 3 maintains humidity, and the return water of the first-stage cooler 2 is mixed with the water supply of the liquid supply main pipe 6 and flows into the second-stage cooler 3, which increases the water inlet temperature of the second-stage cooler 3 and exceeds the dew point temperature of the mixed gas on the air inlet side of the second-stage cooler 3. Therefore, the mixed gas passes through the second-stage cooler 3 and is only cooled without dehumidification. Under the joint action of the first-stage cooler 2 and the second-stage cooler 3, the effect of refrigeration and humidification is achieved.

[0077] In order to improve the operating effect of the air-conditioning unit under different conditions, in the rapid dehumidification state, the liquid supply amount of the first-stage surface cooler 2 and the second-stage surface cooler 3 is the same, so that both stages of the surface cooler have a good dehumidification effect; in the refrigeration without dehumidification state and the refrigeration humidification state, the liquid supply amount of the first-stage surface cooler 2 is greater than that of the second-stage surface cooler 3. At this time, the cooling medium allocated to the second-stage surface cooler 3 is less, and the return water of the first-stage surface cooler 2 can be mixed in to effectively increase the inlet liquid temperature of the second-stage surface cooler 3, thereby weakening the dehumidification capacity of the second-stage surface cooler 3.

[0078] like Figure 1As shown, in a preferred embodiment, a secondary return air structure is designed between the primary surface cooler 2 and the secondary surface cooler 3. The secondary return air structure introduces indoor return air in the rapid dehumidification state, the cooling without dehumidification state, and the cooling and humidification state, that is, the corresponding working state of the secondary return air structure is added in each state introduced above.

[0079] like Figure 5 As shown, in the rapid dehumidification state, the air supply fan is turned off, and the air inlet sides of the first-stage surface cooler 2 and the second-stage surface cooler 3 both introduce indoor return air (the first-stage return air structure and the second-stage return air structure are both open), the liquid outlet of the first-stage surface cooler 2 is connected to the return liquid main pipe 7, and the two-stage surface coolers perform cooling and dehumidification independently. The indoor return air is sent back to the room after double dehumidification by the first-stage surface cooler 2 and the second-stage surface cooler 3, with a larger return air volume and a faster dehumidification effect.

[0080] like Figure 6 As shown, in the cooling but not dehumidifying state, the blower is turned on, the air inlet side of the first-stage cooler 2 does not introduce indoor return air, and the air inlet side of the second-stage cooler 3 introduces indoor return air (the first-stage return air structure is closed, and the second-stage return air structure is opened), and the liquid outlet of the first-stage cooler 2 is connected to the liquid inlet of the second-stage cooler 3. The high-temperature and high-humidity outdoor fresh air is converted into low-temperature and low-humidity gas through the primary cooler 2, and then mixed with the indoor return air introduced at the air inlet side of the secondary cooler 3. The indoor return air can flow back to the room through the secondary return air structure, replenishing the fresh air volume without the need to design an additional exhaust duct. The return water of the primary cooler 2 is mixed with the supply water of the liquid supply main 6 and flows into the secondary cooler 3, which increases the inlet water temperature of the secondary cooler 3 and exceeds the dew point temperature of the mixed gas on the air inlet side of the secondary cooler 3 (although the indoor return air will cause a slight increase in the dry-bulb temperature of the mixed gas on the air inlet side of the secondary cooler 3, the increased dry-bulb temperature will still be at a relatively low level, and the corresponding dew point temperature will also be relatively low, and the inlet water temperature of the secondary cooler 3 will still be higher than the dew point temperature). Therefore, the mixed gas will only be cooled but not dehumidified when passing through the secondary cooler 3.

[0081] like Figure 7As shown, in the cooling and humidification state, the blower is turned on, and the air inlet sides of the first-stage cooler 2 and the second-stage cooler 3 both introduce indoor return air (the first-stage return air structure and the second-stage return air structure are both open), and the liquid outlet of the first-stage cooler 2 is connected to the liquid inlet of the second-stage cooler 3. The outdoor high-temperature and high-humidity fresh air is first mixed with the indoor return air introduced from the air inlet side of the first-stage cooler 2 to reduce the dry-bulb temperature of the outdoor air and the dew point temperature of the mixed gas in this section, thereby greatly reducing the dehumidification effect of the first-stage cooler 2, so that the mixed gas flowing through the first-stage cooler 2 maintains humidity. The first-stage cooler 2 delivers low-temperature and high-humidity gas, which is then mixed with the indoor return air introduced from the air inlet side of the second-stage cooler 3. The indoor return air is used to supplement the air volume, and the return water of the first-stage cooler 2 is mixed with the water supply of the liquid supply main 6 and flows into the second-stage cooler 3. The inlet water temperature of the secondary cooler 3 is increased, exceeding the dew point temperature of the mixed gas on the air inlet side of the secondary cooler 3 (although the indoor return air will cause a slight increase in the dry-bulb temperature of the mixed gas on the air inlet side of the secondary cooler, the increased dry-bulb temperature will still be at a relatively low level, and the corresponding dew point temperature will also be relatively low, and the inlet water temperature of the secondary cooler 3 will still be higher than the dew point temperature). Therefore, the mixed gas will only be cooled but not dehumidified when passing through the secondary cooler 3. Under the joint action of the primary cooler 2 and the secondary cooler 3, the effect of refrigeration and humidification is achieved.

[0082] For ease of understanding, the following is a table showing the relationship between indoor relative humidity and dry-bulb and wet-bulb dew point temperatures. The table provides three values ​​for illustration:

[0083] Dry bulb temperature (℃) Wet bulb temperature (℃) Dew point temperature(℃) Relative humidity 30 24 21.703 61.08％ 27 18 12.82 41.37％ 24 14 5.09 31.64％

[0084] When the air conditioning unit is running, the dry-bulb and wet-bulb temperatures will drop under the action of the air conditioning, and the dew point temperature will also drop. The lower the relative humidity of the gas. Taking a common application scenario as an example, the supply and return water temperature of the air conditioning unit in the cooling mode is set at 6 / 11°C. The water supply temperature of the first-stage condenser is lower than the dew point temperature of the outdoor high-temperature and high-humidity air. After the low-temperature air flowing out of the first-stage condenser is mixed with the indoor return air, the gas temperature is still at a low level, and the corresponding dew point temperature is also low. The liquid supply of the first-stage condenser is greater than that of the second-stage condenser. The return water of the first-stage condenser flowing into the second-stage condenser will raise the inlet water temperature of the second-stage condenser, making its temperature higher than the dew point temperature of the mixed gas, ensuring that the mixed gas is only cooled but not dehumidified when passing through the second-stage condenser.

[0085] like Figure 8 As shown, the present invention also proposes a control method for an air conditioning unit, and the control method is applied to the above-mentioned air conditioning unit, comprising:

[0086] Detect the actual humidity of the indoor environment and analyze the actual humidity With user set humidity Humidity deviation

[0087] According to humidity deviation The size of the air conditioning unit is selected according to its operating status.

[0088] The benefit of this design is that by monitoring the humidity of the indoor environment, a more reasonable operating state of the air-conditioning unit can be selected to ensure that the indoor humidity remains within the range set by the user, avoiding discomfort to the human body caused by excessively high or low humidity.

[0089] Specifically, the operating status of the air-conditioning unit selected according to the analysis results includes:

[0090] when When the humidity in the room is too high, the air conditioner unit will enter the rapid dehumidification state, effectively reducing the indoor humidity and avoiding the discomfort caused by excessive humidity.

[0091] when When the indoor humidity is within the acceptable range, the air conditioning unit enters the cooling but not dehumidifying state to maintain the suitability of the indoor temperature and humidity;

[0092] when When the humidity in the room is too low, the air conditioner unit will enter the cooling and humidifying state, increasing the humidity while cooling, ensuring that the indoor environment is cool but not too dry, thus improving indoor comfort.

[0093] in, α1 and α2 are the set humidity values.

[0094] The benefit of this design is that it can accurately control the operating status of the air-conditioning unit under different humidity conditions, avoid unnecessary dehumidification or humidification operations, improve the energy efficiency of the air-conditioning system, and maintain stable indoor humidity.

[0095] In a preferred embodiment of the present invention, the control method further comprises:

[0096] When the air conditioning unit enters the fast dehumidification state, according to the humidity deviation Control the return air volume of the return air structure and use the humidity deviation More accurate adjustment of the return air volume. By increasing the return air volume, the circulation of indoor humid air can be accelerated and the dehumidification efficiency can be improved. By reducing the return air volume, the load of the air conditioning unit can be reduced, thereby reducing energy consumption.

[0097] And / or when the air-conditioning unit enters the cooling but not dehumidifying state, the primary return air structure is closed, the secondary return air structure is opened, the actual temperature of the indoor environment is detected and the temperature deviation ΔT between the actual temperature T1 and the user set temperature T2 is analyzed, and the return air volume of the return air structure is controlled according to the size of the temperature deviation ΔT. Accurate control of the return air volume helps to achieve rapid temperature adjustment and stable control, and can also avoid energy waste caused by over-cooling or insufficient cooling;

[0098] And / or when the air conditioning unit enters the cooling and humidification state, the return air structure is controlled to operate at a set mid-range return air volume. The mid-range return air volume helps to balance the changes in indoor humidity, which can both meet the cooling demand and maintain the suitability of the indoor humidity.

[0099] This design realizes intelligent control of the air-conditioning unit, and can dynamically adjust the return air volume according to different operating conditions and indoor environmental parameters, which helps to improve the operating efficiency of the air-conditioning system and user experience.

[0100] Specifically, according to the humidity deviation Controlling the return air volume of the return air structure includes:

[0101] when When the humidity deviation is small, the return air structure operates at the set low return air volume to avoid excessive dehumidification;

[0102] when When , it indicates that the humidity deviation is moderate, and the return air structure operates at the set mid-range return air volume to avoid large fluctuations in indoor humidity;

[0103] when When the humidity deviation is large, the return air structure runs at the set high return air volume, which can quickly reduce the indoor humidity;

[0104] Among them, α3 and α4 are set humidity values.

[0105] This design improves the accuracy of humidity control by dynamically adjusting the return air volume, providing users with a more comfortable indoor environment. At the same time, it can reduce unnecessary energy consumption and improve the operating efficiency of the air-conditioning unit.

[0106] Specifically, the return air volume of the return air structure is controlled according to the size of the temperature deviation ΔT, including:

[0107] When 0℃≤ΔT<β1, it means that the temperature deviation is small, and the return air structure operates at the set low return air volume to avoid over-cooling;

[0108] When β1≤ΔT<β2, it means that the temperature deviation is moderate, and the return air structure operates at the set mid-range return air volume to avoid large fluctuations in indoor temperature;

[0109] When β2≤ΔT, it means that the temperature deviation is large, and the return air structure operates at the set high return air volume, which can quickly reduce the indoor temperature;

[0110] Among them, ΔT=T1-T2, β1 and β2 are set temperature values.

[0111] This design improves the accuracy of temperature control by dynamically adjusting the return air volume, providing users with a more comfortable indoor environment. At the same time, it can reduce unnecessary energy consumption and improve the operating efficiency of the air-conditioning unit.

[0112] In addition, as an optimization, when ΔT<0℃, it means that the indoor temperature is lower than the user-set temperature, the supply fan and return air structure are turned off, and the two-stage surface cooler stops supplying water. This design can avoid the indoor temperature being too low due to over-cooling, and can also reduce the energy consumption of the air-conditioning unit and improve the user experience.

[0113] It should be pointed out that the α1, α2, α3 and α4 are all relative humidity, T1, T2, β1 and β2 are all dry bulb temperatures, and the indoor temperature and humidity can be detected at regular intervals (e.g., 20 minutes), that is, after the air conditioning unit enters the current operating state and runs for a period of time, the indoor temperature and humidity are re-detected. In actual application, the detection interval time and the temperature and humidity setting values ​​can be set according to personal preferences or usage requirements, so as to customize the indoor temperature and humidity environment more flexibly.

[0114] For ease of understanding, an application example of the present invention is used as an example for illustration.

[0115] After the air-conditioning unit enters the cooling mode, the supply and return water temperature of the air-conditioning unit is set to 6 / 11℃, and the supply fan operates at the set high air volume, α1 is -3%, α2 is 3%, α3 is 10%, α4 is 20%, β1 is 3℃, β2 is 7℃, and the first-level return air fan and the second-level return air fan are both equipped with three wind speeds, namely high wind speed, medium wind speed and low wind speed.

[0116] like The air conditioning unit enters the rapid dehumidification state, and the two-stage surface cooler supplies water at a ratio of 1:1. When the first and second return fans are both turned on at high speed, When the primary return fan and the secondary return fan are both turned on the medium wind gear, The first-stage return air fan and the second-stage return air fan both have their low air dampers open;

[0117] like The air conditioning unit enters the cooling but not dehumidifying state, and the first-stage surface cooler and the second-stage surface cooler supply water in a ratio of 3:2. When ΔT>7℃, the second-stage return fan opens the high wind gear. When 7℃>ΔT>3℃, the second-stage return fan opens the medium wind gear. When 0℃≤ΔT<3℃, the second-stage return fan opens the low wind gear. When ΔT<0℃, the supply fan and return air structure are turned off, and the two-stage surface cooler stops supplying water.

[0118] like The air-conditioning unit enters the refrigeration and humidification state, the first-level surface cooler and the second-level surface cooler supply water at a ratio of 3:2, and the first-level return air fan and the second-level return air fan are both turned on the medium wind gear.

[0119] It should be noted that the terms used above are only for describing specific embodiments and are not intended to limit exemplary embodiments according to the present invention. When the terms "comprise" and / or "include" are used in this specification, they indicate the presence of features, steps, operations, devices, components and / or combinations thereof. The order of execution of actions, steps, etc. in the devices and methods shown in the specification and the accompanying drawings can be implemented in any order as long as there is no special explicit limitation on the order and the output of the previous processing is not used in the subsequent processing. Similar terms of order used for the convenience of description do not mean that they must be implemented in such an order.

[0120] Techniques, methods, and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and apparatus should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limiting. Therefore, other examples of the exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following figures, and therefore, once an item is defined in one figure, it does not need to be further discussed in subsequent figures.

[0121] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An air conditioning unit, characterized in that: include: A fresh air passage, wherein a blower is installed in the fresh air passage; The two-stage surface cooler is a primary surface cooler and a secondary surface cooler which are sequentially arranged in the fresh air channel along the air supply direction, the liquid inlet of the primary surface cooler and the liquid inlet of the secondary surface cooler are both connected to the liquid supply main pipe, the liquid outlet of the primary surface cooler can be switched to connect to the liquid inlet of the secondary surface cooler or the liquid return main pipe, and the liquid outlet of the secondary surface cooler is connected to the liquid return main pipe; The return air structure includes a primary return air structure for introducing indoor return air into the air inlet side of the primary surface cooler.

2. The air conditioning unit according to claim 1, characterized in that: The return air structure also includes a secondary return air structure for introducing indoor return air into the air inlet side of the secondary surface cooler.

3. The air conditioning unit according to claim 2, characterized in that: The primary return air structure comprises: a primary return air inlet and a primary return air fan, wherein the primary return air inlet is located at the air inlet side of the primary surface cooler; The secondary air return structure comprises: a secondary air return port and a secondary air return fan, wherein the secondary air return port is located between the air outlet side of the primary surface cooler and the air inlet side of the secondary surface cooler.

4. The air conditioning unit according to claim 1, characterized in that: The liquid inlet of the primary cooler and the liquid inlet of the secondary cooler are both connected to the liquid supply main pipe through a control valve, and the control valve is used to adjust the liquid supply amount of the primary cooler and the secondary cooler.

5. The air conditioning unit according to any one of claims 1 to 4, characterized in that: The air conditioning unit can operate in at least one of a rapid dehumidification state, a cooling without dehumidification state, and a cooling and humidification state; In the rapid dehumidification state, the blower is turned off, the air inlet side of the primary surface cooler introduces indoor return air, and the liquid outlet of the primary surface cooler is connected to the liquid return main pipe; In the cooling but not dehumidifying state, the blower is turned on, the air inlet side of the first-stage cooler does not introduce indoor return air, and the liquid outlet of the first-stage cooler is connected to the liquid inlet of the second-stage cooler; In the cooling and humidifying state, the blower is turned on, the air inlet side of the primary cooler introduces indoor return air, and the liquid outlet of the primary cooler is connected to the liquid inlet of the secondary cooler.

6. The air conditioning unit according to claim 5, characterized in that: In the rapid dehumidification state, the liquid supply amount of the first-stage surface cooler and the second-stage surface cooler is the same; in the refrigeration without dehumidification state and the refrigeration humidification state, the liquid supply amount of the first-stage surface cooler is greater than that of the second-stage surface cooler.

7. The air conditioning unit according to claim 5, characterized in that: The air inlet side of the two-stage surface cooler introduces indoor return air in the rapid dehumidification state, the cooling without dehumidification state, and the cooling and humidification state.

8. A control method for an air conditioning unit, the control method being applied to the air conditioning unit according to any one of claims 5 to 7, characterized in that: include: Detecting the actual humidity of the indoor environment and analyzing the humidity deviation Δφ between the actual humidity φ1 and the user-set humidity φ2; The operating state of the air conditioning unit is selected according to the size of the humidity deviation Δφ.

9. The control method according to claim 8, characterized in that: Selecting the operating state of the air conditioning unit according to the analysis result includes: When Δφ≥α2, the air conditioning unit enters a rapid dehumidification state; and / or when α2>Δφ≥α1, the air conditioning unit enters a cooling but not dehumidifying state; and / or when Δφ<α1, the air conditioning unit enters a cooling and humidifying state; Among them, Δφ=φ1-φ2, α1 and α2 are the set humidity values.

10. The control method according to claim 9, characterized in that: The control method further comprises: When the air conditioning unit enters the rapid dehumidification state, the return air volume of the return air structure is controlled according to the humidity deviation Δφ; and / or when the air conditioning unit enters the cooling but not dehumidifying state, detecting the actual temperature of the indoor environment and analyzing the temperature deviation ΔT between the actual temperature T1 and the user set temperature T2, and controlling the return air volume of the return air structure according to the size of the temperature deviation ΔT; And / or when the air conditioning unit enters the refrigeration and humidification state, the return air structure is controlled to operate at a set mid-range return air volume.

11. The control method according to claim 10, characterized in that: Controlling the return air volume of the return air structure according to the humidity deviation Δφ comprises: When α3>Δφ≥α2, the return air structure operates at a set low return air volume; When α4>Δφ≥α3, the return air structure operates at the set mid-range return air volume; When Δφ≥α4, the return air structure operates at the set high-end return air volume; Among them, α3 and α4 are set humidity values.

12. The control method according to claim 10, characterized in that: Controlling the return air volume of the return air structure according to the temperature deviation ΔT includes: When 0℃≤ΔT<β1, the return air structure operates at the set low return air volume; When β1≤ΔT<β2, the return air structure operates at the set mid-range return air volume; When β2≤ΔT, the return air structure operates at the set high-end return air volume; Among them, ΔT=T1-T2, β1 and β2 are set temperature values.

13. The control method according to claim 12, characterized in that: Controlling the return air volume of the return air structure according to the size of the temperature deviation ΔT further includes: when ΔT<0°C, turning off the air supply fan and the return air structure.

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