Phase change thermal storage assisted start-up system and start-up control method based on heat pump dryer

Abstract

This invention discloses a phase change heat storage assisted start-up system and start-up control method based on a heat pump dryer, aiming to solve the problems of slow preheating, low initial energy efficiency, and reliance on electric auxiliary heating in heat pump dryers at low temperatures. The system includes a refrigerant circulation loop, an air circulation loop, and a control system. The compressor exhaust port in the refrigerant circulation loop is connected to a phase change heat storage heat exchange module and a condenser via a three-way proportional control valve. The phase change heat storage heat exchange module encapsulates a phase change material. The control system adjusts the three-way proportional control valve to distribute the refrigerant flow according to the ambient temperature and the phase change energy storage state. This invention utilizes the heat release of the phase change material to achieve rapid start-up, shortens the drying time, recovers waste heat to reduce condensing pressure, and improves system energy efficiency and reliability.

Description

Technical Field

[0001] This invention relates to a phase change heat storage auxiliary start-up system and start-up control method based on a heat pump dryer, belonging to the technical field of heat pump dryer equipment. Background Technology

[0002] With the profound transformation of global energy consumption structures and consumers' increasing demands for energy efficiency and care quality in home appliances, heat pump dryers, with their superior energy-saving characteristics and gentle protection of fabric fibers, have gradually replaced traditional exhaust and condenser dryers, becoming the mainstream technology for modern household drying equipment. The core of a heat pump drying system lies in constructing a thermodynamic closed loop based on a reverse Carnot cycle. Through the coordinated work of the compressor, condenser, throttling element, and evaporator, it achieves deep dehumidification and efficient heating of the circulating air. In this process, the heat pump system not only recovers the latent heat of moisture in the air through evaporator condensation, but also converts this heat and the compressor's power consumption into the temperature rise of the air through the condenser, thus completing the drying task with extremely low energy input.

[0003] Within the existing technological framework, the operational efficiency of heat pump dryers highly depends on the stable establishment of refrigerant circulation pressure and the continuous accumulation of heat in the air circuit. Specifically, after the system enters the stable drying stage, the heat exchange temperature difference on the condenser surface can be maintained within an ideal range, ensuring that the circulating air obtains sufficient kinetic energy to remove moisture from the clothes. This design principle based on energy cycle compensation demonstrates excellent energy efficiency ratio and drying consistency under standard indoor ambient temperatures. The mature application of existing technologies has enabled heat pump dryers to establish significant technological barriers in the fields of energy conservation, emission reduction, and fabric care, providing a solid engineering foundation for achieving low-carbon household washing and drying processes.

[0004] However, a deeper examination of the thermodynamic evolution of heat pump systems reveals a significant imbalance in the spatiotemporal distribution of their energy cycle mechanism. This inherent defect is particularly pronounced in low-temperature environments or during winter startup. From a thermodynamic perspective, heat pump systems are essentially in a state of severe energy depletion during the "cold start-up" phase. Due to the low ambient temperature, both the initial suction and discharge pressures of the system are extremely low, resulting in insufficient refrigerant mass flow rate. The heat pump cycle requires a prolonged transient process to reach thermal equilibrium. Specifically, in the first 15 to 20 minutes after the program starts, the temperature rise in the air circulation loop is extremely slow, and the condenser cannot provide sufficient sensible heat output. During this time, the clothes inside the drum are still in an inefficient tumbling state, and the rate of moisture evaporation is almost stagnant. This not only forces a longer total drying time, significantly reducing the user experience, but also causes components such as the drive motor to operate inefficiently, resulting in unnecessary mechanical wear and energy loss.

[0005] To address this technical bottleneck of delayed start-up, the mainstream approach in the industry currently focuses on introducing PTC electric auxiliary heating modules. While this solution can quickly compensate for the heat gap and shorten preheating time through electrothermal conversion during the initial startup phase, its technical paradox is also quite evident. First, the high-power operation of the PTC module significantly increases the instantaneous energy consumption and peak current of the entire machine. This not only directly contradicts the original technical intention of heat pump dryers, which prioritizes "high energy efficiency," but also places higher demands on the household power grid load. Second, the introduction of electric auxiliary heating disrupts the original thermodynamic balance of the heat pump cycle, potentially leading to abnormal fluctuations in condensing pressure and affecting the long-term operational reliability of the system. A deeper contradiction lies in the fact that existing heat pump dryer systems often suffer from a misalignment between "heat waste" and "energy demand" over time: in the middle and later stages of a drying task, the system often generates a large amount of excess condensing waste heat that needs to be dissipated through the environment; however, at the beginning of the next drying task, the system is forced into a long preheating wait due to a lack of startup energy. This cross-cycle energy distribution imbalance, along with the lack of existing technology for the system's own waste heat recovery and spatiotemporal transfer capabilities, constitutes a deep-seated technical bottleneck that limits further breakthroughs in the performance of heat pump clothes drying systems.

[0006] Correspondingly, how to break the excessive dependence of heat pump cycles on the initial thermal environment without sacrificing the system's energy efficiency ratio, and explore an innovative mechanism that can achieve efficient heat storage and on-demand release between different operating stages, and solve the problems of "slow temperature difference establishment and long preheating cycle" in cold operating conditions through non-energy-consuming heat compensation methods, has become a key challenge and an urgent technical problem for those skilled in the art in optimizing the performance of heat pump drying systems and improving user interaction experience. Summary of the Invention

[0007] Therefore, the purpose of this invention is to provide a phase change heat storage assisted start-up system and start-up control method based on a heat pump dryer. Based on realizing the basic functions of heat pump dryer, it solves the problems of slow start-up preheating, low initial energy efficiency and excessive reliance on electric auxiliary heating in low temperature environment by introducing a phase change heat storage mechanism and multi-loop fluid control logic.

[0008] The objective of this invention is achieved through the following technical solution: A phase change thermal storage auxiliary start-up system based on a heat pump dryer, comprising: A refrigerant circulation loop is provided, in which a compressor, a phase change thermal storage heat exchange module, a condenser, a throttling element, and an evaporator are connected sequentially in the direction of refrigerant flow. The discharge port of the compressor is connected to the inlet end of a three-way proportional control valve through a first refrigerant pipeline. The first outlet end of the three-way proportional control valve is connected to the refrigerant inlet of the phase change thermal storage heat exchange module through a second refrigerant pipeline, and its second outlet end is connected to the refrigerant inlet of the condenser through a third refrigerant pipeline. An air circulation loop is provided, in sequence according to the airflow direction, consisting of a drum, a filter, the evaporator, the condenser, the phase change heat storage and heat exchange module, and a circulating fan. The control system is used to control the refrigerant flow distribution ratio between the phase change thermal storage heat exchange module and the condenser in real time by adjusting the three-way proportional regulating valve according to the system operation stage.

[0009] Furthermore, the phase change thermal storage heat exchange module includes an inner shell and an outer shell, with polyurethane foam insulation material filling the space between the inner shell and the outer shell; the inner shell is filled with a phase change material that has undergone vacuum degassing treatment, and a finned tube heat exchanger is embedded inside the phase change material.

[0010] Furthermore, multiple radially distributed copper thermally conductive fins extending into the phase change material are provided on the inner wall surface of the inner shell; the phase change material is a paraffin-based composite material with a phase change critical temperature of 55℃-65℃, a latent heat value of not less than 200kJ / kg, and is uniformly doped with 3%-5% expanded graphite by mass; the polyurethane foam insulation material has a thickness of 20mm-30mm, a closed-cell rate greater than 95%, and a thermal conductivity lower than... .

[0011] Furthermore, the three-way proportional control valve is driven by a stepper motor to rotate the valve core, and the valve core has a V-shaped notch to achieve quasi-linear control of flow rate and rotation angle.

[0012] Furthermore, the control system includes a central processing unit and signal-connected ambient temperature sensors, a phase change module temperature sensor, a compressor exhaust temperature sensor, a drum inlet air temperature sensor, and a condenser inlet temperature sensor. The central processing unit receives analog signals from each sensor and converts them into digital signals. The ambient temperature sensor is located at the air inlet of the dryer casing and is used to monitor the external ambient temperature T in real time. env The phase change module temperature sensor is embedded at the geometric center of the phase change thermal storage heat exchange module to monitor the thermal energy storage state temperature T of the phase change material. pcm The compressor exhaust temperature sensor is installed at the compressor exhaust port to monitor the compressor exhaust temperature T in real time.dis The drum inlet air temperature sensor is located at the leeward end of the last bend in the air circulation loop before the drum, and is used to provide feedback on the final air temperature T entering the drum. in The condenser inlet temperature sensor is installed at the inlet of the condenser to monitor the temperature of the gas entering the condenser in real time.

[0013] Furthermore, the phase change thermal storage auxiliary start-up system based on the heat pump dryer also includes: A bypass damper mechanism is installed on the air-side channel of the phase change thermal storage heat exchange module; A high-strength flexible shock-absorbing joint is installed at the connection between the compressor's exhaust pipe and the phase change heat storage and heat exchange module. A mechanical pressure relief valve is installed at the refrigerant inlet end of the phase change thermal storage heat exchange module. An airflow straightening grille is installed between the condenser outlet and the inlet of the phase change thermal storage heat exchange module in the air circulation loop.

[0014] A startup control method based on the above-mentioned startup system includes three startup control modes: heat release startup mode, steady-state drying mode, and heat storage and recovery mode. The control system determines that the system is in a low-temperature cold start condition and adopts a heat release start mode. In the heat release start mode, the central processing unit controls the first outlet of the three-way proportional regulating valve to be fully opened and the second outlet to be fully closed, so that all the high-temperature gaseous refrigerant discharged by the compressor enters the phase change heat storage and heat exchange module. When the inlet air temperature of the drum reaches a certain stable value, a steady-state drying mode is adopted. In the steady-state drying mode, the central processing unit adjusts the opening of the three-way proportional regulating valve to reduce the refrigerant flow to the phase change heat storage heat exchange module and correspondingly increase the refrigerant flow to the condenser. In the later stages of the drying process, a heat storage and recovery mode is adopted. In this mode, the central processing unit adjusts the three-way proportional control valve to allow some of the high-temperature gaseous refrigerant to enter the phase change heat storage and exchange module. The phase change material absorbs the excess heat of the refrigerant and undergoes a phase change from solid to liquid, storing this energy as latent heat.

[0015] Furthermore, through the external ambient temperature T env The thermal energy storage state temperature T of phase change materials pcm The air temperature T entering the drum in The discharge temperature T of the compressor dis To determine the startup control mode, including: When the ambient temperature T env Below 15℃, and thermal energy storage state temperature T pcmWhen the temperature is above 45℃, the heat release start-up mode is used; When the air inlet temperature of the roller reaches a preset threshold T set A steady-state drying mode is adopted; When the discharge temperature T of the compressor dis The temperature is raised to 70℃-85℃, and a heat storage and recovery mode is adopted.

[0016] Furthermore, in the heat release start-up mode, the circulating fan operates at a low speed of 800 rpm to 1000 rpm to increase the residence time of air in the phase change heat storage heat exchange module, and the control system reduces the opening of the electronic expansion valve, which is a throttling element, to accelerate the establishment of system exhaust pressure and help the system reach thermodynamic equilibrium more quickly. In steady-state drying mode, the central processing unit linearly adjusts the opening of the three-way proportional control valve using a PID algorithm, ultimately switching the three-way proportional control valve to a fully open state at the second outlet. This returns the refrigerant circulation loop to standard heat pump operation mode, and with T... in As the speed increases, the circulating fan speed linearly increases to the rated speed. In the heat storage and recovery mode: the control system adjusts the three-way proportional regulating valve to allow at least 30% of the high-temperature gaseous refrigerant to enter the phase change heat storage and heat exchange module. The phase change material absorbs the excess heat of the refrigerant and undergoes a phase change from solid to liquid, storing this part of the energy in the form of latent heat. The control system's regulation logic for the three-way proportional control valve is based on the following mathematical model: valve opening D = f(ΔT, dP / dt), where ΔT is the difference between the target inlet air temperature and the actual inlet air temperature, and dP / dt is the rate of change of the system condensing pressure.

[0017] Furthermore, the central processing unit records historical operating data through non-volatile memory and automatically optimizes the switching timing and heat storage depth of the three-way proportional regulating valve based on ambient temperature and clothing load.

[0018] Compared with the prior art, the beneficial effects of the present invention are: (1) The phase change thermal storage assisted start-up system described in this invention cleverly solves the performance bottleneck of heat pump dryers under low-temperature start-up conditions by utilizing the high energy efficiency storage characteristics of phase change materials and precise three-way fluid distribution control logic. It not only avoids the high energy consumption drawbacks of traditional PTC electric auxiliary heating, achieving true "zero extra energy consumption" rapid start-up, but also optimizes the overall thermodynamic efficiency of the system through a cross-time-domain heat scheduling scheme. This innovative system-level design significantly shortens the total drying time while improving the stability of system operation, providing a solid technical guarantee for the widespread application of heat pump drying technology in cold regions, and possesses extremely high engineering application value and energy-saving and environmental protection significance.

[0019] (2) The phase change heat storage assisted start-up system described in this invention has a compact structure, with all functional modules integrated into the standard dryer base space. Through optimized refrigerant pipeline design, the overall weight increase is no more than 3kg, while the start-up preheating efficiency is improved by more than 300%. This significant technological advancement marks a leap in heat pump drying technology from a single reverse Carnot cycle application to multi-source energy efficiency collaborative management, setting a new technological benchmark for the development of next-generation high-efficiency and high-comfort home appliances.

[0020] (3) Good adaptability: The system described in this invention is not only suitable for household stand-alone dryers, but can also be extended to washer-dryer combos or large-scale commercial drying equipment. In larger-scale applications, the same startup acceleration effect can be obtained simply by proportionally increasing the capacity of the phase change heat storage and heat exchange module and the amount of phase change material. Since the technical solution of this invention is based on the system's own waste heat conversion and does not involve complex chemical reactions or high-value precious metals, it has excellent cost controllability and technological maturity in large-scale industrial production.

[0021] (4) This invention solves the long-standing problem of start-up efficiency in the heat pump dryer industry by systematically reshaping the thermodynamic architecture and utilizing the physical properties of phase change materials. Through deterministic mechanical structure design and rigorous electronic control logic, this invention provides a low-carbon, high-efficiency, and highly reliable drying solution, which is in full compliance with the current technological trend of the home appliance industry towards green and intelligent transformation.

[0022] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will now be described in further detail with reference to the accompanying drawings, wherein: Figure 1 This is a schematic diagram of the overall structural flow path of the phase change thermal storage assisted start-up system based on a heat pump dryer as described in this invention; Figure 2 This is a schematic diagram of the internal structure of the phase change thermal storage and heat exchange module in this invention; Figure 3 This is a schematic diagram of the control system in this invention; Figure 4 This is a flowchart of the switching control logic for the three working modes in this invention.

[0024] The attached diagram is labeled as follows: 1. Compressor; 2. Phase change heat storage and heat exchange module; 3. Condenser; 4. Throttling element; 5. Evaporator; 6. Drum; 7. Filter; 8. Circulating fan; 9. Three-way proportional control valve; 10. First refrigerant line; 11. Second refrigerant line; 12. Third refrigerant line; 13. Phase change material; 14. Finned tube heat exchanger; 15. Copper thermal conductive fins; 16. Inner shell; 17. Outer shell; 18. Polyurethane foam insulation material; 19. Central processing unit; 20. Ambient temperature sensor; 21. Phase change module temperature sensor; 22. Compressor exhaust temperature sensor; 23. Drum inlet air temperature sensor; 24. Bypass damper mechanism; 25. Vibration damping joint; 26. Pressure relief valve; 27. Airflow rectification grille; 28. Condenser inlet temperature sensor. Detailed Implementation

[0025] 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. Example 1

[0026] like Figures 1-4 As shown, the first embodiment of the present invention provides a phase change thermal storage auxiliary start-up system based on a heat pump dryer, comprising: The refrigerant circulation loop is connected in sequence according to the refrigerant flow direction, including compressor 1, phase change heat storage module 2, condenser 3, throttling element 4, and evaporator 5. Compressor 1 is a variable frequency rotary compressor, and its exhaust port is connected to the inlet end of a three-way proportional control valve 9 through a first refrigerant pipeline 10. The first outlet end of the three-way proportional control valve 9 is connected to the refrigerant inlet of the phase change heat storage module 2 through a second refrigerant pipeline 11, and its second outlet end is connected to the refrigerant inlet of the condenser 3 through a third refrigerant pipeline 12. The air circulation loop is connected in sequence according to the air flow direction, including roller 6, filter 7, evaporator 5, condenser 3, phase change heat storage and heat exchange module 2 and circulating fan 8. The control system is used to control the refrigerant flow distribution ratio between the phase change thermal storage heat exchange module 2 and the condenser 3 in real time by adjusting the three-way proportional regulating valve 9 according to the system operation stage.

[0027] Specifically, the system adopts an energy cross-time domain scheduling design logic in its overall architecture. Its core lies in storing excess heat energy generated during the later stages of system operation using a high-efficiency phase change medium, and releasing it instantaneously during the start-up phase of the next cycle. The system consists of a coupled refrigerant circulation loop, an air circulation loop, and a microprocessor-driven control system. The refrigerant circulation loop, as the core of heat transfer, has internal channels sequentially configured with a variable frequency rotor compressor 1, a phase change heat storage and exchange module 2, a condenser 3, a throttling element 4, and an evaporator 5. On the discharge side of the compressor 1, the first refrigerant line 10 is connected to the inlet of a three-way proportional control valve 9. This three-way proportional control valve 9 is driven by a high-precision stepper motor, and its valve core has a throttling edge with a specific geometry, used to distribute refrigerant flow between the second refrigerant line 11 and the third refrigerant line 12. The second refrigerant line 11 extends into the internal heat exchanger of the phase change heat storage and exchange module 2, while the third refrigerant line 12 bypasses the phase change module and directly leads to the condenser 3. The air circulation loop forms a closed temperature and humidity regulation path. The circulating fan 8 drives the air to flow sequentially through the roller 6 that holds the clothes, the filter 7 that traps lint, the evaporator 5 that is responsible for dehumidification, the condenser 3 that is responsible for primary heating, and the phase change heat storage and heat exchange module 2 that is responsible for enhanced heating.

[0028] The phase change thermal storage heat exchange module 2 adopts a double-shell structure, including an inner shell 16 and an outer shell 17. A polyurethane foam insulation material 18 with a thickness of 20mm to 30mm is filled between the inner shell 16 and the outer shell 17. The closed-cell rate of the polyurethane foam insulation material 18 is greater than 95%, and its thermal conductivity is lower than [missing value]. The inner shell 16 is made of 304 stainless steel, which has good corrosion resistance and pressure resistance, sufficient to withstand the volume expansion stress of the phase change material during the solid-liquid conversion process. The inner shell 16 is filled with phase change material 13 that has undergone vacuum degassing treatment.

[0029] Phase change material 13 is a paraffin-based composite material with a phase change critical temperature of 55℃ to 65℃ and a latent heat value of not less than 200 kJ / kg. To improve heat transfer efficiency, expanded graphite with a mass fraction of 3% to 5% is uniformly doped into phase change material 13 to increase the equivalent thermal conductivity of phase change material 13 to a certain level. above.

[0030] The phase change thermal energy storage heat exchange module 2 is internally equipped with a finned tube heat exchanger 14. The finned tube heat exchanger 14 consists of multiple sets of parallel-arranged copper refrigerant coils and interspersed aluminum heat dissipation fins. The outer diameter of the copper refrigerant coils is 5mm to 7mm, the wall thickness is 0.25mm to 0.35mm, and the coils have internal threads. The aluminum heat dissipation fins have a fin spacing of 1.2mm to 1.5mm and are coated with a hydrophilic nano-coating to reduce airflow resistance and prevent condensate retention. The finned tube heat exchanger 14 adopts a multi-parallel structure with consistent flow channel lengths. Specifically, the refrigerant coils of the phase change thermal energy storage heat exchange module 2 employ a multi-parallel structure with consistent flow channel lengths to ensure uniform refrigerant distribution. At pipe connections, a high-pressure seal is achieved using silver soldering, and the welds show no leakage after a 2.5MPa airtightness test. The phase change material 13 is vacuum degassed before filling to remove internal air bubbles and prevent physical stress damage caused by gas expansion during thermal cycling.

[0031] Specifically, the phase change thermal storage and heat exchange module 2, which serves as the core energy conversion unit of this invention, exhibits extremely high requirements for heat transfer engineering in its internal structure. This module employs a double-shell structure to minimize heat loss to the external environment, with a polyurethane foam insulation material 18 of precisely controlled thickness (25 mm) filling the space between the outer shell 17 and the inner shell 16. The closed-cell rate of this material has been tested to reach over 96%, and its thermal conductivity is as low as... This ensures that the temperature drop rate of the internal phase change material 13 is controlled within 0.45℃ / h even under extreme conditions of an ambient temperature of 5℃. The inner shell 16 is made of 304 stainless steel with a wall thickness of 1.5mm, and its internal space is filled with paraffin-based composite phase change material 13 that has undergone vacuum degassing treatment. The solid-liquid phase transition point of this phase change material 13 is set at 58℃, and its latent heat value is as high as 225kJ / kg. To overcome the technical bottleneck of low thermal conductivity of pure paraffin, 4.2% by mass of expanded graphite is uniformly dispersed in the material, forming a continuous thermally conductive network, thereby increasing the equivalent thermal conductivity of the matrix material to a higher level. A finned tube heat exchanger 14 is embedded inside the phase change material 13. The heat exchanger consists of four sets of parallel internally threaded copper tubes with an outer diameter of 6.35 mm and a wall thickness of 0.3 mm. The fins are made of hydrophilic aluminum foil with a thickness of 0.12 mm and a fin spacing of 1.35 mm. This high-density heat exchange area design ensures efficient heat exchange between the refrigerant, the phase change material and the circulating air.

[0032] Multiple radially distributed copper thermally conductive fins 15 are welded to the inner wall of the inner shell 16, extending into the phase change material 13. In this embodiment, the heat exchange pipelines of the phase change thermal storage module 2 are staggered, with the pipe spacing controlled at 12 mm and the row spacing controlled at 10 mm. This arrangement allows the heat generated by the refrigerant flowing within the pipes to penetrate more evenly into the deeper layers of the phase change material through radial radiation and convection, preventing localized overheating or insufficient energy storage. Simultaneously, the copper thermally conductive fins 15 welded to the inner wall of the inner shell, extending into the phase change material, further shorten the heat conduction path, keeping the overall module's response time within 30 seconds.

[0033] The three-way proportional control valve 9 is driven by a stepper motor to rotate the valve core. The valve core has a V-shaped notch to achieve quasi-linear control of flow rate and rotation angle. The control system's regulation logic for the three-way proportional control valve 9 is based on a mathematical model: valve opening D = f(ΔT, dP / dt), where ΔT is the difference between the target inlet air temperature and the actual inlet air temperature, and dP / dt is the rate of change of the system condensing pressure. Specifically, the three-way proportional control valve 9 uses a rotor-type stepper motor to drive the valve core to rotate. The valve core has a specific V-shaped notch, which enables a quasi-linear relationship between flow rate and rotation angle. The stepper motor has a step angle of 1.8°, and the total stroke corresponds to 500 pulses, enabling a control accuracy of 0.2% of the total flow rate, providing precision support at the execution level for refined energy management.

[0034] The circulating fan 8 is driven by a brushless DC motor (BLDC), and its speed is adjusted in real time by the control system.

[0035] The throttling element 4 is an electronic expansion valve, the opening of which is controlled in a closed loop by the control system based on the superheat at the evaporator outlet.

[0036] Filter 7 employs a double-layer fine filter structure with pore sizes of 150 mesh and 200 mesh respectively. This ensures that even under high-speed airflow during the heat release phase, fabric fibers will not enter the fin gaps of the phase change heat storage heat exchange module, effectively preventing heat exchange efficiency degradation and potential fire hazards.

[0037] The heat exchange area ratio of condenser 3 to evaporator 5 is designed to be 1.3:1. This ratio, combined with the auxiliary adjustment of the phase change module, enables the system to maintain a good thermal balance at all stages.

[0038] The control system includes a central processing unit 19 and signal-connected sensors: an ambient temperature sensor 20, a phase change module temperature sensor 21, a compressor exhaust temperature sensor 22, a drum air inlet temperature sensor 23, and a condenser inlet temperature sensor 28. The central processing unit receives analog signals from each sensor and converts them into digital signals via a 12-bit analog-to-digital converter (ADC). The ambient temperature sensor 20 is located at the air inlet of the dryer casing and is used to monitor the external ambient temperature T in real time. env The phase change module temperature sensor 21 is embedded at the geometric center of the phase change thermal storage heat exchange module 2 to monitor the thermal energy storage state temperature T of the phase change material. pcm The drum inlet air temperature sensor 23 is located at the leeward end of the last bend before the air enters the drum 6 in the air circulation loop, and is used to provide feedback on the final air temperature T entering the drum. in The compressor discharge temperature sensor 22 is installed at the discharge port of compressor 1 to monitor the discharge temperature T of compressor 1 in real time. dis The condenser inlet temperature sensor 28 is installed at the inlet of condenser 1 to monitor the temperature of the gas entering condenser 1 in real time.

[0039] In the electrical connections of this system, all sensor cables are wrapped with a high-temperature resistant shielding layer and kept away from strong electromagnetic interference sources such as switching power supplies to ensure a signal-to-noise ratio higher than 60dB. The control board surface is coated with a moisture-proof, salt spray-proof, and corrosion-proof paint to meet the long-term operating requirements of high-humidity environments such as laundry rooms. Example 2

[0040] As another improvement of the present invention, the air-side channel of the phase change thermal storage heat exchange module 2 is designed with a bypass damper mechanism 24. The bypass damper mechanism 4 is driven by a stepper motor. When the system is in the non-start-up phase and thermal storage is not required, the damper switches to the bypass path, allowing the circulating air to bypass the phase change thermal storage heat exchange module 2 and directly enter the condenser 3. This design aims to reduce the air-side resistance (wind resistance) during steady-state operation of the system, reduce the power consumption of the circulating fan 8, and thus further improve the overall energy efficiency ratio (COP) of the system. Example 3

[0041] In the system integration design of this invention, a high-strength flexible shock-absorbing joint 25 is used at the connection between the exhaust pipe of the compressor 1 and the phase change heat storage and heat exchange module 2. The shock-absorbing joint 25 is made of ethylene propylene diene monomer (EPDM) rubber and stainless steel braided mesh, and its design pressure resistance is not less than 4.5 MPa. It can effectively absorb the instantaneous impact pressure when the compressor starts up and the high-frequency vibration during operation, preventing the refrigerant pipeline from breaking due to fatigue stress and ensuring the system's service life of more than 10 years. Example 4

[0042] A mechanical pressure relief valve 26 is installed at the refrigerant inlet of the phase change thermal storage heat exchange module 2. The opening pressure of the mechanical pressure relief valve 26 is set to 4.2MPa-4.5MPa. When an extreme fault occurs in the system causing an abnormal increase in pressure, the mechanical pressure relief valve 26 automatically opens, guiding the refrigerant to the low-pressure side or the safety exhaust pipeline, fundamentally eliminating the risk of module overpressure explosion. In addition, the central processing unit 19 also monitors the compressor current and the solenoid valve coil resistance in real time. Once an electrical abnormality is detected, the power supply is immediately cut off and an error reporting program is executed, displaying the fault code through the user interface, thus realizing intelligent equipment maintenance management. Example 5

[0043] An airflow rectification grille 27 is installed between the outlet of the condenser 3 and the inlet of the phase change thermal storage module 2 in the air circulation loop. The airflow rectification grille 27 consists of a series of guide vanes arranged at a specific angle. Specifically, the airflow rectification grille 27 consists of multiple guide vanes arranged at a 15-degree angle. Its function is to transform the non-uniform turbulent air flowing out of the condenser into a relatively stable laminar or weakly turbulent flow, allowing the air to make more sufficient contact with the heat dissipation fins of the phase change thermal storage module 2, thereby improving the heat exchange efficiency by 8% to 12%. Example 6

[0044] The central processing unit in the control system also includes a non-volatile memory (EEPROM) for recording energy efficiency parameters and heat recovery curves for each drying task. Using this data, the system can build a characteristic model tailored to specific user habits. When it predicts a short interval between the next start-up, it automatically adjusts the heat storage depth, thereby minimizing compressor power consumption while ensuring startup speed.

[0045] The startup control method based on the above startup system includes three startup control modes: heat release startup mode, steady-state drying mode, and heat storage and recovery mode.

[0046] Heat release start-up mode: When the ambient temperature T detected by the ambient temperature sensor 20... env Below 15℃, and the temperature T detected by the phase change module temperature sensor 21 pcm When the temperature is above 45°C, the central processing unit 19 controls the first outlet of the three-way proportional regulating valve 9 to be fully opened and the second outlet to be fully closed, so that all the high-temperature gaseous refrigerant discharged from the compressor 1 enters the phase change heat storage and heat exchange module 2.

[0047] Specifically, in the heat release start-up mode, the control system determines that the system is in a low-temperature cold start condition. At this time, the central processing unit 19 sends a pulse signal to the three-way proportional regulating valve 9 to control the valve core to operate, so that the first outlet end is fully opened and the second outlet end is fully closed. The high-temperature, high-pressure gaseous refrigerant discharged from the compressor 1 enters the phase change heat storage and exchange module 2. During this process, the phase change material transforms from liquid to solid (or cools down within the solid range), releasing a large amount of latent heat of phase change. The circulating air flowing through the phase change heat storage and exchange module 2 absorbs this heat in a very short time. According to the heat balance equation: , where m air For air mass flow rate, Cp air The specific heat of air at constant pressure is used. Since the instantaneous heat exchange power provided by the phase change material can reach 2000W to 3000W, the air temperature in the air circulation loop can be raised from the ambient temperature to above 40°C within 3 minutes, which greatly shortens the time it takes for the moisture in the clothing to reach the evaporation start temperature.

[0048] In the heat release start-up mode, the circulating fan 8 operates at a low speed of 800 rpm to 1000 rpm to increase the residence time of air in the phase change heat storage heat exchange module 2, and the control system reduces the opening of the electronic expansion valve, which is a throttling element 4, to accelerate the establishment of system exhaust pressure and help the system reach thermodynamic equilibrium more quickly.

[0049] Steady-state drying mode: When the inlet air temperature T detected by the drum inlet air temperature sensor 23... in Reaching the preset threshold T set At a temperature of 45°C, the central processing unit 19 linearly adjusts the opening of the three-way proportional control valve 9 using a PID algorithm, reducing the refrigerant flow to the phase change heat storage module 2 and correspondingly increasing the refrigerant flow to the condenser 3. Finally, the three-way proportional control valve 9 switches to a fully open state at the second outlet, and the refrigerant circulation loop returns to the standard heat pump operation mode, where the condenser 3 serves as the main heating source, utilizing the sensible and latent heat of refrigerant condensation to continuously heat the air.

[0050] The proportional coefficient Kp, integral coefficient Ki, and derivative coefficient Kd of the PID control algorithm are all pre-calibrated using experimental data. During the heat release phase, Kp is set to a larger value to achieve a rapid response; during the steady-state transition phase, Ki is increased to eliminate static deviations and ensure that the air temperature fluctuation range is controlled within ±1.5℃. This refined algorithm control, combined with a high-precision NTC temperature sensor, enables the system of this invention to adapt to various complex indoor and outdoor environmental changes and always maintain operation at the optimal energy efficiency point.

[0051] In steady-state drying mode, as T inAs the speed increases, the speed of the circulating fan 8 increases linearly to the rated speed, such as increasing the speed of the circulating fan 8 to 2500rpm-2800rpm, in order to enhance the overall circulation flow and increase the rate of moisture removal. The air-side channel of the phase change thermal storage heat exchange module 2 is designed with a bypass damper mechanism 24 driven by a stepper motor. In steady-state drying mode, the bypass damper mechanism 24 switches to the bypass path, so that the circulating air avoids the phase change thermal storage heat exchange module 2.

[0052] Heat storage and recovery mode: In the later stages of the drying process, the control system monitors the exhaust temperature T of the compressor 1. dis As the load inside the drying chamber gradually decreases, the return air temperature rises, leading to an increase in the exhaust temperature T. dis The temperature often rises to 70°C to 85°C. When the exhaust temperature Tdis is in the range of 70°C to 85°C, adjusting the three-way proportional control valve 9 allows some of the high-temperature gaseous refrigerant to enter the phase change heat storage module 2. The phase change material absorbs the excess heat of the refrigerant, undergoing a phase change from solid to liquid, storing this energy as latent heat. In this mode, the phase change material 13 absorbs heat for phase change energy storage from solid to liquid, which not only achieves waste heat recovery but also effectively reduces the condensing pressure of the system, prevents the compressor from overheating due to high-temperature and high-pressure conditions, and improves the operational reliability of the system.

[0053] The control system's regulation logic for the three-way proportional control valve 9 is based on the following mathematical model: valve opening D = f(ΔT, dP / dt), where ΔT is the difference between the target inlet air temperature and the actual inlet air temperature, and dP / dt is the rate of change of the system condensing pressure. This control model ensures the smoothness of the air temperature rise during heat release, preventing damage to fabric fibers due to excessively rapid heat release.

[0054] The control system has a self-learning function. The central processing unit 19 records historical operating data through non-volatile memory and automatically optimizes the switching timing and heat storage depth of the three-way proportional regulating valve 9 based on ambient temperature and clothing load. For example, in extremely cold regions (T... env When the temperature is below 0℃, the system will extend the duration of the heat storage and recovery mode to ensure that the phase change material is completely melted in order to store the highest energy density for the next program call.

[0055] Furthermore, in the initial heat release start-up mode, the control system exhibits precise logical scheduling. The ambient temperature sensor 20 detects that the external ambient temperature Tenv is below a preset low-temperature threshold, such as 12°C, while the phase change module temperature sensor 21 confirms that Tpcm is in a sufficient energy storage state, such as >55°C. At this time, the central processing unit 19 outputs a full-stroke pulse signal to the three-way proportional regulating valve 9 via the electronic drive circuit, fully opening the first outlet. At this point, all the superheated steam discharged from the compressor 1 at a certain pressure enters the phase change heat storage heat exchange module 2 via the second refrigerant pipeline 11. Simultaneously, the circulating fan 8 operates at a preset start-up speed, such as 900 rpm, causing air to flow at a low velocity through the aluminum heat dissipation fins of the phase change heat storage heat exchange module 2. Since the phase change material 13 is undergoing a physical transformation from liquid to solid at this time, the enormous latent heat of phase change it releases is rapidly conducted to the airflow through the fins. Experimental data shows that in this mode, the inlet air temperature T entering the drum 6... in It can rapidly increase the temperature from 10°C to 48°C within 150 seconds, maintaining an instantaneous heating power between 2500W and 2800W. Compared to traditional heat pump systems that rely solely on compressor temperature rise, the preheating time is reduced by more than 75%.

[0056] As the drying process enters a steady-state drying mode, the control system monitors the feedback signal from the drum inlet air temperature sensor 23 in real time. When T in After stabilizing within the preset process temperature range, such as 55℃-60℃, the central processing unit 19 initiates the PID control program to adjust the opening of the three-way proportional control valve 9. During this stage, the flow rate allocated to the third refrigerant line 12 gradually increases, and the condenser 3 begins to bear the main heating load. At this time, the opening of the electronic expansion valve is finely adjusted according to the superheat at the outlet of the evaporator 5, with the superheat setpoint maintained at approximately 5K to ensure the system COP is at its maximum. To further reduce air resistance, the bypass damper mechanism 24 located on the air passage side of the phase change heat storage module 2 opens under the drive of a stepper motor, allowing some circulating air to directly bypass the phase change module and enter the drum, thereby reducing the overall system pressure loss by 45Pa and effectively reducing the power consumption of the circulating fan 8.

[0057] In the latter third of the drying process, the system automatically switches to heat storage and recovery mode. As the moisture content of the fabric decreases, the latent heat exchange load on evaporator 5 reduces, causing the suction and discharge pressures of compressor 1 to rise simultaneously, and the discharge temperature T... disThe temperature often exceeds 80℃. In this mode, the control system activates the three-way proportional regulating valve 9 again, guiding approximately 30% of the high-temperature gaseous refrigerant flow back to the phase change heat storage module 2. At this time, the phase change material 13 absorbs the sensible heat and part of the latent heat of condensation of the refrigerant, and the temperature rises from the solid phase to the liquid phase, completing the secondary energy storage. This process not only prepares the heat for the next start-up but also plays a certain role in auxiliary condensation, causing the condensing pressure to drop by approximately 0.2 MPa, thus preventing the compressor from being frequency-limited or shutting down due to high-pressure overheating.

[0058] To verify the practical engineering effect of a heat pump drying system with phase change thermal storage assisted start-up function, detailed experimental data were collected in this embodiment. The experimental environment was set in a constant temperature and humidity laboratory, with a constant ambient temperature of 7.5℃ and a relative humidity of 60%. The load material was standard cotton fabric with an initial moisture content of 65% and a target final moisture content of 3%. The following quantitative comparisons are made using Example 1 (applying the technology of this invention), Comparative Example 1 (standard heat pump system), and Comparative Example 2 (heat pump system with PTC electric auxiliary heating).

[0059] Table 1: Comparison of Operating Performance Data of Heat Pump Clothes Drying Systems ; A thorough analysis of the data in Table 1 reveals that Example 1 demonstrates significant superiority in the low-temperature start-up phase. Under the same low-temperature environment, the present invention significantly reduces the time required to raise the inlet air temperature to 40°C from 1020 seconds in Comparative Example 1 to 165 seconds. Even compared to Comparative Example 2, which is equipped with a 1500W PTC heater, the present invention achieves a preheating speed that is nearly 40% faster without consuming additional electrical energy. In terms of total power consumption, Example 1 consumes only 0.82 kWh, saving approximately 43% of electrical energy compared to Comparative Example 2. This fully demonstrates the energy efficiency advantages of using phase change materials for cross-temporal thermal energy scheduling. Furthermore, the compressor in Example 1 maintains a maximum discharge temperature of 78.5°C, effectively extending the life of the lubricating oil and the mechanical life of the compressor, and avoiding the long-term high-pressure operation risk caused by the mismatch in condensation load in Comparative Example 1.

[0060] In terms of structural dynamics design, this embodiment also features meticulous attention to detail. Considering the vibrations generated by the compressor 1 during variable frequency operation, a high-performance vibration damping joint 25 is installed at the physical interface between the first refrigerant line 10 and the phase change thermal storage heat exchange module 2. This vibration damping joint 25 employs a corrugated stainless steel hose covered with an EPDM braided layer, achieving a fatigue life exceeding 200,000 cycles at a working pressure of 2.0 MPa. Simultaneously, to ensure absolute pressure safety within the phase change thermal storage heat exchange module 2, a mechanical pressure relief valve 26 is integrated at its refrigerant inlet. The opening pressure of this relief valve is set at 4.25 MPa. If the electronic expansion valve malfunctions, causing high-pressure runaway in the system, the relief valve will open instantaneously, directing high-pressure gas into the low-pressure return gas line, ensuring that the casing does not suffer structural damage.

[0061] In the air circulation loop, before the air enters the phase change thermal storage heat exchange module 2, a set of airflow rectification grilles 27 is installed. This grille consists of 12 guide vanes, each 0.8 mm thick and tilted at a 15-degree angle. Through computational fluid dynamics (CFD) simulation optimization, this structure can reconstruct the turbulent airflow after passing through the condenser 3 into a quasi-laminar state, thereby increasing the local heat transfer coefficient h of the air as it passes through the aluminum heat sink fins. In conjunction with this, filter 7 adopts a combination structure of 180-mesh stainless steel fine mesh and activated carbon fiber layer, which not only effectively prevents the heat exchange efficiency from being reduced due to the clogging of the tiny gaps in the phase change module by lint, but also plays a certain role in odor adsorption.

[0062] The control system is implemented at the software level based on an embedded real-time operating system. The self-learning fuzzy control algorithm integrated within the central processing unit 19 can dynamically correct the adjustment curve of the three-way proportional control valve 9 based on historical drying records. For example, when the user performs two consecutive drying tasks, the system automatically identifies the thermal state of the phase change material 13, thereby shortening the duration of the heat release mode and entering steady-state drying earlier to prevent the air temperature inside the drum from rising too quickly. The parameters Kp, Ki, and Kd of the PID control algorithm adopt a segmented calibration strategy: during the initial temperature rise phase, a larger Kp (1.5-2.2) is used to obtain the fastest response; after entering the target temperature range of ±1℃, Kp is reduced to 0.8, while Ki (0.05-0.12) is increased to eliminate system steady-state error.

[0063] The compressor 1 is a variable frequency rotary compressor with an operating frequency range of 15Hz to 120Hz. During the heat release start-up phase, the control system forces the compressor to operate in the high-frequency range of 85Hz to cooperate with the phase change module to quickly establish a heat exchange potential difference. Once the inlet air temperature stabilizes, the frequency is lowered to the energy-efficient range of 45Hz. This electromechanical-hydraulic coupled control logic enables the entire heat pump system to maintain high-efficiency operation under different loads (1kg to 10kg).

[0064] After the phase change thermal storage heat exchange module 2 is assembled with the inner shell 16 and the finned tube heat exchanger 14, it must undergo a 48-hour helium leak test to ensure that the annual leakage rate is less than 0.1 grams. The filling process of the phase change material 13 is completed in a vacuum environment, with a filling rate of 92% of the shell volume. The reserved 8% space is used to compensate for the volume expansion of the material when it changes from a solid phase to a liquid phase, thereby eliminating the potential for fatigue cracks in the inner shell 16. The inner wall of the inner shell 16 is additionally welded with radially distributed thermally conductive fins 15. The fins are made of high thermal conductivity copper and are directly brazed to the surface of the copper tubes of the finned tube heat exchanger 14, which greatly enhances the thermal penetration depth inside the phase change material.

[0065] The circulating fan 8 employs sensorless control technology based on space vector PWM (SVPWM). During low-temperature start-up, due to the higher air density, the fan load torque increases. The control system automatically increases the output torque through current closed-loop compensation technology to ensure stable airflow at low speeds. In heat storage recovery mode, the fan speed increases to 1.1 times the rated speed (approximately 3100 rpm) to increase air circulation on the condenser side, helping to lower the system condensing temperature and further improve the overall energy efficiency ratio.

[0066] The three-way proportional regulating valve 9 is driven by a stepper motor with 500 discrete positions. Each pulse corresponds to a 0.36-degree rotation of the valve core, which enables the refrigerant mass flow rate control accuracy through the phase change heat storage module 2 to reach ±0.5 kg / h. Under special operating conditions with extremely low ambient temperatures (e.g., -5℃ to 0℃), the system will trigger a forced pre-heat storage logic. That is, in the last 5 minutes before the end of this drying cycle, even if the compressor exhaust temperature has begun to drop, the three-way valve will remain in the heat storage position to maximize the extraction of residual heat from the system and ensure that the heat storage percentage of the PCM module reaches 100% when it starts up next time.

[0067] The drum inlet air temperature sensor 23 is installed at the leeward end of the last bend before the air circulation loop enters the drum. This arrangement can effectively avoid the interference of the dynamic pressure generated by the air jet on the temperature sensor, so that the collected temperature signal can better reflect the true thermal state of the air entering the drying chamber, providing a more accurate input for the PID algorithm and ensuring that the temperature control accuracy is maintained at an extremely high level of ±0.5℃.

[0068] The aforementioned startup system and startup control method successfully overcome the performance bottleneck of heat pump dryers under low-temperature startup conditions. It not only achieves efficient heat recovery and on-demand distribution but also optimizes system reliability, safety protection, and user experience in multiple dimensions. Experimental data demonstrates that this solution achieves the expected design targets in shortening drying time, reducing operating energy consumption, and protecting fabric fibers, laying a solid engineering foundation for the large-scale application of heat pump dryer technology in cold climates. In subsequent large-scale production, the phase change thermal storage heat exchange module 2 can be modularly pre-assembled, and its universal pipe interface design allows it to be compatible with various models of heat pump dryer platforms. The control system firmware supports remote OTA upgrades and can continuously optimize the heating strategy based on climate data packages from different regions around the world. This innovative hardware and software integration model enables the system described in this invention to exhibit excellent performance in complex and ever-changing operating environments.

[0069] The above description is merely a preferred embodiment of the present invention and is not intended to limit the scope of the present invention in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments without departing from the technical solution of the present invention and based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A phase change heat storage auxiliary start-up system based on a heat pump dryer, characterized in that, include: The refrigerant circulation loop is connected in sequence with a compressor (1), a phase change heat storage module (2), a condenser (3), a throttling element (4), and an evaporator (5) in the direction of refrigerant flow. The exhaust port of the compressor (1) is connected to the inlet end of a three-way proportional control valve (9) through a first refrigerant pipeline (10). The first outlet end of the three-way proportional control valve (9) is connected to the refrigerant inlet of the phase change heat storage module (2) through a second refrigerant pipeline (11), and its second outlet end is connected to the refrigerant inlet of the condenser (3) through a third refrigerant pipeline (12). An air circulation loop is connected in sequence according to the air flow direction, including a roller (6), a filter (7), the evaporator (5), the condenser (3), the phase change heat storage and heat exchange module (2), and a circulating fan (8). The control system is used to control the refrigerant flow distribution ratio between the phase change heat storage heat exchange module (2) and the condenser (3) in real time by adjusting the three-way proportional regulating valve (9) according to the system operation stage.

2. The phase change heat storage auxiliary start-up system based on a heat pump dryer according to claim 1, characterized in that, The phase change heat storage and heat exchange module (2) includes an inner shell (16) and an outer shell (17). The space between the inner shell (16) and the outer shell (17) is filled with polyurethane foam insulation material (18). The inner shell (16) is filled with phase change material (13) that has been vacuum degassed. A finned tube heat exchanger (14) is embedded inside the phase change material (13).

3. The phase change heat storage auxiliary start-up system for a heat pump dryer according to claim 2, characterized in that, Multiple radially distributed copper thermally conductive fins (15) extending into the phase change material (13) are provided on the inner wall surface of the inner shell (16); the phase change material (13) is a paraffin-based composite material with a phase change critical temperature of 55℃-65℃ and a latent heat value of not less than 200kJ / kg, and is uniformly doped with expanded graphite at a mass fraction of 3%-5%; the polyurethane foam insulation material (18) has a thickness of 20mm-30mm, a closed-cell rate of more than 95%, and a thermal conductivity of less than 200kJ / kg. .

4. The phase change heat storage auxiliary start-up system for a heat pump dryer according to claim 1, characterized in that, The three-way proportional control valve (9) is driven by a stepper motor to rotate the valve core, which has a V-shaped notch to achieve quasi-linear control of flow rate and rotation angle.

5. The phase change heat storage auxiliary start-up system for a heat pump dryer according to claim 4, characterized in that, The control system includes a central processing unit (19) and connected to it an ambient temperature sensor (20), a phase change module temperature sensor (21), a compressor exhaust temperature sensor (22), a drum air inlet temperature sensor (23), and a condenser inlet temperature sensor (28). The central processing unit (19) receives analog signals from each sensor and converts them into digital signals. The ambient temperature sensor (20) is located at the air inlet of the dryer casing and is used to monitor the ambient temperature T in real time. env The phase change module temperature sensor (21) is embedded at the geometric center of the phase change thermal storage heat exchange module (2) to monitor the thermal energy storage state temperature T of the phase change material. pcm The compressor exhaust temperature sensor (22) is installed at the exhaust port of the compressor (1) to monitor the exhaust temperature T of the compressor (1) in real time. dis The drum inlet air temperature sensor (23) is located at the leeward end of the last bend before the air circulation loop enters the drum (6), and is used to provide feedback on the final air temperature T entering the drum. in The condenser inlet temperature sensor (28) is installed at the inlet of the condenser (1) to monitor the gas temperature entering the condenser (1) in real time.

6. The phase change thermal storage auxiliary start-up system for a heat pump dryer according to any one of claims 1-5, characterized in that, Also includes: Bypass damper mechanism (24) is installed on the air side channel of the phase change heat storage heat exchange module (2). A high-strength flexible shock-absorbing joint (25) is installed at the connection between the exhaust pipe of the compressor (1) and the phase change heat storage heat exchange module (2). A mechanical pressure relief valve (26) is installed at the refrigerant inlet end of the phase change heat storage heat exchange module (2). An airflow straightening grille (27) is installed between the outlet of the condenser (3) in the air circulation loop and the inlet of the phase change heat storage heat exchange module (2).

7. A startup control method based on the above-described startup system, characterized in that, It includes three start-up control modes: heat release start-up mode, steady-state drying mode, and heat storage and recovery mode. The control system determines that the system is in a low temperature cold start condition and adopts a heat release start mode. In the heat release start mode, the central processing unit (19) controls the first outlet end of the three-way proportional regulating valve (9) to be fully opened and the second outlet end to be fully closed, so that all the high temperature gaseous refrigerant discharged by the compressor (1) enters the phase change heat storage heat exchange module (2). When the air inlet temperature of the drum (6) reaches a certain stable value, a steady-state drying mode is adopted. In the steady-state drying mode, the central processing unit (19) adjusts the opening of the three-way proportional regulating valve (9), reduces the refrigerant flow to the phase change heat storage heat exchange module (2), and correspondingly increases the refrigerant flow to the condenser (3). In the later stages of the drying task, a heat storage and recovery mode is adopted. In the heat storage and recovery mode, the central processor (19) adjusts the three-way proportional regulating valve (9) to allow some high-temperature gaseous refrigerant to enter the phase change heat storage and heat exchange module (2). The phase change material absorbs the excess heat of the refrigerant and undergoes a phase change from solid to liquid, storing this part of the energy in the form of latent heat.

8. The start-up control method according to claim 7, characterized in that, By the ambient temperature T env The thermal energy storage state temperature T of phase change materials pcm The air temperature T entering the drum (6) in The exhaust temperature T of the compressor (1) dis To determine the startup control mode, including: When the ambient temperature T env Below 15℃, and thermal energy storage state temperature T pcm When the temperature is above 45℃, the heat release start-up mode is used; When the air inlet temperature of the roller (6) reaches the preset threshold T set A steady-state drying mode is adopted; When the exhaust temperature T of the compressor (1) dis The temperature is raised to 70℃-85℃, and a heat storage and recovery mode is adopted.

9. The start-up control method according to claim 8, characterized in that, In the heat release start-up mode, the circulating fan (8) runs at a low speed of 800 rpm to 1000 rpm to increase the residence time of air in the phase change heat storage heat exchange module (2), and the control system reduces the opening of the electronic expansion valve (4) as a throttling element to accelerate the establishment of system exhaust pressure and help the system reach thermodynamic equilibrium state more quickly. In steady-state drying mode, the central processing unit (19) linearly adjusts the opening of the three-way proportional regulating valve (9) through a PID algorithm, ultimately switching the three-way proportional regulating valve (9) to a fully open state at the second outlet end. The refrigerant circulation loop returns to the standard heat pump operation mode, and with T in As the speed increases, the speed of the circulating fan (8) increases linearly to the rated speed; In the heat storage and recovery mode: the control system adjusts the three-way proportional regulating valve (9) to allow at least 30% of the high-temperature gaseous refrigerant to enter the phase change heat storage heat exchange module (2). The phase change material absorbs the excess heat of the refrigerant and undergoes a phase change from solid to liquid, storing this part of the energy in the form of latent heat. The control system adjusts the three-way proportional control valve (9) based on the following mathematical model: valve opening D=f(ΔT,dP / dt), where ΔT is the difference between the target inlet air temperature and the actual inlet air temperature, and dP / dt is the rate of change of the system condensing pressure.

10. The start-up control method according to claim 9, characterized in that, The central processing unit (19) records historical operating data through non-volatile memory and automatically optimizes the switching time and heat storage depth of the three-way proportional regulating valve (9) according to ambient temperature and clothing load.

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