Defrosting refrigeration compression condensing unit with hot fluorine

Abstract

The invention discloses a hot fluorine defrosting refrigeration compression condensing unit which comprises a supporting frame, an evaporator and a double-compression mechanism. The evaporator is connected to the liquid storage device through a first connecting pipeline, and an expansion valve is arranged on the first connecting pipeline; the double-compression mechanism is communicated to the four-way reversing valve through an upper pipeline, and an oil separator is arranged on the outer side of the compressor in an attached mode. The system further comprises a temperature sensor and a controller, the temperature sensor is arranged on the surface of the evaporator, and the controller controls the four-way reversing valve and the compressor to operate according to detection signals of the temperature sensor. A lower pipeline of the evaporator is communicated with an air suction port of the compressor; a second interface and a liquid accumulator form a refrigerant circulation loop through an expansion valve; the four-way reversing valve guides exhaust gas of the compressor to the condenser in a refrigeration mode, defrosting is directly conducted through heat of the exhaust gas of the compressor, and energy consumption is remarkably reduced; double-compression mechanism parallel connection and oil separation design improve system stability and service life, and an intelligent control strategy improves operation efficiency.

Description

Technical Field

[0001] The invention relates to the technical field of condensing machines, and in particular to a refrigeration compression condensing unit with hot fluorine defrosting. Background Art

[0002] In the fields of cold chain logistics, food processing, and pharmaceutical storage, refrigeration compression condensing units are the core equipment for maintaining low-temperature environments. Especially in low-temperature and high-humidity scenarios (such as cold storage and quick-freezing workshops), the surface of the evaporator is very easy to frost, resulting in a sharp drop in heat exchange efficiency. If defrosting is not timely, it will not only increase energy consumption, but may also cause equipment failure or even downtime risks. Traditional units need to be frequently shut down for manual defrosting or rely on external electric heating for defrosting, which seriously restricts continuous operation capabilities. Therefore, it is urgent to develop efficient, low-energy consumption automatic defrosting technology to meet the industry's dual needs for stability and energy saving.

[0003] At present, most mainstream refrigeration units use electric heating defrost or reverse cycle defrost solutions: the electric heating method directly heats the evaporator by adding electric heating pipes. Although the structure is simple, the additional energy consumption is extremely high, accounting for about 15%-30% of the total energy consumption of the system, which significantly increases the operating cost; although the reverse cycle defrost uses the heat of the refrigerant in the system, it requires frequent switching of the compressor start and stop and valve action, resulting in drastic fluctuations in pipeline pressure. Long-term operation is prone to problems such as compressor liquid hammer and lubricating oil retention, shortening the life of the equipment. Especially in high humidity environments, the above defects are further magnified - the energy consumption of electric heating increases exponentially with the increase in the frequency of defrosting, and the insufficient system stability of the reverse cycle aggravates the wear of the compressor, making it difficult to meet the core needs of the cold chain scenario for continuous refrigeration and low maintenance costs.

[0004] In view of this, it is necessary to improve the refrigeration unit technology in the prior art to solve the technical problems of excessively high energy consumption of electric heating defrosting and poor stability of the reverse cycle defrosting system. Summary of the invention

[0005] The object of the present invention is to provide a refrigeration compression condensing unit with hot fluorine defrosting to solve the above technical problems.

[0006] To achieve this object, the present invention adopts the following technical solutions: A refrigeration compression condensing unit with hot fluorine defrosting comprises a support frame, an evaporator transversely penetrating and fixed in the support frame, and a double compression mechanism fixed to the side wall of the support frame; The first end of the evaporator is provided with a first interface, the second end is provided with a second interface, and the second end is connected to a liquid storage device for storing liquid Freon refrigerant through a first connecting pipeline, and the first connecting pipeline is provided with an expansion valve; The dual compression mechanism comprises two compressors arranged side by side, each of the compressors having an exhaust port and an air intake port, the exhaust port being connected to a four-way reversing valve for switching the flow direction of the refrigerant through an upper pipeline, and the air intake port being connected to a first interface of the evaporator through a lower pipeline; wherein an oil separator for separating and recovering lubricating oil is provided on the outer side of the compressor; It also includes a control system, which includes a temperature sensor and a controller, wherein the temperature sensor is arranged on the surface of the evaporator, and the controller controls the operation of the four-way reversing valve and the compressor according to the detection signal of the temperature sensor; Among them, the first interface of the evaporator is connected to the compressor suction port through the lower pipeline, and the second interface forms a refrigerant circulation loop through the expansion valve and the liquid receiver; the four-way reversing valve directs the compressor exhaust to the condenser in the refrigeration mode, and switches to directly direct the compressor exhaust to the evaporator in the defrost mode.

[0007] Optionally, the oil separator includes a plurality of split separators, and the plurality of split separators are distributed circumferentially along the side wall of the compressor; The split separator has an outlet end and an inlet end, wherein the outlet end is communicated with the compressor through an oil return pipeline, and a solenoid valve is arranged on the oil return pipeline.

[0008] Optionally, the split separator includes an outer shell, a separation chamber is formed inside the outer shell, the separation chamber accommodates a filter cartridge assembly, and a filter chamber is formed in the middle of the filter cartridge assembly; wherein the separation chamber is communicated with the inlet end, and the filter chamber is connected to the outlet end.

[0009] Optionally, a high-pressure buffer portion is provided between the inlet end of the split separator and the exhaust port of the compressor, and a deflection baffle is provided in the high-pressure buffer portion for reducing the air flow velocity and preliminarily separating the oil droplets.

[0010] Optionally, the condenser includes a plurality of condensing monomers connected in sequence, the condensing monomers include a first monomer and a second monomer arranged at a preset angle, and the first monomer and the second monomer are connected via a bending portion; A plurality of heat dissipation fins are arranged at intervals along the length direction of the condensing unit, and the heat dissipation fins are used to dissipate heat from the refrigerant in the condensing unit.

[0011] The present invention also provides a control method for a refrigeration compression condensing unit with hot fluorine defrosting, which is used to control the refrigeration compression condensing unit with hot fluorine defrosting as described above. The control method specifically comprises the following steps: S1, real-time collection of evaporator surface temperature data, compressor suction and exhaust pressure gradient data and operating current data, the collected data is used to generate a dynamic feature data set through a data fusion algorithm, and the temperature abnormal distribution characteristics of the local frosting area on the evaporator surface are identified; S2, based on the dynamic feature data set, input the frost layer prediction model, output the frost layer thickness evolution curve and frost critical parameters on the evaporator surface; if the frost layer parameters exceed the preset safety threshold or the frost rate reaches the dynamic control boundary, generate a defrost mode switching instruction; S3, responding to the defrost mode switching instruction, performing step-by-step coordinated control: Adjust the operating power of the dual compression mechanism according to the preset frequency reduction curve, and simultaneously switch the four-way reversing valve to the defrosting direction; Based on the real-time pressure feedback signal, the pressure inside the evaporator is dynamically adjusted to the stable range of defrosting conditions; S4, in the defrost mode, monitors the changes in the evaporator surface temperature field and the fluctuation characteristics of the compressor exhaust pressure in real time, and adjusts the compressor power output and the pressure regulating valve action parameters through dynamic control strategies, so that the evaporator surface temperature rises to the defrost termination threshold at a preset rate; if it is detected that the pressure or temperature deviates abnormally from the safety tolerance, the protective mode is triggered to switch back.

[0012] Optionally, after step S4, the following steps may be further performed: S5, after defrosting is completed, switch to refrigeration mode and collect system energy efficiency parameters and environmental status data, update frost layer prediction model parameters and defrost trigger logic through adaptive learning mechanism; load the optimized control strategy into the controller to form a dynamic closed-loop control system.

[0013] 8. The control method of the refrigeration compression condensing unit with hot fluorine defrosting according to claim 6, characterized in that the step S2 specifically comprises the following steps: S21, extracting the evaporator surface temperature gradient distribution, the compressor suction and exhaust pressure fluctuation frequency and the current harmonic component from the dynamic feature data set, generating a correlation feature matrix through an encoder, and mapping it to the initial state parameters of frost layer growth; S22, inputting the spatiotemporal correlation feature matrix into a pre-trained frost layer prediction model, wherein the model extracts local spatial features of frost layer distribution on the evaporator surface through a convolutional neural network, and combines a long short-term memory network to predict the frost layer thickness evolution trend in the time dimension, and outputs a frost layer thickness distribution map and a frost rate vector for each area on the evaporator surface; S23, based on the frost layer thickness distribution map and the frost rate vector, calculate the global average frost layer thickness avg, the maximum frost layer thickness δmax and the frost rate gradient ∇δ, combine the real-time data of the ambient humidity sensor, and generate a comprehensive evaluation value of the frost critical parameters through the dynamic weight function W (δavg, ∇δ, humidity).

[0014] Optionally, the step S23 further includes the following steps: S24, comparing the comprehensive evaluation value with a preset safety threshold δthreshold and a dynamic control boundary ∇δboundary, and generating a primary defrost trigger signal if any of the following conditions is met: δavg ≥ δthreshold and ∇δ ≥ 0.8∇δ boundary; δmax ≥ 1.2δ threshold; At the same time, the historical defrost cycle data and the current compressor load rate are introduced to correct the confidence of the primary trigger signal through the decision tree algorithm; S25, if the corrected confidence exceeds the preset credible threshold, the primary defrost trigger signal is input into the instruction generator, and the priority weight of the defrost instruction is dynamically adjusted through the fuzzy logic controller in combination with the abnormal distribution characteristics of the evaporator surface temperature and the trend of the compressor exhaust pressure, to generate a defrost mode switching instruction with a weight label; S26, performing redundant verification on the defrost mode switching instruction: If the current operating frequency of the compressor is lower than the minimum safe frequency or the pressure in the evaporator exceeds the upper limit of the fault tolerance, the command will be frozen and an alarm will be triggered; Otherwise, the instruction is loaded into the controller queue and the historical feature library of the frost layer prediction model is updated synchronously.

[0015] Optionally, the step S4 specifically includes the following steps: S41, real-time collection of evaporator surface temperature field distribution, compressor exhaust pressure fluctuation data and ambient humidity data, generating real-time feature vectors of the defrosting process through feature extraction algorithms, and marking local overheating areas in the temperature field and abnormal frequency bands of the pressure spectrum; S42, based on the real-time feature vector, combined with the preset defrost termination threshold and the safe temperature rise rate constraint, the temperature target trajectory curve of each area on the evaporator surface is calculated through the trajectory planning model, and the initial control parameters of the compressor power adjustment amount and the pressure regulating valve opening are output; S43, executing a dynamic control strategy according to the initial control parameters, specifically: The output power of the dual compression mechanism is dynamically adjusted according to the slope of the temperature target trajectory curve, so that the surface temperature of the evaporator rises at the planned rate; Based on the abnormal energy distribution of pressure fluctuation data, the opening gradient of the pressure regulating valve is adjusted to suppress pressure oscillation; S44, calculating the evaporator surface temperature field uniformity index and the compressor exhaust pressure deviation in real time to determine the corresponding risk signal level, and triggering the corresponding level of protective mode switchback instruction according to the risk signal level; S45, responding to the protection mode switchback instruction and executing corresponding actions.

[0016] Compared with the prior art, the present invention has the following beneficial effects: when the refrigeration mode is started, the controller starts the dual compression mechanism, sucks in low-temperature and low-pressure gaseous refrigerant, and forms high-temperature and high-pressure gas after compression; after the high-temperature gas separates the lubricating oil through the oil separator, it enters the condenser through the four-way reversing valve to dissipate heat and condense into high-pressure liquid; the liquid refrigerant enters the liquid storage for temporary storage, is throttled and reduced in pressure by the expansion valve to become a low-temperature and low-pressure two-phase fluid, and is transported to the evaporator to absorb heat and evaporate; the evaporated low-temperature gas returns to the compressor suction port through the lower pipeline to complete the refrigeration cycle; the defrost mode is triggered, the temperature sensor detects that the frost on the evaporator surface is too thick or reaches the set time, and the controller turns off the refrigeration mode The four-way reversing valve switches the flow direction, and the compressor exhaust passes through the oil separator and directly enters the evaporator, where the high-temperature gas releases sensible heat and latent heat to melt the frost layer. The defrosted refrigerant bypasses the expansion valve to the liquid receiver, and then returns to the compressor after dissipating heat through the condenser, forming a defrost cycle. When the evaporator surface temperature is monitored, it automatically switches back to refrigeration mode when it reaches the set threshold. The unit achieves seamless switching between refrigeration and defrost modes through a four-way reversing valve, and uses the compressor exhaust heat to directly defrost, significantly reducing energy consumption. The dual compression mechanism parallel connection and oil separation design improve system stability and life, and the intelligent control strategy improves operating efficiency, making it suitable for continuous refrigeration needs in low temperature and high humidity environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0018] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which the present invention can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by the present invention, should still fall within the scope of the technical contents disclosed by the present invention.

[0019] Figure 1 This is a schematic diagram of the overall structure of a refrigeration compression condensing unit with hot fluorine defrosting according to the first embodiment of the present invention; Figure 2 This is a schematic diagram of the main structure of the refrigeration compression condensing unit with hot fluorine defrosting in the first embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the liquid storage device of the refrigeration compression condensing unit with hot fluorine defrosting in the first embodiment of the present invention; Figure 4 This is a schematic cross-sectional structure diagram of an oil separator of a refrigeration compression condensing unit with hot fluorine defrosting according to the first embodiment of the present invention; Figure 5 This is a schematic structural diagram of a condenser with a hot fluorine defrosting refrigeration compression condensing unit according to the first embodiment of the present invention; Figure 6 This is a front view structural schematic diagram of a condenser of a refrigeration compression condensing unit with hot fluorine defrosting according to the first embodiment of the present invention; Figure 7 It is a flow chart of the control method of the refrigeration compression condensing unit with hot fluorine defrosting according to the second embodiment of the present invention.

[0020] Illustrations: support frame 1, evaporator 2, dual compression mechanism 3, first interface 4, second interface 5, liquid reservoir 7, first connecting pipeline 6, expansion valve 8, compressor 9, upper pipeline 10, four-way reversing valve 11, temperature sensor 12, controller 13, condenser 14, outer shell 15, filter cartridge assembly 17, filter chamber 18, separation chamber 16, high-pressure buffer part 19, deflection baffle 20, condensation unit 21, first unit 22, second unit 23, bending part 24, heat dissipation fin 25, oil separator 26. DETAILED DESCRIPTION

[0021] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described below are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] In the description of the present invention, it should be understood that the terms "upper", "lower", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present invention. It should be noted that when a component is considered to be "connected" to another component, it may be directly connected to the other component or there may be a centrally arranged component at the same time.

[0023] The technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0024] Embodiment 1: Combination Figures 1 to 6As shown, an embodiment of the present invention provides a refrigeration compression condensing unit with hot fluorine defrost, including a supporting frame 1, an evaporator 2 which is transversely penetrated and fixed in the supporting frame 1, and a double compression mechanism 3 which is fixed to the side wall of the supporting frame 1; a first end of the evaporator 2 is provided with a first interface 4, a second end is provided with a second interface 5, and the second end is connected to a liquid reservoir 7 for storing liquid Freon refrigerant through a first connecting pipe 6, and an expansion valve 8 is provided on the first connecting pipe 6; the evaporator 2 is transversely penetrated and fixed in the supporting frame 1, and a first interface 4 (connected to the suction side of the compressor 9) and a second interface 5 (connected to the liquid reservoir 7 through the expansion valve 8) are respectively provided at both ends thereof, forming a main passage for the refrigerant circulation.

[0025] The dual compression mechanism 3 includes two compressors 9 arranged side by side, each compressor 9 has an exhaust port and an air intake port, the exhaust port is connected to a four-way reversing valve 11 for switching the flow direction of the refrigerant through an upper pipeline 10, and the air intake port is connected to the first interface 4 of the evaporator 2 through a lower pipeline; wherein, an oil separator 26 for separating and recovering lubricating oil is closely attached to the outer side of the compressor 9; the dual compression mechanism 3 is symmetrically arranged on the side wall of the support frame 1, and the refrigeration capacity is increased by parallel operation.

[0026] It should be noted that the dual compression mechanism 3 adopts a side-by-side layout, and the exhaust port of each compressor 9 is connected to the four-way reversing valve 11 through the upper pipeline 10 to realize the switching of the refrigerant flow direction; the air intake port is directly connected to the first interface 4 of the evaporator 2 through the lower pipeline to form a low-temperature gas reflux channel. The oil separator 26 attached to the outside of the compressor 9 separates the lubricating oil in the exhaust gas through a centrifugal or filtering mechanism, and returns it to the crankcase of the compressor 9 through the return oil pipeline to prevent the lubricating oil from entering the evaporator 2 and affecting the heat exchange efficiency. This design significantly reduces the energy loss caused by oil retention during the defrosting process, while extending the life of the compressor 9.

[0027] It also includes a control system, which includes a temperature sensor 12 and a controller 13. The temperature sensor 12 is arranged on the surface of the evaporator 2, and the controller 13 controls the operation of the four-way reversing valve 11 and the compressor 9 according to the detection signal of the temperature sensor 12; wherein the first interface 4 of the evaporator 2 is connected to the air intake port of the compressor 9 through the lower pipeline, and the second interface 5 forms a refrigerant circulation loop through the expansion valve 8 and the liquid storage tank 7; the four-way reversing valve 11 guides the exhaust gas of the compressor 9 to the condenser 14 in the refrigeration mode, and switches to guide the exhaust gas of the compressor 9 directly to the evaporator 2 in the defrost mode.

[0028] The working principle of the present invention is as follows: when the refrigeration mode is started, the controller 13 starts the dual compression mechanism 3, sucks in low-temperature and low-pressure gaseous refrigerant, and forms high-temperature and high-pressure gas after compression; after the high-temperature gas separates the lubricating oil through the oil separator 26, it enters the condenser 14 through the four-way reversing valve 11 to dissipate heat and condense into high-pressure liquid; the liquid refrigerant enters the liquid storage 7 for temporary storage, is throttled and reduced in pressure by the expansion valve 8 to become a low-temperature and low-pressure two-phase fluid, and is transported to the evaporator 2 to absorb heat and evaporate; the evaporated low-temperature gas returns to the suction port of the compressor 9 through the lower pipeline to complete the refrigeration cycle; the defrost mode is triggered, the temperature sensor 12 detects that the frost on the surface of the evaporator 2 is too thick or reaches the set time, and the controller 13 turns off the refrigeration mode; the four-way reversing valve 11 The flow direction is switched by valve 11, and the exhaust gas of compressor 9 directly enters evaporator 2 after passing through oil separator 26, and the high-temperature gas releases sensible heat and latent heat to melt the frost layer; the defrosted refrigerant bypasses to liquid storage tank 7 through expansion valve 8, and then returns to compressor 9 after heat dissipation through condenser 14, forming a defrost cycle; when the surface temperature of evaporator 2 is monitored, it automatically switches back to refrigeration mode after reaching the set threshold; this unit realizes seamless switching between refrigeration and defrost mode through four-way reversing valve 11, and uses the exhaust heat of compressor 9 to directly defrost, which significantly reduces energy consumption; the parallel connection of dual compression mechanism 3 and oil separation design improve system stability and life, and the intelligent control strategy improves operating efficiency, which is suitable for continuous refrigeration needs in low temperature and high humidity environments.

[0029] In this embodiment, the oil separator 26 includes a plurality of split separators, which are distributed circumferentially along the side wall of the compressor 9; the split separator has an outlet end and an inlet end, and its outlet end is connected to the compressor 9 through an oil return pipeline, and an electromagnetic valve is provided on the oil return pipeline.

[0030] The oil separator 26 adopts a split modular design, with multiple separators evenly distributed along the circumference of the side wall of the compressor 9. The inlet end of each separator is connected to the exhaust port of the compressor 9, and the outlet end is connected to the crankcase of the compressor 9 through an independent oil return pipeline, and a solenoid valve is provided on the oil return pipeline. The split layout can perform directional separation based on the oil mist distribution characteristics of different exhaust areas of the compressor 9, thereby improving the oil droplet capture efficiency; the solenoid valve dynamically adjusts the oil return frequency according to the load of the compressor 9 to avoid the risk of liquid hammer caused by excessive lubricating oil returning at one time.

[0031] In this embodiment, it is further explained that the split separator includes an outer shell 15, a separation chamber 16 is formed inside the outer shell 15, the separation chamber 16 accommodates a filter cartridge assembly 17, and a filter chamber 18 is formed in the middle of the filter cartridge assembly 17; wherein the separation chamber 16 is connected to the inlet end, and the filter chamber 18 is connected to the outlet end.

[0032] The outer shell 15 of the split separator is provided with a separation chamber 16, in which a multi-layer filter cartridge assembly 17 is placed, and a through filter chamber 18 is formed in the middle of the filter cartridge. After the exhaust gas of the compressor 9 enters the separation chamber 16 from the inlet end, it is first roughly separated by centrifugal force, and large oil droplets adhere to the chamber wall; the remaining oil-containing gas is finely filtered through the microporous structure of the filter cartridge, and the clean gas is discharged from the outlet end, and the separated lubricating oil gathers at the bottom of the filter chamber 18 and flows back into the compressor 9. The filter cartridge is made of stainless steel sintered material, which is resistant to high temperature and high pressure and can be disassembled and cleaned, which significantly extends the maintenance cycle.

[0033] In this embodiment, a high-pressure buffer portion 19 is provided between the inlet end of the split separator and the exhaust port of the compressor 9. A deflection baffle 20 is provided in the high-pressure buffer portion 19 to reduce the air flow velocity and preliminarily separate the oil droplets.

[0034] In the present embodiment, it is further described that the condenser 14 includes a plurality of condensing monomers 21 connected in series, the condensing monomers 21 include a first monomer 22 and a second monomer 23 arranged at a preset angle, and the first monomer 22 and the second monomer 23 are connected by a bending portion 24; a plurality of heat dissipation fins 25 are arranged at intervals along the length direction of the condensing monomer 21, and the heat dissipation fins 25 are used to dissipate heat from the refrigerant in the condensing monomer 21.

[0035] The condenser 14 is composed of a plurality of condensation units 21 connected in sequence. Each unit includes a first unit 22 and a second unit 23 at an angle of 90°-120°. The two units transition through an arc-shaped bend 24 to form a continuous serpentine flow channel. Aluminum heat sink fins 25 are welded at intervals along the length of the unit. The surface of the fin is stamped with spoiler protrusions, which can destroy the boundary layer and enhance air turbulence. The heat dissipation efficiency is increased by 25% compared with traditional flat fins. The modular unit design supports flexible expansion of the length of the condenser 14, and the bend 24 can adapt to the orientation requirements of different installation spaces, which is particularly suitable for the compact layout of cold chain equipment with limited space.

[0036] Embodiment 2: Combination Figure 7 As shown, the present invention also provides a control method for a refrigeration compression condensing unit with hot fluorine defrosting, which is used to control the refrigeration compression condensing unit with hot fluorine defrosting as in Example 1. The control method specifically includes the following steps: S1, collects the surface temperature data of evaporator 2, suction and exhaust pressure gradient data of compressor 9 and operating current data in real time, generates a dynamic feature data set through data fusion algorithm, and identifies the abnormal temperature distribution characteristics of the local frosting area on the surface of evaporator 2.

[0037] S2, based on the dynamic feature data set, inputs the frost layer prediction model, outputs the frost layer thickness evolution curve and frost critical parameters on the surface of evaporator 2; if the frost layer parameters exceed the preset safety threshold or the frost rate reaches the dynamic control boundary, a defrost mode switching instruction is generated.

[0038] S3, responds to the defrost mode switching instruction and performs step-by-step coordinated control: Adjust the operating power of the dual compression mechanism 3 according to the preset frequency reduction curve, and simultaneously switch the four-way reversing valve 11 to the defrosting flow direction; Based on the real-time pressure feedback signal, the pressure in the evaporator 2 is dynamically adjusted to a stable range of defrosting conditions.

[0039] S4, in the defrost mode, monitor the changes in the surface temperature field of the evaporator 2 and the exhaust pressure fluctuation characteristics of the compressor 9 in real time, adjust the power output of the compressor 9 and the action parameters of the pressure regulating valve through a dynamic control strategy, so that the surface temperature of the evaporator 2 rises to the defrost termination threshold at a preset rate; if it is detected that the pressure or temperature deviates abnormally from the safety tolerance, the protective mode is triggered to switch back.

[0040] S5, after defrosting is completed, switch to the refrigeration mode and collect system energy efficiency parameters and environmental status data, update the frost layer prediction model parameters and defrost trigger logic through the adaptive learning mechanism; load the optimized control strategy into the controller 13 to form a dynamic closed-loop control system.

[0041] The beneficial effects of this method are as follows: by integrating the evaporator 2 temperature, compressor 9 pressure and current data, the characteristics of the frosting area are identified in real time to provide dynamic input for frost layer prediction; based on the frost layer evolution model, the critical state of frosting is predicted, and the defrost triggering timing is accurately determined to avoid energy efficiency loss caused by premature or delayed defrosting; through the coordinated control of compressor 9 frequency reduction and four-way valve switching, a smooth transition from refrigeration to defrosting mode is achieved, and at the same time, the evaporator 2 pressure is dynamically adjusted to a stable range to prevent pressure mutations from damaging components; during defrosting, the temperature rise rate is controlled in real time to ensure rapid defrosting without overheating, and emergency switching is performed through the abnormal feedback mechanism to ensure system safety, thereby providing a low-energy, stable and intelligent control method suitable for refrigeration compression condensing units.

[0042] In this embodiment, it is specifically explained that step S2 specifically includes the following steps: S21, extracting the surface temperature gradient distribution of the evaporator 2, the suction and exhaust pressure fluctuation frequency of the compressor 9 and the current harmonic components from the dynamic feature data set, generating a correlation feature matrix through an encoder, and mapping it to the initial state parameters of the frost layer growth; This step extracts the evaporator surface temperature gradient distribution (reflecting local frost non-uniformity), the compressor suction and exhaust pressure fluctuation frequency (characterizing system load changes) and the current harmonic component (indicating the motor operating status) from the dynamic feature data set, and uses the space-time encoder to fuse these heterogeneous data into a unified space-time correlation feature matrix. The encoder eliminates the sensor acquisition delay through the time alignment algorithm, and normalizes the physical dimensions of temperature, pressure, and current, and finally maps them to the initial state parameters of frost layer growth (including frost density, area coverage, etc.). This process realizes the effective association of multimodal data and provides standardized input for subsequent model prediction.

[0043] S22, inputting the spatiotemporal correlation feature matrix into the pre-trained frost layer prediction model, the model extracts the local spatial features of the frost layer distribution on the surface of the evaporator 2 through a convolutional neural network, and combines the long short-term memory network to predict the frost layer thickness evolution trend in the time dimension, and outputs the frost layer thickness distribution map and frost rate vector of each area on the surface of the evaporator 2; The spatiotemporal correlation feature matrix is ​​input into the pre-trained frost layer prediction model. The model uses a convolutional neural network (CNN) to extract the local spatial characteristics of the frost layer distribution on the evaporator surface (such as frost crystal morphology and frost directionality), and uses a long short-term memory network (LSTM) to learn the trend of frost layer thickness evolution over time. The output of the CNN-LSTM hybrid architecture includes: Frost thickness distribution map: the real-time frost thickness value of each area of ​​the evaporator is marked in a grid format; Frost rate vector: quantifies the frost growth rate per unit time in different areas.

[0044] This model breaks through the limitations of traditional single-point monitoring and realizes full-dimensional dynamic perception of frost layer evolution.

[0045] S23, based on the frost layer thickness distribution map and the frost rate vector, calculate the global average frost layer thickness avg, the maximum frost layer thickness δmax and the frost rate gradient ∇δ, and combine the real-time data of the ambient humidity sensor to generate a comprehensive evaluation value of the frost critical parameters through the dynamic weight function W (δavg, ∇δ, humidity).

[0046] S24, comparing the comprehensive evaluation value with the preset safety threshold δthreshold and the dynamic control boundary ∇δboundary, and generating a primary defrost trigger signal if any of the following conditions is met: δavg ≥ δthreshold and ∇δ ≥ 0.8∇δ boundary; δmax ≥ 1.2δ threshold; At the same time, the historical defrost cycle data and the current load rate of compressor 9 are introduced, and the confidence of the primary trigger signal is corrected through the decision tree algorithm.

[0047] It should be noted that the historical defrost cycle data (such as the average defrost interval) and the current compressor load rate are introduced, and the historical false trigger cases are analyzed through the decision tree algorithm to correct the confidence of the primary trigger signal. For example: if the load rate is less than 50% and the historical false trigger rate is high, the confidence is reduced by 20% to reduce ineffective defrosting.

[0048] S25, if the corrected confidence exceeds the preset credible threshold, the primary defrost trigger signal is input into the instruction generator, and the priority weight of the defrost instruction is dynamically adjusted through the fuzzy logic controller 13 in combination with the abnormal distribution characteristics of the surface temperature of the evaporator 2 and the exhaust pressure trend of the compressor 9, to generate a defrost mode switching instruction with a weight label; If the corrected confidence level exceeds the preset credible threshold (e.g. ≥85%), the primary defrost trigger signal is input into the command generator. Combined with the abnormal distribution characteristics of the evaporator surface temperature (e.g. the proportion of local high temperature areas) and the compressor exhaust pressure trend (pressure rise rate), the priority weight of the defrost command is dynamically calculated through the fuzzy logic controller.

[0049] S26, redundant verification of the defrost mode switching instruction: If the current operating frequency of the compressor 9 is lower than the minimum safe frequency or the pressure in the evaporator 2 exceeds the upper limit of the fault tolerance, the instruction is frozen and an alarm is triggered; Otherwise, the instruction is loaded into the queue of the controller 13, and the historical feature library of the frost layer prediction model is updated synchronously.

[0050] It should be noted that if the parameters are normal, the command will be loaded into the controller queue, and the current frost layer data, environmental parameters and command execution results will be stored in the historical feature library for incremental training of the frost layer prediction model. This closed-loop mechanism enables the model to be continuously optimized and gradually reduce the misjudgment rate.

[0051] In this embodiment, it is specifically explained that step S4 specifically includes the following steps: S41, collecting the surface temperature field distribution of the evaporator 2, the exhaust pressure fluctuation data of the compressor 9 and the ambient humidity data in real time, generating a real-time feature vector of the defrosting process through a feature extraction algorithm, and marking the local overheating area in the temperature field and the abnormal frequency band of the pressure spectrum; S42, based on the real-time feature vector, combined with the preset defrost termination threshold and the safe temperature rise rate constraint, the temperature target trajectory curve of each area on the surface of the evaporator 2 is calculated through the trajectory planning model, and the initial control parameters of the power adjustment amount of the compressor 9 and the opening of the pressure regulating valve are output; S43, executing a dynamic control strategy according to the initial control parameters, specifically: The output power of the dual compression mechanism 3 is dynamically adjusted according to the slope of the temperature target trajectory curve, so that the surface temperature of the evaporator 2 increases at the planned rate; Based on the abnormal energy distribution of pressure fluctuation data, the opening gradient of the pressure regulating valve is adjusted to suppress pressure oscillation; S44, calculating the uniformity index of the surface temperature field of the evaporator 2 and the exhaust pressure deviation of the compressor 9 in real time to determine the corresponding risk signal level, and triggering the corresponding level of protective mode switching back instruction according to the risk signal level; A multi-level risk signal is generated if any of the following conditions are met: The temperature field uniformity index is lower than the preset tolerance and the area of ​​the local overheating area accounts for more than 10%; The exhaust pressure deviation exceeds the dynamic safety limit for 3 seconds.

[0052] S45, responding to the protection mode switchback instruction, executing corresponding actions, specifically the following actions: If it is a level 1 risk, reduce the power of compressor 9 to a safe baseline and maintain the current defrost mode; If it is a secondary risk, switch back to cooling mode immediately and close the pressure regulating valve.

[0053] As described above, the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features thereof may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A refrigeration compression condensing unit with hot fluorine defrosting, characterized in that: It includes a support frame, an evaporator transversely penetrating and fixed in the support frame, and a dual compression mechanism fixed to the side wall of the support frame; The first end of the evaporator is provided with a first interface, the second end is provided with a second interface, and the second end is connected to a liquid storage device for storing liquid Freon refrigerant through a first connecting pipeline, and the first connecting pipeline is provided with an expansion valve; The dual compression mechanism comprises two compressors arranged side by side, each of the compressors having an exhaust port and an air intake port, the exhaust port being connected to a four-way reversing valve for switching the flow direction of the refrigerant through an upper pipeline, and the air intake port being connected to a first interface of the evaporator through a lower pipeline; wherein an oil separator for separating and recovering lubricating oil is provided on the outer side of the compressor; It also includes a control system, which includes a temperature sensor and a controller, wherein the temperature sensor is arranged on the surface of the evaporator, and the controller controls the operation of the four-way reversing valve and the compressor according to the detection signal of the temperature sensor; Among them, the first interface of the evaporator is connected to the compressor suction port through the lower pipeline, and the second interface forms a refrigerant circulation loop through the expansion valve and the liquid receiver; the four-way reversing valve directs the compressor exhaust to the condenser in the refrigeration mode, and switches to directly direct the compressor exhaust to the evaporator in the defrost mode.

2. The refrigeration compression condensing unit with hot fluorine defrosting according to claim 1 is characterized in that: The oil separator comprises a plurality of split separators, and the plurality of split separators are distributed circumferentially along the side wall of the compressor; The split separator has an outlet end and an inlet end, wherein the outlet end is communicated with the compressor through an oil return pipeline, and a solenoid valve is arranged on the oil return pipeline.

3. The refrigeration compression condensing unit with hot fluorine defrosting according to claim 2 is characterized in that: The split separator comprises an outer shell, a separation chamber is formed inside the outer shell, a filter cartridge assembly is accommodated in the separation chamber, a filter chamber is formed in the middle of the filter cartridge assembly; wherein the separation chamber is communicated with the inlet end, and the filter chamber is connected with the outlet end.

4. The refrigeration compression condensing unit with hot fluorine defrosting according to claim 3 is characterized in that: A high-pressure buffer is arranged between the inlet end of the split separator and the exhaust port of the compressor, and a deflection baffle is arranged inside the high-pressure buffer to reduce the air flow velocity and preliminarily separate the oil droplets.

5. The refrigeration compression condensing unit with hot fluorine defrosting according to claim 1, characterized in that: The condenser comprises a plurality of condensing monomers connected in sequence, wherein the condensing monomers comprise a first monomer and a second monomer arranged at a preset angle, and the first monomer and the second monomer are connected via a bending portion; A plurality of heat dissipation fins are arranged at intervals along the length direction of the condensing unit, and the heat dissipation fins are used to dissipate heat from the refrigerant in the condensing unit.

6. A control method for a refrigeration compression condensing unit with hot fluorine defrosting, characterized in that: Used to control the refrigeration compression condensing unit with hot fluorine defrosting according to any one of claims 1 to 5, the control method specifically comprises the following steps: S1, real-time collection of evaporator surface temperature data, compressor suction and exhaust pressure gradient data and operating current data, the collected data is used to generate a dynamic feature data set through a data fusion algorithm, and the temperature abnormal distribution characteristics of the local frosting area on the evaporator surface are identified; S2, based on the dynamic feature data set, input the frost layer prediction model, output the frost layer thickness evolution curve and frost critical parameters on the evaporator surface; if the frost layer parameters exceed the preset safety threshold or the frost rate reaches the dynamic control boundary, generate a defrost mode switching instruction; S3, responding to the defrost mode switching instruction, performing step-by-step coordinated control: Adjust the operating power of the dual compression mechanism according to the preset frequency reduction curve, and simultaneously switch the four-way reversing valve to the defrosting direction; Based on the real-time pressure feedback signal, the pressure inside the evaporator is dynamically adjusted to the stable range of defrosting conditions; S4, in the defrost mode, monitors the changes in the evaporator surface temperature field and the fluctuation characteristics of the compressor exhaust pressure in real time, and adjusts the compressor power output and the pressure regulating valve action parameters through dynamic control strategies, so that the evaporator surface temperature rises to the defrost termination threshold at a preset rate; if it is detected that the pressure or temperature deviates abnormally from the safety tolerance, the protective mode is triggered to switch back.

7. The control method of a refrigeration compression condensing unit with hot fluorine defrosting according to claim 6, characterized in that: After step S4, the following steps are also included: S5, after defrosting is completed, switch to refrigeration mode and collect system energy efficiency parameters and environmental status data, update frost layer prediction model parameters and defrost trigger logic through adaptive learning mechanism; load the optimized control strategy into the controller to form a dynamic closed-loop control system.

8. The control method of a refrigeration compression condensing unit with hot fluorine defrosting according to claim 6, characterized in that: The step S2 specifically includes the following steps: S21, extracting the evaporator surface temperature gradient distribution, the compressor suction and exhaust pressure fluctuation frequency and the current harmonic component from the dynamic feature data set, generating a correlation feature matrix through an encoder, and mapping it to the initial state parameters of frost layer growth; S22, inputting the spatiotemporal correlation feature matrix into a pre-trained frost layer prediction model, wherein the model extracts local spatial features of frost layer distribution on the evaporator surface through a convolutional neural network, and combines a long short-term memory network to predict the frost layer thickness evolution trend in the time dimension, and outputs a frost layer thickness distribution map and a frost rate vector for each area on the evaporator surface; S23, based on the frost layer thickness distribution map and the frost rate vector, calculate the global average frost layer thickness avg, the maximum frost layer thickness δmax and the frost rate gradient ∇δ, combine the real-time data of the ambient humidity sensor, and generate a comprehensive evaluation value of the frost critical parameters through the dynamic weight function W (δavg, ∇δ, humidity).

9. The control method of a refrigeration compression condensing unit with hot fluorine defrosting according to claim 7, characterized in that: The step S23 further includes the following steps: S24, comparing the comprehensive evaluation value with a preset safety threshold δthreshold and a dynamic control boundary ∇δboundary, and generating a primary defrost trigger signal if any of the following conditions is met: δavg ≥ δthreshold and ∇δ ≥ 0.8∇δ boundary; δmax ≥ 1.2δ threshold; At the same time, the historical defrost cycle data and the current compressor load rate are introduced to correct the confidence of the primary trigger signal through the decision tree algorithm; S25, if the corrected confidence exceeds the preset credible threshold, the primary defrost trigger signal is input into the instruction generator, and the priority weight of the defrost instruction is dynamically adjusted through the fuzzy logic controller in combination with the abnormal distribution characteristics of the evaporator surface temperature and the trend of the compressor exhaust pressure, to generate a defrost mode switching instruction with a weight label; S26, performing redundant verification on the defrost mode switching instruction: If the current operating frequency of the compressor is lower than the minimum safe frequency or the pressure in the evaporator exceeds the upper limit of the fault tolerance, the command will be frozen and an alarm will be triggered; Otherwise, the instruction is loaded into the controller queue and the historical feature library of the frost layer prediction model is updated synchronously.

10. The control method of a refrigeration compression condensing unit with hot fluorine defrosting according to claim 6, characterized in that: The step S4 specifically comprises the following steps: S41, real-time collection of evaporator surface temperature field distribution, compressor exhaust pressure fluctuation data and ambient humidity data, generating real-time feature vectors of the defrosting process through feature extraction algorithms, and marking local overheating areas in the temperature field and abnormal frequency bands of the pressure spectrum; S42, based on the real-time feature vector, combined with the preset defrost termination threshold and the safe temperature rise rate constraint, the temperature target trajectory curve of each area on the evaporator surface is calculated through the trajectory planning model, and the initial control parameters of the compressor power adjustment amount and the pressure regulating valve opening are output; S43, executing a dynamic control strategy according to the initial control parameters, specifically: The output power of the dual compression mechanism is dynamically adjusted according to the slope of the temperature target trajectory curve, so that the surface temperature of the evaporator rises at the planned rate; Based on the abnormal energy distribution of pressure fluctuation data, the opening gradient of the pressure regulating valve is adjusted to suppress pressure oscillation; S44, calculating the evaporator surface temperature field uniformity index and the compressor exhaust pressure deviation in real time to determine the corresponding risk signal level, and triggering the corresponding level of protective mode switchback instruction according to the risk signal level; S45, responding to the protection mode switchback instruction and executing corresponding actions.

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