Air conditioning system cold storage amount calculation method and system and storage medium

Abstract

The application discloses a kind of air conditioning system cold storage capacity calculation method, system and storage medium, it is related to air conditioning field, to calculate the cold storage capacity of air conditioning system in real time.The calculation method includes the following steps: obtaining the temperature of cold storage medium;According to temperature, judge the phase that energy accumulator of air conditioning system is located: no phase change stage or phase change stage;According to the phase that energy accumulator is located, calculate the cold storage capacity of energy accumulator.The air conditioning system cold storage capacity calculation method provided in the above technical solution belongs to the energy-saving air conditioner in the strategic emerging industry classification and international patent classification.This method judges whether energy accumulator is in phase change stage or no phase change stage according to the temperature of cold storage medium, different cold storage capacity calculation methods can be used for different stages, and calculation is more simple and accurate.

Description

Technical Field

[0001] This invention relates to the field of air conditioning, and more specifically to a method, system, and storage medium for calculating the cold storage capacity of an air conditioning system. Background Technology

[0002] There is currently an air conditioning system that, without changing the connecting pipes between the outdoor and indoor units, adds an energy accumulator to the pipes. By controlling the opening and closing of valves inside the energy accumulator, different refrigerant circulation paths can be achieved, enabling switching between multiple modes such as energy storage, energy release, and conventional air conditioning control.

[0003] The inventors discovered that existing technologies have at least the following problems: To achieve optimal overall energy efficiency of the air conditioning system, i.e., optimal overall energy efficiency during operation in both cold storage and cold release modes, on-demand cold storage is required. Currently, the industry cannot obtain the amount of cold stored in the accumulator, making on-demand cold storage difficult to achieve. Summary of the Invention

[0004] This invention proposes a method, system, and storage medium for calculating the cold storage capacity of an air conditioning system, which enables real-time calculation of the cold storage capacity when the air conditioning system is in cold storage mode, without increasing equipment costs.

[0005] This invention provides a method for calculating the cold storage capacity of an air conditioning system, comprising the following steps: Obtain the temperature of the cold storage medium; The stage of the energy storage device in the air conditioning system is determined based on the temperature: either the stage without phase change or the stage of phase change. The energy storage capacity of the energy storage device is calculated based on the stage in which the energy storage device is located.

[0006] In some embodiments, the cold storage medium is water, and if the temperature of the cold storage medium is greater than the phase change temperature, the accumulator is in a phase-change-free stage. When the air conditioning system is in the phase-change-free stage, the first total cold storage capacity of the energy storage device in this stage is calculated using the following formula. :

[0007] in, The total mass of water stored in the accumulator. The specific volume of water, The water temperature at the end of the cooling process. The water temperature at which cold storage occurs during the phase-change-free stage.

[0008] In some embodiments, the cold storage medium is water, and if the temperature of the cold storage medium is less than or equal to the phase change temperature, the energy storage device is in the phase change stage. The method for calculating the cold storage capacity of the air conditioning system also includes the following steps: Obtain the thickness of the ice layer on the outside of the heat exchange coil of the accumulator. ; According to the thickness Determine whether the energy storage device is in the first or second stage of the phase transition phase.

[0009] In some embodiments, the thickness of the ice layer on the outside of the heat exchange coil of the accumulator is calculated using the following formula. :

[0010] in, It is a constant. The heat exchange time of the accumulator when the temperature of the cold storage medium is the phase change temperature.

[0011] In some embodiments, the It is directly proportional to the temperature difference between the inside and outside of the heat exchange coil of the accumulator.

[0012] In some embodiments, if the thickness of the ice layer on the outside of the heat exchange coil of the accumulator Less than or equal to the set value If the thickness of the ice layer on the outside of the heat exchange coil of the accumulator is [missing information], then the accumulator is in the first stage of phase change; if ... Greater than the set value Then the energy storage device is in the second stage of the phase transition phase.

[0013] In some embodiments, when the energy storage device is in the first stage of the phase change phase, the second total cold storage capacity of the energy storage device is calculated using the following formula. :

[0014] in, This is the first total cold storage capacity of the accumulator. The energy storage capacity of the energy storage device during the first stage of phase change is... The total mass of water stored in the accumulator. The specific volume of water, The water temperature at the end of the cooling process. The water temperature at which cold storage occurs during the phase-change-free stage; The thickness of the ice layer on the outside of the heat exchange coil of the accumulator is The amount of ice formed at that time; The enthalpy of phase transition of water; The density of the cold storage medium, Let π be the mathematical constant pi, L be the thickness of the ice layer on the outside of the heat exchange coil of the accumulator, and r be the diameter of the heat exchange coil of the accumulator. The length of a single heat exchange coil in the accumulator. The number of heat exchange coils located in the energy storage medium.

[0015] In some embodiments, when the energy storage device is in the second stage of the phase change phase, the third total cold storage capacity of the energy storage device is calculated using the following formula. :

[0016] in, This is the first total cold storage capacity of the accumulator. The energy storage capacity of the energy storage device during the first stage of phase change is... The total mass of water stored in the accumulator. The specific volume of water, The water temperature at the end of the cooling process. The water temperature at which cold storage occurs during the phase-change-free stage; The thickness of the ice layer on the outside of the heat exchange coil of the accumulator is The amount of ice formed at that time; The enthalpy of phase transition of water; The density of the cold storage medium, Let π be the mathematical constant pi, L be the thickness of the ice layer on the outside of the heat exchange coil of the accumulator, and r be the radius of the heat exchange coil of the accumulator. Figure 5 As shown, since r is relatively small, Figure 5 The middle arrows are close together, but they indicate the radius of the heat exchange coil. The length of a single heat exchange coil in the accumulator. The number of heat exchange coils located in the energy storage medium; To obtain the initial conversion efficiency of the second stage of phase transition for experimental testing; Conversion efficiency when fully iced; The time required for the second stage of phase transition to be fully filled with ice; This refers to the cold storage capacity during the second stage of the phase change in the accumulator. The electrical energy consumed for cold storage in the second stage of phase change; This refers to the duration of the second stage of cooling.

[0017] This invention also provides a system for calculating the cold storage capacity of an air conditioning system, comprising: Memory; and A processor coupled to the memory is configured to execute, based on instructions stored in the memory, the air conditioning system cold storage capacity calculation method provided by any of the technical solutions of the present invention.

[0018] This invention also provides a computer-readable storage medium, characterized in that it stores a computer program thereon, which, when executed by a processor, implements the method for calculating the cold storage capacity of an air conditioning system as provided in any of the technical solutions of this invention.

[0019] The method for calculating the cold storage capacity of the air conditioning system provided by the above technical solution falls under the category of energy-saving air conditioning in the strategic emerging industries classification and international patent classification. It determines whether the accumulator is in the phase change stage or the non-phase change stage based on the temperature of the cold storage medium. Different cold storage capacity calculation methods can be used for different stages, making the calculation simpler and more accurate. Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings: Figure 1 This is a schematic diagram of the structure of an air conditioning system to which the air conditioning system cold storage capacity calculation method provided in this embodiment of the invention is applicable.

[0021] Figure 2 This is a schematic diagram of the refrigerant flow direction in the air conditioning system in cold storage mode, to which the air conditioning system cold storage capacity calculation method provided in this embodiment of the invention is applicable.

[0022] Figure 3 This is a schematic diagram of the refrigerant flow direction of the air conditioning system in cooling mode and cold storage mode, to which the air conditioning system cold storage capacity calculation method provided in this embodiment of the invention is applicable.

[0023] Figure 4 A top view of the icing state of the air conditioning system to which the air conditioning system cold storage capacity calculation method provided in this embodiment of the invention is applicable.

[0024] Figure 5 A front view of the icing state of the accumulator in an air conditioning system to which the air conditioning system cold storage capacity calculation method provided in this embodiment of the invention applies.

[0025] Figure 6 A schematic diagram of the method for calculating the cold storage capacity of an air conditioning system provided in this embodiment of the invention.

[0026] Figure label: 1. Outdoor unit; 101. Outdoor unit liquid pipe; 102. Outdoor unit gas pipe; 2. Indoor unit; 201. Indoor unit liquid main pipe; 202. Indoor unit gas main pipe; 203. Indoor unit control valve; 204. Indoor unit heat exchanger; 3. Accumulator; 301. First liquid pipe; 302. First gas pipe; 303. Second liquid pipe; 304. Second gas pipe; 305. First control valve; 306. Accumulator heat exchanger control valve; 307. Third control valve Valve; 308, Fourth control valve; 309, Fifth control valve; 310, Energy storage heat exchanger; 3101, Gas collection side of energy storage heat exchanger; 3102, Liquid collection side of energy storage heat exchanger; 3103, Inlet pipe temperature sensor of energy storage heat exchanger; 3104, Outlet pipe temperature sensor of energy storage heat exchanger; 3105, Cold storage medium temperature sensor; 311, Sixth control valve; 310a, Energy storage water tank; 310b, Heat exchange coil; 310c, Icing boundary. Detailed Implementation

[0027] The following is combined Figures 1-6 The technical solutions provided by this invention will be described in more detail below. The descriptions of exemplary embodiments are merely illustrative and are in no way intended to limit this disclosure or its application or use. This disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make this disclosure thorough and complete, and to fully express the scope of this disclosure to those skilled in the art. It should be noted that, unless otherwise specifically stated, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as merely exemplary and not as limiting.

[0028] The terms “first,” “second,” and similar words used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as “including” or “contains” mean that the element preceding the word covers the element listed after the word, and do not exclude the possibility of covering other elements as well.

[0029] In this disclosure, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may be not directly connected to the other devices but have an intermediary device.

[0030] All terms used in this disclosure, including technical or scientific terms, have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as a dictionary, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0031] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment shall be considered part of the specification.

[0032] The dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Common structural elements or elements of the same kind are given the same reference numerals in the various drawings, and repeated descriptions of them are omitted where appropriate.

[0033] The inventors discovered that existing technologies suffer from at least the following problems: For ice storage air conditioners using water as the cold storage medium, the energy efficiency in cold storage mode is affected by the thickness of the ice layer. During pure water cold storage operation, the heat exchange efficiency is relatively constant due to the absence of ice resistance within the accumulator. However, during the phase change phase, the heat exchange efficiency gradually decreases as the thickness of the ice layer adhering to the heat exchange pipes increases. When the ice layer is sufficiently thick, excessive ice resistance leads to a phenomenon where the cold storage mode generates excessive output energy consumption but the increase in ice accumulation is slow, resulting in a slow increase in cold storage capacity. Because the heat exchange efficiency in the cold storage mode of the energy storage air conditioning system is low, and the operating efficiency decreases with increasing ice accumulation, resulting in high power consumption, it is necessary to rationally plan the operating duration of the cold storage mode, which is equivalent to rationally planning the cold storage capacity. The required cold storage capacity depends on the user's need for the accumulator to release cold energy during peak cooling periods to achieve peak demand reduction.

[0034] The inventors discovered that the difficulty in calculating the cold storage capacity of an accumulator using ice storage lies in calculating the enthalpy of phase change. Current methods involve installing a level gauge inside the accumulator. By detecting the rise in liquid level during freezing, the mass of water undergoing phase change can be calculated, thus determining the total cold storage capacity. Commercially available level gauges are primarily hydraulic, detecting changes in liquid level through changes in water pressure. However, this method has a problem: the level gauge probe needs to be placed in an unfrozen area. When the hydraulic pressure is low, meaning the liquid level is close to the probe (e.g., about 15cm), it easily falls into the level gauge's detection blind zone.

[0035] For energy storage air conditioning systems, due to objective factors such as the floor space and load-bearing capacity of the installation site, a small and lightweight design is required. This requires the freezing rate of the medium water during cold storage to be as high as possible. In this case, as the freezing rate increases, the unfrozen area inside the accumulator gradually decreases, and the height of the ice layer from the liquid surface will enter the detection blind zone of the liquid level gauge, making accurate detection impossible.

[0036] There is another type of level gauge that is not affected by the liquid level, namely the radar level gauge. On the one hand, it is slightly more expensive, which increases the equipment cost of the energy storage device. On the other hand, the level gauge needs to be suspended at a certain height above the liquid surface, which is not conducive to the miniaturization design of the energy storage air conditioning system.

[0037] Accordingly, this invention proposes a method for calculating the cold storage capacity based on the heat exchange characteristics of ice storage without increasing equipment costs. The method targets the amount of cooling demand from the accumulator during the user's cold release period, operates in cold storage mode, and monitors the cold storage capacity in real time. When the target cold storage capacity is reached, cold storage is terminated to avoid energy loss caused by excessive cold storage and improve the energy efficiency of cold storage operation.

[0038] Before introducing the method for calculating the cold storage capacity of an air conditioning system provided in the embodiments of the present invention, the structure and corresponding working mode of the air conditioning system will be introduced first.

[0039] See Figures 1 to 3 The air conditioning system includes an outdoor unit module, an indoor unit module, and an energy storage module. The outdoor unit module includes an outdoor unit gas pipe 102 and an outdoor unit liquid pipe 101. The indoor unit module includes an indoor unit gas pipe main 202 and an indoor unit liquid pipe main 201. The energy storage module includes a first gas pipe 302, a first liquid pipe 301, a second gas pipe 304, and a second liquid pipe 303.

[0040] A refrigerant inlet temperature sensor 3103 is installed on the pipe on the liquid collection side of the heat exchanger 310 to detect the temperature of the refrigerant entering the heat exchanger 310 in either the cold storage mode or the simultaneous cooling and cold storage mode. A refrigerant outlet temperature sensor 3104 is installed on the pipe on the gas collection side of the heat exchanger 310 to detect the temperature of the refrigerant flowing out of the heat exchanger 310 in both modes. In addition, a cold storage medium temperature sensor 3105 is installed inside the heat exchanger 310 to monitor the temperature of the internal cold storage medium in real time. This embodiment uses water as the cold storage medium and a phase change temperature of 0°C as an example for description.

[0041] See Figure 2When the air conditioning system is in cold storage mode, the fifth control valve 309 and the sixth control valve 311 open, making their respective branches conductive. The first control valve 305, the third control valve 307, and the fourth control valve 308 close, making their respective branches disconnected. The energy storage heat exchanger control valve 306 maintains a certain opening, while the indoor unit control valve 203 closes. At this time, the indoor unit 2 stops operating, and the energy storage unit 3 and the outdoor unit 1 form a complete refrigerant circulation path. All the cooling capacity generated by the compressor is used for cold storage in the energy storage unit 3.

[0042] See Figure 3 When the air conditioning system is in cooling and cold storage mode, the first control valve 305, the fifth control valve 309, and the sixth control valve 311 open, making their respective branches conductive. The third control valve 307 and the fourth control valve 308 close, making their respective branches disconnected. The energy storage heat exchanger control valve 306 and the indoor unit control valve 203 both maintain a certain opening. At this time, the energy storage unit 3 and the indoor unit 2 are arranged in parallel, forming a refrigerant circulation path together with the outdoor unit 1. The cooling capacity generated by the compressor is simultaneously supplied to the energy storage unit 3 for cold storage and to the indoor unit 2 for cooling.

[0043] See Figure 4 and Figure 5 The accumulator 3 includes an energy storage tank 310a, in which a heat exchange coil 310b is arranged. The low-temperature refrigerant in the heat exchange coil 310b exchanges heat with the medium water outside the heat exchange coil 310b. As the cold storage process progresses, ice will adhere to the outer wall of the heat exchange coil 310b and gradually thicken. After the heat exchange coil is filled with ice and forms an ice ball, the freezing process will further spread to the water around the ice ball, continuously completing the cold storage and forming an ice boundary 310c.

[0044] See Figure 6 This invention provides a method for calculating the cold storage capacity of an air conditioning system, comprising the following steps: Step S100: Obtain the temperature of the cold storage medium. The cold storage medium can be, for example, water. Specifically, the current temperature of the cold storage medium can be collected in real time by a cold storage medium temperature sensor 3105 installed inside the energy storage heat exchanger 310. The collection frequency can be set according to actual operating conditions to ensure the accuracy and real-time nature of the temperature data, providing a reliable basis for subsequent stage judgments and cold storage capacity calculations. Using water as the cold storage medium is convenient to obtain, low in cost, and has moderate latent heat of phase change, which can meet the cold storage requirements of the air conditioning system. It is compatible with the structural design of the aforementioned energy storage water tank, ensuring a stable and efficient cold storage process.

[0045] Step S200: Determine the stage of the accumulator 3 in the air conditioning system based on the temperature: either the stage without phase change or the stage of phase change.

[0046] The energy storage device 3 is in two stages: the no-phase-change stage and the phase-change stage. The phase-change stage is further divided into the first stage and the second stage.

[0047] As described above, the accumulator 3 includes an energy storage tank 310a, and a heat exchange coil 310b is arranged inside the energy storage tank 310a. The low-temperature refrigerant inside the heat exchange coil 310b exchanges heat with the cold medium water outside the heat exchange coil 310b.

[0048] When the temperature of the cold storage medium is higher than its phase change temperature, the accumulator 3 is in a phase-change-free stage. At this time, the cold storage medium only achieves cold storage through temperature reduction, without undergoing a change in state. If the cold storage medium is water, and the temperature of the cold storage medium... Greater than 0℃, that is Then, accumulator 3 is in the no-phase-change stage. If the temperature of the cold storage medium... Less than or equal to 0℃, that is Then the accumulator 3 is in the phase transition stage.

[0049] When the temperature of the cold storage medium drops to the phase change temperature and begins to freeze, the accumulator 3 enters the phase change stage. The first stage of the phase change is the cold storage stage where ice forms between the heat exchange coils. In this stage, ice adheres to the heat exchange coils 310b and conducts heat to the surrounding water to freeze. Since the energy storage heat exchanger 310 inside the accumulator 3 is equipped with multiple heat exchange coils 310b, and each heat exchange coil 310b has multiple bends, ice will form simultaneously at each bend. Therefore, this stage is a cold storage stage in which multiple ice columns freeze simultaneously.

[0050] In the first stage, the maximum set thickness of the ice layer, i.e., the set value. This can be pre-set based on experience. That is, if the ice thickness does not reach the set value... When the ice layer thickness exceeds the set value, the air conditioning system is determined to be in the first stage. At that time, the air conditioning system is judged to be in the second stage. See also Figure 4 Optional, It is half the spacing between the heat exchange coils 310b.

[0051] As the cold storage process progresses, ice will adhere to the outer wall of the heat exchange coil 310b and gradually thicken. When the ice layer thickness reaches... At that time, ice had formed between heat exchange coils 310b, and the unfrozen area was... Figure 4 The region between the boundary shown by the ice layer boundary 310c and the boundary shown by the energy storage tank 310a achieves cold storage through heat exchange with the ice ring 310c, and then enters the second stage of phase change, that is, the thickness of the ice layer attached to the heat exchange coil 310b is greater than... The first stage is followed by the second stage, which enables the freezing and cold storage of the unfrozen areas, thus completing the entire cold storage process.

[0052] Specifically, after the heat exchange coils 310b are filled with ice to form ice clusters, the second phase of phase change begins. The ice clusters and the outermost layer of unfrozen water continue to conduct heat and freeze. The second phase is the process of the ice clusters spreading outwards to the water surrounding them until the medium water in the entire energy storage tank 310a reaches a stable cold storage state. During this period, the ice boundary 310c gradually forms.

[0053] Step S300: Calculate the cold storage capacity of the accumulator 3 according to the stage at which the accumulator 3 is located.

[0054] The calculation methods for cold storage capacity differ depending on the stage. In the stage without phase change, the cold storage capacity is minimal. In the first stage of phase change, the cold storage capacity calculation needs to consider both sensible heat and latent heat changes, and the cold storage capacity is greater than that in the stage without phase change. In the second stage of phase change, the ice layer is thicker, resulting in a greater cold storage capacity, which is greater than that in the first stage.

[0055] When the air conditioning system is in the phase-change-free stage, the first total cooling capacity of accumulator 3 in this stage is calculated using the following formula. :

[0056] in, The total mass of water stored in accumulator 3. The specific volume of water, The water temperature at the end of the cooling process. The water temperature at which cold storage occurs during the phase-change-free stage.

[0057] To accurately calculate the cold storage capacity during the phase change stage, the phase change stage needs to be divided into a first stage and a second stage.

[0058] In some embodiments, the method for calculating the cold storage capacity of an air conditioning system further includes the following steps: First, obtain the thickness of the ice layer on the outside of the heat exchange coil 310b of the accumulator 3. .

[0059] Specifically, the thickness of the ice layer on the outside of the heat exchange coil 310b of the accumulator 3 can be calculated using the following method. : The cold storage enters the phase transition stage, at which point the ice layer thickness... With heat exchange temperature difference , Duration of heat exchange at ≤0℃ Satisfying functional relations The controller can obtain the water temperature Duration and the temperature difference between the refrigerant and the water inside the heat exchange coil 310b The real-time icing thickness was calculated. .

[0060] Heat exchange temperature difference Specifically, it refers to the temperature difference between the refrigerant inside the heat exchange coil 310b and the ice layer on the outside. The refrigerant temperature at the inlet and outlet of the heat exchange coil 310b is different, so the average temperature of the refrigerant at the inlet and outlet of the heat exchange coil 310b can be taken as the refrigerant temperature.

[0061] Specifically, the thickness of the ice layer on the outside of the heat exchange coil of accumulator 3 can be calculated using the following formula. :

[0062] in, It is a constant. The heat exchange time of accumulator 3 when the temperature of the cold storage medium is 0℃. The temperature difference between the inside and outside of the heat exchange coil 310b of the accumulator 3 is directly proportional to the temperature difference between the inside and outside; the greater the temperature difference, the better. The larger the value of , the smaller the temperature difference. The smaller the value, the more accurately the ice thickness can be calculated.

[0063] Secondly, according to thickness Determine whether accumulator 3 is in the first or second stage of the phase transition. Thickness Then it is in the first stage. Thickness If so, it is in the second stage. This method of judgment is accurate and fast.

[0064] The following describes how to calculate the cold storage capacity of the first and second stages. When accumulator 3 is in the first stage, it means that accumulator 3 has already gone through the phase-change-free stage. Therefore, when calculating the cold storage capacity of the first stage, the cold storage capacity accumulated in the phase-change-free stage needs to be considered. When accumulator 3 is in the second stage, it means that accumulator 3 has gone through both the phase-change-free stage and the first stage. Therefore, when calculating the cold storage capacity of the second stage, the cold storage capacity accumulated in both the phase-change-free stage and the first stage needs to be considered.

[0065] In some embodiments, when the energy storage device 3 is in the first stage of the phase change phase, the second total cold storage capacity of the energy storage device 3 is calculated using the following formula. :

[0066] in, This is the first total cold storage capacity of accumulator 3. The first stage of phase change cold storage capacity of accumulator 3 The total mass of water stored in accumulator 3. The specific volume of water, The water temperature at the end of the cooling process. The water temperature at which cold storage occurs during the phase-change-free stage; The thickness of the ice layer on the outside of the heat exchange coil of accumulator 3 is The amount of ice formed at that time; The enthalpy of phase transition of water; The density of the cold storage medium, Let π be the mathematical constant pi, L be the thickness of the ice layer on the outside of the heat exchange coil of accumulator 3, and r be the diameter of the heat exchange coil of accumulator 3. The length of a single heat exchange coil in accumulator 3. This refers to the number of heat exchange coils located in the energy storage medium.

[0067] In some embodiments, when the energy storage device 3 is in the second stage of the phase change phase, the third total cold storage capacity of the energy storage device 3 is calculated using the following formula. :

[0068] in, This is the first total cold storage capacity of accumulator 3. The first stage of phase change cold storage capacity of accumulator 3 The total mass of water stored in accumulator 3. The specific volume of water, The water temperature at the end of the cooling process. The water temperature at which cold storage occurs during the phase-change-free stage; The thickness of the ice layer on the outside of the heat exchange coil of accumulator 3 is The amount of ice formed at that time; The enthalpy of phase transition of water; The density of the cold storage medium, Let π be the mathematical constant pi, L be the thickness of the ice layer on the outside of the heat exchange coil of accumulator 3, and r be the radius of the heat exchange coil of accumulator 3. The length of a single heat exchange coil in accumulator 3. This refers to the number of heat exchange coils in the energy storage medium. To obtain the initial conversion efficiency of the second stage of phase transition for experimental testing; To determine the conversion efficiency when the ice is fully stored; The time required for the second stage of phase transition to be fully filled with ice; This refers to the cold storage capacity of the second phase of phase change in accumulator 3. It is the cold storage capacity of the non-phase change stage alone. This refers to the cold storage capacity of the first stage alone. It is the cold storage capacity of the second stage alone.

[0069] In the second stage, since the heat exchange coils 310b are already covered with ice, the thickness of the ice layer overflowing from the outside is different from the thickness of the ice layer between the heat exchange coils 310b. Therefore, the amount of ice in the second stage cannot be calculated by the formula. So, the conversion efficiency of electrical energy to cold energy is used to calculate the cold storage capacity in the second stage.

[0070] Furthermore, due to the excessive ice resistance at this stage, even with increased work output from the outdoor compressor and increased power consumption of the air conditioning system, the ice formation remains slow. Therefore, there are multiple conversion efficiencies between electrical energy and cooling capacity. Consequently, the second stage requires adjustment to optimize the electrical energy to cooling capacity conversion efficiency to its highest point. The conversion efficiency of electrical energy to cooling energy in the second stage of phase change. The efficiency decreases approximately linearly with the duration of cold storage t. Therefore, the initial conversion efficiency of the second stage of phase transition is obtained based on experimental testing. Conversion efficiency when ice is fully stored The time required for the second stage of phase transition to fully accumulate ice. The formula for calculating the conversion efficiency of electrical energy to cold energy under different cold storage durations in the second stage of phase change was obtained. In actual calculations, the electrical energy consumed by the cold storage in the second stage of phase change is obtained. and the duration of the second stage of cooling. The conversion efficiency is calculated using the above conversion efficiency formula. Then, the cold storage capacity of the second stage alone is calculated using the formula. .

[0071] When calculating the second-stage cold storage capacity, the conversion efficiency between electrical energy and cold energy needs to be adjusted to the highest level. The following method can be used specifically for this: By adjusting the opening of the energy storage heat exchanger control valve 306 and compressor operating frequency Adjust the refrigerant flow rate and temperature entering heat exchange coil 310b. The specific process is as follows: Obtain the temperature of the cold storage medium. Refrigerant inlet temperature of energy storage heat exchanger Refrigerant outlet temperature of energy storage heat exchanger Energy storage heat exchanger control valve opening and compressor operating frequency .Compare and , The size relationship, when < + ,and < + When this happens, the compressor's operating frequency will be reduced. At the same time, close the control valve of the energy storage heat exchanger. .in, The first water temperature threshold is denoted as , and is the set value. This is the second water temperature threshold, which is the set value. .

[0072] The system will be checked again after the preset time has elapsed. and , The size relationship, if it appears ≥ ,in The third temperature threshold indicates that insufficient compressor work is the dominant factor compared to the reduced refrigerant flow. At this point, the heat storage heat exchanger control valve maintains its current opening, and the compressor frequency is increased. Then continue running for the preset time.

[0073] If it appears < ,but ≥ ,in, The third temperature threshold indicates that, compared to insufficient compressor work, insufficient refrigerant flow due to throttling is the dominant factor. Therefore, the compressor frequency remains unchanged, and the control valve of the energy storage heat exchanger is opened wider. . .

[0074] Repeat the above steps to adjust the temperature until the temperature of the cold storage medium is reached. Controlled within ( + )≤ < ( + ),and( + )≤ < ( + Within the range of ), the system operates at the point of highest conversion efficiency between electrical energy and cooling capacity.

[0075] The above-mentioned technical solution provides a method for calculating the cold storage capacity of an air conditioning system. Based on the characteristics of ice storage heat exchange, the cold storage process is clearly divided into a non-phase change stage and a phase change stage. Furthermore, depending on whether the heat exchange coils 310b are fully filled with ice, the phase change stage is further subdivided into the first phase change stage (not fully filled with ice) and the second phase change stage (fully filled with ice). The corresponding calculation method is adopted in combination with the cold storage characteristics of each stage, which effectively improves the accuracy and specificity of the cold storage capacity calculation, avoids the errors caused by a single calculation method, and ensures that the cold storage capacity calculation results are highly matched with the actual cold storage conditions.

[0076] Furthermore, the aforementioned technical solution employs a phased, differentiated calculation approach for calculating the cold storage capacity during the phase transition stage. In the first phase of the phase transition, the actual ice storage volume is calculated, combined with relevant ice storage parameters, to determine the cold storage capacity, accurately reflecting the changes in cold storage capacity during ice formation at this stage. The second phase of the phase transition utilizes the conversion efficiency between power consumption and cold storage capacity, eliminating the need for complex ice parameter acquisition, simplifying the calculation process, reducing computational costs, and ensuring the convenience and practicality of cold storage capacity calculation at this stage.

[0077] This invention provides an air conditioning system cold storage capacity calculation system, including a memory and a processor coupled to the memory. The processor is configured to execute the air conditioning system cold storage capacity calculation method in any of the foregoing embodiments based on instructions stored in the memory.

[0078] Memory may include, for example, system memory, fixed non-volatile storage media, etc. System memory may store, for example, the operating system, application programs, boot loader, and other programs.

[0079] Some embodiments of this disclosure also provide a computer-readable storage medium having a computer program stored thereon. When executed by a processor, this program implements the method for calculating the cold storage capacity of an air conditioning system according to any of the above embodiments.

[0080] The processors described herein may include general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs) or other programmable logic devices, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in alternatives, it may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors cooperating with a DSP core, or any other such configuration.

[0081] Storage media can be any available medium that can be accessed by a computer. By way of example and not limitation, such computer-readable media may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Any connection is also properly referred to as computer-readable media. For example, if software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then such coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of media. As used herein, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs, where disks typically reproduce data magnetically, and discs reproduce data optically using lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0082] Those skilled in the art will understand that the method embodiments of this disclosure can be provided as a method, system, or computer program product. Therefore, this disclosure can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this disclosure can take the form of a computer program product embodied on one or more computer-usable non-transitory storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0083] This disclosure is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart illustrations and / or block diagrams. Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0084] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0085] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0086] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the invention and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0087] In the description of this invention, each technical feature may be combined with other technical features where feasible.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. However, these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for calculating the cold storage capacity of an air conditioning system, characterized in that, Includes the following steps: Obtain the temperature of the cold storage medium; The stage of the energy storage device in the air conditioning system is determined based on the temperature: either the stage without phase change or the stage of phase change. The energy storage capacity of the energy storage device is calculated based on the stage in which the energy storage device is located.

2. The method for calculating the cold storage capacity of an air conditioning system according to claim 1, characterized in that, The cold storage medium is water. If the temperature of the cold storage medium is greater than the phase change temperature, the accumulator is in the non-phase change stage. When the air conditioning system is in the phase-change-free stage, the first total cold storage capacity of the energy storage device in this stage is calculated using the following formula. : in, The total mass of water stored in the accumulator. The specific volume of water, The water temperature at the end of the cooling process. The water temperature at which cold storage occurs during the phase-change-free stage.

3. The method for calculating the cold storage capacity of an air conditioning system according to claim 1, characterized in that, The cold storage medium is water. If the temperature of the cold storage medium is less than or equal to the phase change temperature, the energy storage device is in the phase change stage. The method for calculating the cold storage capacity of the air conditioning system also includes the following steps: Obtain the thickness of the ice layer on the outside of the heat exchange coil of the accumulator. ; According to the thickness Determine whether the energy storage device is in the first or second stage of the phase transition phase.

4. The method for calculating the cold storage capacity of an air conditioning system according to claim 3, characterized in that, The thickness of the ice layer on the outside of the heat exchange coil of the accumulator is calculated using the following formula. : in, It is a constant. The heat exchange time of the accumulator when the temperature of the cold storage medium is the phase change temperature.

5. The method for calculating the cold storage capacity of an air conditioning system according to claim 4, characterized in that, The It is directly proportional to the temperature difference between the inside and outside of the heat exchange coil of the accumulator.

6. The method for calculating the cold storage capacity of an air conditioning system according to claim 3, characterized in that, If the thickness of the ice layer on the outside of the heat exchange coil of the accumulator Less than or equal to the set value If the thickness of the ice layer on the outside of the heat exchange coil of the accumulator is [missing information], then the accumulator is in the first stage of phase change; if ... Greater than the set value Then the energy storage device is in the second stage of the phase transition phase.

7. The method for calculating the cold storage capacity of an air conditioning system according to claim 6, characterized in that, When the energy storage device is in the first stage of phase change, the second total cold storage capacity of the energy storage device is calculated using the following formula. : in, This is the first total cold storage capacity of the accumulator. The energy storage capacity of the energy storage device during the first stage of phase change is... The total mass of water stored in the accumulator. The specific volume of water, The water temperature at the end of the cooling process. The water temperature at which cold storage occurs during the phase-change-free stage; The thickness of the ice layer on the outside of the heat exchange coil of the accumulator is The amount of ice formed at that time; The enthalpy of phase transition of water; The density of the cold storage medium, Let π be the mathematical constant pi, L be the thickness of the ice layer on the outside of the heat exchange coil of the accumulator, and r be the radius of the heat exchange coil of the accumulator. The length of a single heat exchange coil in the accumulator. The number of heat exchange coils located in the energy storage medium.

8. The method for calculating the cold storage capacity of an air conditioning system according to claim 6, characterized in that, When the energy storage device is in the second stage of the phase change phase, the third total cold storage capacity of the energy storage device is calculated using the following formula. : in, This is the first total cold storage capacity of the accumulator. The energy storage capacity of the energy storage device during the first stage of phase change is... The total mass of water stored in the accumulator. The specific volume of water, The water temperature at the end of the cooling process. The water temperature at which cold storage occurs during the phase-change-free stage; The thickness of the ice layer on the outside of the heat exchange coil of the accumulator is The amount of ice formed at that time; The enthalpy of phase transition of water; The density of the cold storage medium, Let π be the mathematical constant pi, L be the thickness of the ice layer on the outside of the heat exchange coil of the accumulator, and r be the radius of the heat exchange coil of the accumulator. The length of a single heat exchange coil in the accumulator. The number of heat exchange coils located in the energy storage medium; To obtain the initial conversion efficiency of the second stage of phase transition for experimental testing; To determine the conversion efficiency when the ice is fully stored; The time required for the second stage of phase transition to be fully filled with ice; The electrical energy consumed for cold storage in the second stage of phase change; This refers to the duration of the second stage of cooling.

9. A system for calculating the cold storage capacity of an air conditioning system, characterized in that, include: Memory; and A processor coupled to the memory, the processor being configured to execute the method for calculating the cold storage capacity of an air conditioning system as described in any one of claims 1-8, based on instructions stored in the memory.

10. A computer-readable storage medium, characterized in that, It stores a computer program that, when executed by a processor, implements the method for calculating the cold storage capacity of an air conditioning system as described in any one of claims 1-8.

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