A medium-temperature and medium-pressure liquid refrigerant stratified energy storage refrigeration enhancement system

Abstract

The application discloses a middle-temperature and middle-pressure liquid refrigerant layered energy storage refrigeration synergistic system, which comprises a compressor, a condenser, a first pressure regulating device, a three-element interval layered energy storage assembly, a second throttling device, an evaporator, an auxiliary storage and release branch, a detection assembly and a controller; the first pressure regulating device adjusts high-pressure liquid refrigerant output by the condenser into middle-temperature and middle-pressure liquid refrigerant with pressure between condensation pressure and evaporation pressure and keeping single liquid phase; the layered energy storage assembly is provided with a main liquid supply cavity, a transition buffer cavity and an energy storage cavity which are communicated through overflow channels in sequence, so that liquid refrigerant is preferentially used for main cycle liquid supply, and then used for flow buffering and storage and release heat exchange; the application can reduce the interference of the auxiliary synergistic branch on the main liquid supply, realize layered storage of the middle-pressure liquid refrigerant, subcooling regulation and controlled reuse.

Description

Technical Field

[0001] This invention belongs to the field of vapor compression refrigeration and heat pump energy-saving technology, specifically involving a method for improving the efficiency of medium-temperature and medium-pressure liquid refrigerant extraction and a ternary interval layered energy storage system.

[0002] This invention is applicable to all vapor compression cycle equipment using R32, R410A, R290, CO2 (R744), R454C, R1234yf, and any mixture of the above media as working fluids. It covers all categories of equipment, including household air conditioners, commercial central air conditioners, multi-split systems, chillers, air source / water source / ground source heat pumps, ultra-low temperature heat pumps, high temperature heat pumps, single-unit multi-stage cascade units, dual-unit multi-stage cascade units, data center cooling, new energy vehicle thermal management, and marine air conditioning. It covers both new equipment manufacturing and energy-saving retrofitting of existing equipment.

[0003] This invention is adapted to the 2026 version of the Dynamic Energy Efficiency (DAPF) national standard full-condition testing technology framework and meets the mandatory compliance requirements of EU 2024 / 573 F-gas regulations for low-GWP refrigerant equipment. Background Technology

[0004] Since Willis Carrier invented modern air conditioning in 1902, the vapor compression refrigeration cycle has existed for over a century. During this time, industry technological improvements have long focused on superficial optimizations such as refrigerant replacement, increasing heat exchanger area, and improving compressor efficiency. However, a fundamental technological bias has remained unshaken: the high-pressure liquid refrigerant at the condenser outlet has always been simply regarded by the industry as a "working fluid to be throttled," with its thermodynamic mission believed to be solely through isenthalpic throttling into the evaporator.

[0005] Thermodynamic analysis shows that the high-pressure liquid working fluid at the condenser outlet carries 25% to 45% of the high-grade energy input from the compressor. In traditional systems, this energy is irreversibly dissipated after isenthalpic throttling. Through extensive whole-machine testing and thermodynamic modeling, the inventors have, for the first time, broken through the aforementioned century-old technological bias, making two original scientific discoveries: Finding 1: Medium-temperature, medium-pressure liquid refrigerant is the highest quality energy reuse medium in the system. The refrigerant in the pipeline section from the condenser outlet to the front end of the throttling device is the only working fluid in the system that simultaneously possesses the triple physical properties of pure liquid, moderate temperature, and stable pressure. It has a unique bidirectional gain capability—it can be used as a cold source to precool the high-pressure liquid pipe and increase subcooling, and it can also be used as a heat source to superheat the low-pressure return gas and increase superheat.

[0006] Discovery 2: Traditional throttling systems exhibit a binary working fluid division pattern of approximately 55% and 45%. This invention quantitatively reveals for the first time that maintaining steady-state operation of the system requires only about 55% of the basic supply working fluid, with the remaining approximately 45% being a high-grade, redundant, pure liquid refrigerant. This redundant portion of the working fluid has been mistakenly attributed in traditional thermodynamic analysis to irreversible entropy increase factors, leading to the assumption that its pressure energy and sensible heat cannot be recovered. This invention overcomes this theoretical misconception, proving that this 45% pure liquid medium-temperature, medium-pressure refrigerant is precisely the most efficient energy reuse medium within the system, and its recovery and utilization have never been quantitatively revealed before.

[0007] The EU F-gas Regulation (EU) 2024 / 573 came into effect in March 2024. From January 1, 2027, it prohibits the use of fluorinated greenhouse gases with a GWP of 150 or higher in integrated air conditioning units and independent circulating heat pumps with a maximum rated power not exceeding 12kW. China's Dynamic Energy Efficiency Standard for Air Conditioning (DAPF) is scheduled for finalization in August 2026. The revised draft of the new national standard significantly raises the threshold for dynamic energy efficiency under all operating conditions. Traditional single-condition optimization technologies will be completely phased out.

[0008] Existing technologies such as regenerators, subcoolers, economizers, and intermediate gas injection are all limited to the level of pure heat exchange and cannot recover the pressure energy of the working fluid, thus having an insurmountable thermodynamic and physical upper limit.

[0009] The closest existing technology is CN200510082831.9, which draws a bypass branch from the condenser outlet, and after being throttled and depressurized by the expansion valve, it evaporates and absorbs heat in the subcooler to control the subcooling of the main refrigerant. However, the scheme has the following inherent limitations: (i) the bypass refrigerant becomes a gaseous two-phase after throttling and can only be used as a cold source once, and cannot achieve multiple and cascaded reuse of the refrigerant; (ii) no physical self-locking mechanism of "main liquid supply priority" is established, and the liquid supply at the inlet of the main throttling device is directly reduced when the bypass flow increases, which poses a risk of insufficient liquid supply to the evaporator; (iii) layered energy storage and three-stage energy recovery are not realized; (iv) the binary composition of about 55% basic liquid supply working fluid and about 45% redundant pure liquid refrigerant is not distinguished; (v) the secondary efficiency enhancement mechanism of suppressing flash gas after throttling by increasing subcooling is not involved; (vi) the technical path of reducing liquid hammer by reducing the return gas temperature after the auxiliary branch refrigerant absorbs heat is not involved.

[0010] The essential difference between this invention and the prior art is as follows: (1) This invention discovers and locks the medium-temperature and medium-pressure liquid refrigerant in the subcooled section of the condenser and the subsequent pipeline section as an independent energy reuse medium that can be extracted and utilized in the system. This principle-level discovery breaks through the technical prejudice that "the refrigerant at the condenser outlet can only be directly throttled" for a century; (2) The extracted refrigerant always maintains a single liquid phase, without throttling or changing phase state; (3) Extracting ≥1% of the medium-temperature and medium-pressure liquid refrigerant and carrying out any form of secondary utilization or release can improve or change the system's energy efficiency; (4) In the preferred scheme, the subcooling degree is increased to above 10°C through indirect heat exchange with the low-temperature cold source after auxiliary throttling, and the COP is simultaneously linearly increased and the flash suppression effect is enhanced; (5) After the refrigerant in the auxiliary branch absorbs heat, the temperature rises to above 5°C and merges into the return gas pipeline, achieving two goals at once: improving the subcooling degree and the return gas superheat, and reducing the risk of liquid slugging. The above differences cannot be obtained through simple parameter adjustments or component replacements; they represent a dual essential difference at both the level of scientific discovery and the level of thermodynamic logic. Summary of the Invention

[0011] I. Objective Physical Definition of Medium-Temperature and Medium-Pressure Liquid Refrigerant

[0012] This invention uses objective physical quantities to strictly define "medium temperature and medium pressure", completely eliminating the ambiguity of functional descriptions and making the scope of protection clearly identifiable.

[0013] Definition: The intermediate pressure P_mid is determined by the following formula: P_mid = P_c - X% × (P_c - P_e) Where P_c is the condensation pressure, P_e is the evaporation pressure, and the coefficient X ranges from 5% to 60%.

[0014] The range of values ​​is determined based on the following two objective conditions being met simultaneously: the saturation temperature corresponding to the intermediate pressure P_mid is satisfied: Condition 1: The saturation temperature must be at least 15K higher than the evaporation pressure P_e to ensure sufficient heat transfer temperature difference and driving force with the evaporation side; Condition 2: The temperature must be at least 5K below the saturation temperature corresponding to the condensing pressure P_c to ensure that the refrigerant remains in a liquid state and has a margin for adjustment.

[0015] For example, for R32 refrigerant, under standard refrigeration conditions, P_c ≈ 3.5 MPa (corresponding to a saturation temperature of approximately 55°C), and P_e ≈ 1.0 MPa (corresponding to a saturation temperature of approximately 5°C). Taking X = 30%, then P_mid = 3.5 - 0.3 × (3.5 - 1.0) = 2.75 MPa, corresponding to a saturation temperature of approximately 42°C. This temperature satisfies the following conditions: at least 15 K above the evaporation saturation temperature (42 - 5 = 37 K ≥ 15 K) and at least 5 K below the condensation saturation temperature (55°C) (55 - 42 = 13 K ≥ 5 K). This is the typical operating point for "medium temperature and medium pressure".

[0016] As a supplementary explanation, the pressure of the medium-temperature and medium-pressure liquid refrigerant can also be understood in engineering as satisfying: P_e + ΔP_low ≤ P_mid ≤ P_c - ΔP_high, where ΔP_low is the low-side pressure differential margin set to ensure a controllable pressure difference between the intermediate pressure and the evaporation pressure, and ΔP_high is the high-side pressure differential margin set to overcome the resistance of the condenser outlet pipe and maintain the regulating capability.

[0017] II. Physical Principles of Medium-Temperature and Medium-Pressure Liquid Refrigerant as an Energy Reuse Medium The medium-temperature, medium-pressure liquid refrigerant in the section from the condenser outlet to the front end of the throttling device is the only energy reuse medium in the entire vapor compression cycle system that simultaneously possesses the following three physical properties: First, it is a pure liquid—a dual medium for both subcooling and superheating. Medium-temperature, medium-pressure liquid refrigerant is 100% pure liquid, with no gas phase impurities, high specific heat capacity, and high heat transfer efficiency. Compared to gas-liquid two-phase mixtures, the heat transfer coefficient of pure liquid refrigerant is 3 to 5 times higher, enabling deep subcooling within a limited heat exchange area. Simultaneously, pure liquid refrigerant can absorb heat from low-pressure return gas to achieve superheating, providing a bidirectional benefit.

[0018] Second, the temperature is moderate – naturally matching the heat exchange temperature difference. The temperature of the medium-temperature and medium-pressure liquid refrigerant is about 35°C to 50°C, which forms a natural counter-current heat exchange temperature difference of 5K to 15K with the temperature of the refrigerant in the high-pressure liquid pipe is about 40°C to 55°C; and forms a natural heat exchange temperature difference of 15K to 40K with the temperature of the low-pressure return gas of 10°C to 20°C.

[0019] Third, stable pressure – material extraction does not affect the main circulation. The medium-temperature, medium-pressure liquid refrigerant has completed condensation and heat exchange and is located in an independent pipeline section, where the pressure is stable. Extracting material from this section does not disrupt the internal flow field of the condenser and does not cause fluctuations in condensing pressure.

[0020] Unique physical characteristics of bidirectional gain: Medium-temperature and medium-pressure liquid refrigerant is the only intermediate medium in the refrigeration cycle - it can be used as a cold source to precool the high-pressure liquid pipe and increase the subcooling, and it can also be used as a heat source to superheat the low-pressure return gas and increase the superheat.

[0021] III. Physical Delineation and Locking of the Pure Liquid Refrigerant Extraction Section Through extensive experiments and thermodynamic analysis, the inventors have for the first time precisely defined a specific section in a vapor compression cycle in which pure, medium-temperature, medium-pressure single-phase liquid refrigerant can be stably extracted.

[0022] Inside the condenser, the refrigerant undergoes three distinct phase regions: a superheated vapor region at the inlet, a gas-liquid two-phase condensation region in the middle, and a subcooled liquid region near the outlet. One of the core findings of this invention is that only in the subcooled liquid region can the refrigerant be guaranteed to be 100% pure liquid, containing no gaseous components. In the superheated and two-phase regions, due to the presence of gaseous or gas-liquid mixtures, it is impossible to guarantee the extraction of a stable pure liquid refrigerant. If the refrigerant is extracted from the two-phase region, the extracted working fluid will inevitably be a gas-liquid mixture, whose phase, density, and flow rate fluctuate drastically with the load, thus losing its foundation as a stable energy reuse medium.

[0023] The experiment further revealed that, under standard refrigeration conditions, for common R32 or R410A air conditioning systems, when the condensing temperature is approximately 50°C to 55°C, the pure liquid subcooled refrigerant in the condenser typically begins to stably form in the last fifth of the condenser piping, at which point the refrigerant temperature has dropped below approximately 50°C. This pattern provides a clear physical criterion for determining the extraction point.

[0024] Therefore, the specific extraction section of this invention is precisely defined as: the subcooled section within the condenser where the refrigerant temperature has dropped below the saturation temperature corresponding to the current pressure, or the piping section following the subcooled section and preceding the throttling device. This limitation excludes any method of extracting refrigerant from the superheated zone, two-phase zone, or evaporator side of the condenser, because these methods either cannot obtain 100% pure liquid refrigerant, or the pressure and temperature of the refrigerant do not meet the "medium temperature and medium pressure" conditions, thus failing to achieve the energy reuse function disclosed in this invention.

[0025] The reason for not drawing materials from other pipelines in the system is not merely because it is "engineering infeasible," but rather based on the aforementioned objective physical laws: The superheated zone (inlet section) of the condenser contains high-temperature and high-pressure gas, and no liquid refrigerant can be extracted.

[0026] Condenser two-phase zone (middle section): gas and liquid are mixed, making it impossible to stably extract a single liquid phase.

[0027] Before the subcooling zone of the condenser: the refrigerant is in a saturated state, and even slight pressure fluctuations can cause flashing, making it impossible to guarantee the stability of pure liquid extraction.

[0028] After the throttling device: the refrigerant pressure has dropped to near the evaporation pressure, and the temperature is too low, so it loses its value as a "medium temperature and medium pressure" energy reuse medium.

[0029] Only the subcooled section within the condenser and its downstream piping can simultaneously satisfy the triple physical characteristics of "pure liquid," "moderate temperature," and "stable pressure," making it the only feasible extraction section determined by physical laws. Any attempt to extract pure liquid refrigerant from non-subcooled regions is thermodynamically unsustainable.

[0030] IV. Binary Division of Working Fluid and Principle of Redundant Working Fluid Recovery

[0031] This invention, through extensive field measurements, quantitatively reveals for the first time that in traditional throttling refrigeration systems, approximately 55% of the base refrigerant is used to maintain steady-state operation, while the remaining approximately 45% is high-grade redundant pure liquid refrigerant. This redundant refrigerant has long been considered an irreversible entropy increase factor in traditional thermodynamic analysis and thus regarded as an unrecoverable energy loss. This invention overcomes this technical bias, proving that this 45% pure liquid medium-temperature, medium-pressure refrigerant is precisely the most efficient energy reuse medium within the system.

[0032] Under full-load rated operating conditions, the minimum throttling liquid mass flow rate required to maintain the target superheat at the evaporator outlet is measured, and the mass of working fluid required for the basic supply per unit cycle is obtained by integration. The total mass of medium-temperature, medium-pressure liquid refrigerant in the pipeline section from the condenser outlet to the front end of the throttling device is denoted as M_total. The redundant working fluid mass M_redundant = M_total - M_base. When the ratio of M_redundant / M_total is in the range of 0.42 to 0.48, it is determined that the system has approximately 45% recoverable redundant pure liquid refrigerant.

[0033] This invention pioneers an overflow-type self-locking main and secondary zoned liquid storage structure and a ternary zone-layered energy storage component. It physically separates approximately 55% of the basic supply working fluid from approximately 45% of the redundant, surplus pure liquid refrigerant using a purely physical mechanical self-locking method: the main storage zone or main supply chamber prioritizes 100% supply to the main circulation system, while only the surplus pure medium-temperature, medium-pressure liquid refrigerant exceeding the safe level of the main storage zone or main supply chamber automatically flows into the secondary energy storage zone or transition buffer / energy storage chamber through the overflow structure. The secondary energy storage zone or energy storage chamber provides sealed, layered energy storage and tiered reuse of the redundant working fluid, achieving secondary and multiple efficiency enhancements. The recovery of redundant working fluid increases the system's high-pressure working fluid recovery rate from 0% to over 40%.

[0034] It should be emphasized that the aforementioned ternary zone and overflow self-locking structure are preferred embodiments of the present invention, but not the only way to achieve extraction and utilization. The core of the present invention lies in the discovery that the medium-temperature, medium-pressure liquid refrigerant in the subcooled section of the condenser and its downstream piping section is an extractable and usable independent energy reuse medium. Any act of extracting ≥1% of the medium-temperature, medium-pressure liquid refrigerant from this section and performing any form of secondary utilization or release falls within the protection scope of the present invention. Regardless of whether a simple bypass pipeline or a complex liquid storage structure is used, as long as the core step of "extraction + secondary utilization / release" is implemented, the principle discovery of the present invention is utilized.

[0035] V. Principle of Liquid Phase Margin Determination

[0036] Whether a medium-temperature, medium-pressure liquid refrigerant can enter a stratified energy storage module depends not only on the pressure location but also on the liquid phase margin. The liquid phase margin is defined as: ΔT_sub_mid = T_sat(P_mid) - T_mid Where T_sat(P_mid) is the saturation temperature of the refrigerant at the intermediate pressure P_mid, and T_mid is the refrigerant temperature at the inlet of the extraction component.

[0037] When ΔT_sub_mid is not less than the preset minimum liquid margin (usually 3K to 5K), it is determined that the refrigerant remains in a single liquid phase; when ΔT_sub_mid is less than the minimum liquid margin, the pressure drop should be reduced or the extraction branch should be closed to prevent flash refrigerant from entering the energy storage chamber.

[0038] VI. Three-dimensional tiered energy storage architecture (preferred implementation method) In a preferred embodiment, this invention constructs a complete ternary interval layered energy storage system: (I) Structural Hierarchy: Main liquid supply chamber → Transition buffer chamber → Energy storage chamber, with two overflow channels forming a mechanical liquid supply priority. The liquid refrigerant entering the ternary layered energy storage component sequentially satisfies the liquid supply needs of the main liquid supply chamber, the storage needs of the transition buffer chamber, and the storage needs of the energy storage chamber. The outlet of the main liquid supply chamber is directly connected to the second throttling device and the evaporator. The transition buffer chamber absorbs short-term flow fluctuations at the outlet of the first pressure regulating device, and the energy storage chamber stores surplus working fluid for cascade energy recovery. The two overflow channels form a mechanical liquid supply priority, ensuring that even if the controller loses its active regulation of the auxiliary branch, the liquid refrigerant entering the main liquid supply chamber will still flow to the second throttling device through the bottom outlet of the main liquid supply chamber first, and will not directly cut off the liquid supply to the evaporator due to the opening of the auxiliary storage and release branch.

[0039] The correspondence between the ternary layered energy storage components and the main and secondary zone liquid storage structures is as follows: the main storage zone corresponds to the main liquid supply chamber + the transition buffer chamber, which together undertake the functions of priority liquid supply and flow buffering; the secondary energy storage zone corresponds to the energy storage chamber, which undertakes the functions of surplus working fluid storage and cascade energy recovery.

[0040] (II) Functional Hierarchy: The adjustable liquid storage ratio is divided into three non-overlapping operating ranges: Stable liquid supply range (1% to 30% trace range): Perform pre-cooling at the front end of the evaporator to reduce flash loss; Sensible heat regulation range (30% to 50% phase change energy efficiency range): Simultaneous implementation of cooling precooling and phase change storage and heat release of medium temperature and medium pressure refrigerant external heat source for bidirectional efficiency enhancement, heating DAPF is increased by more than 1.2; Composite storage and release range (50% to 80% large capacity range): Performs long-term thermal energy storage and release across seasons and days.

[0041] The threshold values ​​are not based on a fixed ratio independent of the model, but are calibrated step by step during the equipment commissioning phase based on the compressor suction superheat, main liquid pipe subcooling, evaporation pressure and exhaust temperature.

[0042] The adjustable liquid storage ratio is the ratio of the sum of the refrigerant masses in the transition buffer chamber and the energy storage chamber to the total refrigerant mass of the system. The adjustable liquid storage mass within the stratified energy storage module is: M_adjustable = ρ_liquid × (V_buffer + V_storage) Where ρ_liquid is the liquid density of the refrigerant at intermediate pressure and corresponding temperature, V_buffer is the liquid volume determined based on the liquid level of the transition buffer chamber, and V_storage is the liquid volume determined based on the liquid level of the energy storage chamber.

[0043] The system load rate is defined as: LR = Q_demand / Q_rated, where Q_demand is the current demand load determined based on the indoor and outdoor temperature difference, the number of terminal units turned on, and the compressor operating status, and Q_rated is the rated load of the unit.

[0044] (III) Safety Constraints: The upper limit of the safe liquid storage is determined based on the following constraints: the suction superheat is not lower than the minimum superheat, the exhaust temperature is not higher than the upper limit, and the evaporation pressure deviation does not exceed the allowable deviation. Excessive storage of refrigerant in the energy storage chamber will reduce the effective circulation quality within the main cycle and increase the superheat at the evaporator outlet. This invention determines the operating range separately by adjusting the liquid storage ratio rather than the geometric volume of the liquid storage chamber.

[0045] VII. The dual-effect synergistic mechanism of subcooling heat exchange and flash suppression in the main liquid pipe, and the dual-benefit return gas heating path (preferred implementation method) (I) Indirect heat exchange architecture and full protection of heat exchangers Medium-temperature, medium-pressure liquid refrigerant from the transition buffer chamber and / or energy storage chamber is throttled and depressurized to near its evaporation pressure by an auxiliary throttling device, forming a gas-liquid mixture at a temperature of approximately 5℃±3℃. This low-temperature cold source is introduced into the low-temperature side of the main liquid pipe subcooling heat exchanger, where it undergoes non-contact indirect heat exchange with the medium-temperature, medium-pressure liquid refrigerant at the condenser outlet on the high-temperature side.

[0046] The auxiliary mass flow rate is: m_aux = C_v × α × √(ΔP_aux), where m_aux is the refrigerant mass flow rate of the auxiliary branch, C_v is the flow coefficient of the auxiliary throttling device, α is the relative opening of the auxiliary throttling device, and ΔP_aux is the pressure difference between the two ends of the auxiliary throttling device.

[0047] The controller adjusts the opening of the auxiliary throttling device based on the subcooling deviation and the suction superheat limit deviation. It's not advisable to have a larger subcooling; when the subcooling increment has reached the economic limit allowed by the current heat exchanger and compressor, further increasing the auxiliary flow may result in an increase in compression work exceeding the increase in cooling capacity. The controller then stops increasing the auxiliary branch opening accordingly.

[0048] The dual-benefit return gas heating path: After heat exchange in the main liquid pipe subcooling heat exchanger, the refrigerant in the auxiliary branch absorbs heat from the high-pressure side, and its temperature rises from 5℃±3℃ to above 5℃, gradually changing from a gas-liquid mixed state to a superheated state. This heated refrigerant flows into the compressor return gas pipeline or liquid storage tank, simultaneously increasing the return gas superheat, reducing the risk of liquid carryover in the return gas, and minimizing the risk of liquid slugging in the compressor. This is the "dual benefit": the refrigerant in the auxiliary branch first acts as a low-temperature cold source in the main liquid pipe subcooling heat exchanger to increase the subcooling of the main cycle and increase the cooling capacity; then, it acts as a superheated medium in the return gas pipeline to increase the return gas temperature, ensuring the safe operation of the compressor.

[0049] Main liquid tube subcooling heat exchanger types include, but are not limited to: Plate heat exchangers: brazed plate type, detachable plate type, and semi-brazed plate type; Shell-and-tube heat exchangers: single-tube, double-tube, and multi-head spiral shell-and-tube; Shell and tube heat exchangers: fixed tube sheet type, floating head type, U-tube type; Microchannel heat exchangers: parallel flow microchannel, multi-port extruded tube microchannel; Coaxial tube heat exchanger: A coaxial tube heat exchanger with a spiral bellows inner tube. Falling film heat exchangers: vertical falling film type and horizontal falling film type.

[0050] The above heat exchanger types can be used individually or in any combination. The high-temperature side refrigerant and the low-temperature side refrigerant are physically isolated through the heat exchange wall, maintaining an indirect heat exchange method that is non-contact and non-mixing.

[0051] (II) Mechanism of COP Enhancement by Subcooling Extensive experimental verification shows that in R32 air conditioning systems, for every 1K increase in subcooling, the system COP increases by more than 0.6%, with a measured average of approximately 0.67%. A linear regression equation was obtained through fitting: COP improvement (%) = 0.67 × ΔT_sub - 1.28 (R² = 0.998, extremely high goodness of fit) Based on measured data, supercooling is divided into three levels: low, medium, and high. The gear's subcooling range increases COP, reduces flash gas emissions, and is applicable to various scenarios. Low-end 8K-12K: 2.0%-4.9% (New Level 1 Energy Efficiency Equipment) (9.5%-21.4%) Mid-range (12K-20K): 4.9%-10.6% 21.4%-40.5% Regular new machine mass production and existing machine upgrades High-end (20K-24K and above): 10.6%-12.6% and above, 40.5%-45.2% and above; extreme climate zones and superimposed systems. Existing regenerator and subcooler solutions typically only increase the subcooling to the 5K to 8K range. In a preferred embodiment, this invention increases the subcooling to over 10K, significantly exceeding existing technology and constituting one of the operational parameter fingerprints for determining whether the technical solution of this invention is adopted.

[0052] (III) Mechanism of secondary enhancement by flash suppression

[0053] This invention significantly reduces the temperature of the liquid refrigerant entering the second throttling device by increasing the subcooling of the main liquid pipe to over 10°C. Experiments show that increasing the subcooling from 5K to 20K reduces the amount of flash gas after throttling by more than 40%.

[0054] The reduction of flash gas results in the following secondary synergistic effects: The dryness of the refrigerant at the evaporator inlet decreases, and the two-phase heat transfer coefficient increases by 10% to 15%. With an increased effective heat exchange area in the evaporator, the evaporation temperature can be increased by 1K to 2K. The compressor's suction volume is reduced, resulting in a 2% to 3% increase in volumetric efficiency; Evaporation pressure fluctuations are reduced, resulting in more stable system operation.

[0055] In summary, the contribution of subcooling improvement to APF is achieved through two paths: Path one is that subcooling improvement directly increases the cooling capacity per unit mass, resulting in a linear increase in COP; Path two is that subcooling improvement suppresses flashover after throttling, improves the heat exchange efficiency of the evaporator and the volumetric efficiency of the compressor, resulting in secondary efficiency enhancement.

[0056] (iv) Unique advantages of non-contact indirect heat exchange There are fundamental differences between this scheme and the scheme of direct heat exchange between low-pressure return gas and high-pressure liquid pipe in the regenerator: (1) media isolation, no risk of cross-contamination; (2) can withstand the high pressure difference between the high-temperature side and the low-temperature side; (3) liquid-liquid / gas-liquid indirect heat exchange coefficient is higher than gas-gas direct heat exchange; (4) control loops are decoupled from each other and have strong independence.

[0057] VIII. Overlay System Adaptation Scheme This invention is applicable to single-unit multi-stage cascade units and dual-unit multi-stage cascade units. In a cascade system, the low-pressure stage condenser and the high-pressure stage evaporator are coupled through an interstage heat exchanger, which simultaneously undertakes the condensation function of the low-pressure stage and the evaporation function of the high-pressure stage.

[0058] Three deployment modes are provided: Mode 1 (Low-Pressure Stage Extraction): Medium-temperature, medium-pressure liquid refrigerant is extracted from the interstage piping section between the low-pressure stage condenser outlet and the front end of the high-pressure stage throttling device. Since the low-pressure stage condensing temperature is typically -5℃ to 15℃, the extracted refrigerant temperature is relatively low, resulting in a particularly significant subcooling effect on the high-pressure stage liquid line, with subcooling reaching over 25K. This further increases the COP by 0.2 to 0.5 compared to a single-stage system.

[0059] Mode 2 (High-Pressure Stage Extraction): Extraction occurs in the interstage piping section between the high-pressure stage condenser outlet and the front end of the low-pressure stage throttling device. The high-pressure stage condensing temperature is typically 30°C to 55°C, resulting in a suitable extracted refrigerant temperature for scenarios involving external heat sources coupled with thermal storage.

[0060] Mode 3 (Dual-stage collaborative extraction): Refrigerant is extracted simultaneously from the interstage piping sections of both stages. The low-pressure stage extracts refrigerant for subcooling the high-pressure stage, and the high-pressure stage extracts refrigerant for superheating the return gas of the low-pressure stage, forming a cross-stage bidirectional efficiency-enhancing closed loop. The overall DAPF improvement is further increased by 0.2 to 0.5 compared to the single-stage system.

[0061] IX. Synergistic Effect of Non-azeotropic Mixed Working Fluids and Layered Energy Storage Non-azeotropic working fluids exhibit temperature glide characteristics during phase change, with a difference between their bubble point and dew point temperatures. In heat exchange, non-azeotropic working fluids can optimize the temperature matching between the working fluid and the heat source, reducing the heat transfer temperature difference within the heat exchanger and thus minimizing irreversible losses during the heat exchange process.

[0062] This invention is the first to deeply couple the temperature glide characteristics of non-azeotropic working fluids with stratified energy storage: When the liquid ratio in the secondary energy storage zone is within the 30% to 50% phase change efficiency range, the low-boiling-point component in the non-azeotropic working fluid preferentially evaporates and absorbs heat, while the high-boiling-point component preferentially condenses and releases heat, forming a micro-circulation within the energy storage chamber. The low-boiling-point component preferentially evaporates in the upper part of the energy storage chamber, absorbing heat from the main liquid pipe side; the high-boiling-point component preferentially condenses in the lower part of the energy storage chamber, releasing the latent heat of phase change. This micro-circulation significantly increases the effective heat storage density within the energy storage chamber compared to single-component refrigerants. The wider the temperature glide, the more significant the thermal stratification effect of the energy storage chamber, and the greater the increase in DAPF.

[0063] When the refrigerant is a non-azeotropic mixture, the controller determines the liquid storage ratio boundary value of the three energy storage zones based on the temperature slip width of the working fluid: when the slip width is ≥5K, the second liquid storage boundary value is increased to 45% to 55% to make full use of the phase change latent heat energy storage advantage of the non-azeotropic working fluid in a wide temperature range.

[0064] Meanwhile, the refrigerant replacement cycle of the energy storage chamber is automatically adjusted according to the working fluid's temperature glide characteristics: for non-azeotropic mixed working fluids, the replacement cycle is shortened by 20% to 30% compared to pure working fluids to prevent component stratification shift due to long-term stagnation and ensure that the temperature glide characteristics do not decay. For single-component refrigerants, the replacement cycle can be appropriately extended. The same control parameters cannot be mechanically applied to both.

[0065] 10. Vacuum-free integrated indoor unit The system features an integrated indoor unit assembly; the refrigerant connection pipes and the non-vacuum valve of the indoor unit are integrally welded together, and are pre-sealed and pre-charged with refrigerant before leaving the factory, with a static vacuum level not exceeding 20Pa at the factory; no on-site vacuuming is required after system installation, and the stratified energy storage effect remains unchanged. The coupling of the stratified energy storage structure with the integrated vacuum indoor unit can generate an additional synergistic energy efficiency gain of 0.06 to 0.10.

[0066] XI. Modification of Locking and Marking After the modification is completed, an irremovable modification nameplate is set on the outer surface of the equipment. The nameplate indicates the modification date, the type of working medium after modification, and the identification of the modification service provider. The controller stores the modified control logic and operating parameters in an unwritable encrypted storage module. The controller is locked in the modification mode and cannot be rolled back to the control logic before the modification.

[0067] 12. Controller Hardware Binding Architecture The controller described in this invention is a dedicated hardware controller, comprising the following inseparable hardware modules: (1) Status acquisition hardware: A first temperature sensor connected to the condenser outlet, a liquid level sensor connected to the auxiliary energy storage area or energy storage chamber, a second temperature sensor connected to the compressor exhaust port, a third temperature sensor connected to the high-temperature side outlet of the main liquid pipe subcooling heat exchanger, a liquid level sensor connected to the main liquid supply chamber, a liquid level sensor connected to the transition buffer chamber, and a pressure sensor. All sensor data are directly input to the controller chip without being converted by the software intermediate layer.

[0068] (2) Decision execution hardware: Independent PWM drive circuits connected to the first pressure regulating device, the second throttling device, the auxiliary throttling device, the return liquid regulating valve and the storage and release circulation valve. Each drive circuit directly controls the opening or closing of the corresponding actuator.

[0069] (3) Storage hardware: A one-time programmable storage chip with adjustable liquid ratio from 1% to 80%, first liquid boundary value, second liquid boundary value, safe liquid upper limit calculation logic, and cooperative gain mapping table.

[0070] Each PWM drive signal output by the controller directly acts on the corresponding physical actuator, directly changing the thermodynamic parameters of the refrigerant, such as pressure, temperature, flow rate, or level. All control logic is programmed into the one-time programmable memory area of ​​the hardware chip. Modifying the controller parameters requires replacing the entire hardware chip; it cannot be overwritten by software upgrades.

[0071] During the power-on self-test, the controller of this system can output electronic identification information containing the patent authorization number to the display screen. This information is stored in conjunction with the controller's hardware code.

[0072] Thirteen, Self-inspection of infringement and solidification of evidence The system includes an infringement self-inspection and evidence solidification device: a unique hardware encoding module (composed of a physical identifier code burned into the one-time programmable storage area of ​​the system controller chip, which cannot be erased or tampered with), a running fingerprint acquisition module (four sensors), a parameter comparison module (a threshold comparison circuit solidified in the controller's read-only memory), and an unwritable encrypted storage module (storing factory preset parameters that cannot be overwritten or erased by software updates).

[0073] When all four operating parameters fall within the numerical range defined in the claims, a device identification code containing a timestamp and hardware encoding is automatically generated. Modifying controller parameters requires a complete replacement of the hardware chip; it cannot be overridden by software upgrades.

[0074] XIV. Summary of Key Invention Points The core contributions of this invention compared to the prior art can be summarized into the following eleven key inventive points: (I) Principle-level discovery: The medium-temperature and medium-pressure liquid refrigerant in the subcooled section of the condenser and its downstream piping section was discovered and identified as an independent energy reuse medium that can be extracted and utilized in the vapor compression cycle system. This breaks through the technical prejudice that "the refrigerant at the condenser outlet can only be directly throttled" for a century. Furthermore, the "medium temperature and medium pressure" is precisely defined by the objective physical formula P_mid = P_c - X% × (P_c - P_e), which completely eliminates the ambiguity of the protection boundary. (II) Physical definition of the pure liquid extraction section: For the first time, the exclusive section for the stable extraction of pure medium-temperature and medium-pressure single-phase liquid refrigerant is precisely defined as the subcooled section in the condenser where the refrigerant temperature has dropped below the saturation temperature corresponding to the current pressure and the subsequent pipeline. This reveals the physical law of the stable generation of pure liquid refrigerant in the last fifth section of the condenser at a temperature of about 50°C, and eliminates the scheme of extraction from the superheated zone and the two-phase zone. (III) Binary Division Law: For the first time, the binary division law of the traditional throttling system is quantitatively revealed, with an effective utilization rate of about 55% for refrigerant and a redundancy of about 45% for pure liquid refrigerant. This breaks through the traditional theoretical misconception that the 45% redundant working fluid is regarded as an irreversible entropy increase factor, and proves that it is the most efficient energy reuse medium in the system. (iv) Simplified extraction and utilization scheme: A basic technical scheme is proposed to extract ≥1% of medium-temperature and medium-pressure liquid refrigerant from a dedicated section and reuse or release it in any form. This scheme does not depend on a specific liquid storage structure or heat exchange device and is the widest protection scope of this invention. (V) Ternary interval layered energy storage architecture: In the preferred scheme, a ternary interval layered energy storage architecture is created for the first time, which divides the entire adjustable liquid storage ratio from 1% to 80% into three non-overlapping operating intervals: stable liquid supply interval, sensible heat regulation interval, and composite storage and release interval. (vi) Liquid margin determination mechanism: Establish a liquid margin determination mechanism that uses the difference between the saturation temperature under intermediate pressure and the actual temperature of the refrigerant as the quantitative criterion for the single-phase / two-phase state of the refrigerant. (vii) Dual-path effect enhancement of subcooling and flash suppression: A non-contact indirect heat exchange scheme between the low-temperature cold source in the auxiliary branch and the high-pressure refrigerant in the main liquid pipe is proposed, which increases the subcooling degree from 5-8K in the traditional system to more than 10℃. It also provides full protection through heat exchanger type, covering plate type, shell and tube type, shell and tube type, microchannel type, coaxial tube type, falling film type and any combination thereof. The dual-path effect enhancement mechanism of subcooling degree enhancement is discovered and verified: Path one is the direct effect enhancement of COP by 0.67% for every 1℃ increase in subcooling degree; Path two is the secondary effect enhancement of more than 40% reduction in flash gas amount after throttling due to the increase in subcooling degree. (viii) Two-in-one return gas temperature rise path: Discover and utilize the two-in-one technical path of the auxiliary branch refrigerant absorbing heat and the temperature rising to above 5℃: the auxiliary branch refrigerant first acts as a low temperature cold source in the main liquid pipe subcooling heat exchanger to increase the subcooling of the main circulation and increase the cooling capacity, and then acts as a superheating medium in the return gas pipeline to increase the return gas temperature and reduce the risk of compressor liquid slugging. (ix) Multi-dimensional and three-dimensional protection: Construct a protection network of nine independent claims covering the minimally simplified extraction and utilization method, extraction and utilization system, dual-purpose method, redundant working fluid binary division, core energy storage system, control method, liquid storage structure, energy efficiency control, and infringement self-inspection device; the system is compatible with single-level system, single-machine multi-level cascade system and dual-machine multi-level cascade system; (x) Dual locking mechanism of parameter fingerprint and circumvention judgment: Establish a dual infringement locking mechanism of structural circumvention judgment and parameter fingerprint judgment. The operating parameters such as supercooling ≥10K, superheating 3K to 8K, and COP increase ≥2% constitute an unavoidable infringement judgment fingerprint. Supplemented by hardware coding, operating fingerprint collection, threshold comparison circuit and unwritable storage module, a complete infringement self-inspection and evidence solidification closed loop is formed. (xi) Full coverage of all refrigerants, all scenarios and the entire life cycle: The system is compatible with R32, R410A, R290, R134a, R454B, R407C, CO2 and multi-component mixed refrigerants. It can be detached and connected to existing equipment in the form of independent modular assemblies, covering all scenarios of new machine mass production and existing equipment renovation. The energy efficiency improvement after renovation is independent of the type of refrigerant.

[0075] XV. Energy Efficiency Synergistic Control Methods The controller has a built-in collaborative gain mapping table, which is obtained through experimental calibration at no less than 5 extraction ratio points. It includes the contribution of subcooling directly to COP and the secondary contribution of flash gas suppression to evaporation efficiency.

[0076] The controller determines the target subcooling ΔT_target by consulting a mapping table based on the refrigerant ratio y in the energy storage cavity. Then, it adjusts the opening of the auxiliary throttling device according to the deviation between the target and actual subcooling, forming a closed-loop control. This method translates the theoretical calculation model into an executable table-lookup algorithm in an industrial controller, demonstrating high engineering practicality.

[0077] Beneficial effects Breaking through a century of technological bias, a principle-level discovery: For the first time, it was discovered that the medium-temperature, medium-pressure liquid refrigerant in the subcooled section of the condenser and its subsequent piping sections is an independent energy reuse medium that can be extracted and utilized within the system. For the first time, it quantitatively revealed the binary division law of 55% / 45% working fluid, breaking through the traditional theoretical misconception that the 45% redundant pure liquid refrigerant is regarded as irreversible entropy increase. The "medium temperature, medium pressure" is precisely defined by the objective physical formula P_mid = P_c - X% × (P_c - P_e), and the protection range is clear and specific. Physical definition of the pure liquid extraction section: For the first time, the exclusive section where pure liquid refrigerant can be stably extracted is defined as the subcooled section of the condenser and its subsequent piping. This reveals the physical law of the stable generation of pure liquid refrigerant in the last fifth of the condenser section, below about 50°C, which eliminates extraction schemes outside the subcooled section. This provides a solid physical basis for the rights protection argument. The minimalist solution covers all scenarios: The basic technical solution for extracting ≥1% medium-temperature and medium-pressure liquid refrigerant and reusing or releasing it in any form does not rely on specific liquid storage structures or heat exchange devices, and competitors cannot circumvent it by replacing or simplifying the structure. Leapfrog improvement in energy efficiency: The heating DAPF is increased by more than 1.2 in the 30% to 50% phase change energy efficiency range, the APF of the whole unit reaches 1.66 times the national standard first-level energy efficiency benchmark value, the high-pressure working fluid recovery rate is ≥40%, the energy storage density is more than 3 times that of water thermal storage and more than 1.5 times that of PCM paraffin energy storage, and no additional pumping power consumption is required. The dual-path approach of supercooling enhancement and flash suppression achieves two goals at once: the supercooling is increased to above 10°C (current technology typically only offers 5-8K), and each 1°C increase in supercooling increases the COP by 0.67%, reducing flash gas emissions by more than 40% after throttling; the refrigerant in the auxiliary branch absorbs heat and its temperature rises to above 5°C before flowing into the return gas pipeline, simultaneously increasing the superheat of the return gas and reducing the risk of liquid slugging, thus achieving two goals at once; Main liquid tube subcooling heat exchanger type full range protection: Cover plate type, shell and tube type, microchannel type, coaxial tube type, falling film type and any combination thereof. The non-contact indirect heat exchange method has unique advantages such as media isolation, pressure difference resistance, high heat exchange efficiency and independent control. Universal for all refrigerants and permanently compliant with regulations: Compatible with R32, R410A, R290, R134a, R454B, R407C, CO2 and multi-component mixed refrigerants, meeting the low GWP compliance requirements of the 2027 EU F-gas regulations and compatible with the 2026 version of the DAPF national standard. Overlay system adaptation: Provides three deployment modes: low-pressure stage extraction, high-pressure stage extraction, and dual-stage collaborative extraction, with an overall DAPF improvement of 0.2 to 0.5 compared to single-stage systems; The system covers both new production and existing equipment retrofitting: The ternary interval layered energy storage components are provided in the form of independent modular assemblies. During retrofitting, there is no need to replace the original compressor, heat exchanger or refrigeration oil. The energy efficiency improvement after retrofitting is independent of the refrigerant type; it is also applicable to equipment using refrigerants such as R22 that have been banned. Overflow self-locking mechanical liquid supply priority: The main liquid supply chamber is given priority in liquid supply through a purely physical means, and only the excess working fluid enters the energy storage chamber. Even if the controller fails, the liquid supply to the evaporator will not be cut off, which is extremely safe. Liquid margin determination mechanism: The single-phase / two-phase state of the refrigerant is quantitatively determined by objective temperature difference, which prevents flash refrigerant from accidentally entering the energy storage cavity from the principle level; Controller hardware-bound architecture: Status acquisition, decision execution, and parameter storage are all embedded in a dedicated hardware chip, which cannot be overwritten or tampered with by software upgrades, forming a physical barrier against reverse engineering. Infringement self-inspection and evidence solidification: Unique hardware code + four-sensor operation fingerprint + threshold comparison circuit + unwritable storage module to achieve proactive protection of patent rights and automatic evidence collection; Dual locking of avoidance judgment and parameter fingerprint: Structural replacement still falls within the protection scope. The measured parameters (supercooling ≥10K, superheating 3K to 8K, COP increase ≥2%) falling within the limited range constitute the basis for infringement judgment, and the cost of rights protection and evidence collection is extremely low. Synergistic effect of non-azeotropic mixed working fluid: For the first time, temperature glide characteristics are coupled with the depth of stratified energy storage. When the glide width is ≥5K, the liquid ratio boundary value and replacement cycle are automatically adjusted to maximize the utilization of the latent heat of phase change energy storage in a wide temperature range. Vacuum-free integrated indoor unit: It is pre-sealed and vacuum-sealed before leaving the factory, so there is no need to vacuum on site after installation. It generates additional synergistic energy efficiency gains when coupled with the layered energy storage structure. Controller Locking and Modification Nameplate: Once modified, the controller cannot be reverted, and the modification nameplate cannot be removed, forming a permanent modification record and genuine identification. The significant advantages of this invention compared to the closest existing technology, CN200510082831.9: Under the same operating conditions, the DAPF of this invention is 3.4 to 4.3 times that of the existing technology, achieving unexpected technical effects; when the "overflow self-locking" mechanical sequence is removed, the DAPF increase drops sharply to 0.15, which in turn verifies the irreplaceability of the overflow self-locking layered energy storage structure. Attached Figure Description

[0078] Figure 1 This is a flowchart of a medium-temperature, medium-pressure liquid refrigerant stratified energy storage and refrigeration efficiency enhancement system according to the present invention; Figure 2 This is a partial view of the overflow self-locking main and auxiliary partition liquid storage structure; Figure 3This is a flow chart of a three-stage stratified energy recovery process; Figure 4 This is a logic block diagram for all-season adaptive regulation. Detailed Implementation

[0079] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. 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.

[0080] All embodiments use the APF benchmark value of 5.0 for Grade 1 energy efficiency specified in the national standard GB 21455-2024 and the DAPF benchmark value of 5.5 for Grade 1 energy efficiency in the 2026 version as a unified reference benchmark.

[0081] Example 0 (Simplest Implementation - Bypass Direct Extraction and Storage) A 1.5 HP household R32 air conditioner is used. A bypass capillary tube is installed in the piping section after the subcooling section of the condenser and before the throttling device to extract approximately 5% of the medium-temperature, medium-pressure liquid refrigerant (P_mid satisfies the definition of claim 1, X≈35%), and this is introduced into a sealed liquid storage tank for storage and later use. When the system needs it, the stored liquid refrigerant is released back to the low-pressure side to participate in the circulation. This embodiment demonstrates that even without using any complex energy storage components or heat exchangers, the secondary utilization of medium-temperature, medium-pressure liquid refrigerant can be achieved simply through bypass extraction + storage + release, falling within the widest protection scope of this invention. Testing shows that this scheme can improve the system COP by approximately 1.5%.

[0082] Example 1 (Extraction, storage, and release – confirming that any secondary use constitutes infringement) Based on Example 0, the stored liquid refrigerant is directly discharged to an external recycling container (simulating a maintenance and recycling scenario). This is the "extraction + release" utilization method, which falls within the protection scope of "secondary utilization or release" in Independent Claim 1 of this invention. This embodiment demonstrates that regardless of whether the utilization method after extraction is beneficial (improving energy efficiency), neutral (storage for later use), or seemingly harmful (emission), as long as the act of extracting ≥1% of medium-temperature, medium-pressure liquid refrigerant from the subcooled section of the condenser and its downstream pipelines and performing secondary utilization or release is carried out, the principle discovery of this invention is utilized, constituting infringement.

[0083] Example 2 (Optimal Scheme for 1.5HP Home Wall-Mounted Air Conditioner with Ternary Interval Layered Energy Storage) The unit is equipped with a ternary-level stratified energy storage module, with an adjustable liquid refrigerant storage ratio of 40% at medium temperature and medium pressure, and is matched with a pre-sealed indoor unit that does not require vacuuming. A brazed plate heat exchanger is used as the main liquid pipe subcooling heat exchanger. According to actual measurements in the enthalpy difference laboratory based on GB / T 7725 standard operating conditions, the modified unit has an APF of 8.3 and a DAPF of 9.0. The net APF increase contributed by this invention is 2.5 (8.3-5.8), making the unit's APF 1.66 times the national standard level 1 energy efficiency benchmark value of 5.0.

[0084] Verification of the binary working fluid partitioning in Example 2: Actual measurements showed that the basic liquid working fluid, with an effective utilization rate of approximately 55%, maintained steady-state operation of the main circulation. The remaining approximately 45% redundant pure liquid refrigerant entered the energy storage chamber through an overflow self-locking structure for stratified energy storage and cascaded reuse. Before the modification, this 45% redundant working fluid was entirely dissipated ineffectively; after the modification, a recovery rate of 40.5% was achieved through three-stage cascaded energy recovery.

[0085] Verification of the dual benefits of Example 2: After the refrigerant in the auxiliary branch absorbs heat through the subcooling heat exchanger in the main liquid pipe, its temperature rises from approximately 5°C to approximately 12°C. Upon entering the return gas line, this increases the compressor suction superheat from 3K to 5.2K, effectively reducing the risk of liquid slugging. Simultaneously, the subcooling in the main liquid pipe increases from 5K to 21.5K, achieving both enhanced subcooling efficiency and increased return gas temperature.

[0086] Equilibrium analysis in Example 2: Before and after the project renovation Compressor input voltage 100% (Base 100%) The high-pressure working fluid at the condenser outlet is 42% After throttling, the working fluid concentration is 18% (throttling loss 24%) and 35% (throttling loss only 7%). Evaporator outlet working fluid: 12%-22% System efficiency 38% 58% High-pressure working fluid recovery rate: 0% - 40.5% Example 3 (Verification of 1.5HP One-to-Two Multi-Indoor Unit Adaptation) The outdoor unit is equipped with a ternary zone-level energy storage component, with an adjustable and stable liquid refrigerant storage ratio of 40% at medium temperature and medium pressure. When driving a 1.5 HP indoor unit and a 1 HP indoor unit simultaneously, the tiered energy storage structure automatically adapts to the load changes of both units. Actual measurements show that the DAPF (Daily Amount Per Utilization) increases by more than 1.2 on the 1.5 HP indoor unit side and by more than 1.0 on the 1 HP indoor unit side.

[0087] Example 4 (1.5HP three-split commercial multi-split air conditioner) The outdoor unit is equipped with a ternary layered energy storage module. The excess working fluid in the energy storage chamber is distributed to the three branch indoor units on demand through multiple bypass branches, realizing the collaborative reuse of redundant working fluid across branches in a one-to-three multi-split system scenario. The energy efficiency of each branch is improved in a balanced manner, and the overall unit's DAPF is improved by more than 1.0.

[0088] Example 5 (Refrigeration and freezing unit with large capacity and long-term energy storage) The energy storage chamber is expanded to store 70% of medium-temperature, medium-pressure liquid refrigerant, making it suitable for all-weather operation of cold storage. During low-temperature heating and defrosting stages, sensible heat and latent heat of phase change are continuously released, resulting in a DAPF increase of 1.05 under low-temperature conditions.

[0089] Example 6 (Non-destructive retrofitting of existing equipment: controller locking and nameplate labeling) A 1.5 HP R22 air conditioner was retrofitted: the original R22 refrigerant was recycled, the original throttling structure was removed, and an integrated metallurgically welded, vacuum-sealed assembly was installed. The piping section from the condenser outlet to the front end of the original throttling device was connected to a ternary tiered energy storage module. A coaxial tube heat exchanger was used as the main liquid tube subcooling heat exchanger, facilitating installation in confined spaces. After the retrofit, an irremovable retrofit nameplate was installed on the outer surface of the equipment. The controller's modified control logic was permanently stored in an unrewritable encrypted storage module, locked in retrofit mode. After the retrofit, the equipment's APF and DAPF indicators improved simultaneously by 20% to 30%.

[0090] The same modification steps were performed on another existing R410A equipment. The energy efficiency improvement after the modification was basically the same as that after the R22 modification, which verified that the energy efficiency improvement after the modification was not related to the refrigerant type.

[0091] Example 7 (80% extraction upper limit calibration experiment) Using the system of Example 2 as the experimental platform, the extraction ratio was gradually increased under rated refrigeration conditions. The experimental results are as follows: Extraction ratio compressor suction superheat (°C) evaporator outlet superheat (°C) system status 50% 5.83.2 Stable operation 60% 5.52.8 Stable operation 70% 5.22.1 Stable operation 75% 5.11.8 Stable operation 80% of 5.01.5 is operating stably. 82% 4.8 0.9 Suction superheat is below the critical value of 5K 85% of the evaporator outlet is near saturation, posing a risk of liquid slugging. Conclusion: 80% is the safe extraction limit.

[0092] Example 8 (Full-condition adaptability verification) The system from Example 2 underwent full-condition adaptability verification in an enthalpy difference laboratory, with an ambient temperature range of -15°C to 55°C. Operating ambient temperature (°C) Adjustable reservoir ratio (%) Subcooling (K) Superheating (K) Exhaust temperature reduction (°C) Auxiliary branch return gas temperature (°C) APF / DAPF increase Rated cooling capacity: 354021.55.21212.5+2.5 Maximum cooling capacity: 463820.85.51013.2+2.1 Minimum cooling capacity: 214222.54.81411.8+2.8 Customized hot water 74520.26.11110.5+2.3 Maximum heating capacity: 244220.86.5911.0+1.9 Minimum heating capacity: -54821.55.8139.8 +2.6 Ultra-low temperature heating -155022.85.3158.5+3.1 Frosting condition 2 / 13523.24.51612.0+3.5 Conclusion: Under all operating conditions (-15℃ to 55℃), the subcooling at the main liquid pipe subcooling heat exchanger outlet remained ≥20K (far exceeding the 10K infringement determination baseline), the superheat remained between 3K and 8K, the auxiliary branch return gas temperature remained ≥5℃, the exhaust temperature decreased by ≥9℃, the APF / DAPF increased by ≥1.9, and the COP increased by ≥2%. The dual benefits and the infringement parameter fingerprint were both verified under all operating conditions.

[0093] Example 9 (Relationship between supercooling improvement and COP and verification of flash suppression) Using the system of Example 2 as an experimental platform, under rated refrigeration conditions, the refrigerant flow rate on the low-temperature side was changed by adjusting the opening of the auxiliary throttling device. The relationship between the subcooling degree at the high-temperature side outlet of the main liquid pipe subcooling heat exchanger and the system COP and flash gas quantity was measured as follows: Subcooling (K) COPCOP increase (%) Flash gas quantity (g / s) Flash gas decrease (%) Auxiliary branch return gas temperature (°C) 5 (Base) 3.50 Base 4.2 Base 2.5 83.57 + 2.03.89.55.8 103.62 + 3.43.614.37.5 123.67 + 4.93.321.49.2 163.77 + 7.72.833.311.5 203.87 + 10.62.540.513.0 243.94 + 12.62.345.214.5 The fitted linear regression equation is: COP increase (%) = 0.67 × ΔT_sub - 1.28, R² = 0.998.

[0094] Conclusion: For every 1K increase in subcooling, the average COP increases by approximately 0.67%. When the subcooling reaches 10K (the baseline for infringement determination of this invention), the COP increases by 3.4%, flash gas decreases by 14.3%, and the auxiliary branch return gas temperature rises to 7.5℃, demonstrating a dual benefit. When the subcooling increases from 5K to 20K, the COP increases by 10.6%, flash gas decreases by 40.5%, and the auxiliary branch return gas temperature rises to 13.0℃. Existing subcooler solutions typically only increase the subcooling to the 5K to 8K range, with a COP increase of approximately 1.8%-2.4%. The 10K subcooling baseline of this invention significantly surpasses the existing technology. The data verifies the complete technical effect chain of increased subcooling → linear increase in COP → secondary enhancement of flash gas suppression → return gas temperature rise to reduce liquid slugging.

[0095] Example 10 (Performance Comparison of Different Types of Main Liquid Tube Subcooling Heat Exchangers) In the system of Example 2, the following five types of main liquid pipe subcooling heat exchangers were replaced and installed respectively, keeping the heat exchange area basically the same (approximately 0.15 m²), and the subcooling improvement effect was tested: Heat exchanger type, high-temperature side outlet subcooling (K), COP increase (%), auxiliary branch return gas temperature (°C), applicable scenarios Brazed plate heat exchangers 22.5+11.813.5 are the preferred choice for compact spaces. Shell-and-tube heat exchanger 21.8+11.212.8 high pressure differential condition Microchannel heat exchanger 23.2+12.314.2 Lightweight requirements Retrofitting and adding existing coaxial tube heat exchangers (20.5+10.111.5). Shell-and-tube heat exchanger 21.0+10.812.0 large commercial system Conclusion: All five types of heat exchangers can increase the subcooling to over 20K (far exceeding the 10K infringement baseline), and the COP is increased by more than 10% (far exceeding the 2% infringement baseline). The return gas temperature of the auxiliary branch is also increased to over 5℃. This verifies the rationality and technical feasibility of the present invention for the full-domain protection of the main liquid tube subcooling heat exchanger, as well as the universality of the heat exchanger types that achieve two goals at once.

[0096] Example 11 (Verification of Two-Level Collaborative Extraction in Overlapping Systems) On an R32 / R744 two-stage cascade heat pump unit, Mode 3 (two-stage synergistic extraction) was implemented: medium-temperature, medium-pressure liquid refrigerant was extracted from the low-pressure stage condenser outlet for high-pressure stage subcooling, while simultaneously, medium-temperature, medium-pressure liquid refrigerant was extracted from the high-pressure stage condenser outlet for low-pressure stage return gas superheating. Measured results showed that the low-pressure stage subcooling increased from 5K to 22K, and the high-pressure stage superheating increased from 3K to 8K. After absorbing heat, the refrigerant in the auxiliary branch temperature rose above 10℃ before merging into the return gas line. The overall DAPF of the cascade system was further improved by 0.35 compared to the single-stage system.

[0097] Comparative Example 1 (eliminating the stratified reflux structure of the liquid storage) The remaining components are completely identical to those in Example 2, except that the return liquid pipeline from the energy storage chamber to the main liquid supply chamber and the auxiliary storage and release branch are removed. The overall APF of the unit decreases by 0.41, the synergistic additional gain generated by the coupling of each module completely disappears, and the dual benefits of gas return heating are lost.

[0098] Comparative Example 2 (using conventional split-type indoor unit installation) The factory-pre-sealed vacuum-sealed integrated indoor unit is eliminated, and conventional piping and on-site vacuum installation processes are adopted. The energy storage efficiency of the stratified liquid storage system decreases, with the overall APF (Average Power Filter) reduced by 0.08 to 0.10 compared to the integrated vacuum indoor unit.

[0099] Comparative Example 3 (System operating parameters deviate from the specified range) Adjusting the overflow channel height reduced the adjustable liquid storage ratio to 22% and the system subcooling to 5.5K. Measured refrigerant stratified energy storage reuse efficiency decreased by 46%, overall APF decreased by 0.51, and DAPF decreased by 0.59. When the subcooling dropped to 5.5K, the flash gas volume returned to the baseline level, the secondary enhancement effect was lost, the auxiliary branch return gas temperature only rose to 2.8℃, and the risk of liquid slugging increased. COP improvement was only 1.5%, below the 2% infringement baseline.

[0100] Comparative Example 4 (Reverse Verification of Material Extraction from Non-Dedicated Sections) On the same 1.5 HP R32 air conditioner, energy storage was performed by sampling from the condenser inlet (superheated zone), the middle section of the condenser (two-phase zone), the evaporator outlet, and the two-phase zone after throttling. The DAPF increase from sampling in each non-dedicated zone was less than 0.15 or even decreased, with only the DAPF from sampling in the subcooled section of the condenser and its subsequent piping increasing by 1.2. This comparative example verifies the irreplaceable nature of the subcooled zone as a dedicated extraction zone: no liquid refrigerant can be extracted from the superheated zone, and pure liquid working fluid cannot be stably extracted from the two-phase zone.

[0101] Comparative Example 5 (Horizontal comparison with existing energy-saving solutions) On the same 1.5 HP R32 air conditioner, five existing energy-saving solutions in the industry were implemented: inverter compressor upgrade, electronic expansion valve replacement, external economizer with supplemental gas injection to increase enthalpy, conventional liquid receiver capacity expansion, and external PCM paraffin energy storage. The DAPF improvement of each solution was 0.35, 0.28, 0.42, 0.15, and 0.22, respectively, and the COP improvement was less than 2%. This invention achieves a DAPF improvement of 1.2 and a COP improvement of ≥2% in the 30% to 50% phase change energy efficiency range, achieving results far exceeding any single or combined solution with limited hardware incremental costs.

[0102] Comparative Example 6 (Comprehensive comparison with the closest existing technology CN200510082831.9) A comparison was made under the same 1.5 HP R32 air conditioner and the same national standard GB / T 7725 operating conditions: Comparison dimension CN200510082831.9 This invention (30%-50% range) multiple Extraction section of condenser outlet piping (undefined subcooled section) condenser subcooled section and subsequent piping (defined by physical laws) — The maximum increase in supercooling is 8-10K or more, and above 20K, it is ≥2 times. Has the supercooling reached the 10K baseline? No (10K is the maximum limit) Yes (above 20K, far exceeding the baseline) — COP increases by approximately 1.8%-2.4%, or more than 10.6%, or ≥4.4 times. Does the COP improvement reach the 2% baseline threshold? Yes, it far exceeds the baseline. DAPF increase of 0.28-0.35 or above 1.2, ≥3.4 times. Flash gas suppression does not involve a reduction of more than 40%, which is incomparable. Redundant working fluid recovery does not involve 45% recovery + cascade reuse, making it incomparable. Liquid supply priority guarantee is incomparable to (no bypass direct diversion) and (overflow self-locking mechanical priority). Cross-period energy storage is incomparable to large-capacity, long-term energy storage with a capacity of 50%-80%. The auxiliary branch return gas heating reduces liquid slugging and raises the temperature to above 5°C, achieving two benefits in one go. Conclusion: The DAPF improvement of the CN200510082831.9 scheme is 0.28 to 0.35, while the DAPF improvement of this invention in the 30% to 50% phase change efficiency range is over 1.2, which is 3.4 to 4.3 times that of the prior art. This leapfrog improvement cannot be foreseen through simple parameter adjustments or component replacements. When the "overflow self-locking" mechanical sequence is eliminated and only the auxiliary throttling branch is retained, the DAPF improvement drops sharply to 0.15, which in turn verifies the irreplaceability of the overflow self-locking layered energy storage structure. The CN200510082831.9 scheme does not involve the dual-purpose technical path of reducing liquid slugging by allowing the auxiliary branch refrigerant to absorb heat and then return to warm the gas. More importantly, CN200510082831.9 failed to recognize the principle that the medium-temperature and medium-pressure liquid refrigerant in the subcooled section of the condenser is an extractable and usable independent energy reuse medium, and its bypass is only used as a one-time means of subcooling. In contrast, the simplified solution of this invention (Examples 0 and 1) reveals that energy efficiency gains can be achieved by any form of extraction and utilization.

[0103] Example of a single feature point for infringement determination Example 1 (Simplest Extraction and Utilization Determination): If any form of extraction branch (whether a bypass capillary tube, external storage tank, or other structure) is found on the subcooled section of the condenser or on the subsequent high-pressure section of a refrigeration unit, and this extraction branch leads the liquid refrigerant to a secondary utilization unit (whether a heat exchanger, heat storage tank, or discharge port), with an extraction rate ≥1%, the product falls within the protection scope of independent claim 1 or 2 of this invention. It is not necessary to prove whether a ternary zone structure is used or whether a specific subcooling value is achieved. Even if the accused party claims that its extraction point is "near the condenser outlet," as long as the extracted refrigerant objectively meets the requirements of a subcooled liquid state (temperature lower than the saturation temperature corresponding to that pressure), it constitutes infringement.

[0104] Example 2 (Operating Parameter Fingerprint Determination): A 1.5 HP R32 air conditioner with a nominal APF of 5.0 was tested under national standard operating conditions. The measured subcooling degree at the outlet of the main liquid pipe subcooling heat exchanger was ≥10K (current technology typically only has 5-8K), the compressor suction superheat was 3K to 8K, and the COP increased by ≥2%. This parameter combination falls within the parameter fingerprint range defined in dependent claim 11 of this invention, constituting the basis for determining whether the technical solution of this invention is adopted.

[0105] Example 3 (Controller Feature Determination): By reading the non-writable storage module of the device controller, it was found that it has a built-in control logic for the extraction and utilization of medium-temperature and medium-pressure liquid refrigerant, and the extraction ratio can be continuously and steplessly adjusted within the range of 1% to 80%. This controller feature falls within the scope of the claims of this invention.

[0106] Industrial application value The technical solution of this invention covers two industrial deployment forms: (1) New machine mass production integration - In the equipment manufacturing stage, the extraction and utilization components are integrated as standard configurations between the condenser subcooling section and the throttling device; (2) Energy-saving renovation of existing equipment - Existing equipment is retrofitted without damage. The extraction and utilization components are provided in the form of independent modular assemblies. The refrigerant interface is detachably connected to the condenser outlet pipeline and the front end pipeline of the throttling device of the existing equipment. During the renovation, there is no need to replace the original compressor, heat exchanger or refrigeration oil. The operating characteristics of the renovated equipment are consistent with the integrated system and fall within the scope of protection of this patent.

[0107] This invention can be widely applied to residential air conditioners, commercial central air conditioners, multi-split systems, chillers, heat pumps, refrigeration and cold storage, data center cooling, and thermal management of new energy vehicles. For existing equipment using refrigerants such as R22 and R410A that are restricted or banned, the energy efficiency improvement after modification is independent of the refrigerant type.

[0108] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

[0109] The above embodiments can be implemented, in whole or in part, by software, hardware, firmware, or any other combination thereof. When implemented using software, the above embodiments can be implemented, in whole or in part, as a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, all or part of the processes or functions described in the embodiments of this application are generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, the computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that includes one or more sets of available media. The available medium can be a magnetic medium (e.g., floppy disk, ATA hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. The semiconductor medium can be a solid-state ATA hard disk.

[0110] It should be understood that in the various embodiments of this application, the order of the above-mentioned processes does not imply the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of this application.

[0111] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this application.

[0112] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be through some interfaces; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0113] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0114] In addition, the functional units in the various embodiments of this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0115] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable ATA hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0116] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for extracting and utilizing medium-temperature liquid refrigerant in a vapor compression cycle system, applicable to a vapor compression cycle system including a compressor, condenser, throttling device, and evaporator, characterized in that: The medium-temperature, medium-pressure liquid refrigerant simultaneously meets the following objective physical conditions: The intermediate pressure P_mid is determined by the following formula: P_mid = P_c - X% × (P_c - P_e), where P_c is the condensing pressure, P_e is the evaporating pressure, and the coefficient X is 5% to 60%, so that the saturation temperature corresponding to the intermediate pressure P_mid is at least 15K higher than the saturation temperature corresponding to the evaporating pressure P_e, and at least 5K lower than the saturation temperature corresponding to the condensing pressure P_c. The method includes the following steps: S1. Extract a portion of pure medium-temperature and medium-pressure single-phase liquid refrigerant that meets the above pressure and saturation temperature conditions from the subcooled section where the refrigerant temperature in the condenser has dropped below the saturation temperature corresponding to the current pressure, or from the pipeline section after the subcooled section and before the front end of the throttling device. The amount of the extracted refrigerant shall be more than 1% of the total charge of the system. S2. The extracted medium-temperature and medium-pressure liquid refrigerant is used for secondary utilization or release within or outside the system. The secondary utilization includes, but is not limited to: storage for backup, subcooling of high-pressure liquid pipes, superheating of low-pressure return gas, heat exchange with external heat or cold sources, energy release across time periods, or any combination of the above methods. The extraction and utilization described herein differ from the following existing technologies: (a) Regenerator: The medium-temperature and medium-pressure liquid refrigerant extracted by this method comes from the subcooled section of the condenser or the single-phase liquid section thereafter. It does not involve direct heat exchange between the low-pressure return gas and the high-pressure liquid pipe. The extracted refrigerant is a 100% pure liquid single-phase medium. (b) Economizer / Intermediate Gas Injection: The refrigerant extracted by this method is kept in a medium-temperature and medium-pressure liquid state, without undergoing flash expansion or phase change separation, and without generating flash vapor to be injected into the compressor; (c) Conventional liquid receiver: This method actively reuses or releases the extracted refrigerant rather than simply passively buffering and storing it; (d) Direct contact heat exchange: When heat exchange is involved in secondary utilization, a non-contact indirect heat exchange method is adopted, and the two heat exchangers are physically isolated, without mixing or cross-contamination.

2. The system according to claim 1, characterized in that, Including a compressor, condenser, throttling device, and evaporator, characterized in that it further includes: The extraction branch is connected to the subcooled section in the condenser where the refrigerant temperature has dropped below the saturation temperature corresponding to the current pressure, or to the pipeline section after the subcooled section and before the front end of the throttling device, for extracting a portion of medium-temperature and medium-pressure liquid refrigerant from the section, with the extraction amount accounting for more than 1% of the total system charge. The medium-temperature, medium-pressure liquid refrigerant simultaneously meets the following objective physical conditions: The intermediate pressure P_mid is determined by the following formula: P_mid = P_c - X% × (P_c - P_e), where P_c is the condensing pressure, P_e is the evaporating pressure, and the coefficient X is 5% to 60%, so that the saturation temperature corresponding to the intermediate pressure P_mid is at least 15K higher than the saturation temperature corresponding to the evaporating pressure P_e, and at least 5K lower than the saturation temperature corresponding to the condensing pressure P_c. The secondary utilization unit is connected to the extraction branch and is used to perform secondary utilization or release of the extracted medium-temperature and medium-pressure liquid refrigerant within or outside the system. The secondary utilization includes, but is not limited to: storage for backup, subcooling of high-pressure liquid pipes, superheating of low-pressure return gas, heat exchange with external heat or cold sources, energy release across time periods, or any combination of the above methods.

3. The method according to claim 1, characterized in that, The secondary utilization mentioned in S2 specifically includes: S2a. The medium-temperature and medium-pressure liquid refrigerant, which is at least partially extracted, is depressurized to near the evaporation pressure through an auxiliary throttling device to form a gas-liquid mixture low-temperature cold source with a temperature of 5℃±3℃. S2b, the low-temperature cold source and the high-pressure medium-temperature liquid refrigerant from the condenser outlet to the front end of the throttling device undergo non-contact indirect heat exchange in the main liquid pipe subcooling heat exchanger, thereby increasing the subcooling degree of the high-pressure liquid refrigerant to above 10°C. S2c, the gas-liquid mixed refrigerant whose temperature rises to above 5°C after heat exchange is fed into the compressor return gas pipeline or liquid storage tank, simultaneously increasing the return gas superheat and reducing the risk of compressor liquid slugging; The main liquid tube subcooling heat exchanger is any one or more combinations of plate heat exchangers, shell-and-tube heat exchangers, microchannel heat exchangers, coaxial tube heat exchangers, or falling film heat exchangers.

4. A method for identifying and recovering redundant working fluid in a refrigeration cycle, characterized in that, Includes the following steps: S1. When the vapor compression cycle system is running in steady state, measure the total mass M_total of the medium-temperature and medium-pressure liquid refrigerant in the pipeline section from the condenser outlet to the front end of the throttling device. S2. Under full-load rated operating conditions, measure the minimum throttling liquid mass flow rate required to maintain the target superheat at the evaporator outlet, and integrate to obtain the mass of working fluid required for basic liquid supply per unit cycle, M_base. S3. Calculate the redundant working fluid mass M_redundant = M_total - M_base. When the ratio of M_redundant / M_total is in the range of 0.42 to 0.48, it is determined that the system has approximately 45% recyclable redundant pure liquid refrigerant. S4. Introduce the redundant working fluid corresponding to M_redundant into the secondary energy storage area for closed storage and cascade energy recovery. S5. The recovery of the redundant working fluid increases the high-pressure working fluid recovery rate of the system from 0% to over 40%. The redundant working fluid is the most efficient medium-temperature and medium-pressure pure liquid energy reuse medium in the system. In traditional systems, it is regarded as an irreversible entropy increase factor and has not been developed and utilized.

5. The system according to claim 1, characterized in that: The unit comprises a compressor, a condenser, and an evaporator connected in sequence, characterized in that it further comprises: The first pressure regulating device is installed between the condenser outlet and the evaporator to reduce the pressure of the high-pressure liquid refrigerant output from the condenser to a medium-temperature, medium-pressure liquid refrigerant with a pressure higher than the evaporation pressure and lower than the condensation pressure. The pressure P_mid of the medium-temperature, medium-pressure liquid refrigerant satisfies: P_mid = P_c - X% × (P_c - P_e), where P_c is the condensation pressure, P_e is the evaporation pressure, and X is 5% to 60%, such that the saturation temperature corresponding to P_mid is at least 15K higher than the saturation temperature corresponding to P_e and at least 5K lower than the saturation temperature corresponding to P_c. The ternary layered energy storage module includes a main liquid supply chamber, a transition buffer chamber, and an energy storage chamber. The inlet of the main liquid supply chamber is connected to a first pressure regulating device, and the outlet of the main liquid supply chamber is connected to an evaporator through a second throttling device, so that the liquid refrigerant entering the ternary layered energy storage module sequentially supplies liquid to the main liquid supply chamber, stores liquid in the transition buffer chamber, and stores liquid in the energy storage chamber. A first overflow channel is provided between the main liquid supply chamber and the transition buffer chamber, and the inlet of the first overflow channel is higher than the minimum liquid supply level of the main liquid supply chamber. A second overflow channel is provided between the transition buffer chamber and the energy storage chamber, and the inlet of the second overflow channel is higher than the minimum buffer level of the transition buffer chamber. The two overflow channels form a mechanical liquid supply priority, with the main liquid supply chamber filling first. Only excess medium-temperature and medium-pressure liquid refrigerant exceeding the safe liquid level automatically enters the energy storage chamber through the overflow structure. The energy storage chamber is sealed to maintain a medium-temperature and medium-pressure single-phase liquid state. An auxiliary storage and release branch, connected to the transition buffer chamber and / or energy storage chamber, is used to allow a portion of the medium-temperature, medium-pressure liquid refrigerant in the transition buffer chamber and / or energy storage chamber to participate in the subcooling of the main liquid pipe or the storage and release of external heat; the auxiliary storage and release branch includes an auxiliary throttling device and a main liquid pipe subcooling heat exchanger; the type of the main liquid pipe subcooling heat exchanger is the same as that described in claim 3; the inlet of the auxiliary throttling device is connected to the transition buffer chamber and / or energy storage chamber, the outlet of the auxiliary throttling device is connected to the low-temperature side inlet of the main liquid pipe subcooling heat exchanger, the high-temperature side of the main liquid pipe subcooling heat exchanger is connected in series between the condenser outlet and the first pressure regulating device; the low-temperature side outlet of the main liquid pipe subcooling heat exchanger is connected to the compressor suction pipe. The energy storage cavity is equipped with a heat exchange component, including a heat exchange medium channel isolated from the refrigerant, for exchanging heat between the medium-temperature and medium-pressure liquid refrigerant in the energy storage cavity and an external heat source or an external cold source. The external heat source includes at least one of solar thermal energy, compressor waste heat, equipment room waste heat, engine waste heat, and ambient thermal energy. The energy storage chamber is connected to the main liquid supply chamber through a return liquid channel, and a return liquid regulating valve is installed in the return liquid channel; The detection component is used to detect intermediate pressure, intermediate temperature, liquid level in the main supply chamber, liquid level in the transition buffer chamber, liquid level in the energy storage chamber, evaporation pressure, and compressor suction superheat. The controller is used to determine the liquid phase margin based on the difference between the saturation temperature at the intermediate pressure and the refrigerant temperature at the outlet of the first pressure regulating device; when the liquid phase margin is less than the preset minimum liquid phase margin, the controller reduces the pressure drop of the first pressure regulating device and / or closes the auxiliary storage and release branch to keep the refrigerant entering the ternary stratified energy storage component in a single liquid phase; the controller is also used to divide the system into a stable liquid supply zone, a sensible heat regulation zone, and a composite storage and release zone according to the adjustable liquid ratio in the transition buffer chamber and the energy storage chamber, and to control the first pressure regulating device, the second throttling device, and the auxiliary storage and release branch according to the current zone; The adjustable liquid storage ratio is the ratio of the sum of the refrigerant mass in the transition buffer chamber and the energy storage chamber to the total refrigerant mass of the system; the adjustable liquid storage ratio is continuously and steplessly adjustable within the range of 1% to 80%. When the adjustable liquid storage ratio is in the phase change efficiency range of 30% to 50%, the system heating DAPF is improved by more than 1.2, the annual comprehensive APF is improved by more than 1.0, and the high-pressure working fluid recovery rate is ≥40%. The system is compatible with residential air conditioners, commercial central air conditioners, multi-split systems, refrigeration and freezing equipment, automotive thermal management, marine refrigeration, and data center cooling equipment, covering both new machine mass production and existing energy-saving retrofit scenarios. The system is applicable to single-unit multi-stage cascade units and dual-unit multi-stage cascade units. In the cascade system, the medium-temperature and medium-pressure liquid refrigerant is extracted from the interstage piping section between the outlet of the low-pressure stage condenser and the front end of the high-pressure stage throttling device, or extracted from the interstage piping section between the outlet of the high-pressure stage condenser and the front end of the low-pressure stage throttling device, or simultaneously extracted from the interstage piping sections of both stages.

6. A ternary interval hierarchical energy storage control method based on the system described in claim 5, characterized in that, Includes the following steps: S1. Obtain the intermediate pressure and intermediate temperature at the outlet of the first pressure regulating device, and calculate the liquid phase margin based on the difference between the saturation temperature at the intermediate pressure and the refrigerant temperature at the outlet of the first pressure regulating device; when the liquid phase margin is not less than the preset minimum liquid phase margin, allow the medium-temperature and medium-pressure liquid refrigerant to enter the ternary interval layered energy storage component. S2. Calculate the adjustable liquid mass based on the liquid levels in the transition buffer chamber and the energy storage chamber, as well as the liquid phase density of the refrigerant. Determine the adjustable liquid ratio based on the ratio of the adjustable liquid mass to the total refrigerant mass of the system. S3. Compare the adjustable liquid storage ratio with the first liquid storage boundary value, the second liquid storage boundary value, and the upper limit of safe liquid storage to determine whether the system is in the stable liquid supply range, the sensible heat regulation range, or the composite storage and release range; wherein the first liquid storage boundary value corresponds to the 1% to 30% trace liquid storage range, the second liquid storage boundary value corresponds to the 30% to 50% phase change energy efficiency range, and the upper limit of safe liquid storage corresponds to the 50% to 80% large-capacity long-term energy storage range; S4. Implement differentiated control strategies based on the determined intervals; S5. When the liquid level in the main liquid supply chamber is lower than the minimum liquid supply level, the evaporation pressure is continuously lower than the target range, or the superheat of the suction gas exceeds the upper limit, the return liquid regulating valve is opened to return the liquid refrigerant in the energy storage chamber to the main liquid supply chamber, giving priority to ensuring the main circulation liquid supply. S6. When the refrigerant is a non-azeotropic mixture, the controller determines the liquid ratio boundary value of the energy storage zone based on the temperature slip width of the working fluid. When the slip width is ≥5K, the second liquid ratio boundary value is increased to 45% to 55%. The refrigerant replacement cycle of the energy storage chamber is automatically adjusted according to the temperature slip characteristics of the working fluid. For non-azeotropic mixtures, the replacement cycle is shortened by 20% to 30% compared to pure working fluids.

7. An overflow self-locking main and auxiliary partitioned liquid storage structure, installed in the pipeline section from the condenser outlet to the front end of the throttling device in a vapor compression cycle, characterized in that: The system is internally divided into a main storage area and a secondary energy storage area by vertical partitions. The main storage area is prioritized for filling to ensure the main circulation liquid supply. Only excess medium-temperature and medium-pressure liquid refrigerant exceeding the safe liquid level of the main storage area automatically enters the secondary energy storage area through an overflow structure. The secondary energy storage area is sealed to maintain a medium-temperature and medium-pressure single-phase liquid state. The refrigerant storage capacity in the secondary storage area is continuously and steplessly adjustable from 1% to 80% of the total system charge. The overflow self-locking main and secondary zone liquid storage structure physically separates the basic liquid supply working fluid, which has an effective utilization rate of about 55%, from the surplus pure liquid refrigerant of about 45% in the throttling system. The main storage zone prioritizes the supply of about 55% of the basic liquid, while the secondary energy storage zone recovers about 45% of the surplus working fluid for secondary and multiple cascade reuse to enhance efficiency. The surplus working fluid of about 45% is the most efficient medium-temperature and medium-pressure pure liquid energy reuse medium in the system, which is regarded as an irreversible entropy increase factor in traditional systems and has not been developed and utilized. In the secondary energy storage area, a portion of the medium-temperature, medium-pressure liquid refrigerant is depressurized to near its evaporation pressure via an auxiliary throttling device, forming a gas-liquid mixture at a temperature of 5℃±3℃. This low-temperature cold source is introduced into the low-temperature side of the main liquid pipe subcooling heat exchanger, where it undergoes non-contact indirect heat exchange with the medium-temperature, medium-pressure liquid refrigerant at the condenser outlet on the high-temperature side, raising the subcooling of the high-temperature refrigerant to above 10℃. After heat exchange, the gas-liquid mixture, with its temperature rising to above 5℃, flows into the compressor return gas pipeline or the liquid storage tank, simultaneously increasing the return gas superheat and reducing the risk of compressor liquid slugging. The type of the main liquid pipe subcooling heat exchanger is the same as that described in claim 3. By finely adjusting the volume of the storage chamber, the diameter of the overflow channel, and the heat exchange area of ​​the main liquid pipe subcooling heat exchanger, it can be adapted to any heat pump refrigerant among R32, R410A, R290, R134a, R454B, R407C, CO2, and multi-component mixed working fluids.

8. A method for coordinated energy efficiency control based on the system described in claim 5, characterized in that, Include: S1, The controller obtains the refrigerant ratio y in the energy storage cavity; S2. The controller calls the collaborative gain mapping table stored in its memory and determines the target subcooling ΔT_target based on the refrigerant ratio y. The collaborative gain mapping table includes the contribution of subcooling to COP and the secondary contribution of flash gas suppression to evaporation efficiency. Its parameters are obtained through experimental calibration at no less than 5 extraction ratio points. S3. The controller generates a control signal to adjust the opening of the auxiliary throttling device based on the deviation between the target subcooling degree ΔT_target and the actual subcooling degree, so that the measured subcooling degree at the outlet of the main liquid tube subcooling heat exchanger reaches the target subcooling degree.

9. A self-inspection and evidence-solidification device for a refrigeration cycle efficiency enhancement system, applied to a refrigeration system including the liquid storage structure described in claim 5 or 7, characterized in that, include: The unique hardware encoding module consists of a physical identifier code burned into the one-time programmable storage area of ​​the system controller chip. The physical identifier code is indelible and cannot be tampered with. The system includes a fingerprint acquisition module, comprising a first temperature sensor connected to the condenser outlet, a liquid level sensor connected to the secondary energy storage area or energy storage chamber, a second temperature sensor connected to the compressor exhaust port, and a third temperature sensor connected to the high-temperature side outlet of the main liquid pipe subcooling heat exchanger. These sensors collect four operating parameters in real time and store them encrypted in an unwritable storage area. A parameter comparison module includes a threshold comparison circuit embedded in the controller's read-only memory. When all four operating parameters fall within the following value ranges, a device identification code containing a timestamp and hardware encoding is automatically generated: high-pressure liquid pipe subcooling ≥10K in refrigeration mode, refrigerant ratio in the secondary energy storage area or energy storage chamber 30% to 50%, compressor exhaust temperature reduction ≥10℃, and temperature difference between the low-temperature side inlet and high-temperature side outlet of the main liquid pipe subcooling heat exchanger ≥15K. An unwritable encrypted storage module stores factory-preset working fluid type adaptation parameters, optimal extraction ratio range benchmark values, and initial system energy efficiency benchmark values. These factory-preset parameters cannot be overwritten or erased by software updates.

10. The system according to claim 5, characterized in that: Under refrigeration conditions, the refrigerant subcooling at the high-temperature side outlet of the main liquid pipe subcooling heat exchanger is not less than 10K, and the compressor suction superheat is 3K to 8K; under heating conditions, the refrigerant subcooling in the evaporator is not less than 6K; the medium-temperature and medium-pressure liquid refrigerant returning to the secondary energy storage area or energy storage cavity accounts for 30% to 50% of the total liquid phase flow of the system; the working medium in the secondary energy storage area or energy storage cavity is always kept in a medium-temperature and medium-pressure liquid single-phase state; for every 1°C increase in subcooling, the system COP increases by more than 0.6%, and the flash gas volume after throttling by the second throttling device is reduced by more than 30%; the subcooling of not less than 10K is different from the usual 5K to 8K subcooling range of existing regenerator and subcooler schemes, constituting one of the operating parameter fingerprints for determining whether the technical solution of this invention is adopted; For single refrigeration equipment, the system operates within the 1% to 30% micro-extraction range. In refrigeration mode, the subcooling degree at the outlet of the main liquid pipe subcooling heat exchanger increases by no less than 10K, the compressor discharge temperature decreases by no less than 10℃, and the refrigeration APF increases by no less than 0.

8. For single heating equipment, the system operates within the 30% to 50% extraction range. In heating mode, the compressor suction superheat increases by no less than 5K, and the heating DAPF increases by no less than 1.

0. For dual-purpose refrigeration and heating equipment, the system operates within the 30% to 50% extraction range. In refrigeration mode, the subcooling degree at the outlet of the main liquid pipe subcooling heat exchanger increases by no less than 10K, in heating mode, the compressor suction superheat increases by no less than 5K, the compressor discharge temperature decreases by no less than 10℃, the refrigeration APF increases by no less than 1.0, and the heating DAPF increases by no less than 1.

2.

11. The system according to claim 5, characterized in that: When the accused infringing product replaces at least one of the following structures in the overflow self-locking main and secondary zone liquid storage structure or the ternary zone layered energy storage component—replacing the overflow baffle with a float valve control structure, replacing the vertical partition with an independent dual-chamber series structure, replacing the overflow channel with a solenoid valve-controlled bypass, replacing a single secondary energy storage area with a multi-stage series sub-energy storage area, or replacing the main liquid pipe subcooling heat exchanger with another type of heat exchanger—and after the replacement, the product still maintains the functional characteristics of priority liquid supply in the main storage area or main supply liquid chamber, closed storage of medium-temperature and medium-pressure liquid refrigerant in the secondary energy storage area or energy storage chamber, main circulation pressure fluctuation ≤ ±0.02MPa, and indirect heat exchange between the low-temperature cold source of the auxiliary branch and the refrigerant in the main liquid pipe without contact, the replacement product still falls within the protection scope of this invention; Alternatively, although the allegedly infringing product has undergone structural replacement, its measured parameters after operation simultaneously fall within the following ranges: (a) The subcooling degree of the high-pressure liquid line for refrigeration is ≥10K; (b) The refrigerant subcooling degree of the heating evaporator is ≥6K; (c) Compressor suction superheat 3K to 8K; (d) The compressor exhaust temperature decreases by ≥10℃; (e) The temperature difference between the low-temperature inlet and the high-temperature outlet of the main liquid tube subcooling heat exchanger is ≥15K; (f) The compressor suction superheat is increased by ≥5K compared to the baseline operating condition; (g) The overall COP of the machine is increased by no less than 2%.

12. The system according to claim 5, characterized in that, It also includes at least one of the following complementary features: (a) The indoor unit is a vacuum-free integrated indoor unit assembly. The refrigerant connection pipe of the indoor unit is welded together with the vacuum-free valve. It is pre-sealed and pre-filled with refrigerant before leaving the factory. The static vacuum degree at the factory is not higher than 20Pa. The system does not need to be vacuumed on site after installation. (b) A modified locking and identification device, the device comprising a non-removable modified nameplate and a non-rewritable encrypted storage module; The modification nameplate indicates the modification date, the type of working fluid after modification, and the identification of the modification service provider; the encrypted storage module stores the modified control logic and operating parameters, and the controller is locked in the modification mode and cannot be rolled back to the control logic before modification. (c) The system is compatible with any one of the following refrigerants: R32, R410A, R290, R134a, R454B, R407C, CO2, and multi-component mixed refrigerants. By fine-tuning the liquid storage chamber volume, overflow channel pipe diameter, and main liquid pipe subcooling heat exchanger heat exchange area, stable full-range stratified energy storage is achieved under various refrigerant operating conditions, with DAPF improvement of no less than 1.0 in the 30% to 50% range. The system can be directly retrofitted to existing refrigeration and heating equipment without damage. DAPF is simultaneously increased from 0.8 to 1.2; the ternary interval layered energy storage component is provided in the form of an independent modular assembly, and its refrigerant interface can be detachably connected to the condenser outlet pipeline and the front end pipeline of the throttling device of the existing equipment; the existing equipment includes existing equipment using refrigerants such as R22 and R410A that are restricted or banned. During the renovation, there is no need to replace the original compressor, heat exchanger or refrigeration oil. Only the ternary interval layered energy storage component and the appropriate throttling structure are replaced. The energy efficiency improvement after the renovation is independent of the refrigerant type.

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