A cascade rapid refrigeration system for mushroom cryogenic pulverization

Abstract

The present application relates to the technical field of refrigeration equipment, and discloses a cascade rapid refrigeration system for super-low-temperature pulverization of mushroom bacteria, comprising: a cascade refrigeration circulating device, a low-temperature stage circuit provided with a suction buffer container; a pressure potential bypass assembly for establishing a transient liquid supply channel from a high-pressure liquid phase zone to an evaporator; a synchronous negative pressure clamping assembly comprising a low-impedance pipeline connected with the outlet of the evaporator and the suction buffer container and a clamping valve; and a control device for monitoring the load current change rate to synchronously open the pulse valve and the clamping valve. The present application utilizes the low-pressure potential of the suction side to implement differential pressure suction on the evaporator through the low-impedance channel at the pulse injection moment, rapidly dredges the transient flash gas phase working medium, prevents the back pressure from sharply increasing due to the air flow resistance, and ensures the maximum heat transfer temperature difference during the heat shock.

Description

Technical Field

[0001] This invention relates to a cascade rapid refrigeration system for ultra-low temperature pulverization of fungi, belonging to the field of refrigeration equipment technology. Background Technology

[0002] Currently, in the ultra-fine pulverization process of fungal Chinese medicinal materials such as Ganoderma lucidum and Cordyceps sinensis, in order to prevent the degradation of heat-sensitive active ingredients such as polysaccharides and triterpenes due to mechanical friction and heat generation, the pulverization chamber needs to be maintained in a cryogenic temperature environment. Existing industrial-grade cryogenic pulverization equipment adopts a cascade refrigeration system, which uses a multi-stage compression refrigeration cycle to absorb mechanical heat through an evaporator surrounding the outer wall of the pulverization chamber. This type of system is designed based on steady-state heat load and relies on temperature sensors installed in the chamber or pipeline to collect feedback signals. The target temperature is maintained by adjusting the opening of the electronic expansion valve. When processing high-fiber and high-toughness fungal materials, the pulverization operation exhibits transient pulse characteristics. With the violent impact of the material and the blades, mechanical energy is converted into high-density point source heat in milliseconds. Traditional temperature feedback-based control logic is limited by the thermal inertia of the sensor and the conduction time of cold energy within the metal wall, making it difficult to respond in time when thermal shock occurs, resulting in local overheating before the system has acted.

[0003] To address the aforementioned thermal response hysteresis issue, the industry has attempted to introduce a feedforward control strategy based on motor current load, which opens the valve to inject liquid refrigerant when a sudden load change is detected. However, this feedforward strategy still faces physical bottlenecks at the thermodynamic implementation level. For example, the utility model patent with authorization announcement number CN222849507U discloses a cascade refrigeration system. This system focuses on solving the problem of poor oil return in traditional oil-filled compressors in carbon dioxide systems, using an oil-free compressor to simplify the system and improve reliability. However, the prior art is essentially still a typical steady-state refrigeration cycle architecture, mainly focusing on the selection and optimization of refrigerant and compressor, lacking consideration for ultrafine grinding processes. The unique millisecond-level transient pulse heat load dynamic response mechanism in the process does not address how to manage the explosive gaseous working fluid generated by the instantaneous flash evaporation of refrigerant when high-pressure refrigerant is pulsed into the evaporator. Naturally, it cannot solve the problem of instantaneous back pressure surge and heat transfer temperature difference decay inside the evaporator caused by this. Simply pursuing high flow rate injection results in liquid refrigerant entering the evaporator in an insufficiently subcooled state, carrying a large amount of ineffective flash gas, reducing the heat absorption efficiency per unit mass of working fluid. Increasing compressor power or expanding the diameter of the return gas pipeline may alleviate the gas resistance problem, but it increases equipment cost and energy consumption. Moreover, it is easy to cause oil return difficulties or compressor liquid slugging reliability risks during low-load steady-state operation.

[0004] Therefore, the technical problem to be solved by this invention is how to construct a dynamic refrigeration mechanism that avoids fixed flow resistance limitations and maintains constant evaporation pressure and temperature under millisecond-level thermal shock without increasing hardware costs and energy consumption. Summary of the Invention

[0005] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: A cascade rapid cooling system for cryogenic pulverization of fungi, comprising:

[0006] The cascade refrigeration cycle device includes a low-temperature stage refrigeration circuit, which has a high-pressure liquid phase zone, a low-pressure gas phase zone, and an evaporator for heat exchange with the grinding chamber of the pulverizer. The low-pressure gas phase zone is equipped with a suction buffer container.

[0007] The pressure potential energy bypass component includes a high-pressure liquid reservoir and a pulse control valve. The inlet of the high-pressure liquid reservoir is connected to the high-pressure liquid phase zone. The pulse control valve is located between the high-pressure liquid reservoir and the inlet of the evaporator to establish a transient pressure difference supply channel from the high-pressure liquid phase zone to the evaporator.

[0008] The synchronous negative pressure clamping assembly includes a low-impedance bypass line connected in parallel between the gas phase outlet of the evaporator and the suction buffer container, and a clamping control valve installed on the low-impedance bypass line.

[0009] The control device is electrically connected to the drive motor, pulse control valve and clamping control valve of the crusher, respectively, and is used to collect the load current change rate of the drive motor.

[0010] When the load current change rate exceeds the preset threshold, the control device outputs an opening signal to the pulse control valve, using the pressure difference between the high-pressure liquid phase zone and the evaporator to drive the refrigerant in the high-pressure liquid receiver into the evaporator for flash evaporation, and simultaneously outputs an opening signal to the clamp control valve, connecting the evaporator and the suction buffer container, and establishing a transient low flow resistance discharge channel from the evaporator directly to the suction buffer container.

[0011] Preferably, the high-pressure liquid receiver has a heat exchange component inside; the return gas pipeline of the low-temperature stage refrigeration circuit passes through the heat exchange component, and the low-temperature gaseous refrigerant in the return gas pipeline is used to sensibly cool the high-pressure liquid refrigerant stored in the high-pressure liquid receiver.

[0012] Preferably, the control device is configured to control the opening duration of the clamping control valve to be greater than or equal to the opening duration of the pulse control valve.

[0013] Preferably, the low-impedance bypass line is directly connected to the expansion cavity of the suction buffer container, and the inner diameter of the low-impedance bypass line is 1.5 to 2.5 times the inner diameter of the return line of the cryogenic refrigeration circuit.

[0014] Preferably, the control device has a preset nonlinear timing matching logic, which limits the opening duration of the pulse control valve. With load current change rate The following relationship exists between them: ,in, The load current change rate is collected in real time. For the preset threshold, The preset response coefficient, The preset nonlinear gain index, This is the preset basic operating time for the pulse control valve.

[0015] Preferably, the low-temperature stage refrigeration circuit further includes a throttling component, which is connected in parallel with the pressure potential bypass component between the high-pressure liquid phase zone and the evaporator, for providing a basic refrigeration flow to the evaporator when the pulse control valve is closed.

[0016] Preferably, the control device includes a differential signal extraction circuit, which is used to monitor the phase current of the drive motor in real time, filter out steady-state fluctuation signals with a frequency lower than 10Hz, and extract the transient high-frequency component corresponding to mechanical impact as the basis for calculating the load current change rate.

[0017] Preferably, the cascade refrigeration cycle device further includes a high-temperature stage refrigeration circuit and an intermediate condenser-evaporator connecting the high-temperature stage refrigeration circuit and the low-temperature stage refrigeration circuit; the inlet of the high-pressure liquid receiver is directly connected to the low-temperature stage condenser outlet of the intermediate condenser-evaporator.

[0018] Preferably, both the pulse control valve and the clamp control valve are direct-acting cryogenic solenoid valves. The response time of the direct-acting cryogenic solenoid valve is less than or equal to 20 milliseconds, and the flow coefficient of the clamp control valve is greater than that of the pulse control valve.

[0019] Preferably, the evaporator is a jacketed heat exchanger or a coiled heat exchanger that surrounds the outer wall of the pulverizing chamber, and the refrigerant inlet of the evaporator is located in the spatial position corresponding to the concentrated mechanical impact zone inside the pulverizing chamber.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. A synchronous negative pressure clamping path is constructed in the low-temperature stage loop of the cascade refrigeration cycle. The low-pressure potential energy on the suction side is used to solve the back pressure blockage problem caused by the transient phase change of the working fluid in the confined space. By setting a low-impedance bypass pipeline and clamping control valve in parallel between the vapor phase outlet of the evaporator and the suction buffer container of the compressor, the low-impedance channel is opened at the synchronous moment of high-pressure refrigerant pulse injection. By using the transient switching of the fluid loop topology, the low-pressure volume pre-stored in the suction buffer container is used to directly implement pressure difference suction at the evaporator outlet. This facilitates the high-density vapor phase working fluid generated by the instantaneous flash evaporation of the refrigerant, prevents the pressure inside the evaporator from surging due to the backflow resistance, and forcibly anchors the refrigerant phase change process in the designed low-pressure and low-temperature region. This ensures that the system maintains the maximum heat transfer temperature difference during the peak of high-energy mechanical shock heat load, and avoids the reduction of cooling capacity caused by the increase of evaporation pressure in conventional refrigeration systems.

[0022] 2. A heat exchange component is integrated inside the high-pressure liquid receiver to achieve energy self-balancing and improve the quality of the working fluid within the refrigeration cycle. This guides the low-pressure return gas pipeline of the low-temperature stage refrigeration circuit through the cavity of the high-pressure liquid refrigerant receiver. The residual low-temperature sensible heat in the return gas flow is used to deeply subcool the high-pressure liquid refrigerant. Based on the thermodynamic process of counter-flow or cross-flow heat transfer, the enthalpy of the high-pressure liquid is reduced without consuming additional power, reducing the proportion of flash gas during the subsequent throttling process of the refrigerant, increasing the effective heat absorption density of the working fluid per unit mass after entering the evaporator, and moderately increasing the compressor suction temperature. The physical structure eliminates the risk of compressor liquid slugging caused by high-frequency, high-flow injection, ensuring the reliability of core components under varying operating conditions.

[0023] 3. Establish a feedforward pressure potential energy release logic based on mechanical work characteristics to eliminate the lag in traditional temperature feedback cooling and heating response. Utilize the inherent pressure difference between the high-pressure condensing side and the low-pressure evaporating side of the refrigeration cycle as a power source. Monitor the load change rate of the pulverizing motor to trigger the high-pressure subcooled liquid bypass injection. Utilize the millisecond-level transmission speed of electrical signals and the rapid transmission characteristics of pressure waves to ensure that the refrigerant phase change endothermic heat explosion and the physical process of mechanical energy conversion into heat energy highly coincide in the time domain. The energy counterbalancing mechanism ensures that the heat in the pulverizing chamber is absorbed by the refrigerant before it diffuses to the temperature sensor on the chamber wall, fundamentally suppressing the instantaneous temperature rise fluctuations during pulverization, protecting the biological activity of heat-sensitive materials, and solving the supply and demand contradiction of transient pulse heat load that traditional steady-state refrigeration cycles cannot match. Attached Figure Description

[0024] Figure 1 This is a schematic diagram illustrating the overall structure and control principle of the cascade rapid cooling system of the present invention;

[0025] Figure 2 This is a comparison curve of the temperature response of different cooling modes under transient thermal shock conditions according to the present invention;

[0026] Figure 3 This is a flowchart of the feedforward pulse and clamping synchronization control based on the load change rate of the present invention. Detailed Implementation

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] This invention provides a cascade rapid refrigeration system for cryogenic pulverization of fungi, comprising a high-temperature stage refrigeration circuit, a low-temperature stage refrigeration circuit, and an intermediate condenser-evaporator connecting the two. The low-temperature stage refrigeration circuit uses R23 as the refrigerant, and the high-temperature stage refrigeration circuit uses R404A as the refrigerant. The low-temperature stage refrigeration circuit includes a low-temperature compressor, a suction buffer container, the evaporator side of the intermediate condenser-evaporator, and an evaporator surrounding the pulverizing chamber of the pulverizer. A pressure potential energy bypass assembly is connected in parallel between the high-pressure liquid phase region of the low-temperature stage refrigeration circuit and the inlet of the evaporator. This assembly consists of a high-pressure liquid receiver and a pulse control valve connected in series. The inlet of the high-pressure liquid receiver is directly connected to the low-temperature condenser outlet of the intermediate condenser-evaporator, used to intercept and accumulate the refrigerant in a high-pressure liquid state during steady-state operation of the system, establishing a pressure relative to the low-pressure environment inside the evaporator. The potential energy gradient and pulse control valve are selected as direct-acting cryogenic solenoid valves with a response time of less than or equal to 20 milliseconds. They are used to establish a transient differential pressure supply channel from the high-pressure liquid phase zone directly to the evaporator when a control signal is received. In addition, a set of synchronous negative pressure clamping components is installed in parallel between the gas phase outlet of the evaporator and the suction buffer container on the suction side of the cryogenic stage compressor. This includes a low-resistance bypass pipeline with an inner diameter of 1.5 to 2.5 times that of the conventional return gas pipeline of the cryogenic stage refrigeration circuit, and a clamping control valve installed on this pipeline. The clamping control valve is a normally closed solenoid valve with a large flow coefficient. It is used to eliminate the flow resistance limitation of the return gas pipeline when it is opened, and directly short-circuit the evaporator outlet to the low-pressure volume space of the suction buffer container. The control device is electrically connected to the drive motor of the pulverizer, the pulse control valve and the clamping control valve respectively, for performing load feature extraction and actuator timing control.

[0029] In the pulverization of high-fiber, high-toughness fungal materials, the process of converting mechanical energy into heat energy exhibits millisecond-level transient pulse characteristics. This can cause localized instantaneous temperature rises in the pulverization chamber, potentially damaging heat-sensitive components. To address this issue, the control device acquires the phase current signal of the drive motor in real time, uses a built-in differential signal extraction circuit to filter out steady-state current fluctuations with frequencies below 10Hz, and extracts the transient high-frequency components corresponding to mechanical impacts to calculate the load current change rate. When the calculated load current change rate Exceeding the preset load change rate threshold At this time, the control device determines that a high-energy heat release is about to occur in the pulverizing chamber and outputs an opening signal to drive the pulse control valve to operate. At this point, the system utilizes the pressure difference between the approximately 1.8 MPa high pressure in the high-pressure receiver and the approximately 0.1 MPa low pressure in the evaporator to drive the liquid refrigerant to be instantaneously injected into the evaporator without mechanical pump assistance. The latent heat absorption effect of the refrigerant liquid-phase flash evaporation completes the energy offset before the heat diffuses to the chamber wall. The load change rate threshold is [not specified in the original text]. The calibration procedure involves continuously collecting current data for 10 minutes and calculating the rate of change while the crusher is running under no-load conditions. The maximum rate of change during this time period is taken as the background noise baseline, which is 1.2 times the maximum value. Under rated load, a trial run is conducted, and the peak current rate of change at the moment of material crushing is recorded. The value between the background noise baseline and the peak value under rated load is selected as the baseline. This value is typically set to 30% to 40% of the rated load peak. To address the potential for vapor phase explosion and back pressure surge caused by a large amount of liquid refrigerant being instantaneously injected into the confined evaporator space, the control device executes synchronous negative pressure clamping logic. The control device outputs a pulse control valve opening signal at the synchronized moment... The synchronous output signal opens the clamping control valve. The low-pressure volume pre-stored in the suction buffer container is drawn into the evaporator outlet through a low-impedance bypass line, allowing the high-density gaseous working fluid generated by flash evaporation to be discharged at a high flow rate. This clamps the internal pressure of the evaporator within the designed low-pressure range, maintaining the minimum saturation temperature of the refrigerant during the phase change process. To remove residual gas film and prevent pressure rebound, the control device controls the opening duration of the clamping control valve. Greater than the opening duration of the pulse control valve Both follow The temporal relationship, in which The relaxation time is between 200 milliseconds and 500 milliseconds.

[0030] To address the issue of insufficient refrigerant subcooling in the high-pressure receiver under continuous pulse injection conditions, a heat exchange component is integrated within the high-pressure receiver. The low-pressure return gas line of the cryogenic stage refrigeration circuit passes through this heat exchange component before entering the compressor. The low-temperature sensible heat (approximately -70°C) in the return gas flow exchanges heat with the high-pressure liquid refrigerant (approximately -40°C) stored in the high-pressure receiver in a counter-current or cross-flow manner. This process lowers the temperature of the high-pressure liquid to below -60°C, reducing the specific enthalpy of the liquid and increasing the effective heat absorption per unit mass of refrigerant entering the evaporator. Simultaneously, the increased superheat after heat absorption by the return gas prevents the risk of compressor liquid slugging due to high-frequency injection. The control device incorporates pre-set nonlinear timing matching logic to dynamically adjust the refrigerant injection quantity and the opening duration of the pulse control valve based on the impact intensity. Compared with the real-time acquired load current change rate The relationship between them follows a functional formula ,in, This is the preset basic action time for the pulse control valve. The value range is the minimum fully open response time of the solenoid valve, and it is usually set to 20 milliseconds to 30 milliseconds. The preset nonlinear gain index is used to adjust the system's sensitivity to strong impacts, especially for hard materials like Ganoderma lucidum. Set to 1.5 to 2.0; The response coefficient is calibrated by measuring the maximum injection time required to maintain a temperature rise of no more than 2°C under the system's maximum design heat load condition. and the corresponding maximum load change rate These values ​​are then substituted into the formula for reverse calculation. The low-temperature refrigeration circuit also includes a throttling component, which uses a set of capillary tubes or electronic expansion valves with fixed flow resistance. It is connected in parallel with the pressure potential energy bypass component between the high-pressure liquid phase zone and the evaporator. During steady-state operation when the pulse control valve is closed, the refrigerant enters the evaporator only through the throttling component, providing the basic refrigeration flow required to meet the frictional heat generation and ambient heat leakage during the no-load operation of the pulverizer, so as to maintain the basic low-temperature environment of the pulverizing chamber.

[0031] Example 1: This example simulates a high-intensity cryogenic pulverization scenario for dried Ganoderma lucidum fruiting bodies. Ganoderma lucidum fruiting bodies have a highly lignified fibrous structure and a hard chitinous cell wall. In traditional pulverization processes, the high temperatures generated by prolonged mechanical shearing easily degrade Ganoderma lucidum polysaccharides and triterpenoid active ingredients. Although conventional cascade refrigeration systems can maintain a low static ambient temperature, they cannot provide timely and effective cooling compensation when dealing with the millisecond-level point source thermal shock released during material crushing. This is due to the lag in temperature sensor response and the flow resistance effect caused by refrigerant vaporization, resulting in local instantaneous temperature rises exceeding the safety threshold of active ingredients. This example aims to verify the technical effectiveness of the proposed cascade rapid refrigeration system in solving the aforementioned thermodynamic lag and flow resistance problems. During system initialization, the cascade refrigeration unit is started, and the cryogenic compressor in the cryogenic stage refrigeration circuit begins operation. After compression, R23 refrigerant enters the intermediate condenser evaporator, where it is condensed into a high-pressure subcooled liquid at -40°C and 1.8MPa. At this time, the pulse control valve is closed, and the refrigerant enters the evaporator surrounding the grinding chamber at a small flow rate through a parallel throttling assembly, maintaining the no-load reference temperature of the grinding chamber at -80°C. Simultaneously, a portion of the high-pressure liquid refrigerant is trapped and stored in the high-pressure receiver, establishing a potential energy reserve relative to the low-pressure environment inside the evaporator. The grinding operation begins, and the Ganoderma lucidum material is fed into the grinding zone. When the hard material violently impacts the high-speed rotating blades, the load on the drive motor increases instantaneously. The current detection device installed at the motor input captures the phase current signal in real time and filters out low-frequency fluctuations through a differential signal extraction circuit, extracting the high-frequency characteristic component corresponding to the mechanical impact. The control device calculates the load current change rate. When this value exceeds the preset load change rate threshold When the load is set to 35% of the rated peak load, the system is determined to be facing a high-energy thermal shock. The control device immediately outputs an opening signal, driving the pulse control valve with a response time of 20 milliseconds to open. Under the pressure difference of 1.7 MPa, the R23 liquid refrigerant accumulated in the high-pressure receiver instantly bypasses the throttling component and is directly injected into the evaporator. At the same time, the control device outputs the pulse control valve opening signal. Simultaneously, the clamping control valve installed on the low-impedance bypass line is opened, and at this time, the huge low-pressure volume pre-stored in the suction buffer container is used to forcefully draw the evaporator outlet through the low-impedance channel.

[0032] At the instant the refrigerant is injected into the evaporator, the liquid working fluid undergoes violent flash evaporation, absorbing a large amount of latent heat. Due to the action of the synchronous negative pressure clamping component, the high-density gaseous working fluid generated by the flash evaporation is quickly extracted, preventing a surge in back pressure inside the evaporator. The internal pressure of the evaporator is always clamped within the design low-pressure range, ensuring that the refrigerant undergoes phase change and heat absorption at a low temperature of -80℃. This millisecond-level burst of cold energy and the heat generated by mechanical impact achieve precise energy offsetting in the time domain, ensuring that the heat generated at the crushing point is completely absorbed before it diffuses to the cavity wall. As the material crushing is completed, the motor load drops, and the load current change rate... When the pulse drops below the threshold, the control device, based on nonlinear timing matching logic, adjusts the pulse control valve opening duration. After completion, the clamp control valve closes with a delay. After 300 milliseconds (set to shut off) to completely remove residual gas film, the system smoothly switches back to steady-state mode with liquid supply maintained by the throttling component. The high-pressure liquid receiver starts accumulating liquid refrigerant again, waiting for the next impact. Throughout the process, the temperature fluctuation inside the pulverizing chamber is limited to within ±2℃ to avoid thermal damage to the active ingredients of Ganoderma lucidum.

[0033] Example 2: This example aims to verify the actual temperature control performance and system reliability of the above-mentioned cascade rapid cooling system under high-energy transient thermal shock conditions. This example constructs an experimental platform with high-precision dynamic measurement capabilities and designs a multi-dimensional comparative experimental system including the sample group of this invention, the missing clamp group, and the conventional cooling group, to empirically demonstrate the synergistic effect of the two core mechanisms: feedforward pulse jet and synchronous negative pressure clamping. The experimental platform uses an industrial-grade ultrafine pulverizer with a rated power of 15kW as the load source. The outer wall of the pulverizing chamber is surrounded by a jacketed evaporator manufactured according to the design requirements of this invention. The high-temperature stage refrigeration circuit is charged with R23 refrigerant, and the high-temperature stage refrigeration circuit is charged with R404A refrigerant. The system is equipped with a 5L high-pressure liquid receiver and a suction buffer container with integrated heat exchange components. The data acquisition system includes a high-frequency current sensor with a sampling frequency of 1kHz for monitoring motor load, a patch thermocouple with a response time of less than 100 milliseconds for measuring the temperature of the inner wall of the crushing chamber, and a high-frequency pressure sensor for recording pressure fluctuations at the evaporator inlet and outlet in real time. All sensor data are transmitted to the data logger in real time via an industrial bus to ensure the originality and traceability of the data.

[0034] To simulate non-ideal factors present in real industrial environments, random load disturbances were introduced during the experiment. The heterogeneity of the fungal raw material was simulated by incorporating biomimetic modules with uneven hardness into the standard material. The core parameters of the experiment were set as follows: load change rate threshold. According to the procedure specified in Example 1, the basic operating time of the pulse control valve is 5.0 A / s. Set to 25 milliseconds; the delayed closing time of the clamp control valve. The timeout was set to 300 milliseconds. Three control groups were set up for the experiment: Group A was the prototype group of this invention, with full pulse jet and synchronous clamping functions enabled; Group B was the clamping-deficient group, with pulse jet function enabled but synchronous negative pressure clamping component disabled; Group C was the conventional refrigeration group, using a traditional temperature feedback-based electronic expansion valve adjustment mode. The experiment consisted of three stages: no-load steady-state maintenance, single strong impact test, and continuous high-frequency impact test. In the no-load steady-state stage, all three systems were able to maintain the crushing chamber temperature within the range of -80℃±1℃. The single strong impact test stage simulated the crushing process of a single hard material, with the motor current at 20 milliseconds. The pressure rises sharply within seconds; see Table 1. After detecting the sudden change in load, Group A's pulse valve and clamping valve act synchronously, and the evaporator outlet pressure only fluctuates slightly, with the peak pressure controlled within 0.12 MPa. The corresponding saturation temperature fluctuation does not exceed 3°C, and the temperature rise of the inner wall of the pulverizing chamber is limited to 1.5°C. Although Group B has pulse injection, due to the lack of negative pressure clamping, the evaporator outlet pressure instantly soars to 0.35 MPa, causing the saturation temperature to increase sharply to -55°C, losing the deep cooling capacity, and the temperature rise of the chamber wall reaches 8.2°C. Group C, due to the lag in temperature feedback, only begins to respond 2 seconds after the impact occurs, at which time the temperature rise of the chamber wall has exceeded 12°C.

[0035] Table 1: Comparison of Key Performance Indicators for Each Group under a Single Strong Impact Test

[0036]

[0037] Data shows that Group B, which only has liquid inlet without exhaust optimization, suffers from limited cooling efficiency due to the back pressure surge caused by gas phase flow resistance, failing to realize the potential of high-pressure injection. Group A, by simultaneously establishing a low-impedance exhaust channel, successfully eliminated this thermodynamic bottleneck, achieving transient balance of inlet and outlet flow rates. During the continuous high-frequency impact test phase, simulating continuous feeding conditions, Group A, relying on the regenerative exchange component in the high-pressure liquid reservoir, continuously subcooled the high-pressure liquid using the return gas cooling capacity, maintaining a high-density refrigerant injection. The average temperature of the pulverizing chamber remained stable at -78℃. If the regenerative component was removed (supplementary experiment), as the high-pressure liquid temperature increased, the proportion of flash gas in the injection fluid increased, and the cooling capacity gradually decreased. The temperature rise during the 10th impact was 40% higher than that during the 1st impact, confirming the crucial role of the regenerative subcooling mechanism in maintaining the system's continuous operational capability. In summary, this demonstrates that the system architecture combining feedforward pulse injection and synchronous negative pressure clamping is superior in dealing with millisecond-level high-energy thermal shocks. It not only solves the lag problem of traditional temperature control but also avoids the gas resistance problem associated with transient phase changes.

[0038] Example 3: This example combines Figures 1 to 3 A description of a cascade rapid cooling system for cryogenic pulverization of fungi, as follows: Figure 1As shown, the drive motor, which acts as a load source and generates mechanical shock heat, outputs a phase current signal. This signal is connected to a differential signal extraction circuit. After filtering out steady-state fluctuations and extracting the transient high-frequency components corresponding to the mechanical shock, the signal is transmitted to the control device. The control device performs timing matching based on the calculated load change rate k, and outputs an activation signal. The pulse control valve connected between the high-pressure liquid phase zone and the evaporator utilizes the high-pressure liquid refrigerant accumulated in the high-pressure receiver and subcooled by the intermediate condenser evaporator and the regenerator assembly to establish a transient pressure differential liquid supply channel and perform flash injection into the pulverized chamber evaporator. On the other hand, it simultaneously outputs an opening signal to the clamp control valve connected between the evaporator gas phase outlet and the suction buffer container to establish a transient discharge channel from the evaporator directly to the suction buffer container. It uses the low-pressure volume in the suction buffer container to perform pressure differential suction on the high-density gas phase working fluid generated by flash evaporation in the evaporator, thereby eliminating the back pressure surge through the low-impedance bypass pipeline. At the same time, it maintains the throttling component and the pressure potential energy bypass component in parallel to provide the basic refrigeration flow rate in the non-pulse state.

[0039] like Figure 2 As shown, the horizontal axis represents time t in seconds, and the vertical axis represents temperature T in degrees Celsius. The graph contains three dynamic curves: the solid line representing the sample group of this invention shows that the temperature remained stable at around -80 degrees Celsius within the range of 0 to 2.0 seconds, with only very slight fluctuations; the dashed line representing the group without clamping shows that the temperature rapidly rose from -80 degrees Celsius to a peak of -60 degrees Celsius after the impact, and then slowly fell back; the dotted line representing the conventional refrigeration group shows that the temperature showed a lagging upward trend, reaching a peak of -68 degrees Celsius at around 1.0 seconds. With the simultaneous activation of pulse injection and negative pressure clamping mechanisms, the system can effectively suppress temperature fluctuations caused by transient thermal shock; Figure 3 As shown, the system's control logic flow begins with the operator performing system initialization and parameter self-calibration, entering the steady-state basic cooling stage. At this time, the low-temperature environment is maintained by maintaining the throttling component, while the system establishes high-pressure pressure potential energy and uses regenerative subcooling to improve the quality of the working fluid. The control device monitors the load change rate in real time and filters out steady-state fluctuation signals through a differentiating circuit. When the load change rate is determined to be greater than the preset threshold, the system exits the steady-state logic and, based on the preset nonlinear timing calculation results, synchronously triggers feedforward pulse injection and synchronous negative pressure clamping actions. The feedforward pulse injection injects cold energy into the evaporator by opening the differential pressure channel, while the synchronous negative pressure clamping eliminates the back pressure of the gas phase through low-impedance suction. The two work together to achieve energy offsetting.

[0040] Example 4: This example illustrates the engineering procedure for systematically calibrating and optimizing key parameters of the preset nonlinear timing matching logic in the control device for specific high-hardness fungal materials. In actual industrial deployment, to ensure that the system achieves accurate energy offsetting for materials with different physical properties, the response coefficient must be adjusted. Nonlinear gain index and clamp relaxation time Parameter tuning based on measured data is performed. This tuning process initiates the system's parameter self-learning mode. Under stable no-load operation of the crusher, the control device continuously collects phase current data of the drive motor at a sampling frequency of 1kHz, calculates the first derivative, generates a background noise distribution map, and sets the load change rate threshold. The threshold value is set to 1.3 times the peak value of the background noise, thus establishing a benchmark for identifying effective impact signals; the response coefficient is then applied. After thermodynamic boundary calibration, the system enters full-load simulated operating condition. A constant heat flux equivalent to 95% of the motor's rated power is applied to the evaporator side using a standard calorimeter module. The control device gradually increases the opening duration of the pulse control valve until the evaporator return gas superheat stabilizes within the range of 5°C to 8°C. At this point, the corresponding maximum opening time is recorded. and the simulated maximum load change rate Using the formula The inverse operation logic is used to initially determine the response coefficient. The baseline value ensures that the system has sufficient cooling capacity under extreme operating conditions, and addresses the nonlinear gain exponent. To determine the impact level, a gradient impact response test was performed. Representative dried Ganoderma lucidum fruiting bodies were selected as test materials and divided into three impact levels (low, medium, and high) according to hardness and volume. These materials were then sequentially fed into the grinding chamber. The control device monitored the peak temperature fluctuation of the inner wall of the grinding chamber after each impact event. Initial settings were configured... The value is 1.0. If the monitoring data shows that the temperature rise under high-energy impact exceeds the temperature rise under low-energy impact by more than 20%, it indicates that the system's nonlinear response to strong impact is insufficient, and the control device will gradually increase the value. The value is incremented by 0.1 each time until the temperature fluctuation amplitude under each energy level impact tends to be consistent, thereby obtaining the optimal nonlinear gain index that adapts to the crushing characteristics of the specific material. This value usually converges between 1.6 and 1.8.

[0041] Finally, the relaxation time of the synchronous negative pressure clamping component is measured. In the optimized configuration, after the pulse injection ends, a high-frequency pressure sensor monitors the pressure decay curve at the evaporator outlet. If a pressure rebound peak exceeding 0.05 MPa is observed at the moment the clamping control valve closes, it indicates that undischarged gaseous working fluid remains in the evaporator, and the control device immediately extends the range. The system continues until the pressure decay curve exhibits a smooth, monotonically decreasing characteristic without secondary rebound, thereby determining the shortest effective clamping time to completely clear the gas film. This prevents back pressure surges and avoids the waste of low-pressure suction resources caused by excessive suction. Through the above closed-loop calibration process, the system completes the solidification of parameters from general control logic to specific working conditions, ensuring the accuracy of cold compensation for each mechanical impact in actual production.

[0042] Example 5: This example addresses the differences in physical properties between different batches of fungal raw materials and the seasonal temperature fluctuations in the production environment. It establishes a standardized pre-deployment calibration procedure for on-site deployment. The aim is to determine the optimal control parameters for the system under specific operating conditions through a series of controlled initialization tests. No-load baseline calibration is performed by placing the pulverizer in no-load operation and continuously collecting motor current and pulverizing chamber temperature data for 30 minutes. Statistical methods are used to calculate the mean and standard deviation of the current signal, and a load change rate threshold is set. The initial setting is 3 times the standard deviation of the current change rate to ensure effective filtering of background noise caused by mechanical vibration and electromagnetic interference. At the same time, the heat leakage coefficient of the system under steady-state operation is measured as a reference for maintaining the basic flow setting of the throttling component.

[0043] The system performs dynamic load response tuning, selects a standard sample of the batch of raw materials for trial crushing, and automatically records the evaporator outlet pressure peak and return gas superheat change curve during the pulse jet process. If the pressure peak exceeds the preset safety threshold or the return gas superheat is lower than 5°C, the control device will automatically fine-tune the basic action time of the pulse control valve. and the delayed closing time of the clamp control valve This standardized procedure ensures that the system meets cooling requirements while keeping pressure fluctuations and overheating within safe limits. Before each piece of equipment is put into actual production, the control logic has been optimized for the current material characteristics and environmental conditions.

[0044] Example 6: This example discloses the digital processing procedure for load current signal analysis and safety logic determination within the control device. Addressing electromagnetic interference present in industrial environments, the control device employs a least-squares linear fitting algorithm based on a sliding time window to calculate the load current change rate. Instead of directly using the difference between adjacent sampling points, the time length of the sliding window is set. The control device performs linear regression on the current sampling sequence within this window, which lasts from 20 to 50 milliseconds, and establishes the slope of the resulting regression line as the real-time value. The algorithm effectively smooths out random noise spikes.

[0045] Before the pulse control valve opens, the control device performs a pre-safety logic check and reads the intake pressure in the intake buffer container in real time. ,like If the pressure exceeds the preset safety interlock threshold, it indicates that the low-pressure side volume is occupied or the compressor is under high load. The control device will forcibly lock the pulse injection function and maintain liquid supply by maintaining the throttling component until... To reduce pressure to a safe range and avoid the risk of compressor overload shutdown due to excessive return gas pressure, the flow resistance of the throttling component is selected using a steady-state thermal balance calibration method. With the pulverizer unloaded and in thermal balance, the capillary tube length is adjusted until the superheat of the evaporator outlet is stabilized between 5°C and 10°C. This ensures that during the intermittent period when the pulse control valve is closed, the system can maintain the low-temperature reference environment of the pulverizing chamber with minimal energy consumption.

[0046] Example 7: Load Current Change Rate The signal processing and calculation control device includes a high-precision current detection module for real-time acquisition of the phase current signal of the drive motor. The sampling frequency is set not lower than The differential signal extraction circuit uses a least-squares linear fitting algorithm based on a sliding time window to calculate the load current change rate. Set the duration of the sliding window. for Control device Current sampling sequence within the window The slope of the regression line when performing linear regression. Established as the real-time load current change rate, linear fitting calculations exhibit excellent signal-to-noise ratio for transient impact signals, smoothing random noise glitches and ensuring the reliability of the pulse trigger signal. Specific calculations are then performed. Steps: Input: Time window Internal collection Current sampling points ,in Solution: Perform least squares method to minimize the sum of squared residuals. Where b is the intercept of the regression line, and the output is the slope of the regression line obtained by solving the system of linear equations. This refers to the real-time load current change rate and the load change rate threshold. The final value was continuously collected under the stable no-load operation of the crusher. Calculate the standard deviation of the current change rate data. Take three standard deviations As a background noise benchmark for identifying impact signals, ensure The determination of this is based on statistical evidence, and it filters out background noise caused by mechanical vibration and electromagnetic interference.

[0047] Example 8: The low-resistance bypass pipeline design ensures rapid discharge of the instantaneous flash vapor working fluid, preventing a surge in instantaneous back pressure inside the evaporator. The inner diameter of the bypass pipeline... Inner diameter of the return gas pipe of the low-temperature stage refrigeration circuit multiple relationship Set at to Within this range, the calculation and engineering verification of flow resistance are based on a fluid dynamics model: pipe diameter Increase When doubled, flow resistance Approximate reduction times; selection Not less than To ensure a flow resistance reduction of more than seven times, achieving the low impedance target, the clamp control valve opening duration... It must be greater than the pulse control valve opening duration. The relationship is Relaxation time The optimized procedure involves using a high-frequency pressure sensor to monitor the evaporator outlet pressure in real time. After the pulse control valve closes, the control device continues to open the clamp control valve until the pressure... Falling back to steady-state operating pressure of Within this range, this pressure drop threshold ensures that the residual high-density gas film inside the evaporator is completely removed, preventing gas film backflow from causing a secondary pressure rebound at the moment the clamp valve closes. For mushroom materials with high hardness and high fiber content, it balances the cooling capacity compensation requirements with the compressor suction superheat, and uses a non-linear gain index. The determination follows the gradient impact response test, which involves crushing materials of low, medium, and high impact levels and adjusting... The value is up to the maximum temperature rise fluctuation of the inner wall of the crushing chamber under the impact of each energy level. tending to The minimum fluctuation range, which converges to to between.

[0048] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.

Claims

1. A cascade rapid cooling system for cryogenic pulverization of fungi, characterized in that, include: The cascade refrigeration cycle device includes a low-temperature stage refrigeration circuit. The low-temperature stage refrigeration circuit has a high-pressure liquid phase zone, a low-pressure gas phase zone, and an evaporator for heat exchange with the grinding chamber of the pulverizer. The low-pressure gas phase zone is equipped with a suction buffer container. The pressure potential energy bypass component includes a high-pressure liquid reservoir and a pulse control valve. The inlet of the high-pressure liquid reservoir is connected to the high-pressure liquid phase zone. The pulse control valve is located between the inlet of the high-pressure liquid reservoir and the inlet of the evaporator to establish a transient pressure difference supply channel from the high-pressure liquid phase zone to the evaporator. The synchronous negative pressure clamping assembly includes a low-impedance bypass line connected between the vapor phase outlet of the evaporator and the suction buffer container, and a clamping control valve installed on the low-impedance bypass line. The control device is electrically connected to the drive motor, pulse control valve, and clamp control valve of the pulverizer, respectively, and is used to collect the load current change rate of the drive motor. When the load current change rate exceeds the preset threshold, the control device outputs an opening signal to the pulse control valve, uses the pressure difference between the high-pressure liquid phase zone and the evaporator to drive the refrigerant in the high-pressure liquid receiver into the evaporator for flash evaporation, and simultaneously outputs an opening signal to the clamp control valve to connect the evaporator and the suction buffer container, establishing a transient low flow resistance discharge channel from the evaporator directly to the suction buffer container.

2. The cascade rapid cooling system for cryogenic pulverization of fungi according to claim 1, characterized in that, The high-pressure liquid receiver has a heat exchange component inside. The return gas pipeline of the low-temperature refrigeration circuit passes through the heat exchange component, and the low-temperature gaseous refrigerant in the return gas pipeline is used to sensibly cool the high-pressure liquid refrigerant stored in the high-pressure liquid receiver.

3. The cascade rapid cooling system for cryogenic pulverization of fungi according to claim 1, characterized in that, The control device is configured to control the opening duration of the clamp control valve to be greater than or equal to the opening duration of the pulse control valve.

4. The cascade rapid cooling system for cryogenic pulverization of fungi according to claim 1, characterized in that, The low-impedance bypass line is directly connected to the expansion chamber of the suction buffer container. The inner diameter of the low-impedance bypass line is 1.5 to 2.5 times the inner diameter of the return line of the cryogenic refrigeration circuit.

5. The cascade rapid cooling system for cryogenic pulverization of fungi according to claim 1, characterized in that, The control device has a pre-set nonlinear timing matching logic, which limits the opening duration of the pulse control valve. With load current change rate The following relationship exists between them: ,in, The load current change rate is collected in real time. For the preset threshold, The preset response coefficient, The preset nonlinear gain index, This is the preset basic operating time for the pulse control valve.

6. The cascade rapid cooling system for cryogenic pulverization of fungi according to claim 1, characterized in that, The low-temperature stage refrigeration circuit also includes a throttling component, which is connected in parallel with the pressure potential bypass component between the high-pressure liquid phase zone and the evaporator, and is used to provide a basic refrigeration flow to the evaporator when the pulse control valve is closed.

7. The cascade rapid cooling system for cryogenic pulverization of fungi according to claim 1, characterized in that, The control device includes a differential signal extraction circuit, which is used to monitor the phase current of the drive motor in real time, filter out steady-state fluctuation signals with frequencies below 10Hz, and extract transient high-frequency components corresponding to mechanical shocks as the basis for calculating the load current change rate.

8. The cascade rapid cooling system for cryogenic pulverization of fungi according to claim 1, characterized in that, The cascade refrigeration cycle device also includes a high-temperature stage refrigeration circuit and an intermediate condenser-evaporator connecting the high-temperature stage refrigeration circuit and the low-temperature stage refrigeration circuit; the inlet of the high-pressure liquid receiver is directly connected to the low-temperature stage condenser outlet of the intermediate condenser-evaporator.

9. A cascade rapid cooling system for cryogenic pulverization of fungi according to claim 1, characterized in that, Both the pulse control valve and the clamp control valve are direct-acting cryogenic solenoid valves. The response time of the direct-acting cryogenic solenoid valve is less than or equal to 20 milliseconds, while the flow coefficient of the clamp control valve is greater than that of the pulse control valve.

10. A cascade rapid cooling system for cryogenic pulverization of fungi according to claim 1, characterized in that, The evaporator is a jacketed heat exchanger or a coil heat exchanger that surrounds the outer wall of the pulverizing chamber. The refrigerant inlet of the evaporator is located in the spatial position corresponding to the concentrated mechanical impact zone inside the pulverizing chamber.

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