Air conditioning unit and control method thereof

Abstract

The application discloses an air conditioning unit and a control method thereof. The air conditioning unit comprises a supply air passage and a return air passage in communication with a room, and a first-stage evaporator, a rotary dehumidifier adsorption zone and a second-stage evaporator are arranged in the supply air passage in sequence along the supply air direction. The supply air passage is provided with a primary mixed return air outlet and a secondary mixed return air outlet in communication with the return air passage. The primary mixed return air outlet is located between the air outlet side of the first-stage evaporator and the air inlet side of the rotary dehumidifier adsorption zone, and the secondary mixed return air outlet is located between the air outlet side of the rotary dehumidifier adsorption zone and the air inlet side of the second-stage evaporator. According to the application, the indoor return air is introduced into the air inlet side and the air outlet side of the rotary dehumidifier adsorption zone, the indoor return air with low temperature and low humidity is used to supplement the fresh air volume, the burden of the air conditioning unit is reduced, and the return air volume of the primary return air and the secondary return air can be adjusted to accurately adjust the supply air temperature.

Description

Technical Field

[0001] This invention relates to the field of air conditioning unit technology, and in particular to a high-efficiency heat and cold recovery air conditioning unit and its control method. Background Technology

[0002] In archives and other places where textual and audiovisual materials need to be preserved for a long time, maintaining a constant temperature and humidity is crucial to ensure the integrity and readability of the materials. These places typically require a low-temperature, low-humidity environment to prevent paper materials from becoming damp and moldy, and to prevent adverse changes in the physical and chemical properties of audiovisual materials.

[0003] However, current air conditioning systems used to maintain a constant low temperature and low humidity indoor environment in archives are characterized by a low proportion of fresh air, low indoor return air temperature, and high regenerated air temperature. Directly exhausting the low-temperature indoor return air to the outside results in a waste of cooling capacity, and the indoor environment relies entirely on the air conditioning units to cool and dehumidify the outdoor fresh air, increasing the burden on the air conditioning units. In addition, directly exhausting the high-temperature regenerated air to the outside results in a waste of heat, and the low-temperature airflow after dehumidification and cooling relies on electric heating devices to regulate the supply air temperature, leading to unnecessary energy consumption.

[0004] Therefore, how to design efficient heat and cold recovery air conditioning units and their control methods is a technical problem that the industry urgently needs to solve. Summary of the Invention

[0005] To address the energy waste problem of existing air conditioning units, this invention proposes an air conditioning unit and its control method. This air conditioning unit can recover and utilize the cooling capacity of indoor return air and use the regenerated air as a heat source for reheating the supply air, thereby achieving precise control of the supply air temperature and meeting the requirements for efficient and energy-saving operation of the unit.

[0006] The technical solution adopted in this invention is to design an air conditioning unit, including: an air supply duct and a return air duct connected to the indoor unit. The air supply duct is equipped with a primary evaporator, a rotary dehumidifier adsorption zone, and a secondary evaporator arranged sequentially along the air supply direction. The air supply duct is provided with a primary mixing return air inlet and a secondary mixing return air inlet connected to the return air duct. The primary mixing return air inlet is located between the air outlet side of the primary evaporator and the air inlet side of the rotary dehumidifier adsorption zone, and the secondary mixing return air inlet is located between the air outlet side of the rotary dehumidifier adsorption zone and the air inlet side of the secondary evaporator.

[0007] Furthermore, the air supply duct is also equipped with a pre-cooling section located on the air inlet side of the primary evaporator, and the pre-cooling section is connected to the return air duct through the pre-cooling return air inlet.

[0008] Furthermore, the precooling section is equipped with a precooling heat exchanger, which has a return air heat exchange pipeline for circulating indoor return air. The indoor return air sent out from the precooling return air outlet is discharged outdoors through the return air heat exchange pipeline.

[0009] Furthermore, the air conditioning unit also includes a regeneration channel, within which regeneration air heating devices and a rotary dehumidifier regeneration zone are installed sequentially along the regeneration air direction. The air supply channel also has a reheat section located on the air outlet side of the secondary evaporator, which is connected to the air outlet end of the regeneration channel via a regeneration air vent.

[0010] Furthermore, the reheat section is equipped with a reheat heat exchanger, which has a reheat air heat exchange pipeline for circulating reheat air. The reheat air delivered from the reheat air outlet is discharged outdoors through the reheat air heat exchange pipeline.

[0011] Furthermore, a humidifier is installed inside the air supply duct, located on the air outlet side of the reheat heat exchanger.

[0012] This invention also proposes a control method for an air conditioning unit, which is applied to the aforementioned air conditioning unit. The control method includes:

[0013] Detect the actual supply air temperature in the air supply duct;

[0014] Compare the actual supply air temperature with the target temperature range;

[0015] When the actual supply air temperature is higher than the target temperature range, reduce the opening of the damper at the primary mixing return air inlet and increase the opening of the damper at the secondary mixing return air inlet.

[0016] When the actual supply air temperature is lower than the target temperature range, increase the opening of the damper at the primary mixing return air inlet and decrease the opening of the damper at the secondary mixing return air inlet.

[0017] When the actual supply air temperature is within the target temperature range, the opening of the damper at both the primary mixing return air inlet and the secondary mixing return air inlet remains unchanged.

[0018] Furthermore, control methods also include:

[0019] Detect the actual supply air temperature in the supply air duct and the actual return air temperature in the return air duct;

[0020] Analyze the changes in actual supply air temperature and actual return air temperature;

[0021] When the actual supply air temperature fluctuates, adjust the opening of the pre-cooling return air inlet damper according to the actual supply air temperature.

[0022] When the actual return air temperature fluctuates and the actual supply air temperature is stable, the opening of the damper at the pre-cooling return air inlet is adjusted according to the actual return air temperature.

[0023] When both the actual supply air temperature and the actual return air temperature are stable, the opening of the damper at the pre-cooled return air inlet remains unchanged.

[0024] Further analysis of the changes in actual supply air temperature and actual return air temperature includes:

[0025] Determine whether the actual supply air temperature is within the target temperature range. If it is, the actual supply air temperature is stable; otherwise, the actual supply air temperature fluctuates.

[0026] Determine whether the actual return air temperature is within the target temperature range. If it is, the actual return air temperature is stable; otherwise, the actual return air temperature fluctuates.

[0027] Furthermore, adjusting the opening of the pre-cooling return air inlet damper according to the actual supply air temperature includes:

[0028] Compare the actual supply air temperature with the target temperature range;

[0029] When the actual supply air temperature is higher than the target temperature range, increase the opening of the damper at the pre-cooling return air inlet;

[0030] When the actual supply air temperature is lower than the target temperature range, reduce the opening of the damper at the pre-cooled return air inlet.

[0031] Furthermore, adjusting the opening of the pre-cooling return air inlet damper according to the actual return air temperature includes:

[0032] Compare the actual return air temperature with the target temperature range;

[0033] When the actual return air temperature is higher than the target temperature range, reduce the opening of the damper at the pre-cooled return air inlet;

[0034] When the actual return air temperature is lower than the target temperature range, increase the opening of the damper at the pre-cooled return air inlet.

[0035] Furthermore, control methods also include:

[0036] Detect the actual supply air temperature in the air supply duct;

[0037] Compare the actual supply air temperature with the target temperature range;

[0038] When the actual supply air temperature is higher than the target temperature range, reduce the regeneration air volume at the regeneration air outlet;

[0039] When the actual supply air temperature is lower than the target temperature range, increase the regeneration air volume at the regeneration air outlet;

[0040] When the actual supply air temperature is within the target temperature range, the regeneration air volume at the regeneration air outlet remains unchanged.

[0041] Compared with the prior art, the present invention has at least one of the following beneficial effects:

[0042] 1. Design a primary mixing return air inlet and a secondary mixing return air inlet to introduce indoor return air into the air inlet and air outlet sides of the adsorption zone of the rotary dehumidifier. Use the low temperature and low humidity indoor return air to supplement the fresh air volume, reduce the burden on the air conditioning unit, and also achieve the effect of accurately regulating the supply air temperature by adjusting the return air volume of the primary and secondary return air.

[0043] 2. Design pre-cooling return air inlets and regeneration air inlets to pre-cool the high-temperature outdoor fresh air using low-temperature indoor return air, effectively improving the cold energy recovery efficiency of indoor return air. Use high-temperature regeneration air as a heat source for supply air reheating to help regulate supply air temperature and reduce the operating energy consumption of the air conditioning unit.

[0044] 3. By adjusting the return air volume and the regenerated air volume in a coordinated manner, the supply air temperature can be adjusted quickly and accurately, and the air conditioning unit can operate efficiently and energy-savingly. Attached Figure Description

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

[0046] Figure 1 This is a connection diagram according to an embodiment of the present invention;

[0047] Figure 2 This is a connection diagram of another embodiment of the present invention;

[0048] Figure 3 This is a connection diagram of a preferred embodiment of the present invention;

[0049] Figure 4 This is a schematic diagram of the return air treatment process of the control method of the present invention;

[0050] Figure 5 This is a schematic diagram of the fresh air treatment process of the control method of the present invention;

[0051] Figure 6 This is a schematic diagram of the regenerated air treatment process of the control method of the present invention; Attached image description:

[0053] 1. Air filter; 2. Precooling heat exchanger; 3. Primary evaporator; 4. Rotary dehumidifier; 5. Chemical filter; 6. Secondary evaporator; 7. Reheat heat exchanger; 8. Humidifier; 9. Blower; 10. Proportional valve; 11. Regenerated air heating device; 12. Regenerated fan;

[0054] X1, Fresh air; X2, Fresh air; P1, Return air exhaust; P2, Regenerated air exhaust; P3, Reheat exhaust; S, Supply airflow; H, Indoor return air; H1, Pre-cooled return air outlet; H2, Primary mixing return air outlet; H3, Secondary mixing return air outlet; Z, Regenerated air outlet. Detailed Implementation

[0055] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to 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 intended to limit the present invention.

[0056] like Figure 1 As shown, the air conditioning unit proposed in this invention can achieve efficient heat and cold recovery. The air conditioning unit includes: an air supply duct, a return air duct, and a rotary dehumidifier 4. The air supply duct is equipped with a blower 9, which drives the airflow within the air supply duct from the air inlet to the air outlet. The air outlet of the air supply duct is connected to the indoor environment. The air supply duct is equipped with a primary evaporator 3, a rotary dehumidifier adsorption zone, and a secondary evaporator 6, arranged sequentially along the air supply direction. When the air conditioning unit is working, the blower 9 is turned on, and fresh air X1 enters the air supply duct. The airflow first passes through the primary evaporator 3 for cooling, then through the rotary dehumidifier adsorption zone for dehumidification, and then through the secondary evaporator 6 for further cooling. The airflow S, after multiple treatments, enters the indoor environment from the air outlet, thus maintaining a low temperature and low humidity indoor environment.

[0057] Generally, the temperature of indoor return air H is between 6 and 12°C. Directly discharging it outdoors would result in a waste of cooling capacity. To achieve the recycling of indoor return air H, the air supply duct of this invention is provided with a primary mixing return air inlet H2 and a secondary mixing return air inlet H3 connected to the return air duct. The primary mixing return air inlet H2 is located between the air outlet side of the first-stage evaporator 3 and the air inlet side of the adsorption zone of the rotary dehumidifier. The secondary mixing return air inlet H3 is located between the air outlet side of the adsorption zone of the rotary dehumidifier and the air inlet side of the second-stage evaporator 6. The air inlet of the return air duct is connected to the room. The indoor return air H entering the return air duct can flow from the primary mixing return air inlet H2 and the secondary mixing return air inlet H3 into the air supply duct.

[0058] This design introduces indoor return air (H) into the intake and exhaust sides of the rotary dehumidifier's adsorption zone, using the low-temperature, low-humidity indoor return air (H) to supplement the fresh air volume, reducing the load on the air conditioning unit. Furthermore, by adjusting the return air volume of the primary and secondary return air according to the supply air temperature, the temperature of the mixed airflow on the intake side of the secondary evaporator can be changed, thus achieving flexible adjustment of the supply air temperature.

[0059] The design principle is that the set air outlet temperature of the first-stage evaporator 3 is usually close to or equal to the target supply air temperature. That is, the actual air outlet temperature of the first-stage evaporator 3 is close to the actual return air temperature of the return air duct. Introducing the indoor return air H to the air outlet side of the first-stage evaporator 3 can effectively supplement the fresh air volume and reduce the cooling load of the first-stage evaporator 3. However, during the dehumidification process, the rotary dehumidifier 4 adsorbs moisture from the air using an adsorbent. This adsorption process is an exothermic reaction, which causes the airflow temperature on the outlet side to be higher than that on the inlet side. If too much indoor return air H is sent to the inlet side of the dehumidifier's adsorption zone, the temperature of the mixed gas on the inlet side of the secondary evaporator will increase, increasing the cooling load of the secondary evaporator 6. Conversely, if too much indoor return air H is sent to the outlet side of the dehumidifier's adsorption zone, the temperature of the mixed gas on the inlet side of the secondary evaporator will decrease, resulting in the airflow temperature on the outlet side of the secondary evaporator being much lower than the target supply air temperature, increasing the heating load of subsequent supply air reheat. Therefore, a reasonable allocation of the return air volume on the front and rear sides of the dehumidifier's adsorption zone can flexibly adjust the supply air temperature.

[0060] like Figure 2 As shown, in some feasible embodiments of the present invention, the air supply duct is further provided with a pre-cooling section. The pre-cooling section is located on the air inlet side of the primary evaporator 3. The pre-cooling section is connected to the return air duct through the pre-cooling return air inlet H1. The low-temperature indoor return air H pre-cools and cools the high-temperature outdoor fresh air X1 entering the air supply duct in the pre-cooling section, effectively improving the cold energy recovery efficiency of the indoor return air and reducing the cooling load of the primary evaporator 3.

[0061] Because the air supply duct is designed with a primary mixing return air inlet H2 and a secondary mixing return air inlet H3, a certain amount of indoor return air H has already been mixed with fresh air X1 and returned to the room. If the pre-cooling section also adopts a mixing design, the proportion of return air in the supply airflow will be too high, affecting indoor comfort. Therefore, in the preferred solution, the pre-cooling section is equipped with a pre-cooling heat exchanger 2. The pre-cooling heat exchanger 2 has return air heat exchange ducts and fresh air heat exchange ducts. Fresh air X1 entering the air supply duct passes through the fresh air heat exchange duct, and indoor return air H introduced by the pre-cooling return air inlet H1 is discharged outdoors through the return air heat exchange duct. Fresh air X1 and indoor return air H exchange heat in the pre-cooling heat exchanger 2. After absorbing the cold air, the fresh air X1 cools down and then flows to the primary evaporator 3. The purpose of designing the pre-cooling heat exchanger 2 is to both recover and utilize the cold air from the indoor return air H and ensure the proportion of fresh air in the supply airflow S, making the indoor air fresh and optimizing the user experience.

[0062] To facilitate understanding, a specific application example of the present invention will be used for illustration. Based on the temperature and humidity requirements of places such as archives, the air conditioning unit operates in cooling mode almost all year round. Assuming that the air supply target of the air conditioning unit is 8℃ / 95%, and the air outlet target of the first-stage evaporator 3 is also 8℃ / 95%, in summer, the fresh air X1 at 35℃ and the indoor return air H at 8℃ pass through the pre-cooling heat exchanger 2 in a 1:1 ratio. The temperature of the fresh air flowing out of the pre-cooling heat exchanger 2 drops to 23.17℃, reducing the cooling load of the first-stage evaporator 3 by 43.8%. It can be seen that the design of the pre-cooling heat exchanger 2 can significantly reduce the cooling load and achieve energy-saving operation of the unit.

[0063] like Figure 3 As shown, in some feasible embodiments of the present invention, the air conditioning unit further includes: a regeneration channel, wherein a regeneration fan 12 is configured in the regeneration channel, the regeneration fan 12 drives the airflow in the regeneration channel from the air inlet to the air outlet, the air outlet of the regeneration channel is connected to the outside, and a regeneration air heating device 11 and a rotary dehumidifier regeneration zone are installed in the regeneration channel in sequence along the regeneration air direction. When the air conditioning unit is working, the regeneration fan 12 is turned on, the fresh air X2 is first heated by the regeneration air heating device 11, then passes through the rotary dehumidifier regeneration zone, and then is discharged to the outside from the air outlet of the regeneration channel.

[0064] Generally, the exhaust temperature of regenerated air is between 60℃ and 120℃. Directly discharging it outdoors would result in heat waste. To achieve the recycling of regenerated air, the air supply duct of this invention is also equipped with a reheat section. The reheat section is located on the air outlet side of the secondary evaporator 6. The reheat section is connected to the air outlet end of the regeneration duct through the regenerated air inlet Z. The high-temperature regenerated air reheats the airflow on the air outlet side of the secondary evaporator in the reheat section, so that the supply air temperature is within the target temperature range. This design uses high-temperature regenerated air as the heat source for supply air reheating, assists in regulating the supply air temperature, and reduces the operating energy consumption of the air conditioning unit.

[0065] During the operation of the rotary dehumidifier 4, the main function of the regeneration zone is to regenerate the desiccant in the rotor, that is, to desorb the adsorbed moisture so that the rotor can continue to adsorb new moisture. When the outdoor fresh air is heated, its temperature and humidity conditions change; typically, the temperature increases while the relative humidity decreases. Then, the high-temperature, low-humidity air is sent into the regeneration zone, where it comes into contact with the desiccant that has already adsorbed moisture in the rotor. Under high temperature conditions, the moisture absorbed in the rotor is desorbed and enters the regeneration air, significantly increasing the humidity of the regeneration air. The unfiltered, high-humidity regeneration air mixed into the supply air duct affects the supply air humidity and quality. Therefore, in the preferred embodiment, a reheat heat exchanger 7 is installed in the reheat section. The reheat heat exchanger 7 is equipped with a regeneration air heat exchange pipeline and a supply air heat exchange pipeline. The mixed airflow from the secondary evaporator 6 passes through the supply air heat exchange pipeline, and the regeneration air from the regeneration air outlet Z is discharged outdoors through the regeneration air heat exchange pipeline. The mixed airflow and the regeneration air exchange heat within the reheat heat exchanger 7. The mixed airflow absorbs heat and rises in temperature before flowing to the outlet of the supply air duct. The purpose of designing the reheat heat exchanger is to both recover and utilize the heat from the regeneration air and prevent the regeneration air from affecting the humidity and quality of the supply airflow.

[0066] Since the airflow in the air supply duct undergoes dehumidification and multiple cooling processes, the humidity of the air supply airflow may be too low. In order to accurately adjust the humidity of the air supply airflow, a humidifier 8 is also installed in the air supply duct. The humidifier 8 is located on the air outlet side of the reheat heat exchanger 7. When humidification is needed, the humidifier 8 is turned on so that the temperature and humidity of the air flowing out of the air outlet of the air supply duct meet the user's needs.

[0067] It should be understood that the primary mixing return air inlet H2, secondary mixing return air inlet H3, and precooling return air inlet H1 mentioned above are all equipped with adjustable dampers. Since the regenerated air has two flow paths—one to the outside and the other to the reheat heat exchanger 7—a proportional valve 10 can be installed at the air outlet of the regeneration channel to regulate the regenerated air flow rate. Furthermore, the precooling heat exchanger 2 and reheat heat exchanger 7 mentioned above can be heat exchangers with two sets of heat exchange pipelines, including but not limited to plate heat exchangers.

[0068] To improve air supply quality, multi-stage filters can be installed in the air supply duct. For example, an air filter 1 can be installed at the air inlet of the air supply duct or on the air inlet side of the precooling heat exchanger 2, and a chemical filter 5 can be installed between the air outlet side of the rotary dehumidifier 4 and the air inlet side of the secondary evaporator 6. In practical applications, the number and location of filters can be designed according to specific needs, and this invention does not impose any special restrictions on this.

[0069] In the preferred embodiment of the present invention, the air conditioning unit is designed with a primary mixing return air inlet H2, a secondary mixing return air inlet H3, a pre-cooling return air inlet H1, and a regeneration air inlet Z to achieve efficient and energy-saving operation of return air cooling recovery and regeneration air heat recovery.

[0070] like Figure 4 As shown, the present invention also proposes a control method for an air conditioning unit, which is applied to the aforementioned air conditioning unit. The control method includes:

[0071] Detect the actual supply air temperature in the air supply duct;

[0072] Compare the actual supply air temperature with the target temperature range;

[0073] When the actual supply air temperature is higher than the target temperature range, it indicates that the temperature of the mixed airflow on the air inlet side of the secondary evaporator is too high, causing the temperature of the mixed airflow to fail to drop to an appropriate level after passing through the secondary evaporator. At this time, reduce the opening of the damper of the primary mixing return air port H2 and increase the opening of the damper of the secondary mixing return air port H3. This will increase the return air in the low-temperature chamber sent to the air inlet side of the secondary evaporator, effectively reducing the temperature of the mixed airflow on the air inlet side of the secondary evaporator.

[0074] When the actual supply air temperature is lower than the target temperature range, it indicates that the temperature of the mixed airflow on the air inlet side of the secondary evaporator is too low, causing the temperature of the mixed airflow to drop too much after passing through the secondary evaporator. At this time, increase the opening of the damper of the primary mixing return air port H2 and decrease the opening of the damper of the secondary mixing return air port H3. This will increase the return air in the low-temperature chamber sent to the air outlet side of the primary evaporator, effectively increasing the temperature of the mixed airflow on the air inlet side of the secondary evaporator.

[0075] When the actual supply air temperature is within the target temperature range, the opening degree of the damper at the primary mixing return air inlet H2 and the opening degree of the damper at the secondary mixing return air inlet H3 remain unchanged.

[0076] By monitoring the actual supply air temperature in the air supply duct in real time and comparing it with the target temperature range, the opening of the dampers of the primary mixing return air inlet H2 and the secondary mixing return air inlet H3 is quickly adjusted to ensure that the actual supply air temperature is stabilized within the target temperature range.

[0077] like Figure 5 As shown, based on introducing indoor return air into the primary mixing return air inlet H2 and the secondary mixing return air inlet H3, some embodiments of the present invention also include pre-cooling control logic, the specific process of which is as follows:

[0078] Detect the actual supply air temperature in the supply air duct and the actual return air temperature in the return air duct;

[0079] Analyze the changes in actual supply air temperature and actual return air temperature;

[0080] When the actual supply air temperature fluctuates, the opening of the air valve at the pre-cooling return air inlet H1 is adjusted according to the actual supply air temperature. By changing the opening of the air valve, the fresh air temperature on the air inlet side of the primary evaporator is adjusted, so that the actual supply air temperature tends to be stable and indoor comfort is improved.

[0081] When the actual return air temperature fluctuates and the actual supply air temperature is stable, the opening of the air valve of the pre-cooling return air inlet H1 is adjusted according to the actual return air temperature. By changing the opening of the air valve, the cooling capacity supplied by the pre-cooling heat exchanger is adjusted so that the actual supply air temperature remains stable and indoor comfort is guaranteed.

[0082] When both the actual supply air temperature and the actual return air temperature are stable, the opening degree of the damper at the pre-cooled return air inlet H1 remains unchanged.

[0083] By monitoring the actual supply air temperature in the supply air duct and the actual return air temperature in the return air duct in real time, the unit can dynamically adjust the opening of the air valve at the pre-cooling return air inlet H1, thereby achieving a stable supply air temperature and improving the reliability of the air conditioning unit's temperature control.

[0084] In some feasible embodiments, analyzing the changes in actual supply air temperature and actual return air temperature includes:

[0085] Determine whether the actual supply air temperature is within the target temperature range. If it is, the actual supply air temperature is stable; otherwise, the actual supply air temperature fluctuates.

[0086] Determine whether the actual return air temperature is within the target temperature range. If it is, the actual return air temperature is stable; otherwise, the actual return air temperature fluctuates.

[0087] By determining whether the actual supply air temperature and the actual return air temperature are within the target temperature range, the actual current temperature situation can be better reflected, ensuring that the supply air temperature is always maintained within the set target range, and that the indoor environment remains in a low temperature and low humidity state for a long time.

[0088] Specifically, the adjustment methods for the pre-cooling return air vent H1 are as follows:

[0089] The first method involves adjusting the opening of the damper at the pre-cooled return air inlet H1 based on the actual supply air temperature. By comparing the actual supply air temperature with the target temperature range, when the actual supply air temperature is higher than the target temperature range, the opening of the damper at the pre-cooled return air inlet H1 is increased, allowing more low-temperature indoor return air to pass through the pre-cooling heat exchanger 2, thus increasing the cooling capacity supplied to the outdoor fresh air and lowering the supply air temperature. When the actual supply air temperature is lower than the target temperature range, the opening of the damper at the pre-cooled return air inlet H1 is decreased, reducing the amount of low-temperature indoor return air passing through the pre-cooling heat exchanger 2, thus decreasing the cooling capacity supplied to the outdoor fresh air and raising the supply air temperature.

[0090] The second method involves adjusting the opening of the damper at the pre-cooling return air inlet H1 based on the actual return air temperature. By comparing the actual return air temperature with the target temperature range, if the actual return air temperature is higher than the target temperature range, it indicates that the actual return air temperature is too high and the cold recovery efficiency is reduced. In this case, the opening of the damper at the pre-cooling return air inlet H1 is reduced, resulting in less low-temperature indoor return air passing through the pre-cooling heat exchanger 2. If the actual return air temperature is lower than the target temperature range, it indicates that the actual return air temperature is too low and the cold recovery efficiency is increased. In this case, the opening of the damper at the pre-cooling return air inlet H1 is increased, allowing more low-temperature indoor return air to pass through the pre-cooling heat exchanger 2.

[0091] It should be understood that since the pre-cooling return air inlet H1, the primary mixing return air inlet H2, and the secondary mixing return air inlet H3 are all connected to the return air duct, adjusting the opening of the damper of the pre-cooling return air inlet H1 will affect the return air volume of the primary mixing return air inlet H2 and the secondary mixing return air inlet H3. Therefore, after each adjustment of the damper during the control process, the indoor return air will be redistributed to the pre-cooling return air inlet H1, the primary mixing return air inlet H2, and the secondary mixing return air inlet H3, and the supply air temperature will be regulated through the cooperation of the three return air inlets.

[0092] like Figure 6 As shown, based on the primary mixing return air inlet H2, the secondary mixing return air inlet H3, and the precooling return air inlet H1, some embodiments of the present invention also include reheat control logic, the specific process of which is as follows:

[0093] Detect the actual supply air temperature in the air supply duct;

[0094] Compare the actual supply air temperature with the target temperature range;

[0095] When the actual supply air temperature is higher than the target temperature range, it indicates that the heat supplied by the reheat heat exchanger to the mixed airflow is too large. At this time, reduce the regeneration airflow at the regeneration air outlet Z (open the proportional valve 10) to effectively reduce the temperature of the mixed airflow on the outlet side of the reheat heat exchanger.

[0096] When the actual supply air temperature is lower than the target temperature range, it indicates that the heat supplied by the reheat heat exchanger to the mixed airflow is too small. At this time, increase the regeneration airflow at the regeneration air outlet Z (reduce the proportional valve 10) to effectively increase the temperature of the mixed airflow on the outlet side of the reheat heat exchanger.

[0097] When the actual supply air temperature is within the target temperature range, the regeneration air volume of regeneration outlet Z remains unchanged.

[0098] Since the reheat heat exchanger is located on the air outlet side of the secondary evaporator, the mixed airflow will pass through the reheat heat exchanger to regulate its temperature before being sent out of the air supply channel. The heat supplied by the reheat heat exchanger will directly affect the actual air supply temperature. Therefore, the actual air supply temperature is compared with the target temperature range, and the regeneration air volume is adjusted according to the comparison result to achieve the effect of precise control of the air supply temperature.

[0099] It should be understood that in this embodiment, the temperature status of the supply air duct and return air duct is monitored in real time, and the return air volume and regenerated air volume are adjusted in a coordinated manner to achieve rapid and accurate control of the supply air temperature, maximize the recovery and utilization of the cold air of the indoor return air and the heat of the regenerated air, and ensure that the air conditioning unit operates efficiently and energy-savingly, while ensuring that the indoor environment is kept at a low temperature and low humidity for a long time.

[0100] To improve control accuracy, the preferred method is to detect the airflow temperature at the outlet of the supply air duct as the actual supply air temperature, and to detect the airflow temperature at the inlet of the return air duct as the actual return air temperature. Furthermore, after each detection of new actual supply and return air temperatures, the unit will re-analyze the operating status and determine the adjustment actions of each valve. The air valves and proportional valves mentioned above can adjust their openings according to a fixed step or a fixed proportion. This invention does not impose special restrictions on the specific adjustment methods for increasing or decreasing the valve openings.

[0101] It should be noted that the terminology used above is for describing specific embodiments only and is not intended to limit the exemplary embodiments of the present invention. When the terms "comprising" and / or "including" 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 apparatus and methods shown in the specification and drawings can be implemented in any order unless a specific order is expressly specified, and as long as the output of a previous process is not used in a subsequent process. Similar sequential terms used for ease of description do not imply that such an order must be followed.

[0102] Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices 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 limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following figures denote similar items; therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0103] 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 within the protection scope of the present invention.

Claims

1. A control method for an air conditioning unit, wherein the air conditioning unit comprises: The room includes an air supply duct and a return air duct connected to the room. The air supply duct is equipped with a primary evaporator, a rotary dehumidifier adsorption zone, and a secondary evaporator arranged sequentially along the air supply direction. The air supply duct is provided with a primary mixing return air inlet and a secondary mixing return air inlet connected to the return air duct. The primary mixing return air inlet is located between the air outlet side of the primary evaporator and the air inlet side of the rotary dehumidifier adsorption zone. The secondary mixing return air inlet is located between the air outlet side of the rotary dehumidifier adsorption zone and the air inlet side of the secondary evaporator. The air supply duct is also provided with a pre-cooling section located on the air inlet side of the first-stage evaporator. The pre-cooling section is connected to the return air duct through a pre-cooling return air inlet. The pre-cooling section is equipped with a pre-cooling heat exchanger. The pre-cooling heat exchanger is provided with a return air heat exchange pipeline and a fresh air heat exchange pipeline. The fresh air entering the air supply duct passes through the fresh air heat exchange pipeline, and the indoor return air introduced by the pre-cooling return air inlet is discharged to the outside through the return air heat exchange pipeline. The control method is characterized by comprising: The actual supply air temperature of the supply air duct and the actual return air temperature of the return air duct are detected. Compare the actual supply air temperature with the target temperature range; When the actual supply air temperature is higher than the target temperature range, reduce the opening of the damper of the primary mixing return air inlet, increase the opening of the damper of the secondary mixing return air inlet, and increase the opening of the damper of the precooling return air inlet. When the actual supply air temperature is lower than the target temperature range, increase the opening of the damper of the primary mixing return air inlet, decrease the opening of the damper of the secondary mixing return air inlet, and decrease the opening of the damper of the precooling return air inlet. When the actual supply air temperature is within the target temperature range, the opening degree of the damper at the primary mixing return air inlet and the opening degree of the damper at the secondary mixing return air inlet remain unchanged. When the actual supply air temperature is within the target temperature range and the actual return air temperature fluctuates, the opening of the pre-cooling return air inlet damper is adjusted according to the level of the actual return air temperature. When the actual supply air temperature is within the target temperature range and the actual return air temperature is stable, the opening degree of the damper at the pre-cooled return air inlet remains unchanged.

2. The control method according to claim 1, characterized in that, The air conditioning unit also includes: a regeneration channel, in which regeneration air heating devices and a rotary dehumidifier regeneration zone are installed sequentially along the regeneration air direction; The air supply duct is also provided with a reheat section located on the air outlet side of the secondary evaporator, and the reheat section is connected to the air outlet end of the regeneration duct through a regeneration air inlet.

3. The control method according to claim 2, characterized in that, The reheat section is equipped with a reheat heat exchanger, which has a reheat heat exchange pipeline for circulating regenerated air. The regenerated air delivered from the regenerated air outlet is discharged outdoors through the regenerated air heat exchange pipeline.

4. The control method according to claim 3, characterized in that, A humidifier is also installed in the air supply duct, and the humidifier is located on the air outlet side of the reheat heat exchanger.

5. The control method according to claim 1, characterized in that, Adjusting the opening degree of the pre-cooled return air inlet damper according to the actual return air temperature includes: Compare the actual return air temperature with the target temperature range; When the actual return air temperature is higher than the target temperature range, reduce the opening of the damper at the pre-cooled return air inlet; When the actual return air temperature is lower than the target temperature range, increase the opening of the damper at the pre-cooled return air inlet.

6. The control method according to claim 2, characterized in that, The control method further includes: Detect the actual air supply temperature of the air supply duct; Compare the actual supply air temperature with the target temperature range; When the actual supply air temperature is higher than the target temperature range, reduce the regeneration air volume at the regeneration air outlet; When the actual supply air temperature is lower than the target temperature range, increase the regeneration air volume at the regeneration air outlet; When the actual supply air temperature is within the target temperature range, the regeneration air volume at the regeneration air outlet remains unchanged.

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