Multi-module air conditioning unit and risk early warning method for matching cold-carrying media of multi-module air conditioning unit

Abstract

The invention discloses a multi-module air conditioning unit and a risk early warning method matched with a cold carrying medium of the multi-module air conditioning unit. The risk early warning method comprises the following steps: independently recording operation data of each module in recent n times of power-on; the matching risk value P module of the cold-carrying medium of each module is evaluated according to the power-off time length of the unit and the comparison of the operation data and historical records during starting up; a matching risk value P unit of a unit cold-carrying medium is obtained through mutual verification and dynamic adjustment among multiple modules; and comparing the matching risk value of the unit cold-carrying medium with a set threshold value, and if the matching risk value is smaller than the set threshold value, prompting a risk. The technical problems that the outlet water temperature does not meet the requirement, the freezing risk is increased or the energy efficiency is reduced due to the fact that the air conditioner secondary refrigerant is not matched are solved.

Description

Technical Field

[0001] This invention relates to the field of air conditioning technology, and in particular to a risk warning method for multi-module air conditioning units and their matching of cooling media. Background Technology

[0002] Multi-module air conditioning systems are widely used in commercial and industrial environments. The same air conditioning system may have different supply water temperature requirements depending on the operating scenario; in some cases, the supply water temperature needs to be higher, while in others it needs to be lower, and in special cases, the temperature requirements for the cooling medium are even lower. However, a significant problem exists in existing technologies: when users set the anti-freeze protection temperature in different cooling modes, the settings often become mismatched due to the differences in the physical properties of the cooling medium (such as pure water or an aqueous solution with added ethylene glycol). For example, pure water has a freezing point of 0°C, while an aqueous solution of ethylene glycol can freeze to below -20°C. However, existing anti-freeze protection settings usually rely on fixed thresholds or manual adjustments by the user, lacking real-time detection capabilities for changes in the medium type. This leads to problems such as insufficient water temperature, increased risk of freezing, or decreased energy efficiency when the user changes the medium (e.g., from water to an ethylene glycol solution) without adjusting the anti-freeze protection temperature accordingly.

[0003] On the other hand, in industrial applications, during special periods, it is necessary to replace the cooling medium with one that can achieve lower temperatures. When low-temperature cooling is not required, customers may change the cooling medium of the unit to improve energy efficiency and meet energy-saving requirements. Therefore, when starting up after a relatively long period of time following a shutdown, it is necessary to confirm the cooling medium.

[0004] Setting up additional hardware detection devices (such as dedicated sensors) to monitor the cooling medium or frequent manual intervention increases system cost and complexity, and makes it impossible to dynamically adapt to changes in the medium. Especially in multi-module systems, the independent operation of each module may lead to inconsistent data, further exacerbating the risk of mismatch. The current common practice is to rely on historical records or assumptions when restarting after a power outage. This approach is prone to erroneous operations, affecting system reliability and user experience.

[0005] Therefore, proposing an intelligent method for risk warning of refrigerant matching for multi-module air conditioning units is a technical problem that urgently needs to be solved in the industry. Summary of the Invention

[0006] This invention proposes a risk warning method for refrigerant matching and a multi-module air conditioning unit using the warning method to solve technical problems such as unsatisfactory outlet water temperature, increased freezing risk, or decreased energy efficiency caused by refrigerant mismatch.

[0007] The technical solution adopted in this invention is to propose a risk warning method for matching the cooling medium in a modular air conditioning unit, comprising: Record the operating data of each module during its most recent n power-on cycles separately; At startup, the matching risk value P of the cooling medium for each module is assessed based on the duration of the power outage and a comparison of operating data with historical records. 模块 ; The matching risk value P of the cooling medium of the unit is obtained by dynamically adjusting the mutual verification between multiple modules. 机组 ; The risk value of the cooling medium matching of the unit is compared with the set threshold. If it is less than the set threshold, a risk is indicated.

[0008] Furthermore, the recorded operating data for each operation includes: the unit power-on time, the current set refrigerant temperature and its settable range, the anti-freeze protection temperature setting and its settable range, the current lowest refrigerant temperature, the refrigerant matching risk value, the refrigerant type, the current refrigeration mode, the refrigerant temperature change curve, and the compressor refrigeration power curve.

[0009] Furthermore, the maximum matching risk value of the cooling medium during each operation is recorded in this record.

[0010] Furthermore, if the unit's most recent record is empty, then the first start-up operation is taken as the first record, and the matching risk value of the cooling medium is the perfect match value.

[0011] Furthermore, if there was no power outage between the current startup and the previous operation, or if there was a power outage but the outage time did not exceed the set threshold, then the matching risk value of the cooling medium of the unit is considered to be fully matched, and no risk warning is required.

[0012] Furthermore, if a power outage occurs and the outage time exceeds a threshold, each module records the water temperature change curve and the compressor cooling power curve before the refrigerant temperature reaches the set value after power-on. The best-matching historical data is then compared with the current data curve to fit the matching risk value of the refrigerant.

[0013] Furthermore, the fitting includes: calculating the power of the whole machine, the inlet temperature and outlet temperature difference of the cooling medium, the power of the water pump, and the water flow rate of the pipeline based on the operating data after startup; calculating the degree of heat absorption by the cooling medium, D; and using the degree of fit between the selected historical curve and the current operating data curve, as well as the differences between the various data, to recalibrate the current cooling medium matching risk value.

[0014] Preferably, the degree of heat absorption D of the cooling medium is calculated according to the formula D = D1 / D2 and displayed as a percentage (%). Where: D1 is the amount of cold absorbed by this cooling medium, D1=y1 G (Tout - Tin), where y1 is the simplification coefficient for experimental and theoretical calculations of the cooling medium, G is the volumetric flow rate in units (m³ / h), Tout is the outlet temperature, and Tin is the inlet temperature; D2 is the amount of cold energy absorbed, determined by system design or experiments.

[0015] Furthermore, the matching risk value P of the cooling medium for each module was obtained. 模块 Then, the data of each module were compared and matched. The matching risk values ​​of the cooling medium of all modules were arranged in order of magnitude, statistically unreasonable values ​​were removed, and the average of the remaining matching risk values ​​was taken as the matching risk value P of the cooling medium of the unit. 机组 .

[0016] Furthermore, the type of cooling medium used at startup is the same as the type recorded in the previous record. If a risk is detected that the cooling medium is not compatible, the type of cooling medium will be re-evaluated.

[0017] Furthermore, in the risk warning method as described in claim 10, the determination of the type of cooling medium in the aqueous solution is as follows: If the risk assessment of the cooling medium matching is determined to be that no warning or protection is required, then the previously recorded cooling medium type will be used as the current type and recorded. If the temperature of the cooling medium is lower than the set threshold, then it is determined that the cooling medium is an aqueous solution with added ethylene glycol and recorded.

[0018] The present invention also proposes a multi-module air conditioning unit, including multiple parallel modular units and multiple sets of parallel fan coil units, which are connected by pipes. The refrigerant in the pipes circulates between the modular units and the fan coil units by a water pump. When the unit is started, the risk warning method for refrigerant matching mentioned above is used to determine whether the refrigerant is compatible.

[0019] Compared with the prior art, the technical solution proposed in this invention has the following advantages: 1. Based on the existing components (such as temperature sensors, compressor load detection units, and memory chips) and operating data of multi-module air conditioning units, the algorithm intelligently analyzes the matching degree between the cooling medium and the antifreeze protection parameters, achieving risk detection and adaptive protection without the need to add special detection devices.

[0020] 2. First, the matching degree of each module is calculated. Then, through multi-module verification, the system consistency is improved and the failure rate is reduced. Dynamic fitting correction improves the accuracy of judgment, has strong adaptability, and improves energy efficiency.

[0021] 3. Reduce user operating costs and prevent improper water temperature settings that could lead to low unit operating efficiency and protection failures; reduce improper freeze protection that could cause refrigerant freezing, damage to the heat exchanger, and downtime losses. Attached Figure Description

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments, wherein: Figure 1 This is a schematic diagram of the cooling medium piping in a multi-module air conditioning unit; Figure 2 This is a block diagram illustrating the principle of the cooling medium matching risk early warning method proposed in this invention. Figure 3 This is a flowchart of the risk warning method for matching cooling medium proposed in this invention. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the following specific embodiments are only used to explain the invention and do not constitute a limitation thereof.

[0024] The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the scope of the invention. Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of components and steps set forth in these embodiments do not limit the scope of protection of the invention.

[0025] While techniques, methods, and apparatus known to those skilled in the art are not discussed in detail herein, such techniques, methods, and apparatus should be considered part of this specification where appropriate. Any specific values ​​in this specification should be interpreted as merely exemplary and not as limiting the invention.

[0026] For ease of description, the terms used in the specification to describe position, such as "above", "to the left", "in front", etc., are only used to describe the spatial positional relationship between a component and other components in the embodiment shown in the figure. When the position of the component is different, the relative position will change. Therefore, the positional relationship of the embodiment in the figure should not be construed as limiting the present invention.

[0027] Furthermore, it should be noted that the use of terms such as "first" and "second" in the specification is merely for distinguishing similar components and does not imply any order of precedence. Therefore, it should not be construed as limiting the scope of protection of this invention.

[0028] Figure 1 This is a schematic diagram showing the connection between a multi-module air conditioning unit and the indoor fan coil unit via a cooling medium. The following explanation uses water as the cooling medium. Figure 1 It includes four chiller modules installed in parallel outdoors and four fan coil units installed in parallel indoors. The modules and fan coil units are connected by water supply and return pipes, and the pipes are equipped with circulating water pumps (not shown in the figure).

[0029] Multi-module air conditioning units consist of two independent cycles: a refrigerant cycle, which occurs within each individual outdoor module; and a secondary refrigerant cycle, similar to traditional air conditioners, where the refrigerant circulates between the compressor, condenser, expansion valve, and evaporator, exchanging heat with the refrigerant in the evaporator. The secondary refrigerant cycle occurs within the connecting pipes between the multiple outdoor modules and the indoor terminals. Here, the refrigerant exchanges heat with the evaporators of each outdoor module before flowing into the fan coil units of the indoor terminals to exchange heat with the indoor air. In other words, the refrigerant forms a chilled water circulation loop between the evaporators and fan coil units. In this cycle, the refrigerant acts as a "heat transporter." It does not undergo a phase change itself, but only transfers heat through temperature changes.

[0030] The required properties of a refrigerant include good fluidity, high specific heat capacity, low corrosivity, and chemical stability. Water and ethylene glycol aqueous solutions are commonly chosen as refrigerants. Water has a high specific heat capacity, is non-toxic, and low in cost, but its freezing point is 0°C, making it unsuitable for direct use in cold regions where freezing is possible in winter. Ethylene glycol aqueous solutions are the most commonly used antifreeze; depending on the ethylene glycol concentration, the freezing point can drop to -20°C or even lower, making it suitable for applications requiring winter antifreeze or low-temperature operation.

[0031] Taking water as the refrigerant as an example, in cooling mode, the water (e.g., 12°C) after exchanging heat with the evaporator inside the modular unit is pumped through the water supply pipe to the indoor terminal (such as a fan coil unit). The indoor air is blown over the cooling coil inside the terminal by the fan, and the heat of the air is absorbed by the water in the coil, thus lowering the air temperature and achieving cooling. After exchanging heat with the air, the water in the coil increases its own temperature (e.g., from 12°C to 17°C), and then flows back to the outdoor modular unit for heat exchange through the return water pipe, thus forming a chilled water (refrigerant) cycle.

[0032] The advantage of modular air conditioners is that the outdoor unit uses multiple modular units connected in parallel, which can be started in stages / capacity adjusted to adapt to changes in building load.

[0033] As mentioned in the background section, mismatched refrigerants in air conditioning systems can lead to numerous technical problems, such as insufficient outlet water temperature, increased risk of freezing, and decreased energy efficiency.

[0034] The concept of this invention is as follows: based on the existing components (such as temperature sensors, compressor load detection units, and memory chips) and operating data of multi-module air conditioning units, the matching degree between the cooling medium and the antifreeze protection parameters is intelligently analyzed through algorithms. Then, the matching degree value is compared with a set threshold, and a risk warning is given based on the comparison result.

[0035] The present invention is mainly considered in the following aspects: (1) In a multi-module air conditioning system, each module independently records relevant parameters; when the unit is started, the type of medium is dynamically determined by detecting the temperature change curve of the refrigerant medium or the operating status; the replacement risk is assessed based on the duration of power outage; and the matching risk value P of the refrigerant medium of the module unit is recalibrated by combining historical data curve fitting. 模块 Then, the data between the modules are compared and verified, and statistically unreasonable values ​​are removed before assessing the overall risk value P of the unit. 机组 It will then execute the corresponding prompts and protective actions.

[0036] (2) By using multi-module mutual verification and data fitting algorithms (such as least squares method or correlation coefficient analysis), the matching risk value is dynamically adjusted to ensure detection accuracy and consistency. Among them, the matching risk value calculation is based on the comparison between the temperature change curve of the cooling medium and the cooling power curve of the compressor. The most suitable historical record is fitted as the benchmark, and the current data difference is combined for correction to achieve high reliability risk judgment.

[0037] (3) The debugging personnel initialize the first run record through the display board or debugger, set the matching risk value to 100% and the accurate medium type; in subsequent runs, if the power outage time is short (such as less than the preset threshold, such as 1 hour), the previous parameters are directly used; if the power outage time is long, the complete detection process is started; according to the matching risk value result, graded actions are performed, including no prompt, interface or communication prompt, and triggering the anti-freeze protection mechanism.

[0038] (4) When the user changes the cooling mode or settings midway, the judgment logic is rerun to enhance the system's adaptability; the prompting method supports multiple interfaces (such as LCD display) and communication protocols (such as Modbus) to improve the user experience; the protection action is dynamically adjusted according to the P value threshold and the current cooling medium type. For example, when P < 50%, it intervenes in advance when the water temperature is close to the freezing point to avoid equipment damage.

[0039] Figure 2 This is a block diagram illustrating the principle of the cooling medium matching risk warning method proposed in this invention. The risk warning method for cooling medium matching in multi-module air conditioning units proposed in this invention includes: Record the operating data of each module during its most recent n power-on cycles separately; At startup, the matching risk value P of the onboard cooling medium for each module is assessed based on the duration of the power outage and a comparison of operating data with historical records. 模块 ; The matching risk value P of the cooling medium of the unit is obtained by dynamically adjusting the mutual verification between multiple modules. 机组 ; The risk value of the cooling medium matching of the unit is compared with the set threshold. If it is less than the set threshold, a risk is indicated.

[0040] In one specific embodiment, each module unit independently records its five most recent power-on operations. Each record includes: the time of power-on, the current set water temperature and its settable range, the anti-freeze protection temperature setting and its settable range, the current lowest operating water temperature, the matching risk value between different cooling media, the type of cooling media, and the current cooling mode. The matching risk value P ranges from 0% to 100%, with a higher P indicating a better match with the cooling media. The highest matching risk value P is recorded in the current record for each operation. Each time the power button is pressed, the temperature change of the cooling media or the operating status is detected to determine the type of cooling medium, such as pure water or a solution with added ethylene glycol, and this information is recorded in the current record.

[0041] If the unit has just been installed and has not yet been commissioned, the record will be empty. The first record will be the first running status after commissioning, as indicated by the commissioning personnel. The first running record after commissioning is a perfect match, with a match risk value P of 100%. The first record is written via the display panel or by the commissioning personnel. The match risk value P may differ for each module unit, but the cooling medium is the same because all module units share the same cooling medium circulation system.

[0042] Before each subsequent startup, an assessment should be conducted to determine if there is a risk of mismatch between the air conditioning refrigerant and the refrigerant.

[0043] Figure 3 This is a flowchart of the risk warning method for matching cooling medium proposed in this invention.

[0044] The following explanation uses water as the refrigerant. The following checks will be performed each time the unit is started: When starting up, first determine whether there has been a power outage between the current start-up and the previous operation. If there has been no power outage, it is assumed that the cooling medium of the multi-module unit has not been replaced and the operation will continue according to the previous parameters without any prompts or protection.

[0045] The power outage referred to here pertains to the entire unit. Modular units generally do not experience power outages because when the cooling medium is water, it will freeze when the ambient temperature drops below 0 degrees Celsius. Therefore, the unit requires power for anti-freeze protection. If the entire unit loses power, it cannot respond to protection mechanisms, and the water system will freeze and crack, causing damage. However, a power outage is performed when the cooling medium needs to be replaced or drained.

[0046] If a power outage occurred between the current startup and the last operation, it is determined whether the power outage time exceeded the set threshold and whether there is a possibility of replacing the cooling medium. If the time is short, it is assumed that there is no possibility of replacement, and there is no risk; normal operation continues. If the power outage time is too long, exceeding the set threshold, each module records the water temperature change curve and the compressor cooling power curve after startup until the water temperature reaches the set value. These curves are compared with previously recorded data curves, and the best-matching historical matching risk value P is selected as the comparison benchmark.

[0047] By analyzing the operating data after startup, the power output of the entire unit, as well as the inlet and outlet water temperature differences of the module, combined with the water pump power and water flow rate in the pipeline, are calculated to determine the degree of heat absorption by the cooling medium, D. This degree of heat absorption is then used to recalibrate the matching risk value P based on the fit between this degree of heat absorption value D and the selected historical curve and the current operating data curve, as well as the differences between various data points.

[0048] The degree of heat absorption by the cooling medium, D, can be calculated using the following simplified formula: D = D1 / D2, expressed as a percentage (%) Where D1 is the amount of cold absorbed by this cooling medium, and D2 is the amount of cold absorbed that is determined during system design or by experiments; D1=y1 G (Tout - Tin), where y1 is the simplification coefficient for experimental and theoretical calculations under pure water conditions, G is the volumetric flow rate in m³ / h, Tout is the chilled water outlet temperature, and Tin is the chilled water inlet temperature.

[0049] This method utilizes the different properties of various cooling media to calculate the degree of heat absorption by different cooling media. For example, in the laboratory, the above data can be obtained by experimentally determining the heat absorption using water as the medium. The standard program value D for heat absorption is 100%.

[0050] The simplest way is to conduct experiments in the laboratory using ethylene glycol aqueous solutions of different concentrations, establish the above data table and the program D value for heat absorption, and then directly obtain the relevant degree value D in the program by looking up the table.

[0051] The matching risk value P is recalibrated using the degree value D, the degree of fit between the selected historical curve and the current data curve, and the differences between the individual data.

[0052] The matching risk value P is a percentage value. It is calculated by comparing a coefficient with the D value, historical curves, and the curves showing similarity between the unit and the current operating period. Mathematically, the similarity of these curves can be determined using various methods, such as correlation coefficients or error analysis. A simpler calculation involves directly comparing parameters like water temperature within relevant time intervals to obtain a coefficient. For example, if the slope of the current water temperature rise is very close to a previous curve, and the unit's operating power, water flow rate, and velocity are essentially the same, then the coefficient is considered very close to 100%. Multiplying this coefficient by the D value yields the matching risk value P for the modular unit. 模块 .

[0053] Previously recorded data included power-on time, inlet water temperature, outlet water temperature, and compressor power. The change of each data point over time can be fitted into a curve. For example, this curve and a historical curve show similar target temperatures. By aligning the time intervals within a ten-minute period, polynomial fitting and correlation coefficient R² methods were used, finally applying the experimental weighting formula: R² = 0.4. R_in+0.4 R_out+0.2 R_p; In the formula, R_in is the correlation coefficient for inlet water temperature, R_out is the correlation coefficient for outlet water temperature, and R_p is the correlation coefficient for compressor power. These correlation coefficients are calculated using Pearson product-moment correlation coefficients and other methods to determine the relationship between two continuous sequences. The number of coefficients and parameters is determined experimentally.

[0054] For example, the closest P-value was selected as the benchmark, with a weight of 50%. R² accounts for 30% of the P-value, D value accounts for 10%, and parameters such as temperature difference and compressor response speed account for 10%. The final P-value is between 0% and 100%. These are the P-values ​​for each module.

[0055] The number of parameters and the duration can be varied; the more parameters there are, the more accurate the final P-value will be.

[0056] The matching risk value P of each module is obtained internally by the modular machine. 模块 Then, the data from each module is compared and matched to verify the accuracy and compatibility of the data, ultimately obtaining the matching risk value P of the unit calculated by all modules. 机组 .

[0057] The verification is to check the matching risk value P of all module machines. 模块 Sort by size and remove statistically unreasonable values. Since the multi-module machines are of the same model and use the same water system, the calculated values ​​for all modules should not differ significantly. The matching risk value P for the modules with unreasonable values ​​removed is then calculated. 模块Then, the average of the remaining reasonable matching risk values ​​is taken as the matching risk value P of the unit. 机组 .

[0058] Determine the matching risk value P of the generator set 机组 If the value is greater than or equal to 90%, it indicates no risk and no warning or protection is needed; otherwise, continue to assess the matching risk value P of the generator set. 机组 If the risk level is less than 50%, it indicates a high risk and an early warning will be issued. The system will then take protective measures if the water temperature drops to a level that could cause freezing. If not, the system will wait for the user to confirm the risk. If the user does not confirm the risk, the unit will take protective measures according to the set protection level.

[0059] The cooling medium type is based on the previously memorized type. If there is a risk of it being replaced based on the above judgment, the medium type needs to be re-judged. The judgment steps are as follows: If the risk assessment of the cooling medium matching is determined to be that no warning or protection is required, then the previously recorded cooling medium type will be used as the current type and recorded. If the temperature of the cooling medium is lower than the set threshold, then it is determined that the cooling medium is an aqueous solution with added ethylene glycol and recorded.

[0060] If the user switches the cooling mode, sets the water temperature, or changes the antifreeze protection temperature midway, the above cooling medium matching risk assessment needs to be run again.

[0061] This invention solves the problem that when users set different cooling modes, the water temperature may not meet the requirements due to the mismatch between the antifreeze protection setting and the water temperature setting, which may lead to the system freezing and damaging the heat exchanger. By intelligently detecting the risk of replacement of the cooling medium, it prevents freezing, energy efficiency reduction or system failure caused by changes in the medium.

[0062] As an alternative implementation, parameters related to the determination of the cooling medium, such as pump energy consumption calculation and water flow acquisition, can be added. A relevant model can be established through experiments to match the current aqueous solution composition and concentration. This enhances the matching accuracy of various set temperatures and protection values. Regardless of whether the user changes the cooling medium, user-set parameters can be completely eliminated, and relevant parameters can be automatically matched. This completely removes the risk of malfunctions caused by users' unfamiliarity with unit operation.

[0063] This invention obtains a relevant model by conducting experiments in advance and matching various parameters. Subsequently, regardless of what kind of cooling medium the user uses, it is easy to match it with a cooling medium in the model and quickly determine whether the user has replaced the cooling medium. Furthermore, if the model establishes conditions for different concentrations of ethylene glycol solution, it can also determine the concentration and match the antifreeze parameters accordingly without user intervention.

[0064] The above description is merely a specific embodiment of the present invention. It should be noted that any modifications, equivalent substitutions, and variations made within the spirit and framework of the present invention should be included within the protection scope of the present invention.

Claims

1. A risk warning method for matching the cooling medium in a multi-module air conditioning unit, characterized in that, include: Record the operating data of each module during its most recent n power-on cycles separately; At startup, the matching risk value P of the cooling medium for each module is assessed based on the duration of the power outage and a comparison of operating data with historical records. 模块 ; The matching risk value P of the cooling medium of the unit is obtained by dynamically adjusting the mutual verification between multiple modules. 机组 ; The risk value of the cooling medium matching of the unit is compared with the set threshold. If it is less than the set threshold, a risk is indicated.

2. The risk warning method as described in claim 1, characterized in that, The recorded operating data includes: the time the unit is powered on, the current set refrigerant temperature and its settable range, the anti-freeze protection temperature set value and its settable range, the current lowest refrigerant temperature, the refrigerant matching risk value, the refrigerant type, the current refrigeration mode, the refrigerant temperature change curve, and the compressor refrigeration power curve.

3. The risk warning method according to claim 1, characterized in that, During each run, the maximum matching risk value of the cooling medium is recorded in this record.

4. The risk warning method according to claim 1, characterized in that, If the unit's most recent record is empty, then the first start-up operation will be used as the first record, and the matching risk value of the cooling medium will be the perfect match value.

5. The risk warning method as described in claim 1, characterized in that, If there was no power outage between the current startup and the previous operation, or if there was a power outage but the outage time did not exceed the set threshold, then the matching risk value of the cooling medium of the unit is considered to be fully matched, and no risk warning is required.

6. The risk warning method as described in claim 5, characterized in that, If a power outage occurs and the outage time exceeds the threshold, each module records the water temperature change curve and the compressor cooling power curve after power-on and before the refrigerant temperature reaches the set value. The best-matching historical data is selected and compared with the current data curve to fit the matching risk value of the refrigerant.

7. The risk warning method according to claim 6, characterized in that, The fitting process includes: calculating the power of the whole machine, the inlet temperature of the cooling medium, the outlet temperature difference, the power of the water pump, and the water flow rate of the pipeline based on the operating data after startup; calculating the degree of heat absorption by the cooling medium, D; and using this degree of heat absorption, the degree of fit between the selected historical curve and the current operating data curve, as well as the differences between the various data, to recalibrate the current cooling medium matching risk value.

8. The risk warning method as described in claim 7, characterized in that, The degree of heat absorption by the cooling medium, D, is calculated according to the formula D = D1 / D2 and displayed as a percentage (%). Where: D1 is the amount of cold absorbed by this cooling medium, D1=y1 G (Tout - Tin), where y1 is the simplification coefficient for experimental and theoretical calculations of the cooling medium, G is the volumetric flow rate in units (m³ / h), Tout is the outlet temperature, and Tin is the inlet temperature; D2 is the amount of cold energy absorbed, determined by system design or experiments.

9. The risk warning method as described in claim 7, characterized in that, The matching risk value P of the cooling medium for each module was obtained. 模块 Then, the data of each module were compared and matched. The matching risk values ​​of the cooling medium of all modules were arranged in order of magnitude, statistically unreasonable values ​​were removed, and the average of the remaining matching risk values ​​was taken as the matching risk value P of the cooling medium of the unit. 机组 .

10. The risk warning method as described in claim 1, characterized in that, The type of cooling medium used at startup is the same as the one recorded last time. If a risk is detected that the cooling medium is not compatible, the type of cooling medium will be re-evaluated.

11. The risk warning method as described in claim 10, characterized in that, The determination of the type of cooling medium in aqueous solution is as follows: If the risk assessment of the cooling medium matching is determined to be that no warning or protection is required, then the previously recorded cooling medium type will be used as the current type and recorded. If the temperature of the cooling medium is lower than the set threshold, then it is determined that the cooling medium is an aqueous solution with added ethylene glycol and recorded.

12. A multi-module air conditioning unit, comprising multiple parallel-connected modular units and multiple sets of parallel-connected fan coil units, the two being connected by pipes, wherein a refrigerant in the pipes circulates between the modular units and the fan coil units via a water pump, characterized in that, When starting up, the risk warning method for matching the refrigerant medium as described in any one of claims 1-11 is used to determine whether the refrigerant is compatible.

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