Multi-stage temperature-increasing heat pump device, rotary dehumidification system and heat recovery and utilization method

Abstract

The application discloses a kind of multistage temperature rising heat pump system device, rotary dehumidification system and regenerative heat source recycling method.The device includes primary heat exchange circuit, middle heat exchange circuit and end heat exchange circuit.The condenser of each heat exchange circuit is gradually arranged along the regenerative inlet air flow direction, and the regenerative inlet air is gradually heated.The evaporator of each heat exchange circuit is gradually arranged along the regenerative exhaust air flow direction, and the regenerative exhaust air heat is gradually recovered.The end evaporator can be switched, and when the regenerative exhaust air temperature is higher than the external environment temperature, it is located in the regenerative exhaust air channel and exchanges heat with the regenerative exhaust air, and when the regenerative exhaust air temperature is lower than the external environment temperature, it is moved out to exchange heat with the external environment air.The application uses the reverse matching strategy of evaporation end and condensation end, so that the highest grade heat source drives the circuit with the lowest condensation temperature to undertake the optimal efficiency temperature rising task with very high energy efficiency ratio, significantly reduces the regeneration energy consumption of rotary dehumidifier, and improves the overall energy efficiency ratio of the system.

Description

Technical Field

[0001] This application relates to the field of air conditioning and heat recovery technology, and in particular to multi-stage heating heat pump devices, rotary dehumidification systems and heat recovery and utilization methods. Background Technology

[0002] Rotary dehumidifiers are widely used deep dehumidification devices in industrial and commercial fields. Their working principle is as follows: when humid air passes through the processing zone of the rotating dehumidification wheel, the moisture is adsorbed by the adsorption material on the wheel, thus achieving air dehumidification; when the wheel rotates to the regeneration zone, the adsorption material is heated and desorbed by high-temperature regeneration air, so that the wheel can restore its dehumidification capacity.

[0003] The regeneration process requires heating the regeneration intake air to a relatively high temperature, typically between 80°C and 140°C. This heating process consumes a significant amount of energy and is a major component of the energy consumption of rotary dehumidifiers. In traditional rotary dehumidifier systems, regeneration heating is usually achieved using electric heaters, steam heaters, or gas heaters. Although the temperature of the regeneration exhaust air decreases after desorption, it still carries a large amount of waste heat, including both sensible heat and latent heat carried by the evaporation of moisture released from the adsorbent material during the high-temperature desorption process. This waste heat is usually directly discharged into the atmosphere in traditional systems, resulting in serious energy waste.

[0004] Existing technologies also employ heat pumps to recover and regenerate waste heat from exhaust air, but these technologies have the following drawbacks: First, because there is a large temperature difference between the regeneration exhaust temperature and the target regeneration temperature, if a single-stage heat pump is used to directly raise the heat from the exhaust side to the regeneration temperature, the compressor needs to operate under high compression ratio conditions, which leads to a sharp drop in compressor efficiency, a low system energy efficiency ratio, and the compressor operating under high load conditions for a long time, resulting in an increased failure rate and a shortened service life.

[0005] Secondly, the regenerated exhaust air contains two different grades of heat: sensible heat and latent heat, each with different release temperature ranges and characteristics. Traditional single-stage or simple two-stage heat pump systems do not set differentiated evaporation and condensation temperature ranges for different grades of heat, resulting in significant irreversible losses during heat recovery and actual system efficiency far below theoretical values.

[0006] Third, when environmental conditions change, such as in low-temperature winter environments, the temperature of the regenerated exhaust air after multi-stage evaporator recovery may already be lower than the ambient temperature. In this case, continuing to extract heat from the even colder exhaust air will lead to excessively low evaporation temperature, excessively high compression ratio, and further deterioration of system efficiency. Existing technologies lack adaptive adjustment mechanisms for this condition.

[0007] Therefore, it is necessary to propose a new multi-stage heating heat pump system that can efficiently recover heat of different grades in the regenerated exhaust air in stages, and has the ability to adaptively switch to changes in the external ambient temperature, so as to significantly reduce the regeneration energy consumption of the rotary dehumidifier. Summary of the Invention

[0008] The purpose of this invention is to provide a multi-stage heating heat pump device, a rotary dehumidifier system, and a method for recovering and utilizing the regenerated heat source of a rotary dehumidifier, in order to solve the technical problems in the prior art, such as low efficiency of waste heat recovery from the regenerated exhaust air of the rotary dehumidifier, insufficient energy efficiency due to excessively high compression ratio of a single-stage heat pump, and lack of adaptive adjustment capability under extreme environmental conditions.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides a multi-stage heating heat pump device, comprising a primary heat exchange circuit, a secondary heat exchange circuit, and a final heat exchange circuit, wherein each heat exchange circuit comprises a compressor, a condenser, an expansion valve, and an evaporator connected in sequence. The condensers of each heat exchange circuit are arranged in stages along the regeneration air inlet flow direction to heat the regeneration air in stages; the evaporators of each heat exchange circuit are arranged in stages along the regeneration exhaust air flow direction to recover the heat of the regeneration exhaust air in stages. The final stage evaporator can be switched, while the remaining evaporators are located in the regeneration exhaust duct. When the regeneration exhaust air temperature is higher than the ambient temperature, the final stage evaporator is located in the regeneration exhaust air duct and exchanges heat with the regeneration exhaust air. When the regeneration exhaust air temperature is lower than the ambient temperature, the final stage evaporator moves out to the ambient environment and exchanges heat with the ambient air.

[0010] Furthermore, the evaporator disposed in the regeneration exhaust duct includes a primary evaporator and a secondary evaporator arranged sequentially along the regeneration exhaust flow direction; the primary evaporator is used to recover the sensible heat of the regeneration exhaust above the dew point temperature; the secondary evaporator is used to recover the latent heat of condensation and sensible heat released during the cooling of the regeneration exhaust to below the dew point temperature; the final evaporator is located downstream of the secondary evaporator when it is located in the regeneration exhaust duct.

[0011] Furthermore, the primary heat exchange circuit includes the primary evaporator and the primary condenser, and the difference between the evaporation temperature and the condensation temperature of the primary heat exchange circuit is ≤15℃.

[0012] Furthermore, the temperature rise of the regeneration air by the final stage condenser is less than that by the primary stage condenser; the temperature rise of the regeneration air by the primary stage condenser is 10-20℃, and the temperature rise of the regeneration air by the final stage condenser is 3-8℃.

[0013] Furthermore, the intermediate condenser raises the temperature of the regeneration air intake by 20-35°C.

[0014] Furthermore, the intermediate evaporator is equipped with a condensate collection tray and a drain pipe, the fin surface of the intermediate evaporator is coated with a hydrophilic coating, and the fin spacing of the intermediate evaporator is greater than the fin spacing of the primary evaporator.

[0015] Furthermore, the fin spacing of the primary evaporator is 1.8-2.2 mm, and the fin spacing of the intermediate evaporator is 2.5-3.5 mm.

[0016] In a second aspect, the present invention provides a rotary dehumidification system, comprising: A rotary dehumidifier, comprising a dehumidifying rotor, a regeneration air inlet channel, and a regeneration air outlet channel, wherein a spare heater is provided on the regeneration air inlet channel; In any of the above-described multi-stage heating heat pump devices, the condensers of each heat exchange circuit are arranged sequentially and located upstream of the standby heater.

[0017] Thirdly, the present invention provides a method for recovering and utilizing the regenerative heat source of a rotary dehumidifier, employing any of the multi-stage heating heat pump devices described above, the method comprising the following steps: S100, the evaporator in the regeneration exhaust duct absorbs the heat of the regeneration exhaust air and transfers the heat to the corresponding condenser through its respective heat exchange circuit, heating the regeneration intake air step by step. S200. Determine the relationship between the regeneration exhaust air temperature and the external ambient temperature: When the regeneration exhaust air temperature is not lower than the external ambient temperature, the final stage evaporator is located in the regeneration exhaust air channel to absorb the waste heat of the regeneration exhaust air; when the regeneration exhaust air temperature is lower than the external ambient temperature, the final stage evaporator moves out to the external environment to absorb the heat of the external ambient air; the heat absorbed by the final stage evaporator is transferred to the final stage condenser through its heat exchange circuit to perform final stage heating of the regeneration intake air.

[0018] Furthermore, it also includes the following steps: Obtain the actual temperature of the regeneration air intake at the outlet of the final stage condenser; When the actual temperature is lower than the target regeneration temperature and the duration exceeds a preset time threshold, the compressor operating frequency of the heat exchange circuit to which the final evaporator belongs is increased; When the actual temperature is higher than the target regeneration temperature, the operating frequency of the compressor in the heat exchange circuit to which the final evaporator belongs is reduced.

[0019] In summary, this application includes at least one of the following beneficial technical effects: In this invention, the evaporators of each heat exchange circuit are arranged in stages along the regeneration exhaust air flow direction, with the evaporation temperature decreasing step by step along the exhaust air flow direction; the condensers of each heat exchange circuit are arranged in stages along the regeneration inlet air flow direction, with the condensation temperature increasing step by step along the inlet air flow direction. Since the evaporators and condensers of the same heat exchange circuit are located at the same sequence position in their respective channels, a reverse matching relationship is formed where the circuit with the highest evaporation temperature corresponds to the condenser with the lowest condensation temperature, and the circuit with the lowest evaporation temperature corresponds to the condenser with the highest condensation temperature. The primary heat exchange loop has the highest evaporation temperature and the lowest condensation temperature, with a temperature difference of ≤15℃ between the two. Its heating efficiency ratio (EER) can reach over 3.5, undertaking the largest proportion of efficient heating tasks in the system. The final heat exchange loop has the lowest evaporation temperature and the highest condensation temperature. Although its compression ratio is relatively large, its temperature rise is designed to be minimal, limiting its work output. Through this reverse matching strategy, the vast majority of heating tasks in the system are completed by the loop with the highest EER, while only a small portion is handled by loops with lower EERs. The overall weighted EER of the system is significantly better than that of conventional multi-stage heat pump solutions. Attached Figure Description

[0020] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the overall structure of the rotary dehumidification system; In the picture: 100. Primary heat exchange circuit; 110. Primary compressor; 120. Primary condenser; 130. Primary expansion valve; 140. Primary evaporator; 200. Intermediate heat exchange circuit; 210. Intermediate compressor; 220. Intermediate condenser; 230. Intermediate expansion valve; 240. Intermediate evaporator; 300. Final stage heat exchange circuit; 310. Final stage compressor; 320. Final stage condenser; 330. Final stage expansion valve; 340. Final stage evaporator; 400. Rotary dehumidifier. Detailed Implementation

[0022] The technical solution of this application will now be clearly and completely described with reference to the accompanying drawings. The following embodiments are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the following description, the same reference numerals are used to denote the same or equivalent elements, and repeated descriptions are omitted.

[0023] In the description of this application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this application and to simplify the description, and are not intended to indicate or imply that the equipment or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0024] Furthermore, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0025] It should also be further understood that the term “and / or” as used in this application refers to any combination of one or more of the listed items, and all possible combinations thereof.

[0026] Example 1: This embodiment provides a rotary dehumidification system, which includes a rotary dehumidifier 400 and a multi-stage heating heat pump device.

[0027] The rotary dehumidifier 400 features a dehumidifying rotor, a regeneration air inlet duct, and a regeneration air outlet duct. The dehumidifying rotor includes a treatment zone and a regeneration zone. The treatment zone adsorbs moisture from the air, while the regeneration zone uses high-temperature regeneration air to desorb and regenerate the adsorbent material. The regeneration air inlet duct introduces outside air or return air, heats it to the target regeneration temperature, and then sends it to the regeneration zone of the dehumidifying rotor. The regeneration air outlet duct exhausts the high-temperature, high-humidity regeneration air after desorption.

[0028] A backup heater is provided on the regeneration air intake duct. Exemplarily, the backup heater can be an electric heater, a steam coil heater, or a gas heater. The backup heater is used to supplement heating when the heating capacity of the multi-stage heating heat pump unit is insufficient to raise the temperature of the regeneration air intake to the target value.

[0029] It should be noted that under certain operating conditions, if the multi-stage heating heat pump device can raise the regeneration air inlet temperature to near or reach the target regeneration temperature, the standby heater may not need to be started, thus achieving full heat pump driven regeneration heating and further improving energy-saving performance.

[0030] Example 2: This embodiment 1 provides a multi-stage heating heat pump device, which includes three independent heat exchange circuits: a primary heat exchange circuit 100, a secondary heat exchange circuit 200, and a final heat exchange circuit 300. Each heat exchange circuit includes a compressor, a condenser, an expansion valve, and an evaporator connected in sequence, forming an independent closed-loop refrigerant cycle. The refrigerant cycles of the three heat exchange circuits are independent of each other and do not interfere with each other.

[0031] The condensers of each heat exchange circuit are arranged in stages along the regeneration air inlet channel, and are all located upstream of the standby heater. That is, the regeneration air is first heated in stages by the primary condenser 120, the intermediate condenser 220 and the final condenser 320 before reaching the standby heater.

[0032] This arrangement allows the multi-stage heating heat pump unit to preheat the regenerated intake air with the recovered waste heat before the standby heater. The standby heater is only activated as a supplementary heat source when the heat pump system's heating capacity is insufficient, thereby maximizing the energy-saving effect of the heat pump system.

[0033] The structure and working principle of a multi-stage heating heat pump device are described in detail below.

[0034] (a) Stepwise heating on the condenser side Reference Figure 1 The condensers of each heat exchange circuit are arranged in stages along the regeneration airflow direction to heat the regeneration airflow in stages. Along the regeneration airflow direction, they are, in sequence, the primary condenser 120, the intermediate condenser 220, and the final condenser 320.

[0035] The regenerated intake air first flows through the primary condenser 120, exchanging heat with the high-temperature refrigerant in the primary heat exchange circuit 100, completing the first stage of heating. Then, after being heated by the primary condenser 120, the regenerated intake air flows through the intermediate condenser 220, exchanging heat with the high-temperature refrigerant in the intermediate heat exchange circuit 200, completing the second stage of heating. Finally, the regenerated intake air flows through the final condenser 320, exchanging heat with the high-temperature refrigerant in the final heat exchange circuit 300, completing the third stage of heating. After being heated in three stages by the condensers, the temperature of the regenerated intake air is significantly increased before it reaches the standby heater.

[0036] Understandably, along the direction of the regeneration airflow, the primary condenser 120 has the lowest condensing temperature, while the final condenser 320 has the highest condensing temperature, with the condensing temperature of each stage of the condenser gradually increasing. Meanwhile, on the evaporator side, since the evaporators of each heat exchange circuit are arranged in stages along the direction of the regeneration exhaust airflow, the primary evaporator 140 first comes into contact with the hottest regeneration exhaust air, resulting in its highest evaporation temperature; the final evaporator 340 comes into contact with the low-temperature exhaust air or ambient air after deep recovery by the first two stages of evaporators, resulting in its lowest evaporation temperature.

[0037] Since the evaporator and condenser in the same heat exchange circuit are located in the same stage position in their respective channels, the temperatures at the evaporation end and the condensation end show an inverse correspondence: the primary heat exchange circuit 100, to which the primary evaporator 140, which has the highest evaporation temperature, corresponds to the primary condenser 120, which has the lowest condensation temperature; the final heat exchange circuit 300, to which the final evaporator 340, which has the lowest evaporation temperature, corresponds to the final condenser 320, which has the highest condensation temperature.

[0038] It should be noted that this reverse matching relationship between the evaporator and condenser ends differs from the forward matching approach in conventional multi-stage heat pump systems, where a high-temperature heat source drives a high-temperature condenser. In conventional forward matching, the highest-temperature heat source is used to drive the condenser with the highest condensation temperature, which intuitively seems to result in a smaller heat transfer temperature difference and is more reasonable.

[0039] However, the reverse matching strategy of the present invention is designed from the perspective of optimizing the overall energy efficiency of the system: the primary heat exchange circuit 100 uses the highest grade heat source to drive the primary condenser 120 with the lowest condensation temperature, so that the difference between the evaporation temperature and the condensation temperature of the circuit is extremely small, the compression ratio is extremely low, the heating energy efficiency ratio is extremely high, and the circuit undertakes a large proportion of the heating task in the system. Although the final stage heat exchange loop 300 drives the final stage condenser 320 with the lowest grade heat source, resulting in a large difference between the evaporation and condensation temperatures, a high compression ratio, and a relatively low energy efficiency ratio, the actual work done by the loop is strictly controlled at a low level by designing the temperature rise of the final stage condenser 320 to be extremely small.

[0040] From the perspective of the system as a whole, the vast majority of heating tasks are completed by the primary and intermediate heat exchange loops 200, which have the highest energy efficiency ratio, while only a very small proportion of heating tasks are undertaken by the final heat exchange loop 300, which has a lower energy efficiency ratio. The overall weighted energy efficiency ratio of the system is significantly better than that of conventional multi-stage heat pump solutions.

[0041] Reference Figure 1 In a specific application scenario of the present invention, the temperature rise of the regeneration air intake is allocated differently for each stage of the condenser.

[0042] The primary condenser 120 raises the temperature of the regeneration inlet air by 10-20°C. Located at the upstream end of the regeneration inlet air path, the primary condenser 120 experiences the lowest regeneration inlet air temperature, resulting in the lowest condensation temperature for the primary heat exchange loop 100. Because the primary heat exchange loop 100 operates at an extremely low compression ratio under a reverse matching strategy, its energy efficiency ratio is the highest among the three loops. Therefore, the primary condenser 120 undertakes the most energy-efficient temperature-raising task in the system.

[0043] The intermediate condenser 220 raises the temperature of the regeneration inlet air by 20-35°C. Located downstream of the primary condenser 120, the intermediate condenser 220's heat source comes from the latent heat and sensible heat recovered by the intermediate evaporator 240. Since the latent heat energy density in the regeneration exhaust air is much higher than the sensible heat within the same temperature range, the intermediate heat exchange loop 200 can provide a large amount of heat; therefore, the intermediate condenser 220 undertakes the heating task with the largest temperature rise in the system.

[0044] The final stage condenser 320 raises the temperature of the regeneration inlet air by 3-8℃, which is less than the temperature rise of the primary condenser 120. Located at the downstream end of the regeneration inlet air path, the final stage condenser 320 further raises the regeneration inlet air temperature from the outlet temperature of the intermediate condenser 220 to a level close to the target regeneration temperature.

[0045] Understandably, the final-stage heat exchange loop 300 has the largest evaporation-condensation temperature difference in the entire reverse matching strategy: the final-stage evaporator 340 has the lowest evaporation temperature, while the final-stage condenser 320 has the highest condensation temperature among the three loops, corresponding to the highest compression ratio and the lowest relative energy efficiency ratio. By designing the temperature rise of the final-stage condenser 320 to be relatively small and controlling its actual work output to a minimum, the overall weighted energy efficiency ratio of the system is not significantly affected by this loop.

[0046] For example, the above-mentioned gradual heating process is illustrated using a typical application scenario: The target regeneration temperature is 120℃, and the external ambient temperature is 25℃. The initial temperature of the regeneration air intake is about 25℃. After being heated by the primary condenser 120, the temperature rises by about 15℃ to 40℃. After being heated by the intermediate condenser 220, the temperature rises by about 30℃ to 70℃. After being heated by the final condenser 320, the temperature rises by about 5℃ to 75℃.

[0047] At this point, the regeneration inlet air temperature is 75℃, which is 45℃ lower than the target temperature of 120℃. This temperature difference is supplemented by the backup heater. In this scenario, the multi-stage heating heat pump system has raised the regeneration inlet air temperature from 25℃ to 75℃, a total increase of 50℃, significantly reducing the heating load and energy consumption of the backup heater. It should be noted that the above values ​​are illustrative; in actual operation, the temperature rise of each stage of the condenser can be dynamically adjusted according to specific regeneration temperature requirements, exhaust air temperature conditions, and ambient temperature conditions.

[0048] (ii) Stepwise heat recovery on the evaporation side Reference Figure 1 The evaporators of each heat exchange circuit are set up in stages along the direction of regeneration exhaust air flow to recover heat of different grades in the regeneration exhaust air in stages.

[0049] The evaporator installed in the regeneration exhaust duct includes a primary evaporator 140 and an intermediate evaporator 240 arranged sequentially along the regeneration exhaust flow direction. The primary evaporator 140 and the intermediate evaporator 240 are fixedly installed in the regeneration exhaust duct.

[0050] The primary evaporator 140 is used to recover the sensible heat of the regeneration exhaust air above its dew point temperature. The regeneration exhaust air is still at a relatively high temperature when it exits the regeneration zone of the rotary dehumidifier 400, and it carries a large amount of water vapor generated during the desorption process. The evaporation temperature of the primary evaporator 140 is set above the dew point temperature of the regeneration exhaust air; therefore, the regeneration exhaust air only experiences a temperature drop as it flows through the primary evaporator 140, and the water vapor in the exhaust air does not condense. During this stage, all the heat released by the exhaust air is sensible heat.

[0051] The primary evaporator 140 belongs to the primary heat exchange loop 100. The difference between the evaporation temperature and the condensation temperature of the primary heat exchange loop 100 is ≤15℃.

[0052] Understandably, the primary heat exchange loop 100 is the loop that benefits the most from the reverse matching strategy. Since the primary evaporator 140 first comes into contact with the hottest exhaust air from the regeneration zone, its evaporation temperature is the highest among the three loops; at the same time, the primary condenser 120 performs the first stage heating on the lowest temperature regeneration inlet air, and its condensation temperature is the lowest among the three loops.

[0053] The combination of the highest evaporation temperature and the lowest condensation temperature results in a very small difference between the evaporation and condensation temperatures in the primary heat exchange circuit 100, corresponding to an extremely low compressor compression ratio. Under such a low compression ratio, the compressor approaches an isentropic compression process, with both volumetric efficiency and isentropic efficiency in their optimal range. The heating efficiency ratio of this stage of the heat exchange circuit can reach over 3.5.

[0054] This means that for every 1kW of electrical power consumed by the compressor, more than 12kW of heat can be transferred to the regeneration intake air through the primary condenser 120, of which about 11kW comes from the recovery of waste heat from the regeneration exhaust air, and only about 1kW comes from the conversion of compressor power consumption.

[0055] As can be seen, the reverse matching strategy allocates the highest-grade heat source to the loop with the lowest condensation temperature, enabling the primary heat exchange loop 100 to achieve highly efficient heat "transfer" with an extremely high energy efficiency ratio, and undertakes the largest heating task in the system.

[0056] The intermediate evaporator 240 is located downstream of the primary evaporator 140. The regeneration exhaust air has cooled somewhat after sensible heat recovery in the primary evaporator 140. The evaporation temperature of the intermediate evaporator 240 is set below the dew point temperature of the regeneration exhaust air. When the exhaust air temperature drops below the dew point temperature, the water vapor carried in the exhaust air begins to condense on the fin surface of the intermediate evaporator 240, releasing a large amount of latent heat of condensation. Simultaneously, the exhaust air temperature continues to decrease, also releasing sensible heat. Therefore, the intermediate evaporator 240 is used to recover the latent heat of condensation and sensible heat released during the cooling of the regeneration exhaust air to below the dew point temperature.

[0057] It should be noted that in the waste heat composition of regenerated exhaust air, the energy density of latent heat of condensation is much higher than that of sensible heat in the same temperature range. Taking water vapor as an example, the latent heat of condensation of 1 kg of water vapor under standard atmospheric pressure is about 2257 kJ, while the sensible heat released by 1 kg of dry air when cooled by 1°C is about 1 kJ.

[0058] Therefore, the latent heat of condensation released by the regenerated exhaust air during the cooling process across the dew point temperature is a considerable energy source. The intermediate evaporator 240, by operating below the dew point temperature, fully captures this high-density heat and transfers it to the intermediate condenser 220 through the intermediate heat exchange loop 200, providing sufficient heat source guarantee for the intermediate condenser 220 to withstand the maximum temperature rise.

[0059] Since the intermediate evaporator 240 operates below the dew point temperature, water vapor condensation will continuously occur on its fin surface. To accommodate this operating condition, the intermediate evaporator 240 is equipped with a condensate collection tray and a drain pipe.

[0060] A condensate collection tray is located below the intermediate evaporator 240 to collect condensate that condenses and flows down the fin surface. A drain pipe connects to the condensate collection tray to guide the collected condensate out. Exemplarily, the drain pipe can be connected to the building's drainage system or introduced into a collection container for other purposes.

[0061] The fins of the intermediate evaporator 240 are coated with a hydrophilic coating. The function of this hydrophilic coating is to alter the wetting characteristics of the fin surface, allowing condensate to form a uniform thin water film that flows down the fin surface and is discharged, rather than condensing into droplets that remain in the fin gaps. If condensate accumulates in the form of large droplets between the fins, it will block the airflow and increase air resistance; furthermore, the water droplets will obstruct the airflow and reduce the effective heat exchange area of ​​the fins. Both of these issues are detrimental to the heat exchange efficiency of the intermediate evaporator 240 and the unobstructed flow of the regeneration exhaust channel. The hydrophilic coating effectively avoids these problems. For example, the hydrophilic coating can be an inorganic silicon-based hydrophilic coating, an organic polymer hydrophilic coating, or an oxide nanoscale hydrophilic coating.

[0062] The fin spacing of the intermediate evaporator 240 is larger than that of the primary evaporator 140. This larger fin spacing provides sufficient space for condensate to flow and drain along the fin surface, preventing condensate buildup and bridging between fins that could cause water film blockage of the air ducts. It also helps reduce air resistance during condensation. Since the primary evaporator 140 does not involve condensation, its fin surface remains dry, allowing for a denser fin arrangement to achieve a larger heat exchange area within the same volume, thus improving sensible heat recovery efficiency.

[0063] In one specific embodiment, the fin spacing of the primary evaporator 140 is 1.8-2.2 mm, and the fin spacing of the intermediate evaporator 240 is 2.5-3.5 mm. For example, the fin spacing of the primary evaporator 140 can be selected as 2.0 mm, and the fin spacing of the intermediate evaporator 240 can be selected as 3.0 mm.

[0064] (III) Final stage evaporator 340 The final stage evaporator 340 can be switched, and its operating position is adaptively switched based on the comparison between the regeneration exhaust air temperature and the external ambient temperature.

[0065] When the regeneration exhaust air temperature is higher than the ambient temperature, the final-stage evaporator 340 is located in the regeneration exhaust air duct, downstream of the intermediate-stage evaporator 240, and exchanges heat with the regeneration exhaust air after two stages of recovery by the primary evaporator 140 and the intermediate-stage evaporator 240. Although the temperature of the regeneration exhaust air has decreased after these two stages of recovery, it is still higher than the ambient temperature, making it a better heat source than the ambient air. The final-stage evaporator 340 further extracts heat from this portion of the exhaust air waste heat and transfers it to the final-stage condenser 320 through the final-stage heat exchange loop 300, providing final-stage heating for the regeneration intake air.

[0066] When the regeneration exhaust air temperature is lower than the ambient temperature, the final stage evaporator 340 moves out into the external environment to exchange heat with the ambient air. This condition typically occurs in the following scenarios: in rotary dehumidifier systems in winter or cold regions, both the initial temperature of the regeneration intake air and the ambient temperature are low; after the first two stages of evaporators have fully recovered the regeneration exhaust air, the exhaust air temperature has been reduced to a level lower than the ambient temperature. In this situation, if heat continues to be extracted from the lower-temperature exhaust air, the evaporation temperature of the final stage evaporator 340 will be forced to be set at an extremely low level, resulting in an excessively large temperature difference between the evaporation temperature and the condensation temperature of the final stage heat exchange circuit 300, an excessively high compression ratio, a sharp drop in compressor efficiency, and a deterioration in the overall energy efficiency of the system.

[0067] By switching the final stage evaporator 340 to the external environment, the final stage evaporator 340 can absorb heat from the warmer external air, maintain a reasonable evaporation temperature and compression ratio, and ensure the operating efficiency of the final stage heat exchange circuit 300.

[0068] Understandably, this switching mechanism enables the final stage heat exchange loop 300 to extract heat from a higher available heat source under any operating condition, avoiding system efficiency deterioration due to excessively low heat source temperature, and achieving adaptive and efficient operation of the system under different seasons and ambient temperature conditions.

[0069] The switchable settings of the final stage evaporator 340 can be achieved through a variety of mechanisms.

[0070] For example, a guide rail sliding mechanism can be used to install the final stage evaporator 340 on the slide rail. The final stage evaporator 340 can be driven by an electric push rod or a cylinder to switch between the working position inside the regeneration exhaust duct and the working position in the external environment. An openable and closable inlet and outlet can be opened on the side wall of the regeneration exhaust duct.

[0071] For example, this can also be achieved by switching air valves. That is, the final stage evaporator 340 is fixedly installed in an independent heat exchange chamber, which is connected to the regeneration exhaust air channel and the external environment through pipes. Each pipe is equipped with a controllable air valve. When heat needs to be extracted from the regeneration exhaust air, the regeneration exhaust air side valve is opened and the external environment side valve is closed, so that the regeneration exhaust air is introduced into the heat exchange chamber to exchange heat with the final stage evaporator 340. When heat needs to be extracted from the external environment, the regeneration exhaust air side valve is closed and the external environment side valve is opened, so that the external ambient air is introduced into the heat exchange chamber.

[0072] For example, a rotating frame mechanism can also be used to mount the final stage evaporator 340 on a rotatable frame, so that the air inlet and outlet surfaces of the final stage evaporator 340 face the regeneration exhaust duct or the external environment by rotating the frame.

[0073] The switching control of the final stage evaporator 340 can be achieved through the coordinated operation of a temperature sensor and a controller. An exhaust air temperature sensor is installed downstream of the intermediate evaporator 240 in the regeneration exhaust air duct to monitor the regeneration exhaust air temperature after it has been recovered by the two-stage evaporators in real time.

[0074] An ambient temperature sensor is installed outside the equipment to monitor the external air temperature in real time. The controller receives and compares the signals from the two temperature sensors in real time. When the reading of the exhaust temperature sensor is higher than that of the ambient temperature sensor, the controller issues a command to keep or switch the final-stage evaporator 340 in the operating position in the regeneration exhaust duct; when the reading of the exhaust temperature sensor is lower than that of the ambient temperature sensor, the controller issues a command to move the final-stage evaporator 340 out or switch it to the external environment operating position.

[0075] It should be noted that, to avoid frequent switching when the readings of the two temperature sensors are close, a temperature hysteresis can be set in the control logic. For example, the temperature hysteresis can be set to 1-3℃. That is, switching to the external environment is triggered only when the exhaust air temperature is lower than the ambient temperature by more than the hysteresis value, and switching back to the regeneration exhaust air channel is triggered only when the exhaust air temperature is higher than the ambient temperature by more than the hysteresis value.

[0076] The composition and key parameters of the three heat exchange circuits are described in further detail below.

[0077] (a) Primary heat exchange circuit 100 The primary heat exchange circuit 100 includes a primary compressor 110, a primary condenser 120, a primary expansion valve 130, and a primary evaporator 140, which are connected in sequence through refrigerant pipelines to form a closed loop.

[0078] The primary evaporator 140 is located in the regeneration exhaust duct, at the upstream position in the regeneration exhaust air flow direction. It first contacts the high-temperature exhaust air discharged from the regeneration zone of the rotary dehumidifier 400, recovering sensible heat above the dew point temperature. The primary condenser 120 is located in the regeneration inlet air duct, at the upstream position in the regeneration inlet air flow direction, providing the first stage of heating for the lowest-temperature regeneration inlet air.

[0079] The difference between the evaporation temperature and the condensation temperature of the primary heat exchange circuit 100 is ≤15℃, corresponding to a compression ratio of ≤2 for the primary compressor 110. As mentioned earlier, the primary heat exchange circuit 100 is the circuit that benefits the most from the reverse matching strategy, with a heating efficiency ratio of over 3.5, making it the most energy-efficient component in the entire three-stage system.

[0080] The primary condenser 120 raises the temperature of the regeneration inlet air by 10-20°C. For example, under the condition that the initial temperature of the regeneration inlet air is 25°C, the temperature of the regeneration inlet air can be raised to 35-45°C after being heated by the primary condenser 120.

[0081] The refrigerant used in the primary heat exchange circuit 100 can be selected based on its operating temperature range. For example, conventional refrigerants such as R134a, R410A, or R32 can be used. The specific selection of the refrigerant is a conventional design choice that can be determined by those skilled in the art based on actual operating conditions.

[0082] The primary expansion valve 130 is preferably an electronic expansion valve, which can perform precise throttling control based on the superheat of the refrigerant at the outlet of the primary evaporator 140, ensuring that the refrigerant fully evaporates and absorbs heat in the primary evaporator 140. The primary compressor 110 is preferably a variable frequency compressor, which can adjust its speed according to the sensible heat recovery load of the regeneration exhaust air, maintaining high operating efficiency under partial load conditions.

[0083] (II) Intermediate heat exchange loop 200 The intermediate heat exchange circuit 200 includes an intermediate compressor 210, an intermediate condenser 220, an intermediate expansion valve 230, and an intermediate evaporator 240, which are connected in sequence through refrigerant pipelines to form a closed loop.

[0084] The intermediate evaporator 240 is located in the regeneration exhaust air duct, downstream of the primary evaporator 140, and receives the regeneration exhaust air whose temperature has decreased after the sensible heat recovery in the primary evaporator 140. The evaporation temperature of the intermediate evaporator 240 is set below the dew point temperature of the regeneration exhaust air to recover the latent heat of condensation and sensible heat released during the cooling process of the exhaust air to below the dew point temperature. The intermediate condenser 220 is located in the regeneration inlet air duct, downstream of the primary condenser 120, and provides a second stage of heating for the regeneration inlet air after the first stage heating in the primary condenser 120.

[0085] The intermediate condenser 220 raises the temperature of the regeneration air intake by 20-35°C, undertaking the largest temperature-raising task among the three loops. This is understandable, as the latent heat of condensation recovered by the intermediate evaporator 240 has extremely high energy density, providing a sufficient heat source for the intermediate heat exchange loop 200, enabling the intermediate condenser 220 to release a large amount of heat to the regeneration air intake.

[0086] As mentioned earlier, the intermediate evaporator 240 is equipped with a condensate collection tray, a drain pipe and a hydrophilic coating, and the fin spacing is designed to be 2.5-3.5mm, all of which are specially designed to adapt to condensation conditions.

[0087] The refrigerant used in the intermediate heat exchange circuit 200 can be selected according to its operating temperature range. Since the intermediate condenser 220 needs to operate at higher temperatures, refrigerants suitable for medium- and high-temperature conditions, such as R134a, R245fa, or R1234ze, can be selected, for example. The selection principles for the intermediate expansion valve 230 and the intermediate compressor 210 are the same as those for the primary heat exchange circuit 100, preferably an electronic expansion valve and a variable frequency compressor.

[0088] (III) Final stage heat exchange loop 300 The final stage heat exchange circuit 300 includes a final stage compressor 310, a final stage condenser 320, a final stage expansion valve 330, and a final stage evaporator 340, which are connected in sequence through refrigerant pipelines to form a closed loop.

[0089] The final-stage condenser 320 is located in the regeneration air inlet duct, downstream of the intermediate-stage condenser 220. It is the last condenser that the regeneration air passes through before reaching the standby heater, providing final-stage heating for the regeneration air. The final-stage condenser 320 raises the temperature of the regeneration air by 3-8℃.

[0090] The operating position and heat source selection of the final stage evaporator 340 have been described in detail above and will not be repeated here.

[0091] The refrigerant used in the final stage heat exchange circuit 300 needs to withstand high condensing temperatures. Since the final stage condenser 320 is located at the downstream end of the regeneration air inlet path, its condensing temperature is the highest among the three circuits. For example, high-temperature refrigerants such as R245fa, R1233zd(E), or R365mfc can be selected. The final stage expansion valve 330 is preferably an electronic expansion valve. The final stage compressor 310 is preferably a variable frequency compressor, whose operating frequency can be dynamically adjusted according to the closed-loop temperature control strategy described later.

[0092] It should be noted that under the reverse matching strategy, the evaporation-condensation temperature difference in the final stage heat exchange loop 300 is the largest among the three loops, and the final stage compressor 310 experiences the highest compression ratio. Therefore, the rated power of the final stage compressor 310 is significantly higher than that of the primary compressor 110 and the intermediate compressor 210. However, since the temperature rise of the final stage condenser 320 is only 3-8℃, the total amount of heat that the final stage heat exchange loop 300 needs to transfer is limited. Although the final stage compressor 310 has a larger power, its actual operating time or duty cycle can be reasonably adjusted through frequency converter control, so that its actual power consumption as a percentage of the total system power consumption can be effectively controlled.

[0093] Example 3: The present invention also provides a method for recovering and utilizing the regenerative heat source of a rotary dehumidifier 400, which adopts the above-mentioned multi-stage heating heat pump system device, and the method includes the following steps.

[0094] Step S100: The evaporator in the regeneration exhaust duct absorbs the heat from the regeneration exhaust air and transfers the heat to the corresponding condenser through its respective heat exchange circuit, thereby heating the regeneration intake air step by step.

[0095] Specifically, the regeneration exhaust air, after being discharged from the regeneration zone of the rotary dehumidifier 400, enters the regeneration exhaust air duct and first flows through the primary evaporator 140. The low-temperature refrigerant in the primary evaporator 140 absorbs the sensible heat released by the regeneration exhaust air above its dew point temperature and evaporates into a low-pressure gaseous refrigerant. This gaseous refrigerant is then compressed into a high-temperature, high-pressure gaseous refrigerant by the primary compressor 110. It then enters the primary condenser 120, releases heat to the regeneration inlet air, and condenses into a liquid refrigerant. After being throttled and depressurized by the primary expansion valve 130, it returns to the primary evaporator 140, completing one thermodynamic cycle. Through this process, the sensible heat in the regeneration exhaust air is "transported" to the regeneration inlet air side, achieving the first stage of heating.

[0096] The regenerated exhaust air, having cooled slightly after passing through the primary evaporator 140, continues to flow through the intermediate evaporator 240. The low-temperature refrigerant in the intermediate evaporator 240 absorbs the latent heat and sensible heat released during the cooling of the regenerated exhaust air to below its dew point temperature, then evaporates. After being compressed and heated by the intermediate compressor 210, it enters the intermediate condenser 220 to release heat to the regenerated intake air, achieving the second stage of heating. During this process, water vapor in the regenerated exhaust air condenses on the fin surface of the intermediate evaporator 240, releasing latent heat. The condensate is collected in a collection tray and discharged through a drain pipe.

[0097] It should be noted that in step S100, the primary heat exchange circuit 100 operates under high-efficiency conditions with a compression ratio ≤2 because the difference between the evaporation and condensation temperatures is controlled within 15°C. The heating efficiency ratio of this stage circuit is above 3.5. The intermediate heat exchange circuit 200 has a higher difference between the evaporation and condensation temperatures than the primary circuit, but because the latent heat of condensation provides a sufficient heat source, the intermediate circuit as a whole still maintains a good energy efficiency level.

[0098] Step S200: Determine the relationship between the regeneration exhaust temperature and the external ambient temperature, and control the working position of the final stage evaporator 340.

[0099] Downstream of the intermediate evaporator 240 in the regeneration exhaust duct, an exhaust temperature sensor monitors the temperature of the regeneration exhaust air after it has been recycled through the two-stage evaporators in real time. An ambient temperature sensor monitors the ambient air temperature in real time. The controller compares the signals from the two temperature sensors.

[0100] When the regeneration exhaust air temperature is not lower than the ambient temperature, the final-stage evaporator 340 remains in the regeneration exhaust air channel, located downstream of the intermediate-stage evaporator 240, absorbing the waste heat from the regeneration exhaust air recovered by the first two stages. At this time, the regeneration exhaust air is still a better heat source than the ambient air, allowing the final-stage evaporator 340 to operate at a higher evaporation temperature. The final-stage heat exchange circuit 300 has a low compression ratio and high operating efficiency.

[0101] When the regeneration exhaust air temperature is lower than the ambient temperature, the final-stage evaporator 340 moves into the external environment to exchange heat with the ambient air. At this time, the ambient air temperature is higher than that of the deeply cooled regeneration exhaust air, making it a superior heat source. The final-stage evaporator 340 absorbs heat from the ambient air, maintaining a higher evaporation temperature and keeping the compression ratio of the final-stage heat exchange circuit 300 within a reasonable range, thus preventing system efficiency degradation due to excessively low evaporation temperatures.

[0102] Regardless of the operating position of the final-stage evaporator 340, the heat it absorbs is increased in temperature and pressure by the compressor in the final-stage heat exchange circuit 300, and then released to the regeneration intake air at the final-stage condenser 320, completing the final-stage heating of the regeneration intake air. After being heated stage by three condensers, the temperature of the regeneration intake air has been significantly increased, and then it reaches the position of the standby heater. If the regeneration intake air temperature has reached or is close to the target regeneration temperature at this time, the standby heater will not start; if there is still insufficient temperature difference, the standby heater will start to supplement the heating, ensuring that the regeneration intake air reaches the target temperature before being sent to the regeneration zone of the rotary dehumidifier 400.

[0103] Step S300: Closed-loop temperature control of the final stage heat exchange loop 300 This method also includes a step of closed-loop temperature control of the final stage heat exchange circuit 300 to achieve precise adjustment of the regeneration inlet air temperature.

[0104] Obtain the actual temperature of the regeneration intake air at the outlet of the final condenser 320. This temperature represents the final temperature of the regeneration intake air after being heated by the three-stage condenser and is a key indicator for evaluating the overall heating effect of the multi-stage heating heat pump system. For example, a temperature sensor can be installed at the outlet of the final condenser 320 to obtain this temperature value.

[0105] When the actual temperature is lower than the target regeneration temperature and this low-temperature state lasts for more than a preset time threshold, the controller issues a command to increase the operating frequency of the compressor in the final stage heat exchange circuit 300. By increasing the compressor operating frequency, the refrigerant mass flow rate and compressor input power are increased, thereby increasing the heating capacity and condensing temperature of the final stage condenser 320, bringing the regeneration inlet air temperature closer to the target temperature. It should be noted that the purpose of setting the duration threshold is to avoid frequent adjustments to the compressor operating frequency caused by instantaneous fluctuations in the actual temperature, thus improving the stability of system operation. For example, the preset time threshold can be set to 30 seconds to 120 seconds.

[0106] When the actual temperature exceeds the target regeneration temperature, the controller issues a command to reduce the operating frequency of the compressor in the final stage heat exchange circuit 300. By reducing the compressor operating frequency, the refrigerant circulation flow and heating capacity are reduced, avoiding unnecessary energy waste caused by excessively high regeneration inlet air temperature and potential high-temperature damage to the dehumidifying impeller adsorption material.

[0107] Understandably, through the aforementioned closed-loop temperature control strategy, the compressor operating frequency of the final-stage heat exchange loop 300 can be dynamically adjusted according to the actual temperature of the regeneration inlet air at the outlet of the final-stage condenser 320, ensuring that the regeneration inlet air temperature is always maintained within the optimal range near the target regeneration temperature, thus achieving precise temperature control and adaptive operation of the system. Combined with the supplementary heating function of the backup heater, the regeneration inlet air temperature of the entire rotary dehumidification system can be stably maintained at the target value under various operating conditions.

[0108] It should be noted that the type of compressor in the three heat exchange circuits described in this invention is not limited to the examples above. Exemplarily, the compressor can be a rotary compressor, a scroll compressor, or a screw compressor. Each compressor is preferably a variable frequency compressor to achieve flexible adjustment of operating frequency and cooling / heating capacity.

[0109] In addition to electronic expansion valves, thermal expansion valves or capillary bundles can also be used as expansion valves in each heat exchange circuit, for example. Among them, electronic expansion valves are preferred embodiments, as they can perform precise throttling control based on the superheat at the evaporator outlet.

[0110] The specific heat exchanger forms of the condensers and evaporators in each heat exchange loop are not limited to a particular type. For example, the condensers and evaporators can be tube-fin heat exchangers, microchannel heat exchangers, or plate heat exchangers. When used in the regeneration air inlet and regeneration air outlet channels, tube-fin heat exchangers are preferred to balance heat exchange efficiency and airflow resistance.

[0111] It should be noted that the technical features in the above embodiments can be freely combined and used without contradicting each other.

[0112] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-stage heating heat pump device, comprising: A rotary dehumidifier (400) has a dehumidifying rotor, a regeneration air inlet channel and a regeneration air outlet channel, and a standby heater is provided on the regeneration air inlet channel; The feature is that it further includes a primary heat exchange circuit (100), an intermediate heat exchange circuit (200) and a final heat exchange circuit (300), each of the heat exchange circuits including a compressor, a condenser, an expansion valve and an evaporator connected in sequence; The primary heat exchange circuit (100) includes a primary evaporator (140) and a primary condenser (120), the intermediate heat exchange circuit (200) includes an intermediate evaporator (240) and an intermediate condenser (220), and the final heat exchange circuit (300) includes a final evaporator (340) and a final condenser (320). The primary condenser (120), intermediate condenser (220), and final condenser (320) are arranged in stages along the regeneration air inlet flow direction to heat the regeneration air in stages; the primary evaporator (140), intermediate evaporator (240), and final evaporator (340) are arranged in stages along the regeneration exhaust air flow direction to recover the heat of the regeneration exhaust air in stages. The final stage evaporator (340) can be switched, while the other evaporators are located in the regeneration exhaust duct; When the regeneration exhaust temperature is higher than the ambient temperature, the final stage evaporator (340) is located in the regeneration exhaust channel and exchanges heat with the regeneration exhaust. When the regeneration exhaust temperature is lower than the ambient temperature, the final stage evaporator (340) moves out to the ambient environment and exchanges heat with the ambient air. The difference between the evaporation temperature and the condensation temperature of the primary heat exchange circuit (100) is ≤15℃; The primary condenser (120) raises the temperature of the regeneration air intake by 10-20°C, the intermediate condenser (220) raises the temperature of the regeneration air intake by 20-35°C, and the final condenser (320) raises the temperature of the regeneration air intake by 3-8°C.

2. The multi-stage heating heat pump device according to claim 1, characterized in that, The primary evaporator (140) is used to recover the sensible heat of the regeneration exhaust air above the dew point temperature; the intermediate evaporator (240) is used to recover the latent heat of condensation and sensible heat released during the cooling of the regeneration exhaust air to below the dew point temperature; the final evaporator (340) is located downstream of the intermediate evaporator (240) when it is located in the regeneration exhaust air channel.

3. The multi-stage heating heat pump device according to claim 1, characterized in that, The temperature rise of the regeneration air by the final stage condenser (320) is less than that of the temperature rise of the regeneration air by the primary condenser (120).

4. The apparatus according to claim 1, characterized in that, The intermediate evaporator (140) is provided with a condensate collection tray and a drain pipe. The fin surface of the intermediate evaporator (140) is provided with a hydrophilic coating, and the fin spacing of the intermediate evaporator (140) is greater than the fin spacing of the primary evaporator (140).

5. The apparatus according to claim 4, characterized in that, The fin spacing of the primary evaporator (140) is 1.8-2.2 mm, and the fin spacing of the intermediate evaporator (140) is 2.5-3.5 mm.

6. A rotary dehumidification system, characterized in that, include: The multi-stage heating heat pump device according to any one of claims 1-5, wherein the condensers of each heat exchange circuit are arranged sequentially and located upstream of the standby heater.

7. A method for recovering and utilizing the regenerative heat source of a rotary dehumidifier, characterized in that, The method using the multi-stage heating heat pump device according to any one of claims 1-5 includes the following steps: S100, the evaporator in the regeneration exhaust duct absorbs the heat of the regeneration exhaust air and transfers the heat to the corresponding condenser through its respective heat exchange circuit, heating the regeneration intake air step by step. S200. Determine the relationship between the regeneration exhaust air temperature and the external ambient temperature: When the regeneration exhaust temperature is not lower than the ambient temperature, the final stage evaporator (140) is located in the regeneration exhaust channel to absorb the residual heat of the regeneration exhaust; when the regeneration exhaust temperature is lower than the ambient temperature, the final stage evaporator (140) moves out to the ambient environment to absorb the heat of the ambient air; the heat absorbed by the final stage evaporator (140) is transferred to the final stage condenser (320) through its heat exchange circuit to perform final stage heating of the regeneration intake air.

8. The method according to claim 7, characterized in that, It also includes the following steps: Obtain the actual temperature of the regeneration air intake at the outlet of the final stage condenser (320); When the actual temperature is lower than the target regeneration temperature and the duration exceeds a preset time threshold, the compressor operating frequency of the refrigerant circulation loop to which the final evaporator (140) belongs is increased; When the actual temperature is higher than the target regeneration temperature, the compressor operating frequency of the heat exchange circuit to which the final evaporator (140) belongs is reduced.

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