A waste heat recovery type cold heat combined supply single runner dehumidifier system

Abstract

This application relates to the field of air conditioning and industrial dehumidification technology, and discloses a waste heat recovery type combined cooling and heating single-rotor dehumidifier system, including a dehumidifier housing and an external carbon dioxide combined cooling and heating main unit. A carbon dioxide deep dehumidification coil and a dehumidification rotor processing area are arranged along the airflow direction in the processing air channel, while a carbon dioxide condenser and a dehumidification rotor regeneration area are arranged in the regeneration air channel. The main unit connects the coil and condenser through pipelines to construct a transcritical carbon dioxide thermodynamic cycle, transferring the heat absorbed by the deep dehumidification coil to the condenser as a regeneration heat source for release. The system is also equipped with a tiered heating structure consisting of resistance heating and the condenser, as well as an exhaust waste heat recovery device. The central control system performs regeneration heat compensation and optimal high-pressure control based on sensor feedback. This invention reduces system energy consumption and improves operational stability under varying operating conditions through an internal energy coupling mechanism.

Description

Technical Field

[0001] This invention relates to the field of air conditioning and industrial dehumidification technology, specifically a waste heat recovery type combined cooling and heating single-rotor dehumidifier system. Background Technology

[0002] In industrial sectors such as lithium battery manufacturing, pharmaceutical production, and specialty material processing, extremely stringent requirements are placed on the humidity of the production environment. Rotary dehumidification technology is typically employed to obtain dry air with a low dew point. Traditional rotary dehumidification systems, during operation, require deep pre-cooling of the incoming fresh air via a surface cooler to remove some moisture. This usually relies on external cold sources such as chillers, and the resulting condensation heat is often directly released into the atmosphere. Furthermore, after the dehumidification rotor becomes saturated with moisture, it requires regeneration and desorption using high-temperature air, which typically consumes significant amounts of electricity or high-pressure steam. This operating mode, characterized by independent cold and heat sources, unusable waste heat from condensation, and substantial consumption of high-grade regeneration heat energy, results in low overall system energy efficiency and high operating costs.

[0003] Although existing technologies have attempted to utilize heat pump systems to recover condensation heat for rotor regeneration, conventional heat pump cycles are limited by the thermophysical properties of refrigerants. They struggle to provide the high-temperature heat source (e.g., above 100°C) required for rotor regeneration while maintaining high cooling efficiency. Furthermore, existing heat recovery dehumidification systems often lack flexible energy regulation mechanisms. During transitional seasons or winter, when outdoor fresh air humidity loads are low, the condensation heat generated on the heat pump side is insufficient. Alternatively, the high-pressure side pressure of the system may be difficult to maintain within the optimal range under varying ambient temperatures, leading to large fluctuations in regeneration temperature and an inability to guarantee stable dehumidification performance. Simultaneously, the high-temperature, high-humidity exhaust gas discharged during the regeneration process is typically directly emitted, failing to effectively recover and utilize its sensible heat, further exacerbating energy waste. Therefore, developing a dehumidification system that can efficiently achieve internal cooling and heating energy coupling, possesses a cascade heating compensation mechanism, and operates stably has become a pressing technical challenge for the industry. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a waste heat recovery type combined cooling and heating single-rotor dehumidifier system, which solves the problems of independent cold and heat sources, low energy utilization efficiency, and unstable regenerated heat source supply in existing rotary dehumidifier systems, resulting in high system energy consumption and poor stability.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a waste heat recovery type combined cooling and heating single-rotor dehumidifier system, comprising the following steps:

[0006] This invention provides a waste heat recovery type combined cooling and heating single-rotor dehumidifier system, including a dehumidifier housing and a carbon dioxide combined cooling and heating main unit disposed outside the dehumidifier housing. The dehumidifier housing is physically divided into a processing air channel and a regeneration air channel. Within the processing air channel, a processing area consisting of a carbon dioxide deep dehumidification coil and a dehumidification rotor is arranged sequentially along the airflow direction. The carbon dioxide deep dehumidification coil, as one of the evaporation ends of the thermal cycle, utilizes the phase change heat absorption characteristics of the liquid refrigerant to forcibly reduce the temperature of the flowing fresh air to below the dew point temperature, achieving deep cooling and dehumidification. Within the regeneration air channel, a regeneration area consisting of a carbon dioxide dehumidification coil, a carbon dioxide condenser, and a dehumidification rotor is arranged sequentially along the airflow direction. The carbon dioxide dehumidification coil, as the second evaporation end of the thermal cycle, utilizes the phase change heat absorption characteristics of the liquid refrigerant to initially cool and dehumidify the flowing regeneration fresh air, thus, in conjunction with the deep dehumidification coil in the processing air channel, doubly improving the dehumidification efficiency of the dehumidification rotor. The carbon dioxide condenser, acting as the heat release end of the thermodynamic cycle, uses the heat released by the high-temperature working fluid to heat the air entering the regeneration zone. The carbon dioxide combined cooling and heating unit connects two carbon dioxide dehumidification coils and the carbon dioxide condenser via refrigerant piping, constructing a transcritical carbon dioxide thermodynamic cycle. This cycle utilizes the high exhaust temperature of the carbon dioxide working fluid in the transcritical state to extract low-grade heat energy from the fresh air in the deep dehumidification coils. After compression and work to improve the grade, this heat energy is transferred to the carbon dioxide condenser as a high-grade regeneration heat source, achieving internal energy coupling between the dehumidification cooling load and the regeneration heat load.

[0007] In a further embodiment, the component layout of the air handling channel has been optimized. A front surface cooler is located upstream of the CO2 deep dehumidification coil, connected to an external cold source to handle the high-temperature sensible heat load of the fresh air, reducing the heat load on the subsequent deep dehumidification coil. A return air vent and a mixing section are located between the CO2 deep dehumidification coil and the dehumidification rotor's processing area to introduce indoor return air. The low-temperature fresh air after deep dehumidification merges with the return air in the mixing section and undergoes temperature regulation downstream via a middle surface cooler. The middle surface cooler ensures that the temperature of the mixed air entering the dehumidification rotor's processing area is within the optimal adsorption efficiency range of the adsorbent, preventing a decrease in adsorption capacity due to excessively high inlet air temperature.

[0008] In a further embodiment, the processing air channel is configured with a processing fan, a post-cooler, and a post-heater downstream of the processing zone of the dehumidification impeller. The processing fan provides the driving pressure head for airflow. The post-cooler and post-heater, as the final air conditioner components, cool or heat the dry air after dehumidification by the impeller to meet the constant temperature and humidity accuracy requirements of indoor air supply.

[0009] To address the issue of ensuring a sufficient heat source for the regeneration process, a resistance heater is installed within the regeneration air passage. This resistance heater is connected in series between the regeneration zones of the carbon dioxide condenser and the dehumidifier rotor, forming a tiered heating structure together with the carbon dioxide condenser. The carbon dioxide condenser utilizes recovered system waste heat to provide primary basic heating, bearing most of the regeneration heat load; the resistance heater provides secondary supplementary heating. This structure ensures that, under extreme low-temperature conditions or during the initial system startup, when the condensation heat provided by the heat pump side is insufficient to reach the regeneration temperature threshold, the heat gap can be quickly filled by electricity, guaranteeing the regeneration effect of the dehumidifier rotor.

[0010] To further improve system energy efficiency, a regeneration fan and regeneration exhaust vent are installed downstream of the regeneration zone of the dehumidification rotor in the regeneration air duct, and a waste heat recovery device is installed at the regeneration exhaust vent. The waste heat recovery device is configured to allow the high-temperature, high-humidity regeneration exhaust air carrying waste heat to flow through its heat exchange side, extracting the sensible heat energy. This waste heat recovery device can be in the form of a plate air heat exchanger or an intermediate medium heat exchanger. Its heat absorption side is connected to the regeneration exhaust vent, and its heat release side is connected upstream of the air inlet of the regeneration air duct or to the heat source input of the carbon dioxide combined cooling and heating unit, reinjecting the recovered heat into the system circulation, thus reducing the system's net energy consumption.

[0011] In terms of control strategy, the system integrates a central control system and a sensor array distributed within the dehumidifier housing. The sensor array includes at least a first temperature sensor located downstream of the deep carbon dioxide dehumidification coil to monitor the dew point temperature after dehumidification, and a third temperature sensor located before the regeneration zone inlet of the dehumidification impeller to monitor the regeneration inlet air temperature. The central control system executes regeneration temperature compensation control logic based on sensor feedback: when the detected regeneration inlet air temperature is lower than the set regeneration target temperature, it automatically calculates the heat deficit and linearly adjusts the input power of the resistance heating to precisely compensate for insufficient heat supply from the carbon dioxide condenser, maintaining a constant regeneration temperature. Furthermore, the central control system also executes transcritical cycle optimal high-pressure control logic: based on the regeneration air temperature (i.e., the gas cooler outlet operating condition) and the refrigerant outlet temperature, it calculates the optimal exhaust pressure value under the current operating condition in real time and dynamically adjusts the opening of the electronic expansion valve within the carbon dioxide combined cooling and heating unit, ensuring that the high-pressure side pressure of the transcritical cycle always approaches this optimal value, thereby maximizing the system's energy efficiency ratio while ensuring both cooling and heating performance.

[0012] In terms of engineering implementation details, the fins of the carbon dioxide deep dehumidification coil are covered with a hydrophilic anti-corrosion coating to resist the erosion of condensate and corrosive components in the air, extending the equipment's lifespan. Simultaneously, a condensate tray connected to the drain pipe is installed at the bottom of the coil to effectively collect and discharge the large amount of condensate that is released due to the deep cooling of the fresh air, preventing waterlogging and bacterial growth.

[0013] This invention provides a waste heat recovery type combined cooling and heating single-rotor dehumidifier system. It has the following beneficial effects:

[0014] 1. This invention constructs a transcritical carbon dioxide thermodynamic cycle through a carbon dioxide combined cooling and heating host. The low-grade heat absorbed by the carbon dioxide deep dehumidification coil from the treated air is upgraded and transferred to the carbon dioxide condenser for release. The waste heat generated in the refrigeration and dehumidification process is directly converted into a high-grade heat source required for the regeneration heating process. This significantly reduces the dehumidifier's dependence on external regeneration heat sources (such as electric heating or steam) and lowers the overall operating energy consumption of the system.

[0015] 2. This invention employs a tiered heating structure consisting of a carbon dioxide condenser and resistance heating, coupled with the regeneration temperature compensation control logic of the central control system. In low-temperature environments or during the initial system startup phase, when the heat pump side condensation heat is insufficient, the control system automatically calculates the heat deficit and adjusts the resistance heating for precise heat replenishment. This ensures that the air temperature entering the dehumidification rotor regeneration zone remains at the set threshold, thus solving the problem of regeneration temperature fluctuations caused by relying solely on waste heat from the heat pump and guaranteeing the system's operational stability under all-weather, variable operating conditions.

[0016] 3. This invention achieves staged deep dehumidification by connecting a carbon dioxide deep dehumidification coil and a dehumidification rotor in series within the air processing channel. The carbon dioxide deep dehumidification coil utilizes the low-temperature evaporation characteristics of a transcritical cycle to forcibly cool the fresh air below the dew point, removing most of the moisture first and significantly reducing the inlet moisture load of the subsequent dehumidification rotor. This allows the dehumidification rotor to focus on adsorption treatment in low-humidity areas, thereby extending the service life of the rotor adsorbent while ensuring ultra-low dew point air delivery accuracy. Attached Figure Description

[0017] Figure 1 This is a front view of the present invention;

[0018] Figure 2 This is a top view of the present invention;

[0019] Figure 3 This is a schematic diagram of the operation control logic flow of the present invention;

[0020] Figure 4 This is a schematic diagram of the transcritical carbon dioxide energy coupling principle of the present invention.

[0021] The components include: 1. Carbon dioxide combined cooling and heating unit; 2. Air outlet; 3. Medium-efficiency filter; 4. Post-heater; 5. Post-cooler; 6. Processing fan; 7. Resistance heating; 8. Regeneration air inlet; 9. Dehumidification rotor; 10. Regeneration fan; 11. Regeneration exhaust outlet; 12. Waste heat recovery device; 13. Carbon dioxide condenser; 14. Intermediate cooler; 15. Return air outlet; 16. G3 pre-filter; 17. Carbon dioxide deep dehumidification coil; 18. Front cooler; 19. G4 pre-filter; 20. Fresh air inlet. Detailed Implementation

[0022] The technical solutions in 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.

[0023] See attached document Figure 1 and attached Figure 2 This invention provides a waste heat recovery type combined cooling and heating single-rotor dehumidifier system. The system includes a dehumidifier housing and a carbon dioxide combined cooling and heating unit 1 installed outside the housing. The dehumidifier housing is a closed shell structure, its interior divided into a processing air passage and a regeneration air passage by a partition. The carbon dioxide combined cooling and heating unit 1 is connected to a heat exchange assembly installed inside the dehumidifier housing via refrigerant piping, forming a transcritical carbon dioxide thermodynamic cycle.

[0024] The system's functional layout is logically divided along the energy exchange path into: a CO2 dehumidification section, a connecting duct, a CO2 heating section, and subsequent ducts. This structure aims to guide the orderly flow of airflow through the rational planning of the ducts, particularly by delivering regenerated air into the regeneration heating zone. During this process, the system utilizes the characteristics of a transcritical cycle to absorb heat in the CO2 dehumidification section and release heat in the CO2 heating section, thereby achieving precise coupling and transfer of hot and cold energy between different functional temperature zones.

[0025] A fresh air inlet 20 is located on the right side of the dehumidifier housing to introduce outdoor fresh air to be treated. Inside the fresh air inlet 20, along the airflow direction, are sequentially installed a G4 pre-filter 19, a front surface cooler 18, and a carbon dioxide deep dehumidification coil 17. The G4 pre-filter 19 is used to intercept large dust particles in the air. The inlet and outlet water pipes of the front surface cooler 18 are connected to an external cold source for preliminary cooling and dehumidification of the incoming fresh air. The carbon dioxide deep dehumidification coil 17, acting as the evaporator of the carbon dioxide combined cooling and heating system, has its refrigerant inlet and outlet connected via pipes to the low-pressure side of the carbon dioxide combined cooling and heating main unit 1. It utilizes the evaporation of carbon dioxide working fluid to absorb heat and lower the fresh air temperature below the dew point temperature.

[0026] A return air vent 15 is located on one side of the dehumidifier housing, and the return air vent 15 is connected to the indoor return air area via a return air duct. The return air vent 15 is located downstream of the carbon dioxide deep dehumidification coil 17, allowing the low-temperature fresh air treated by the carbon dioxide deep dehumidification coil 17 to merge with the indoor return air entering from the return air vent 15 in the mixing section. Downstream of the mixing section, along the airflow direction, are arranged the middle surface cooler 14, the treatment zone of the dehumidification impeller 9, the treatment fan 6, the rear surface cooler 5, the rear heater 4, the medium-efficiency filter 3, and the air outlet 2. The middle surface cooler 14 is used to regulate the temperature of the mixed air. The dehumidification impeller 9 is continuously rotated by a motor and is divided into a treatment zone and a regeneration zone. When air flows through the treatment zone, moisture is adsorbed by the adsorbent.

[0027] Flexible contact-type sealing components are installed at the boundary between the processing zone and the regeneration zone of the dehumidifying impeller 9, and between the outer circumference of the dehumidifying impeller 9 and the housing. These sealing components are made of high-temperature resistant and wear-resistant silicone rubber or fluororubber and have a double-layer scraper structure. The sealing components are configured to block airflow short-circuit between the processing air passage and the regeneration air passage, and to prevent air bypass leakage caused by pressure difference on both sides of the dehumidifying impeller 9. Furthermore, a fan-shaped purging zone is provided on the regeneration zone outlet side of the dehumidifying impeller 9. This purging zone introduces a small amount of processed dry air through a bypass pipe to blow back the residual high-humidity and hot air in the impeller orifices that has just left the regeneration zone to the regeneration side, preventing it from being carried back into the processing zone during rotation.

[0028] The processing fan 6 provides the power head for airflow. The post-cooling unit 5 and post-heating unit 4 are used for final temperature regulation of the dehumidified air. A medium-efficiency filter 3 is located upstream of the air outlet 2 to remove fine particles. The air outlet 2 is connected to the air supply duct to deliver the treated air into the room.

[0029] Regarding the dehumidification performance on the air-side, the system's dehumidification capacity... Determined by the difference in moisture content before and after the dehumidifying rotor 9, it follows the mass balance relationship:

[0030] ;

[0031] in, This indicates the system's dehumidification capacity, expressed in kilograms per hour (kg / h). This refers to the density of air under standard conditions, expressed in kilograms per cubic meter (kg / m³). 3 ); This indicates the volumetric flow rate through the processing air passage, expressed in cubic meters per hour (m³ / h). 3 / h); This indicates the moisture content of the mixed air before it enters the dehumidification rotor 9 processing zone, expressed in grams per kilogram (g / kg). This indicates the moisture content of the dry air after leaving the dehumidification rotor 9 treatment zone, expressed in grams per kilogram (g / kg).

[0032] A regeneration air inlet 8 is provided on the top or side of the dehumidifier housing to introduce regeneration air. Downstream of the regeneration air inlet 8, along the airflow direction, are arranged sequentially a G3 pre-filter 16, a carbon dioxide condenser 13, and a resistance heater 7. The G3 pre-filter 16 is used for pre-filtration of the regeneration air. The carbon dioxide condenser 13, as a gas cooler for the carbon dioxide combined cooling and heating system, has its refrigerant inlet and outlet connected via pipelines to the high-pressure exhaust side and the front side of the throttling mechanism of the carbon dioxide combined cooling and heating main unit 1, to release exhaust heat in the transcritical cycle to heat the regeneration air. The resistance heater 7, located in series downstream of the carbon dioxide condenser 13, includes a resistance wire heating assembly to provide supplementary heat when the carbon dioxide condensation heat is insufficient.

[0033] Regarding the energy coupling between the carbon dioxide combined cooling and heating unit 1 and the internal components of the dehumidifier housing, the heating power provided by the carbon dioxide condenser 13... The cooling power provided by the CO2 deep dehumidification coil 17 The following thermodynamic equilibrium is satisfied between them:

[0034] ;

[0035] in, This indicates the heat flow rate released by the carbon dioxide condenser 13 to the regeneration air, in kilowatts (kW). The heat flow absorbed by the carbon dioxide deep dehumidification coil 17 from the fresh air is expressed in kilowatts (kW). This indicates the input electrical power of the compressor in the CO2 combined cooling and heating unit 1, expressed in kilowatts (kW).

[0036] A regeneration zone for a dehumidifying impeller 9 is located downstream of the resistance heater 7. High-temperature regeneration air, heated by the regeneration process, passes through this zone, vaporizing and carrying away the moisture adsorbed inside the dehumidifying impeller 9. A regeneration fan 10 is located downstream of the regeneration zone of the dehumidifying impeller 9, and its outlet is connected to a regeneration exhaust port 11. A waste heat recovery device 12 is installed at the regeneration exhaust port 11. The waste heat recovery device 12 is either a gas-to-gas heat exchanger or an intermediate-medium heat exchanger, and its inlet side is connected to the regeneration exhaust port 11 to allow the high-temperature, high-humidity regeneration exhaust air to pass through.

[0037] Regarding the matching of heat demand and heat source in the regeneration process, the regeneration air is heated from its initial temperature to the set regeneration temperature. Total sensible heat power required The calculation is as follows:

[0038] ;

[0039] in, This indicates the total thermal power required for regenerated air heating, expressed in kilowatts (kW). The specific heat capacity of air at constant pressure is expressed in kilojoules per kilogram of degree Celsius (kJ / (kg·℃)). This indicates the volumetric flow rate of regenerated air, expressed in cubic meters per hour (m³ / h). 3 / h); This indicates the set target temperature for entering the regeneration zone of dehumidifier rotor 9, in degrees Celsius (°C). This indicates the initial temperature of the regenerated air before it enters the carbon dioxide condenser 13, in degrees Celsius (°C). The system is configured to prioritize the use of... satisfy ,when At that time, the control resistance heater 7 is turned on to provide differential heat. The waste heat recovery device 12 is configured to extract sensible heat from the discharged regenerated air, recovering the heat flow. Follow the formula below:

[0040] ;

[0041] in, This indicates the recovered heat power, measured in kilowatts (kW). This indicates the heat exchange efficiency of the waste heat recovery device 12; This indicates the volumetric flow rate of the exhaust air passing through the regeneration exhaust port 11, expressed in cubic meters per hour (m³ / h). 3 / h); This indicates the temperature of the regeneration exhaust air before it enters the waste heat recovery device 12, in degrees Celsius (°C). Indicates the initial temperature of the medium (outdoor ambient air or preheated fluid) that exchanges heat with the exhaust air, expressed in degrees Celsius (°C).

[0042] The CO2 combined cooling and heating unit 1 includes a compressor, a gas-liquid separator, and related control valves. The refrigerant flow is as follows: high-temperature, high-pressure CO2 gas discharged from the compressor is piped to the CO2 condenser 13 inside the dehumidifier housing. After releasing heat, it flows back through the pipe to the expansion valve inside the unit to reduce pressure, transforming into a low-temperature, low-pressure gas-liquid mixture. This mixture is then transported to the CO2 deep dehumidification coil 17 inside the dehumidifier housing for heat absorption and evaporation. Finally, the gaseous refrigerant returns to the compressor suction port inside the unit. The front surface cooler 18, middle surface cooler 14, and rear surface cooler 5 are all equipped with refrigerant inlets and outlets, connected to a conventional chiller unit or cooling tower system outside the dehumidifier housing. The rear heater 4 is connected to an external power source or hot water source. The dehumidification impeller 9, the processing fan 6, the regeneration fan 10, and the resistance heater 7 are all connected to the system's central control cabinet via electrical wiring.

[0043] See attached document Figure 1 and attached Figure 2 To achieve the energy coupling and waste heat recovery functions of this invention, the system includes the following key subsystems:

[0044] Transcritical carbon dioxide cogeneration subsystem:

[0045] This subsystem is the core energy conversion and transport unit of this invention. Its physical entities mainly consist of a carbon dioxide combined cooling and heating unit 1 located outside the dehumidifier housing, and a carbon dioxide deep dehumidification coil 17 and a carbon dioxide condenser 13 installed inside the dehumidifier housing. This subsystem uses carbon dioxide (R744) as the circulating working fluid. Carbon dioxide was chosen as the working fluid because of its thermodynamic properties of high-temperature exhaust gas under transcritical cycle conditions. At typical compressor pressure ratios, its exhaust temperature can directly reach the high-temperature range required for the regeneration process, thus making the condensation heat a directly usable high-grade heat source.

[0046] The carbon dioxide combined cooling and heating unit 1 internally encapsulates a compressor, a gas-liquid separator, an electronic expansion valve, and corresponding sensors and controllers. The compressor compresses the low-temperature gaseous carbon dioxide from the evaporator, transforming it into a high-temperature, high-pressure supercritical fluid. This supercritical fluid is transported via a high-pressure refrigerant pipeline to the carbon dioxide condenser 13 installed in the regeneration air passage. In the carbon dioxide condenser 13 (acting as a gas cooler), the supercritical carbon dioxide fluid releases a large amount of heat under approximately constant pressure conditions, its temperature decreases but no phase change occurs, and this process transfers heat to the regeneration air flowing through it.

[0047] After releasing heat, the cooled, high-pressure carbon dioxide fluid returns to the main unit via pipeline, where it is throttled and depressurized by an electronic expansion valve, transforming into a low-temperature, low-pressure gas-liquid two-phase mixture. This low-temperature working fluid is then transported via low-pressure refrigerant pipeline to the carbon dioxide deep dehumidification coil 17 installed in the air handling duct. In the carbon dioxide deep dehumidification coil 17, the low-pressure liquid carbon dioxide absorbs heat from the incoming fresh air and evaporates into gas. This heat absorption process causes the fresh air temperature to drop sharply below its dew point, resulting in the precipitation of a large amount of condensate, achieving deep dehumidification of the fresh air. The evaporated gaseous carbon dioxide returns to the compressor's suction port via pipeline, forming a closed, continuously energy-transferring thermodynamic cycle.

[0048] A stainless steel water collection tray is installed at the bottom of the carbon dioxide deep dehumidification coil 17. The drain outlet of the water collection tray is connected to a water trap pipe to discharge the condensate out of the housing. Considering the corrosive gases contained in the fresh air and the acidity of the condensate, the fin surface of the carbon dioxide deep dehumidification coil 17 is coated with a hydrophilic anti-corrosion coating (such as epoxy resin or nano-coating). Similarly, a condensate drain port is also provided at the bottom of the exhaust side of the waste heat recovery device 12 to discharge the condensate that is released during the heat exchange process of the regenerated exhaust air due to the temperature drop.

[0049] Cascade regenerative heating subsystem:

[0050] This subsystem is responsible for providing a stable and sufficient high-temperature heat source for the regeneration process of the dehumidification rotor 9. It consists of two heating units connected in series, namely the carbon dioxide condenser 13 and the resistance heater 7, which together form a stepped heating structure.

[0051] The first-stage heating unit is the carbon dioxide condenser 13. It is physically installed upstream of the regeneration zone where the regenerated air enters the dehumidification rotor 9. The regenerated air first flows through this unit, receiving exhaust heat released from the carbon dioxide combined cooling and heating subsystem to complete the basic temperature rise. This process utilizes the heat removed by the dehumidification on the processed air side and the heat converted from the compressor's work, making it the main heat source of the system and directly determining the system's basic energy efficiency level.

[0052] The second-stage heating unit is a resistance heater 7. It is physically connected in series downstream of the carbon dioxide condenser 13 and upstream of the regeneration zone of the dehumidification rotor 9. Internally, it contains an array of heating elements made of nickel-chromium alloy or other resistive materials. When the air temperature after the first-stage heating fails to reach the preset regeneration target temperature... At certain times (e.g., during extremely low ambient temperatures in winter or at the initial stage of system startup), the central control system supplies current to the resistance heater 7 via a thyristor or solid-state relay, causing it to generate Joule heat. This provides secondary heating to the already preheated air, ensuring that the air temperature entering the regeneration zone of the rotary wheel precisely meets the requirements. This tiered heating structure ensures that electric heating is used only as a supplementary energy source, rather than the primary heat source, thereby optimizing the energy consumption structure of the regeneration process.

[0053] Exhaust waste heat recovery subsystem:

[0054] This subsystem is specifically designed to recover waste heat carried in the regeneration exhaust air, and its core component is the waste heat recovery device 12 installed at the regeneration exhaust air outlet 11. The device can be a plate air-to-air heat exchanger, a heat pipe heat exchanger, or a coil heat exchange system that uses an intermediate heat medium (such as an aqueous ethylene glycol solution) for circulation.

[0055] In one embodiment, the waste heat recovery device 12 is a plate air-to-air heat exchanger. It has multiple independent channels separated by thin metal plates. High-temperature, high-humidity regeneration exhaust air (hot fluid) and preheated cold fluid (such as outdoor fresh air or regeneration intake air) flow through adjacent channels in a counter-current or cross-flow manner. Heat is conducted from the hot fluid side to the cold fluid side through the metal plates, thereby lowering the temperature of the regeneration exhaust air while raising the temperature of the cold fluid.

[0056] In another embodiment, the waste heat recovery device 12 is an intermediate-medium heat exchange system. This system comprises two independent heat exchange coils and a circulation pump. One coil is installed in the regeneration exhaust duct, absorbing heat from the exhaust to heat the ethylene glycol aqueous solution; the other coil is installed in the air duct requiring preheating (e.g., upstream of the regeneration air inlet 8), where the heated ethylene glycol aqueous solution releases heat. The circulation pump drives the intermediate heat medium to continuously circulate between the two coils, achieving non-contact heat transfer.

[0057] Regardless of the structure adopted, the function of this subsystem is to capture and reuse the sensible heat in the regenerated exhaust air that would otherwise be directly discharged into the atmosphere. The recovered heat can be used to preheat the regenerated air entering the cascade regenerated heating subsystem, thereby reducing the heat load on the subsequent carbon dioxide condenser 13 and resistance heater 7; or, under preset operating conditions, the recovered heat can be used to increase the temperature on the evaporator side of the carbon dioxide heat pump, improving the operating efficiency of the heat pump. This directly reduces the system's net heat input requirement and the thermal pollution emitted into the environment.

[0058] See attached document Figure 1 -Appendix Figure 3 The operation of this invention is based on the coordinated work of two core processes: air handling process and energy coupling mechanism.

[0059] This system employs a three-stage series dehumidification process for the air being processed. Each stage corresponds to the change path of the air state on the enthalpy-humidity chart, thereby achieving the transformation from high-humidity air to low-dew-point dry air.

[0060] The first stage of treatment occurs in the pre-cooling and dehumidification section, which consists of the front surface cooler 18 and the carbon dioxide deep dehumidification coil 17 connected in series. Outdoor fresh air (state point A) first flows through the front surface cooler 18, where an external cold source removes some of the sensible heat from the fresh air, lowering its temperature. Simultaneously, as the air cools below its initial dew point temperature, moisture begins to precipitate, and the state point descends along the isohyet line before moving along the saturated humidity line to state point B. Subsequently, the air enters the carbon dioxide deep dehumidification coil 17, where the low-temperature carbon dioxide working fluid evaporates, forcibly and deeply cooling the air. The air temperature continues to drop significantly along the saturated humidity line to state point C. This process is accompanied by the condensation and precipitation of a large amount of moisture, reducing the absolute moisture content of the fresh air. The temperature at state point C is lower than the final supply air dew point requirement, which is fundamental to achieving deep drying.

[0061] The second stage of treatment occurs in the mixing section and the intermediate surface cooler 14. Low-temperature, dry fresh air from state point C merges with return air (state point D) from the room, which has higher temperature and humidity. The two airflows mix according to their mass ratio, forming a new state point E, with temperature and humidity between points C and D. The mixed air (state point E) flows through the intermediate surface cooler 14, undergoing further cooling to move its state point to state point F. The temperature at state point F is precisely controlled within the temperature range where the dehumidification rotor's adsorption efficiency is optimal.

[0062] The third stage of treatment, namely core adsorption dehumidification, occurs in the treatment zone of dehumidification rotor 9. Air from state point F passes through the densely packed channels containing desiccant inside the rotor. The silica gel or molecular sieve adsorbent within the rotor utilizes its microporous structure to physically adsorb water molecules, capturing and fixing residual water vapor molecules in the air onto its surface. This process is isenthalpic or near-isenthalpic adsorption; the absolute moisture content of the air decreases sharply, but the dry-bulb temperature of the air rises due to the release of adsorption heat. The air state point moves approximately horizontally to the right from point F to the final supply air state point G. State point G represents dry air with high temperature and extremely low humidity. Subsequently, this dry air undergoes temperature regulation via post-cooling 5 or post-heating 4 to meet the final supply air requirements.

[0063] The core working principle of this system is to construct a closed-loop mechanism for internal energy transport and conversion through a carbon dioxide transcritical heat pump cycle, which transforms the cooling load removed from the processing air side into a regenerative heat source that can be directly utilized on the regenerated air side.

[0064] The energy transfer begins at the carbon dioxide deep dehumidification coil 17. Here, liquid carbon dioxide evaporates, absorbing heat from the air and completing the refrigeration process. According to the first law of thermodynamics, this absorbed heat... It did not disappear, but was stored as latent heat in the gaseous carbon dioxide working fluid. Simultaneously, the compressor in the carbon dioxide combined cooling and heating unit 1 performs work on the gaseous working fluid. This compresses it into a supercritical fluid with high temperature and high pressure, and the work done in this compression also increases the enthalpy of the working fluid in the form of heat energy.

[0065] The energy conversion ends at the carbon dioxide condenser 13, which carries the refrigeration load. With compression heat The high-temperature supercritical carbon dioxide fluid, containing total energy, releases heat to the regenerated air flowing through it. The total heat released... This is the sum of the first two. This process realizes the transformation of energy form: the heat that is not needed on the processing air side (i.e., the cooling load) is actively transported and, together with the electrical energy input by the compressor, is converted into the high-grade heat energy needed on the regenerated air side.

[0066] Therefore, the system is no longer a traditional system where cooling and heating are two separate processes consuming external energy. Instead, it forms an organic whole: the product of the cooling process (absorbed heat) becomes the raw material for the heating process. This internal coupling and recycling of energy is the fundamental operating mechanism that distinguishes this system from existing technologies, and it is directly related to the overall energy utilization efficiency of the system. The waste heat recovery device 12 further captures the energy loss discharged by the system to the outside world on this closed loop, turning the originally wasted heat into... The re-injection into the system forms a second energy loop, thereby further reducing the system's demand for total external energy input.

[0067] See attached document Figure 3 and attached Figure 4 In order to achieve stable operation and optimal energy efficiency of the system under different environmental conditions, this invention is equipped with a central control system based on sensor data feedback, which executes the following operation control strategies.

[0068] The system startup process follows strict timing logic to ensure equipment safety and prevent damage to the rotor or condensation before a stable thermal cycle is established.

[0069] Upon triggering the start command, the control system first executes a self-test procedure to confirm that there are no faults reported by the sensors and actuators. Subsequently, the system controls the start of the drive motor of the dehumidification rotor 9, causing it to rotate at a preset low speed (e.g., 8-12 rpm). After confirming that the rotor rotation is correct, the processing fan 6 and the regeneration fan 10 start simultaneously. The frequency of the processing fan 6 gradually increases to the set value, establishing a stable processing airflow. The regenerator fan 10 establishes a stable regenerated air volume. At this point, the system monitors the pressure difference signal on both sides of the dehumidification rotor 9 to confirm that the airflow channel is unobstructed.

[0070] After establishing airflow circulation, the system opens the chilled water valve of the front cooling coil 18 to introduce an external cold source for pre-cooling the fresh air. When the fresh air outlet temperature drops to the set threshold, the system sends a start signal to the carbon dioxide combined cooling and heating unit 1. The compressor inside the unit starts and runs at the lowest frequency, and the electronic expansion valve opens to its initial opening. The control system monitors the compressor's suction and discharge pressures and gradually increases the compressor frequency until the surface temperature of the carbon dioxide deep dehumidification coil 17 reaches below the dew point, and the discharge temperature of the carbon dioxide condenser 13 begins to rise, marking the completion of the transcritical combined cooling and heating cycle.

[0071] During system operation, the control system executes multi-loop PID (proportional-integral-derivative) closed-loop control to coordinate the dehumidification requirements on the treatment side and the heating requirements on the regeneration side.

[0072] First control loop: Fresh air deep dehumidification control

[0073] This circuit uses the dew point temperature or absolute moisture content downstream of the CO2 deep dehumidification coil 17 in the air duct as the controlled variable. A temperature / humidity sensor collects data at this location in real time and feeds it back to the controller. When the monitored dew point temperature exceeds the set target value, the controller outputs a signal to increase the operating frequency of the compressor in the CO2 combined cooling and heating unit 1, increasing the refrigerant flow rate and thus improving the cooling capacity of the CO2 deep dehumidification coil 17. Conversely, the compressor frequency is reduced. At the same time, the controller adjusts the opening of the electronic expansion valve to maintain the superheat at the evaporator outlet within a preset range (e.g., 5K-8K), ensuring that the compressor suction does not carry liquid.

[0074] Furthermore, the control system also executes the optimal high-pressure control algorithm for the transcritical cycle. Since the heat release capacity of the carbon dioxide working fluid in the transcritical region has a non-linear relationship with the exhaust pressure (high-pressure side pressure), the controller calculates in real time the optimal exhaust pressure value corresponding to the maximum energy efficiency ratio (COP) under the current operating conditions, based on the current regeneration inlet air temperature (i.e., the air temperature at the outlet of the gas cooler) and the refrigerant temperature at the outlet of the carbon dioxide condenser 13. The controller fine-tunes the opening of the electronic expansion valve to bring the high-pressure side pressure of the system close to the optimal exhaust pressure value while ensuring superheat. This maximizes efficiency without increasing compressor power consumption. The output.

[0075] Second control loop: Regeneration temperature gradient compensation control

[0076] This circuit uses the regenerated air temperature in the regenerated air duct, before the inlet of the regeneration zone of dehumidifier rotor 9, as the basis for the regeneration air temperature. As a controlled variable, the heating capacity provided by the carbon dioxide condenser 13 is determined primarily by the first control loop (dehumidification demand) since the compressor's operating frequency is mainly determined by the first control loop (dehumidification demand). It is dynamic. The controller compares the current regenerated air temperature in real time. With the set regeneration target temperature (e.g., 120℃).

[0077] when When the temperature deviation is not met, indicating that condensation heat alone is insufficient to meet regeneration requirements, the controller calculates the temperature deviation and linearly adjusts the input power of the resistance heater 7 via a silicon controlled rectifier (SCR). To accurately fill the heat gap.

[0078] when When the controller cuts off the power to the resistance heater 7, the regeneration process relies entirely on the waste heat from the heat pump cycle to achieve zero electrical and thermal energy consumption.

[0079] Third control loop: Precision adjustment and control of air supply status

[0080] This loop uses the air temperature and humidity at air outlet 2 as controlled variables. Although the air processed by dehumidifier 9 is dry, its temperature is relatively high. The controller adjusts the opening of the cold water valve of the cooling coil 5 to lower the temperature, or adjusts the hot water valve / electric heating power of the heating coil 4 to raise the temperature, based on the air supply temperature setpoint, to ensure that the final air supply parameters meet the constant temperature and humidity requirements of the cleanroom or process workshop.

[0081] The system automatically switches between different operating strategies to adapt to seasonal changes based on data from outdoor ambient temperature sensors.

[0082] Winter operating mode:

[0083] When the outdoor fresh air temperature is detected to be lower than the set threshold (e.g., 10°C), the system enters winter mode. At this time, the fresh air humidity is low, and the first control loop automatically reduces the compressor frequency, resulting in increased heat output from the carbon dioxide condenser 13. Reduce. To cope with the lower initial temperature of the regenerated air intake in winter, the control system will:

[0084] Maximize the power output weight of resistance heating 7 to compensate for the insufficient heating capacity of the heat pump.

[0085] By adjusting the frequency of the regeneration fan 10, the regeneration air volume is appropriately reduced while ensuring the regeneration of the rotor. This is to improve the temperature rise per unit air volume.

[0086] By relying on the waste heat recovery device 12, the high temperature of the regenerated exhaust air is used to preheat the cold outdoor regenerated intake air, thereby reducing the load on the resistance heater 7.

[0087] Summer operating mode:

[0088] When the outdoor fresh air temperature is detected to be higher than a set threshold (e.g., 25°C), the system enters summer mode. At this time, the fresh air is highly humid and hot, and the first control loop drives the compressor to operate at high frequency to meet the deep dehumidification requirements, thereby generating a large amount of condensation heat. .at this time, It can usually completely cover or even exceed the heat required for regeneration. The control system will:

[0089] Completely shut off resistance heating 7.

[0090] If the regenerated air temperature If the value exceeds the allowable upper limit, the control system can appropriately increase the frequency of the regeneration fan 10 to remove excess heat with a larger air volume and prevent the dehumidification rotor 9 from overheating.

[0091] In this mode, the waste heat recovery device 12 continues to operate, and the recovered heat can be used to increase the evaporation temperature of the heat pump system or discharged through the bypass path to avoid heat accumulation.

Claims

1. A waste heat recovery type combined cooling and heating single-rotor dehumidifier system, characterized in that, Includes a dehumidifier housing and a carbon dioxide combined cooling and heating unit (1) installed outside the dehumidifier housing; The interior of the dehumidifier housing is divided into a processing air channel and a regeneration air channel. The processing air channel is arranged in sequence along the airflow direction with a carbon dioxide deep dehumidification coil (17) and a dehumidification wheel (9). The carbon dioxide deep dehumidification coil (17) serves as the evaporation end and is used to cool the incoming fresh air to below the dew point. The regeneration air channel is provided with a carbon dioxide condenser (13) and the regeneration zone of the dehumidifying wheel (9) arranged sequentially along the airflow direction. The carbon dioxide condenser (13) serves as the heat release end and is used to heat the regeneration air. The carbon dioxide combined cooling and heating unit (1) is connected to the carbon dioxide deep dehumidification coil (17) and the carbon dioxide condenser (13) through refrigerant pipelines to form a transcritical carbon dioxide thermodynamic cycle, which transfers the heat absorbed by the carbon dioxide deep dehumidification coil (17) to the carbon dioxide condenser (13) for release.

2. The waste heat recovery type combined cooling and heating single-rotor dehumidifier system according to claim 1, characterized in that, The processing air channel is also provided with a front surface cooler (18) upstream of the carbon dioxide deep dehumidification coil (17), which is used to connect an external cold source to pre-cool the fresh air; The processing air channel is further provided with a return air inlet (15) and a mixing section between the processing area of ​​the carbon dioxide deep dehumidification coil (17) and the dehumidification rotor (9), for introducing indoor return air and mixing it with the fresh air that has undergone deep dehumidification; Downstream of the mixing section is a medium surface cooler (14) for adjusting the temperature of the mixed air to match the adsorption characteristics of the dehumidifying impeller (9).

3. The waste heat recovery type combined cooling and heating single-rotor dehumidifier system according to claim 2, characterized in that, The processing air channel is also provided with a processing fan (6), a rear surface cooler (5) and a rear heater (4) in sequence downstream of the processing area of ​​the dehumidifying rotor (9). The processing fan (6) is used to drive air flow, and the post-cooling (5) and post-heating (4) are used to perform final air supply temperature and humidity regulation on the dehumidified dry air.

4. The waste heat recovery type combined cooling and heating single-rotor dehumidifier system according to claim 1, characterized in that, The regenerated air channel is also equipped with a resistance heater (7), which is connected in series between the regeneration zone of the carbon dioxide condenser (13) and the dehumidification wheel (9). The carbon dioxide condenser (13) and the resistance heater (7) form a stepped heating structure, wherein the carbon dioxide condenser (13) is used to provide primary basic heating and the resistance heater (7) is used to provide secondary supplementary heating.

5. A waste heat recovery type combined cooling and heating single-rotor dehumidifier system according to claim 4, characterized in that, The regenerated air channel is also provided with a regenerated fan (10) and a regenerated exhaust port (11) downstream of the regeneration zone of the dehumidifying rotor (9). A waste heat recovery device (12) is installed at the regeneration exhaust port (11). The waste heat recovery device (12) is used to allow the high temperature and high humidity regeneration exhaust to flow through the heat exchange side, thereby extracting the sensible heat energy in the exhaust.

6. A waste heat recovery type combined cooling and heating single-rotor dehumidifier system according to claim 5, characterized in that, The waste heat recovery device (12) is a plate air heat exchanger or an intermediate medium heat exchanger. The heat absorption side of the waste heat recovery device (12) is connected to the regeneration exhaust port (11), and the heat release side of the waste heat recovery device (12) is connected to the upstream of the air inlet of the regeneration air channel or the heat source input end of the carbon dioxide combined cooling and heating host (1).

7. A waste heat recovery type combined cooling and heating single-rotor dehumidifier system according to claim 4, characterized in that, It also includes a central control system and a sensor array distributed within the dehumidifier housing, the sensor array comprising at least: The first temperature sensor located downstream of the carbon dioxide deep dehumidification coil (17) is used to detect the dew point temperature after dehumidification; And a third temperature sensor located in front of the regeneration zone inlet of the dehumidifying impeller (9) for detecting the regeneration air inlet temperature.

8. A waste heat recovery type combined cooling and heating single-rotor dehumidifier system according to claim 7, characterized in that, The central control system is used to execute the regeneration temperature compensation control logic: When the temperature detected by the third temperature sensor is lower than the set regeneration target temperature, the central control system calculates the heat difference and adjusts the input power of the resistance heater (7) to compensate for the insufficient heat supply of the carbon dioxide condenser (13).

9. A waste heat recovery type combined cooling and heating single-rotor dehumidifier system according to claim 7, characterized in that, The central control system is used to execute the transcritical cycle optimal high-pressure control logic: The central control system calculates the optimal exhaust pressure value under the current operating conditions based on the regenerated air temperature and the refrigerant outlet temperature, and adjusts the opening of the electronic expansion valve in the carbon dioxide combined cooling and heating host (1) so that the high-pressure side pressure of the transcritical carbon dioxide thermodynamic cycle approaches the optimal exhaust pressure value.

10. A waste heat recovery type combined cooling and heating single-rotor dehumidifier system according to claim 1, characterized in that, The fins of the deep carbon dioxide dehumidification coil (17) are covered with a hydrophilic anti-corrosion coating, and a water collection tray connected to the drain pipe is provided at the bottom to collect and discharge the condensate that is precipitated due to deep cooling.

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