Transcritical CO2 cycle and closed air path based dehumidification system and control method

Abstract

The invention discloses a dehumidification system based on transcritical CO2 circulation and a closed air path and a control method. The dehumidification system comprises a transcritical CO2 heat pump subsystem and a closed regeneration air path subsystem. The transcritical CO2 heat pump subsystem comprises a compressor, an air cooler, an expansion valve and an evaporator which are sequentially connected through pipelines and form a circulation loop. The closed regeneration air path subsystem comprises a dehumidification rotating wheel regeneration area, a regeneration fan and an auxiliary radiator, and the dehumidification rotating wheel regeneration area, the regeneration fan and the auxiliary radiator are connected with the circulation loop. The system has the beneficial effects of high efficiency, energy conservation, great reduction of operation cost, environmental protection, meeting of green development requirements, deep dehumidification, stable operation and reduction of installation and operation and maintenance difficulty.

Description

Technical Field

[0001] This invention relates to the field of air technology, specifically to a dehumidification system and control method based on transcritical CO2 circulation and closed-loop airflow. Background Technology

[0002] This invention relates to the field of air treatment technology, and in particular to a dehumidification system and its control method. Specifically, it is a cascade regeneration dehumidification system and control method based on transcritical CO2 circulation and closed air path, which is suitable for occasions with strict requirements for air humidity control, such as pharmaceutical storage, precision manufacturing, and low-humidity industrial environments.

[0003] In the field of air handling, dehumidification technology is one of the core technologies for ensuring the stability of environments in special scenarios. Currently, the mainstream dehumidification technologies mainly include condensation dehumidification, solution dehumidification, and rotary dehumidification, but these traditional technologies all have significant limitations: condensation dehumidification, although it does not require a regeneration process, has a generally poor dehumidification effect and cannot meet the needs of deep dehumidification; solution dehumidification has a better dehumidification effect, but the system structure is complex and the operation and maintenance costs are high; rotary dehumidification technology is widely used in deep dehumidification scenarios due to its excellent dehumidification effect, but it requires high-temperature hot air of 100-140℃ for adsorbent regeneration, and traditional power supply methods have obvious drawbacks—energy consumption is extremely high when using electric heating or steam heating, and when using ordinary heat pump systems, the regeneration temperature can only reach 50-60℃ due to the characteristics of the refrigerant, which is difficult to meet the needs of deep regeneration, and the efficiency of heat pumps decreases significantly under high-temperature conditions.

[0004] In recent years, transcritical CO2 heat pump technology has attracted attention due to its environmental friendliness and high-temperature heating capacity. CO2, as a natural working fluid, boasts environmental advantages of ODP=0 and GWP=1. The high-temperature gas generated by its transcritical cycle can match the temperature requirements of rotary dehumidification, providing a new direction for solving the energy supply problem of rotary dehumidification. However, existing heat pump-based dehumidification systems have not yet overcome key technological bottlenecks, particularly in terms of regeneration airflow design and energy utilization efficiency. Related patented technologies also have many limitations. CN 101672502B discloses a heat pump regenerative heating type energy-saving dehumidifier system, including a filter, a main evaporator, an adsorption drying zone of a dehumidifying impeller, a main fan, and a post-heater, sequentially connected to the main air path; a heat pump subsystem and a regeneration fan, wherein the heat pump subsystem includes a recovery condenser and a recovery evaporator; the regeneration fan, recovery condenser, regeneration zone of the dehumidifying impeller, and recovery evaporator are sequentially connected to the circulating air path; the recovery condenser is located at the air inlet of the regeneration zone of the dehumidifying impeller; the recovery evaporator is located at the air outlet of the regeneration zone of the dehumidifying impeller. The heat pump subsystem also includes an auxiliary condenser, which is located on the main air path between the adsorption drying zone of the dehumidifying impeller and the main fan. However, this application uses a subcritical cycle heat pump system with ordinary refrigerant. Due to the limitations of subcritical cycle heat pumps, the regeneration temperature cannot be raised to the high-temperature range required for deep dehumidification, making it difficult to achieve low dew point dehumidification effect, and the energy consumption increases significantly with the increase of regeneration temperature.

[0005] CN114768490A proposes a composite dehumidification system based on transcritical CO2 heat pump regeneration, comprising a transcritical CO2 heat pump and a dehumidification impeller. Humid air is dehumidified by condensation at the cold end of the transcritical CO2 heat pump, then enters the dehumidification zone of the dehumidification impeller for adsorption dehumidification before being discharged. Regeneration air is heated by the hot end of the transcritical CO2 heat pump and then enters the regeneration zone of the dehumidification impeller to regenerate the desiccant. Although this application employs transcritical CO2 heat pump technology, the regeneration air path is an open design, and the CO2 at the air cooler outlet remains in a high-temperature supercritical state, resulting in significant heat waste during the thermal cycle and high operating costs.

[0006] CN114811766A discloses a cascaded subcritical transcritical carbon dioxide combined cooling and heating rotary dehumidifier, comprising a transcritical carbon dioxide refrigeration system, a conventional refrigeration system, a rotary dehumidifier component, and a subcooler. The outlet of the carbon dioxide gas cooler in the transcritical carbon dioxide refrigeration system is connected to the hot-side inlet of the subcooler, and the hot-side outlet of the subcooler is connected to the inlet of the carbon dioxide regenerator. The cold side of the subcooler serves as the evaporator of the conventional refrigeration system, with its cold-side inlet connected to the outlet of the first throttling device of the conventional refrigeration system, and its cold-side outlet connected to the suction port of the first compressor of the conventional refrigeration system. Both the carbon dioxide gas cooler and the condenser are located at the rotary regeneration air inlet. This application employs a combined heat pump system of a conventional refrigerant subcritical cycle heat pump system and CO2, which not only introduces a conventional refrigerant system, increasing additional energy consumption, but also features an open design for the regeneration air path, resulting in low energy recovery efficiency. Furthermore, the parallel connection of the condenser and gas cooler in the subcritical heat pump cycle system for processing regeneration air restricts the increase in regeneration air temperature, significantly reducing the regeneration effect.

[0007] Furthermore, all heat pump regeneration systems that use open regeneration air paths are affected by seasonal environmental changes. Low outdoor temperatures in winter lead to insufficient regeneration temperatures, while high outdoor temperatures in summer reduce the efficiency of the thermal cycle, making it impossible to achieve stable and efficient deep dehumidification operation throughout the year.

[0008] In summary, existing dehumidification technologies generally suffer from problems such as high regeneration energy consumption, low efficiency, insufficient regeneration temperature, and poor operational stability, making it difficult to meet the requirements for deep dehumidification and energy-saving operation in high-humidity environments or low-humidity demand scenarios. Therefore, developing a dehumidification system that can achieve efficient energy utilization, stable high-temperature regeneration, and environmentally friendly reliability has become an urgent technical problem to be solved in this field. Summary of the Invention

[0009] The purpose of this invention is to provide a dehumidification system and control method based on transcritical CO2 circulation and closed-loop airflow to solve the problems mentioned in the background art.

[0010] To achieve the above objectives, the present invention provides the following technical solution: In a first aspect, a dehumidification system based on transcritical CO2 circulation and closed-loop airflow includes a transcritical CO2 heat pump subsystem and a closed-loop regeneration airflow subsystem connected to the transcritical CO2 heat pump subsystem. The transcritical CO2 heat pump subsystem includes a compressor, an air cooler, an expansion valve, and an evaporator connected in sequence through pipelines to form a circulation loop; The closed-loop regeneration air circuit subsystem includes a dehumidifying rotor regeneration zone, a regeneration fan, and an auxiliary radiator. The dehumidifying rotor regeneration zone, the regeneration fan, and the auxiliary radiator are connected to the circulation loop. The outlet of the dehumidifying rotor regeneration zone is connected to the inlet of the regeneration fan, the outlet of the regeneration fan is connected to the air-side inlet of the auxiliary radiator, the air-side outlet of the auxiliary radiator is connected to the air-side inlet of the evaporator, the air-side outlet of the evaporator is connected to the air-side inlet of the air cooler, and the air-side outlet of the air cooler is connected to the dehumidifying rotor regeneration inlet, forming a closed-loop regeneration air circuit.

[0011] Preferably, a pressure switch and an oil separator are connected between the compressor and the air cooler, the pressure switch being located between the compressor and the oil separator, and the oil separator being connected to the air cooler.

[0012] Preferably, the oil separator is also connected to a regenerator via a first filter.

[0013] Preferably, the expansion valve is connected to the regenerator via a second filter and a high-pressure reservoir.

[0014] Preferably, the evaporator is connected to the regenerator via a gas-liquid separator.

[0015] Preferably, the dehumidification impeller adsorption zone includes a dehumidification impeller, a surface cooler, and a processing fan, wherein the dehumidification impeller is connected to the surface cooler, and the processing fan is connected to the dehumidification impeller.

[0016] Preferably, a temperature sensor T1 is provided between the compressor and the oil separator, a temperature sensor T2 is provided between the air cooler and the rotor, a temperature sensor T3 is provided between the auxiliary radiator and the evaporator, a temperature sensor T4 is provided between the evaporator and the air cooler, a temperature sensor T5 is provided between the evaporator and the gas-liquid separator, and a temperature sensor T6 is provided between the regenerator and the compressor.

[0017] Preferably, a pressure sensor P1 is provided between the compressor and the pressure switch, a pressure sensor P2 is provided between the evaporator and the gas-liquid separator, and a pressure sensor P3 is provided between the regenerator and the compressor.

[0018] Preferably, a flow sensor F1 is provided between the surface cooler and the impeller, and a flow sensor F2 is provided between the surface cooler and the impeller.

[0019] Secondly, this application provides a control method based on transcritical CO2 circulation and closed-loop dehumidification, comprising the following steps: S1: Monitor the temperature parameters of key points in the closed regeneration air path; S2: Dynamically adjust the compressor's operating frequency based on temperature parameters; S3: Adjust the opening of the expansion valve according to the carbon dioxide outlet temperature of the air cooler; S4: Adjust the cooling water flow rate of the auxiliary radiator according to the temperature change of the regenerated air; S5: Intelligently adjusts its air volume according to changes in system load.

[0020] Compared with the prior art, the beneficial effects of the present invention are: 1. High efficiency and energy saving, significantly reducing operating costs. Closed-loop energy recovery: The regeneration air path adopts a closed-loop design. The regeneration air circulates in a closed loop of "dehumidifier rotor regeneration outlet → regeneration fan → auxiliary radiator → evaporator → air cooler → dehumidifier rotor regeneration inlet". This avoids heat loss caused by exchange with the outside air, realizes the cascade recovery and efficient utilization of energy, and solves the problem of serious energy waste in traditional open systems.

[0021] Cascaded heat exchange and low heat loss: The air cooler adopts a special structural design, which utilizes the "temperature glide" characteristic of CO2 transcritical cycle to achieve efficient heat transfer with a small temperature difference between CO2 (140℃→28℃) ​​and regenerated air (7℃→120℃), reducing irreversible losses; at the same time, the energy utilization efficiency is further improved by cascaded treatment of regenerated air through evaporator cooling and dehumidification and air cooler reheating.

[0022] Significant comparative advantages: Compared with the energy consumption of traditional rotary dehumidifiers (electric heating) and ordinary heat pump dehumidifiers, the present invention has lower energy consumption and significantly reduced operating costs.

[0023] 2. Environmentally friendly and in line with the needs of green development. The system uses CO2 as the working fluid for the heat pump cycle. Its ozone depletion potential (ODP) is 0 and its global warming potential (GWP) is 1. It is non-toxic, non-flammable, and widely available. It fundamentally avoids the damage to the ozone layer and greenhouse effect caused by traditional CFCs, and fully complies with environmental regulations and the development direction of green energy technology.

[0024] 3. Deep dehumidification to meet stringent humidity requirements. High-temperature regeneration guarantee: The air cooler can stably heat the regenerated air to 100-120℃, which perfectly matches the high-temperature regeneration conditions required for rotary dehumidification (traditional heat pumps can only provide 50-60℃ regeneration air), effectively desorbing moisture from the adsorbent and enabling the treated air to reach an extremely low dew point temperature.

[0025] It is suitable for a wide range of scenarios: it can meet the needs of scenarios with strict control of air humidity, such as low-humidity industrial environments, pharmaceutical warehousing, and precision manufacturing, and solves the pain point of "insufficient regeneration temperature leading to poor dehumidification effect" in existing technologies.

[0026] 4. Stable operation and adaptable to complex environmental changes. Unaffected by external interference: The closed regeneration air path isolates outdoor air, avoiding the problems of "insufficient regeneration temperature" or "low thermal cycle efficiency" caused by seasonal changes (high temperature in summer and low temperature in winter) in traditional open systems, thus achieving stable operation throughout the year.

[0027] Intelligent and precise control: Equipped with an intelligent control subsystem based on fuzzy PID algorithm, it can dynamically adjust the compressor speed, expansion valve opening, cooling water flow and fan air volume according to real-time data from sensors such as temperature and flow rate; it can also automatically switch between normal, energy-saving and deep dehumidification modes according to ambient temperature and humidity to ensure that the system is in the optimal operating state under different loads.

[0028] 5. Simplified layout reduces installation and maintenance difficulty. Space and cost savings: The closed-loop airflow eliminates the regeneration air inlet and outlet pipes of traditional rotary dehumidifiers, simplifying the piping layout in the machine room and significantly saving equipment installation space.

[0029] Convenient operation and maintenance: The system has a high degree of integration and the intelligent control subsystem has fault monitoring and diagnosis capabilities, which can detect operational abnormalities in a timely manner and reduce the cost and difficulty of manual operation and maintenance. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a schematic diagram of the system workflow of the present invention.

[0031] In the diagram: 1. Compressor; 2. Air cooler; 3. Expansion valve; 4. Evaporator; 5. Regeneration fan; 6. Auxiliary radiator; 7. Pressure switch; 8. Oil separator; 9. First filter; 10. Regenerator; 11. Second filter; 12. High-pressure liquid receiver; 13. Dehumidifier impeller; 14. Surface cooler; 15. Processing fan; 16. Gas-liquid separator. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Please see Figure 1 The present invention provides a technical solution: a dehumidification system based on transcritical CO2 circulation and closed-loop airflow, including a transcritical CO2 heat pump subsystem and a closed-loop regeneration airflow subsystem connected to the transcritical CO2 heat pump subsystem; the transcritical CO2 heat pump subsystem includes a compressor 1, an air cooler 2, an expansion valve 3 and an evaporator 4 connected in sequence through pipelines to form a circulation loop 100.

[0034] In the compressor, refrigerant CO2 is compressed into a supercritical high-temperature and high-pressure gas (about 140°C), and then enters the air cooler to heat the regenerated air to 120°C. The temperature of CO2 gradually decreases. Subsequently, CO2 is throttled by the expansion valve to become a low-temperature and low-pressure two-phase flow, enters the evaporator to absorb the heat of the processed air, evaporates into superheated steam, and returns to the compressor to complete the cycle.

[0035] The closed-loop regeneration air circuit subsystem includes a dehumidifying rotor regeneration zone, a regeneration fan 5, and an auxiliary radiator 6. The dehumidifying rotor regeneration zone, the regeneration fan 5, and the auxiliary radiator 6 are connected to the circulation loop. The outlet of the dehumidifying rotor regeneration zone is connected to the inlet of the regeneration fan 5, the outlet of the regeneration fan 5 is connected to the air-side inlet of the auxiliary radiator 6, the air-side outlet of the auxiliary radiator 6 is connected to the air-side inlet of the evaporator 4, the air-side outlet of the evaporator 4 is connected to the air-side inlet of the air cooler 2, and the air-side outlet of the air cooler 2 is connected to the inlet of the dehumidifying rotor regeneration zone, forming a closed-loop regeneration air circuit.

[0036] The regeneration air path is connected as follows: dehumidifier rotary dehumidifier regeneration zone outlet → regeneration fan → auxiliary radiator air side → evaporator air side → air cooler air side → dehumidifier rotary dehumidifier regeneration inlet, forming a complete closed loop. In this design, the regeneration air circulates in a closed loop, avoiding mixing with the outside air and reducing energy loss. It also eliminates the need for regeneration air inlet and outlet ducts in traditional rotary dehumidifier units.

[0037] The compressor 1 is precisely controlled by a controller, which can dynamically adjust the compressor speed, expansion valve opening and regeneration fan air volume based on data from temperature sensor, flow sensor and pressure sensor.

[0038] The controller uses a fuzzy PID control algorithm to adjust the system operating parameters according to real-time load demand, thereby achieving energy-saving and optimized operation.

[0039] In one embodiment of the present invention, a pressure switch 7 and an oil separator 8 are connected between the compressor 1 and the air cooler 2. The pressure switch 7 is located between the compressor 1 and the oil separator 8, and the oil separator 8 is connected to the air cooler 2.

[0040] In one embodiment of the invention, the oil separator 8 is also connected to the regenerator 10 via a first filter 9.

[0041] In one embodiment of the present invention, the expansion valve 3 is connected to the regenerator 10 via the second filter 11 and the high-pressure liquid reservoir 12.

[0042] In one embodiment of the present invention, the evaporator 4 is connected to the regenerator 10 via a gas-liquid separator 16.

[0043] In one embodiment of the present invention, the dehumidification rotor regeneration zone includes a dehumidification rotor 13, a surface cooler 14, and a processing fan 15. The dehumidification rotor 13 is connected to the surface cooler 14, and the processing fan 15 is connected to the dehumidification rotor 13.

[0044] In one embodiment of the present invention, a temperature sensor T1 is provided between the compressor and the oil separator, a temperature sensor T2 is provided between the air cooler 2 and the dehumidification rotor 13, a temperature sensor T3 is provided between the auxiliary radiator 6 and the evaporator 4, a temperature sensor T4 is provided between the evaporator 4 and the air cooler 2, a temperature sensor T5 is provided between the evaporator 4 and the gas-liquid separator 13, and a temperature sensor T6 is provided between the regenerator 10 and the compressor 1.

[0045] In one embodiment of the present invention, a pressure sensor P1 is provided between the compressor 1 and the pressure switch, a pressure sensor P2 is provided between the evaporator 4 and the gas-liquid separator, and a pressure sensor P3 is provided between the regenerator 10 and the compressor 1.

[0046] In one embodiment of the present invention, a flow sensor F1 is provided between the surface cooler and the impeller, and a flow sensor F2 is provided between the surface cooler and the impeller.

[0047] The system works as follows: When the system is in operation, the air to be dehumidified first passes through the dehumidification rotor processing zone, where it is dehumidified by the adsorbent and discharged as dry air. Simultaneously, regeneration air circulates in a closed airflow path, responsible for regenerating the adsorbent.

[0048] The flow and heat exchange process of regenerated air is as follows: I. Airflow Processing: The Drying Process of the Air to be Dehumidified The system serves the air to be dehumidified, and its process revolves around "adsorption dehumidification": After the air enters the system, it first flows through the processing zone of the dehumidification rotor—the adsorbent inside the rotor actively adsorbs the moisture in the air, completing the dehumidification process; the air after adsorption dehumidification becomes dry air and is directly discharged from the system to supply low-humidity demand scenarios (such as pharmaceutical storage and precision manufacturing workshops). During this process, the adsorbent in the dehumidification rotor will gradually lose its dehumidification capacity due to moisture saturation, and needs to be heated and desorbed (i.e., "regenerated") through a closed-loop regeneration air circuit subsystem to restore its adsorption activity.

[0049] II. Closed-loop regenerative ventilation subsystem: Adsorbent regeneration and closed-loop energy recovery The regenerative airflow adopts a closed-loop design, with regenerated air circulating within the closed loop to achieve cascaded utilization of heat and zero energy waste. The specific process is as follows: 1. Initial state of regenerated air: The regenerated air flowing out of the regeneration zone outlet of the dehumidifier rotor has a temperature of about 55℃ and a high humidity content because it has absorbed the moisture and heat desorbed by the adsorbent.

[0050] 2. Preliminary cooling and regulation: After the regenerated air is drawn in by the regenerated fan, it first enters the air side of the auxiliary radiator. The auxiliary radiator uses cooling water with an inlet temperature of 32℃ and an outlet temperature of 37℃ as a cold source to perform preliminary cooling of the regenerated air and precisely control its temperature, in preparation for subsequent deep cooling and dehumidification.

[0051] 3. Deep cooling and dehumidification: The regenerated air, after initial cooling, flows into the air side of the evaporator and exchanges heat with the low-temperature CO2 of the transcritical CO2 heat pump subsystem. The regenerated air is cooled to 7°C, and the moisture in it condenses and precipitates due to the sudden drop in temperature, achieving "drying of the regenerated air itself". The dried regenerated air lays the foundation for subsequent high-temperature heating and rotor regeneration.

[0052] 4. High-temperature heating: The cooled and dried regenerated air (7°C) enters the air side of the air cooler and undergoes efficient heat exchange with the supercritical CO2 at 140°C in the heat pump subsystem. The CO2 releases heat and cools down to 28°C, while the regenerated air absorbs heat and heats up to 120°C, becoming the "high-temperature dried regenerated air" that meets the regeneration requirements of the rotor.

[0053] 5. Rotary regeneration and closed-loop circulation: High-temperature dry regeneration air at 120℃ flows into the inlet of the dehumidifying rotary regeneration zone, heating and desorbing the saturated adsorbent—the moisture in the adsorbent is evaporated by the high temperature and flows out of the regeneration zone with the regeneration air (i.e., returning to the "55℃ humid regeneration air" state in step 1), completing the regeneration cycle; at the same time, the desorbed adsorbent restores its adsorption activity and can continue to treat the air to be dehumidified.

[0054] The entire regeneration air path forms a closed loop of "dehumidifier rotor regeneration outlet → regeneration fan → auxiliary radiator → evaporator → air cooler → dehumidifier rotor regeneration inlet", with no outdoor air being introduced or discharged, achieving complete energy recovery and utilization.

[0055] III. Transcritical CO2 Heat Pump Subsystem: Energy Supply and Cycle The transcritical CO2 heat pump subsystem uses CO2 as an environmentally friendly working fluid (ODP=0, GWP=1). Through a transcritical cycle of "compression-heat release-throttling-heat absorption," it provides the regeneration air path with "the high-temperature heat required for heating" and "the low-temperature cooling required for cooling." The specific process is as follows: 1. Compression, pressure increase, and temperature increase: After being compressed by the compressor, CO2 working fluid becomes a supercritical high-temperature and high-pressure gas at 140℃, which has the ability to provide high-temperature heating.

[0056] 2. Heat release heating of regenerated air: Supercritical CO2 enters the working fluid side of the air cooler and exchanges heat with the low-temperature dry air (7℃) in the regenerated air path - CO2 releases heat, and its temperature drops from 140℃ to 28℃, while the regenerated air absorbs heat and rises to 120℃; This process utilizes the "temperature glide" characteristic of CO2 transcritical cycle to achieve efficient heat transfer with small temperature difference and reduce heat loss in the cycle.

[0057] 3. Throttling: After releasing heat, the CO2 flows through the internal heat exchanger to further cool its temperature before entering the expansion valve. The expansion valve throttles and reduces the pressure of the CO2, turning it into a low-temperature, low-pressure two-phase flow (gas-liquid mixture) with heat absorption capacity.

[0058] 4. Heat absorption and cooling of regenerated air: Low-temperature CO2 enters the working fluid side of the evaporator and exchanges heat with the high-temperature and humid air in the regenerated air path that has been preliminarily cooled in the auxiliary cooler. CO2 absorbs heat and evaporates completely into gas, raising its temperature. The regenerated air is cooled to 7°C and releases moisture. The CO2 gas that has absorbed heat returns to the compressor intake port, completing the transcritical cycle.

[0059] IV. Intelligent Control Subsystem: Dynamic Adaptation and Stable Operation The intelligent control subsystem ensures dehumidification efficiency and energy saving by regulating system operating parameters through a closed-loop system. 1. Parameter monitoring: Temperature sensors (such as air cooler inlet and outlet, evaporator inlet and outlet) are placed at key nodes of the regeneration air path to monitor air and CO2 temperature; flow sensors monitor the flow rate of treatment air and regeneration air; pressure sensors assist in monitoring the operating condition of the heat pump system.

[0060] 2. Intelligent Decision-Making and Execution: The controller adopts a fuzzy PID control algorithm to dynamically adjust based on sensor data. Adjust the compressor speed to match the heating load required by the regenerated air; Adjust the opening of the expansion valve to control the CO2 flow rate in order to stabilize the heat exchange efficiency between the evaporator and the air cooler; Adjust the cooling water flow rate of the auxiliary radiator to precisely control the initial cooling effect of the regenerated air; Adjust the air volume of the regeneration fan to match the regeneration needs of the rotor.

[0061] 3. Adaptive mode switching: The system automatically selects normal mode (daily dehumidification), energy-saving mode (partial load), or deep dehumidification mode (low dew point requirement) according to changes in ambient temperature and humidity, balancing performance and energy consumption.

[0062] This process achieves tiered treatment of regenerated air and tiered utilization of energy: first cooling and dehumidifying, then heating and raising the temperature, which not only ensures the regeneration effect, but also recovers energy to the maximum extent.

[0063] In addition, please see Figure 2 The embodiments of the present invention also provide a control method based on transcritical CO2 circulation and closed-loop dehumidification, comprising the following steps: S1: Monitor the temperature parameters of key points in the closed regeneration air path; S2: Dynamically adjust the compressor's operating frequency based on temperature parameters; S3: Adjust the opening of the expansion valve according to the carbon dioxide outlet temperature of the air cooler; S4: Adjust the cooling water flow rate of the auxiliary radiator according to the temperature change of the regenerated air; S5: Intelligently adjusts its air volume according to changes in system load.

[0064] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A dehumidification system based on transcritical CO2 circulation and closed-loop airflow, characterized in that, It includes a transcritical CO2 heat pump subsystem and a closed-loop regenerative air circuit subsystem connected to the transcritical CO2 heat pump subsystem; The transcritical CO2 heat pump subsystem includes a compressor, an air cooler, an expansion valve, and an evaporator connected in sequence through pipelines to form a circulation loop; The closed-loop regeneration air circuit subsystem includes a dehumidifying rotor regeneration zone, a regeneration fan, and an auxiliary radiator. The dehumidifying rotor regeneration zone, the regeneration fan, and the auxiliary radiator are connected to the circulation loop. The outlet of the dehumidifying rotor regeneration zone is connected to the inlet of the regeneration fan, the outlet of the regeneration fan is connected to the air-side inlet of the auxiliary radiator, the air-side outlet of the auxiliary radiator is connected to the air-side inlet of the evaporator, the air-side outlet of the evaporator is connected to the air-side inlet of the air cooler, and the air-side outlet of the air cooler is connected to the dehumidifying rotor regeneration inlet, forming a closed-loop regeneration air circuit.

2. The dehumidification system based on transcritical CO2 circulation and closed-loop ventilation as described in claim 1, characterized in that: A pressure switch and an oil separator are connected between the compressor and the air cooler. The pressure switch is located between the compressor and the oil separator, and the oil separator is connected to the air cooler.

3. The dehumidification system based on transcritical CO2 circulation and closed-loop ventilation as described in claim 2, characterized in that: The oil separator is also connected to a regenerator via a first filter.

4. The dehumidification system based on transcritical CO2 circulation and closed-loop ventilation as described in claim 3, characterized in that: The expansion valve is connected to the regenerator via a second filter and a high-pressure reservoir.

5. The dehumidification system based on transcritical CO2 circulation and closed-loop ventilation according to claim 4, characterized in that: The evaporator is connected to the regenerator via a gas-liquid separator.

6. The dehumidification system based on transcritical CO2 circulation and closed-loop ventilation as described in claim 5, characterized in that: The dehumidification impeller adsorption zone includes a dehumidification impeller, a surface cooler, and a processing fan. The dehumidification impeller is connected to the surface cooler, and the processing fan is connected to the dehumidification impeller.

7. A dehumidification system based on transcritical CO2 circulation and closed-loop ventilation as described in claim 6, characterized in that: A temperature sensor T1 is provided between the compressor and the oil separator; a temperature sensor T2 is provided between the air cooler and the rotor; a temperature sensor T3 is provided between the auxiliary radiator and the evaporator; a temperature sensor T4 is provided between the evaporator and the air cooler; a temperature sensor T5 is provided between the evaporator and the gas-liquid separator; and a temperature sensor T6 is provided between the regenerator and the compressor.

8. The dehumidification system based on transcritical CO2 circulation and closed-loop ventilation as described in claim 7, characterized in that: A pressure sensor P1 is provided between the compressor and the pressure switch, a pressure sensor P2 is provided between the evaporator and the gas-liquid separator, and a pressure sensor P3 is provided between the regenerator and the compressor.

9. A dehumidification system based on transcritical CO2 circulation and closed-loop ventilation as described in claim 8, characterized in that: A flow sensor F1 is provided between the surface cooler and the impeller, and a flow sensor F2 is provided between the surface cooler and the impeller.

10. A control method based on transcritical CO2 circulation and closed-loop dehumidification, characterized in that, Includes the following steps: S1: Monitor the temperature parameters of key points in the closed regeneration air path; S2: Dynamically adjust the compressor's operating frequency based on temperature parameters; S3: Adjust the opening of the expansion valve according to the carbon dioxide outlet temperature of the air cooler; S4: Adjust the cooling water flow rate of the auxiliary radiator according to the temperature change of the regenerated air; S5: Intelligently adjusts its air volume according to changes in system load.

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