Condenser heat exchange performance detection method and device, terminal equipment and storage medium

Abstract

The embodiment of the present application discloses a kind of condenser heat transfer performance detection method, device, terminal equipment and storage medium, the operating data of water chiller in stable state is obtained in the embodiment of the present application, first target data and second target data are extracted from operating data respectively, and the reference value of heat transfer coefficient is calculated according to first target data and second target data respectively, and finally, the relative size of the calculated value of heat transfer coefficient and reference value is used to determine the heat transfer performance of condenser.The embodiment of the present application improves the accuracy of detecting the heat transfer performance of condenser, and solves the technical problem of low accuracy in detecting the heat transfer performance of condenser in the prior art.

Description

Technical Field

[0001] This application relates to the field of equipment manufacturing and testing, and in particular to a method, apparatus, terminal equipment, and storage medium for testing the heat exchange performance of a condenser. Background Technology

[0002] The operating performance of a chiller unit is related to internal factors such as its design and selection, but it is also easily affected by external factors, the most significant of which are the influences on the evaporation and condensation temperatures. Generally speaking, under the premise of meeting usage requirements, the higher the evaporation temperature and the lower the condensation temperature, the higher the operating efficiency of the chiller unit, i.e., the higher its energy efficiency ratio. The key component determining the condensation temperature is the condenser. Under otherwise constant conditions, the better the heat exchange performance of the condenser, the lower the condensation temperature, and consequently, the higher the energy efficiency ratio of the chiller unit.

[0003] As usage time increases, scale inevitably forms in the cooling water during continuous circulation. This scale, adhering to the inner wall of the condenser's heat exchange pipes, increases the heat transfer resistance of the pipe walls, deteriorating the condenser's heat exchange performance and thus raising the condensing temperature, leading to a decrease in the chiller's energy efficiency ratio (EER). Furthermore, scale also increases the friction loss of the circulating cooling water, causing the cooling water pump to operate at higher power. Therefore, monitoring the condenser's heat exchange performance and promptly addressing any deterioration is crucial for improving the chiller's EER. However, existing methods for testing condenser heat exchange performance suffer from low accuracy and are prone to misjudgment.

[0004] In conclusion, improving the accuracy of condenser heat exchange performance testing has become a pressing technical problem that needs to be solved. Summary of the Invention

[0005] This invention provides a method, apparatus, terminal equipment, and storage medium for testing the heat exchange performance of condensers, solving the technical problem of low accuracy in testing the heat exchange performance of condensers in the prior art.

[0006] In a first aspect, embodiments of the present invention provide a method for testing the heat exchange performance of a condenser, comprising:

[0007] Obtain operating data of the chiller unit under stable conditions;

[0008] First target data is extracted from the operating data, and the calculated value of the heat transfer coefficient of the condenser is calculated based on the first target data. The first target data includes the condenser state parameters of the condenser in a steady state.

[0009] The second target data is extracted from the operating data and input into the pre-set prediction model to obtain the reference value of the heat transfer coefficient of the condenser. The second target data includes the cooling water state parameters, chilled water state parameters and chiller unit state parameters of the condenser under steady state.

[0010] The heat exchange performance of the condenser is determined based on the relative magnitude of the calculated value and the benchmark value.

[0011] Secondly, embodiments of the present invention provide a condenser heat exchange performance testing device, comprising:

[0012] The data acquisition module is used to acquire the operating data of the chiller unit under stable conditions;

[0013] The first calculation module is used to extract first target data from the operating data and calculate the heat transfer coefficient of the condenser based on the first target data. The first target data includes the condenser state parameters of the condenser in a steady state.

[0014] The second calculation module is used to extract the second target data from the operating data, input the second target data into the pre-set prediction model, and obtain the reference value of the heat transfer coefficient of the condenser. The second target data includes the cooling water state parameters, chilled water state parameters and chiller unit state parameters of the condenser in a steady state.

[0015] A heat exchange performance determination module is used to determine the heat exchange performance of the condenser based on the relative magnitude of the calculated value and the benchmark value.

[0016] Thirdly, embodiments of the present invention provide a terminal device, the terminal device including a processor and a memory;

[0017] The memory is used to store computer programs and to transfer the computer programs to the processor;

[0018] The processor is configured to execute a condenser heat exchange performance testing method as described in the first aspect, according to instructions in the computer program.

[0019] Fourthly, embodiments of the present invention provide a storage medium for storing computer-executable instructions, which, when executed by a computer processor, are used to perform a condenser heat exchange performance testing method as described in the first aspect.

[0020] As described above, in this embodiment of the invention, after acquiring the operating data of the chiller unit under stable conditions, first target data and second target data are extracted from the operating data, and a calculated value of the heat transfer coefficient is calculated based on the first target data, and a reference value of the heat transfer coefficient is calculated based on the second target data. Finally, the heat transfer performance of the condenser is determined based on the relative magnitude of the calculated value of the heat transfer coefficient and the reference value. This embodiment of the invention uses the heat transfer coefficient to directly measure the heat transfer performance of the condenser. Compared with the temperature parameters such as the average temperature difference and terminal temperature difference commonly used in existing solutions, which indirectly affect the heat transfer performance of the condenser, the heat transfer coefficient is a direct determining parameter of the heat transfer performance of the condenser, and therefore can more intuitively reflect the heat transfer performance of the condenser. At the same time, using the heat transfer coefficient can adapt to the application scenario of variable flow cooling water systems, i.e., variable frequency water pumps.

[0021] Secondly, this invention utilizes a predictive model to calculate the baseline value of the heat transfer coefficient, ensuring that the baseline value more closely approximates the actual operating conditions of the chiller unit. This avoids the errors arising from heat transfer parameters calculated using condenser structural parameters and empirical heat transfer formulas in existing solutions. Furthermore, the predictive model is adaptable to different types of chiller units and can be updated based on new data, resulting in wider adaptability and more accurate calculation results.

[0022] Finally, in this embodiment of the invention, the heat transfer performance of the condenser is determined based on the relative magnitude of the calculated heat transfer coefficient and the reference value. Since the prediction model already includes the dynamic operation of the chiller unit, the reference value is dynamically changing. Compared with the static reference value used in existing solutions, this avoids the influence of reference value changes during the dynamic operation of the chiller unit, further improving the accuracy of detecting the heat transfer performance of the condenser. Attached Figure Description

[0023] Figure 1 This is a flowchart illustrating a method for testing the heat exchange performance of a condenser, as provided in an embodiment of the present invention.

[0024] Figure 2 Temperature distribution diagram of cooling water and refrigerant inside the condenser provided for embodiments of the present invention.

[0025] Figure 3 This is a schematic diagram illustrating the heat exchange performance testing of a condenser according to an embodiment of the present invention.

[0026] Figure 4 This is a flowchart illustrating another method for testing the heat exchange performance of a condenser provided in an embodiment of the present invention.

[0027] Figure 5 This is a flowchart illustrating the setting level query table provided in an embodiment of the present invention.

[0028] Figure 6This is a schematic diagram of a condenser heat exchange performance testing device provided in an embodiment of the present invention.

[0029] Figure 7 This is a schematic diagram of the structure of a terminal device provided in an embodiment of the present invention. Detailed Implementation

[0030] The following description and accompanying drawings fully illustrate specific embodiments of this application to enable those skilled in the art to practice them. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. The scope of embodiments of this application includes the entire scope of the claims and all available equivalents of the claims. In this document, each embodiment may be referred to individually or collectively by the term "invention," which is merely for convenience and is not intended to automatically limit the scope of the application to any single invention or inventive concept if more than one invention is disclosed. Relational terms such as "first" and "second" are used herein only to distinguish one entity or operation from another, without requiring or implying any actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed. The various embodiments in this document are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the structures, products, etc., disclosed in the embodiments, since they correspond to the disclosed parts, the descriptions are relatively simple; relevant details can be found in the method section.

[0031] A condenser is a type of heat exchanger. Its main function is to exchange heat between the refrigerant and cooling water or air, thereby cooling the refrigerant gas into a refrigerant liquid and completing the condensation process of the refrigeration cycle.

[0032] Existing technologies typically test the heat transfer performance of condensers by calculating the average temperature difference ΔT between the cooling water side and the refrigerant side. m Or end difference T td The heat transfer performance of a condenser is indirectly characterized by ΔT. The average heat transfer temperature difference refers to the temperature difference between the two fluids exchanging heat on either side of the heat transfer wall; the terminal temperature difference refers to the difference between the cooling water outlet temperature and the refrigerant saturation condensation temperature. The better the heat transfer performance of the condenser, the higher the ΔT value. m or T td Small, otherwise ΔT m or Ttd Large. By manually setting ΔT m threshold or T td The threshold, if ΔT m or T td If the threshold is exceeded, the condenser's heat exchange performance is considered to have deteriorated, requiring inspection and cleaning of the condenser. However, due to ΔT m or T td It is an indirect characterization of the condenser's own heat exchange performance. In addition to the condenser, the cooling water flow rate also affects ΔT. m or T td Under the same conditions, the smaller the cooling water flow rate, the longer the ΔT will be. m or T td The smaller the value, the less likely it is to be detected. Therefore, this detection method is generally difficult to apply to variable flow cooling water systems, i.e., variable frequency pump systems. On the other hand, the operating status of chiller units changes with environmental conditions, therefore ΔT... m or T td The temperature difference is usually constantly changing, and setting a static threshold to determine the size of the heat exchange temperature difference can easily lead to misjudgment.

[0033] Other heat exchange performance testing methods typically determine the presence and amount of scale on the condenser surface by directly calculating the fouling thermal resistance or heat transfer coefficient attached to the inner wall of the heat exchanger. Implementing this method usually requires prior knowledge of the condenser's structural parameters, and calculating the heat transfer coefficient necessitates the use of empirical formulas related to heat transfer. However, these empirical formulas are usually derived from extensive laboratory testing and have a narrow scope of application, making it difficult to cover some new heat exchanger structures. Furthermore, the method of calculation using structural parameters and empirical formulas also has two problems: first, manual recalibration is required for different models of chillers; second, even for chillers of the same model, slight structural differences may exist due to manufacturing or installation errors, but these differences cannot be detected and eliminated during calculation.

[0034] Therefore, in order to solve the technical problem of low accuracy in the existing technology for testing the heat transfer performance of condensers, embodiments of the present invention provide a method for testing the heat transfer performance of condensers, such as... Figure 1 As shown, Figure 1 This is a flowchart illustrating a method for testing the heat exchange performance of a condenser according to an embodiment of the present invention. The method for testing the heat exchange performance of a condenser provided in this embodiment can be executed by a terminal device, which can be implemented through software and / or hardware. The terminal device can consist of two or more physical entities, or it can consist of a single physical entity. For example, the terminal device can be a computer, a host computer, or a tablet. The method includes the following steps:

[0035] Step 101: Obtain the operating data of the chiller unit under stable conditions.

[0036] In this embodiment, the calculation and derivation of the condenser's heat exchange performance must adhere to the assumption of thermal equilibrium; therefore, it is necessary to obtain the chiller unit's operating data under steady-state conditions. A steady-state condition refers to a state where the chiller unit's operating data does not change significantly within a certain period of time.

[0037] Step 102: Extract the first target data from the operating data, and calculate the heat transfer coefficient of the condenser based on the first target data. The first target data includes the condenser state parameters under steady-state conditions.

[0038] After acquiring the operational data, it is necessary to further extract the first target data from the operational data. This first target data includes the condenser state parameters under steady-state conditions. Once the first target data is acquired, the calculated value of the condenser's heat transfer coefficient can be determined based on it. The heat transfer coefficient is a parameter used to characterize the heat transfer performance of the condenser; for example, the product of the condenser's heat transfer coefficient K and the heat transfer area A can be used as the heat transfer coefficient KA. In one embodiment, the average temperature difference between the cooling water side and the refrigerant side of the condenser can be calculated based on the first target data. Then, based on the principle of heat balance, the calculated value of the condenser's heat transfer coefficient can be determined using the average temperature difference.

[0039] Based on the above embodiments, step 102, which involves extracting first target data from the operating data and calculating the heat transfer coefficient of the condenser based on the first target data, includes:

[0040] Step 1021: Extract the first target data from the operating data, and calculate the average temperature difference of heat transfer between the cooling water side and the refrigerant side of the condenser based on the first target data.

[0041] When calculating the heat transfer coefficient, the average temperature difference between the cooling water side and the refrigerant side of the condenser is first calculated based on the extracted target data. For example, the flow of cooling water and refrigerant in the condenser is simplified to a single-pass counter-current process, and the superheated and subcooled sections on the refrigerant side of the condenser are ignored. Therefore, the temperature distribution of cooling water and refrigerant inside the condenser is simplified as follows: Figure 2 As shown. The logarithmic mean temperature difference LMTD is used as the average temperature difference ΔT for heat transfer between the condenser cooling water side and the refrigerant side. m The logarithmic mean temperature difference (LMTD) is the average value of the integral of the temperature difference between the two fluids during the heat transfer process in the heat exchanger; the calculation formula is shown in formula (1):

[0042]

[0043] Among them, T cwi This indicates the condenser cooling water inlet temperature, in °C; T cwoThis indicates the condenser cooling water outlet temperature, in °C; T c This represents the saturated condensing temperature of the condenser, in °C. The first target data includes T. cwi T cwo And T c .

[0044] Step 1022: Calculate the heat transfer coefficient of the condenser based on the average temperature difference of heat transfer.

[0045] After calculating the average temperature difference for heat transfer, the heat transfer coefficient of the condenser is further calculated based on the principle of heat balance. In one embodiment, according to the principle of heat balance, the following calculation relationship exists:

[0046] m cw c w (T cwo -T cwi )=KA·ΔT m (2)

[0047] The formula for calculating the heat transfer coefficient KA can be obtained from formula (2):

[0048]

[0049] Where, m cw This indicates the flow rate of cooling water, expressed in kg / s; c w The specific heat capacity of water is expressed as 4.2 kJ / kg at 4℃; ΔT m This represents the average temperature difference for heat transfer, expressed in °C. Similarly, the first target data includes m. cw .

[0050] The above is the specific process for calculating the heat transfer coefficient.

[0051] Step 103: Extract the second target data from the operating data and input the second target data into the pre-set prediction model to obtain the baseline value of the heat transfer coefficient of the condenser. The second target data includes the cooling water state parameters, chilled water state parameters and chiller unit state parameters of the condenser under steady state.

[0052] After acquiring the operational data, a second target data point can be extracted from it. This second target data is then input into a pre-trained prediction model to obtain a baseline value for the condenser's heat transfer coefficient output by the prediction model. For example, a regression model of the heat transfer coefficient can be constructed based on machine learning as the prediction model. The input parameters of the regression model are the second target data, and the output is the baseline value of the heat transfer coefficient. In one embodiment, the second target data includes the chiller unit load rate (PLR) and the cooling water flow rate (m). cw chilled water flow rate (m) ewCooling water inlet temperature T cwi Cooling water outlet temperature T cwo Chilled water inlet temperature T ewi and chilled water outlet temperature T ewo The cooling water flow rate is m cw Cooling water inlet temperature T cwi Cooling water outlet temperature T cwo Here are the cooling water state parameters, and the chilled water flow rate is in meters. ew Chilled water inlet temperature T ewi and chilled water outlet temperature T ewo These are the chilled water status parameters, and the chiller unit load rate (PLR) is the chiller unit status parameter.

[0053] When training the prediction model, historical operating data of the condenser under normal conditions can be obtained. Normal conditions refer to a state where the condenser's heat exchange performance shows no significant decline and the inner wall of the hot water pipes is free of significant scale buildup. Then, historical secondary target data is extracted from the historical operating data. The corresponding historical heat exchange coefficients are labeled in the historical secondary target data, and the prediction model is trained until a well-trained prediction model is obtained. In another embodiment, the prediction model is constructed based on a neural network. The neural network includes an input layer, two hidden layers, and an output layer. The input layer contains seven neurons, the hidden layers contain ten neurons, and the output layer contains one neuron. Neurons in different layers are connected through a fully connected structure. The activation function of the neural network is the ReLU activation function.

[0054] Additionally, it should be noted that there is no specific execution order between steps 102 and 103, and steps 102 and 103 can be executed simultaneously.

[0055] Step 104: Determine the heat exchange performance of the condenser based on the relative magnitude of the calculated value and the benchmark value.

[0056] After obtaining the calculated value and the baseline value of the heat transfer coefficient, the heat transfer performance of the condenser can be determined based on their relative magnitudes. For example, the heat transfer performance can be determined by calculating the ratio between the calculated value and the baseline value; a ratio less than 1 indicates poor heat transfer performance. In another embodiment, the heat transfer performance can also be measured by calculating the difference between the calculated value and the baseline value; a smaller difference indicates poorer heat transfer performance. The overall process is as follows: Figure 3 As shown.

[0057] As described above, in this embodiment of the invention, after acquiring the operating data of the chiller unit under stable conditions, first target data and second target data are extracted from the operating data, and a calculated value of the heat transfer coefficient is calculated based on the first target data, and a reference value of the heat transfer coefficient is calculated based on the second target data. Finally, the heat transfer performance of the condenser is determined based on the relative magnitude of the calculated value of the heat transfer coefficient and the reference value. This embodiment of the invention uses the heat transfer coefficient to directly measure the heat transfer performance of the condenser. Compared with the temperature parameters such as the average temperature difference and terminal temperature difference commonly used in existing solutions, which indirectly affect the heat transfer performance of the condenser, the heat transfer coefficient is a direct determining parameter of the heat transfer performance of the condenser, and therefore can more intuitively reflect the heat transfer performance of the condenser. At the same time, using the heat transfer coefficient can adapt to the application scenario of variable flow cooling water systems, i.e., variable frequency water pumps.

[0058] Secondly, this invention utilizes a predictive model to calculate the baseline value of the heat transfer coefficient, ensuring that the baseline value more closely approximates the actual operating conditions of the chiller unit. This avoids the errors arising from heat transfer parameters calculated using condenser structural parameters and empirical heat transfer formulas in existing solutions. Furthermore, the predictive model is adaptable to different types of chiller units and can be updated based on new data, resulting in wider adaptability and more accurate calculation results.

[0059] Finally, in this embodiment of the invention, the heat transfer performance of the condenser is determined based on the relative magnitude of the calculated heat transfer coefficient and the reference value. Since the prediction model already includes the dynamic operation of the chiller unit, the reference value is dynamically changing. Compared with the static reference value used in existing solutions, this avoids the influence of reference value changes during the dynamic operation of the chiller, further improving the accuracy of detecting the heat transfer performance of the condenser.

[0060] like Figure 4 As shown, Figure 4 This is a flowchart illustrating another method for testing the heat exchange performance of a condenser provided in an embodiment of the present invention. Figure 4 The provided method for testing the heat transfer performance of a condenser is a refinement of the aforementioned method, including the following steps:

[0061] Step 201: Obtain the operating data of the chiller unit under stable conditions.

[0062] Step 202: Extract the first target data from the operating data, and calculate the heat transfer coefficient of the condenser based on the first target data. The first target data includes the condenser state parameters under steady-state conditions.

[0063] Step 203: Extract the second target data from the operating data and input the second target data into the pre-set prediction model to obtain the baseline value of the heat transfer coefficient of the condenser. The second target data includes the cooling water state parameters, chilled water state parameters and chiller unit state parameters of the condenser under steady state.

[0064] Step 204: Calculate the ratio of the calculated value to the baseline value, and determine the heat exchange performance of the condenser based on the calculated ratio.

[0065] In this embodiment, after calculating the heat transfer coefficient and the baseline value, the heat transfer performance of the condenser can be determined by calculating the ratio of the calculated heat transfer coefficient to the baseline value. For example, the calculated heat transfer coefficient obtained by formula (3) can be denoted as KA. true The baseline value of the heat transfer coefficient calculated based on the prediction model is denoted as KA. base , if KA true Less than KA base If the condenser's heat transfer performance is lower than the baseline value, then the current condenser's heat transfer performance is poor. Let R be... KA for KA ture and KA base The ratio when R KA A value less than 1 indicates that the current condenser heat exchange performance is poor, and R KA The smaller the value, the more significant the decrease in heat exchange performance.

[0066] Based on the above embodiments, step 204, which determines the heat exchange performance of the condenser according to the calculated value of the ratio, includes:

[0067] Step 2041: When the calculated value of the ratio is greater than or equal to the preset threshold, the heat exchange performance of the condenser is determined to be of a high level.

[0068] In this embodiment, after calculating the ratio between the calculated value of the heat transfer coefficient and the reference value, the calculated value of the ratio can be compared with a preset threshold. When the calculated value of the ratio is greater than or equal to the preset threshold, the heat transfer performance of the condenser is determined to be of a high level. For example, the threshold can be set to 1, when R... KA When the value is greater than or equal to 1, the heat exchange performance of the condenser is determined to be of a high level.

[0069] Step 2042: When the calculated value of the ratio is less than the preset threshold, the heat exchange performance of the condenser is determined to be of a low level.

[0070] When the calculated value of the ratio is less than a preset threshold, the heat exchange performance of the condenser can be considered low. For example, when the threshold is set to 1, when R... KA If the value is less than 1, the calculated value of the heat transfer coefficient will be less than the reference value, which indicates that the heat transfer performance of the condenser is of a low level.

[0071] Based on the above embodiments, after determining that the heat exchange performance of the condenser is of a low level, the method further includes:

[0072] Step 205: Query the target ratio range in the preset level lookup table where the calculated value of the ratio is located. The level lookup table includes multiple ratio ranges, and each ratio range corresponds to a fault level and the range of change of the energy efficiency ratio.

[0073] In this embodiment, since the heat transfer coefficient is a relatively abstract heat transfer parameter, to facilitate a direct and intuitive determination of the impact of the calculated ratio value on the chiller unit's performance, this embodiment also provides a severity level lookup table for users to visually view the severity of the calculated ratio value. The severity level lookup table includes multiple ratio ranges, and each ratio range corresponds to a fault level. For example, different ratio thresholds R are set according to the degree of decline in condenser heat transfer performance. KA,th R KA,th1 >R KA,th2 >R KA,th3 ..., by dividing multiple ratio intervals using ratio thresholds of different levels [R] KA,th1 ,R KA,th2 ]、[R KA,th2 ,R KA,th3 ]、[R KA,th3 ,R KA,th4 ]……[R KA,thn-1 ,R KA,thn Each ratio interval corresponds to a different fault level F1, F2, ..., with higher fault level numbers indicating greater reduction in condenser heat exchange performance. After obtaining the calculated ratio value, the corresponding target ratio interval can be looked up in the level lookup table based on the calculated value. Furthermore, each ratio interval also corresponds to the range of changes in the energy efficiency ratio, thus quantitatively linking changes in the calculated ratio value to changes in the chiller unit's energy efficiency ratio.

[0074] Step 206: Determine the corresponding target fault level in the level lookup table based on the target ratio range.

[0075] After determining the target ratio range, the target fault level corresponding to the target ratio range can be further determined from the level lookup table.

[0076] Based on the above embodiments, such as Figure 5 As shown, the grade lookup table is pre-configured in the following way:

[0077] Step 401: Determine the first conversion relationship between the calculated value of the heat transfer coefficient and the reference value of the heat transfer coefficient and the saturated condensation temperature.

[0078] In this embodiment, when setting up the grade lookup table, it is first necessary to determine the first conversion relationship between the ratio of the calculated heat transfer coefficient to the baseline heat transfer coefficient and the saturated condensation temperature. Specifically, assuming that the KA value of the condenser decreases, the condenser must ensure the same heat transfer Q as before the decrease. c and the same cooling water inlet / outlet temperature T cwi / T cwo That is, the decay of the KA value is due to ΔT m To supplement this, we can obtain formula (4) from formula (2):

[0079]

[0080] In the formula, KA1 represents the KA value before condenser degradation, KA2 represents the KA value after condenser degradation, and ΔT m1 ΔT represents the average heat transfer temperature difference corresponding to KA1. m2 This represents the average temperature difference for heat transfer corresponding to KA2. ΔT m Using the arithmetic mean temperature difference to simplify the calculation, we get:

[0081]

[0082] In the formula, T c1 T represents the saturated condensation temperature corresponding to KA1. c2 T represents the saturated condensation temperature corresponding to KA2. m This is the average value of the cooling water inlet / outlet temperature, i.e.:

[0083]

[0084] Since the cooling water inlet / outlet temperature T is assumed cwi / T cwo The T values ​​for KA1 and KA2 remain unchanged. m They are the same.

[0085] Remember R T For T c2 With T c1 The ratio of , then from equation (5) we can obtain:

[0086]

[0087] Where k is T m With T c1 The ratio, which ranges from approximately 0.7 to 0.9. In one embodiment, k can be set to a constant of 0.8.

[0088] Formula (7) links the change in KA value with T. c The relationship of change is the first transformation relationship.

[0089] Step 402: Determine the second conversion relationship between the saturated condensation temperature and the energy efficiency ratio of the condenser.

[0090] After determining the first conversion relationship, it is necessary to further determine the second conversion relationship between the saturated condensation temperature and the condenser's energy efficiency ratio. In one embodiment, the second conversion relationship is determined as follows:

[0091] Design a benchmark chiller refrigeration cycle to quantify COP as a function of T. c The changes are caused by variations, where COP is the chiller's energy efficiency ratio, i.e., the cooling capacity per unit power. There are five essential parameters for the design basis chiller's refrigeration cycle: saturated condensing temperature T... c saturated evaporation temperature T e Compressor discharge temperature T d compressor suction temperature T s and condenser outlet temperature T co .

[0092] The load factor (PLR) of a chiller unit typically has a significant impact on the above five parameters. These can be summarized based on historical data from the chiller unit. c T e T d T s T co The mapping relationship with PLR is shown in formula (8):

[0093] Y = f(PLR)(8)

[0094] In the formula, Y is T c T e T d T s T co One of them, f(4), represents the mapping relationship between PLR and Y.

[0095] In one embodiment, the mapping relationship can be constructed as follows. Assuming the load factor PLR ranges from (0, 100), the load factor PLR is divided into n equal intervals: (0, 100 / n], (100 / n, 2*100 / n], ..., ((n-1)*100 / n, 100]. For example, if n is 10, the load factor is divided into 10 equal intervals. Then, within each interval, based on the historical operating data of the chiller unit, the average value of Y falling within that interval is calculated, and this average value is used as the baseline value of Y for that interval. Finally, based on the baseline value of Y in each interval, a lookup table for PLR and Y, i.e., the operating parameter baseline table, can be constructed, as shown in Table 1.

[0096]

[0097]

[0098] Table 1

[0099] Assuming the current PLR falls within the k-th interval, the baseline values ​​of each operating parameter, T, can be obtained from the operating parameter baseline table. c,k T e,k T d,k T s,k T co,k Then, a baseline refrigeration cycle can be constructed within the k-th interval. Based on the refrigerant's physical properties and the refrigeration cycle principle, the baseline COP value for the k-th interval can be calculated. k,base As shown in formula (9):

[0100] COP=g(Tc,Te,Td,Ts,Tco,Ref)(9)

[0101] In the formula, Ref represents the type of refrigerant; g(.) represents the calculation process of COP.

[0102] Based on the baseline refrigeration cycle, only the cold T is considered. c The impact of changes on COP, i.e., in T c,k T e,k T d,k T s,k T co,k In the middle, change T c,k The value of T is maintained. e,k T s,k And T co,k With the value remaining unchanged, the baseline refrigeration cycle after degradation is obtained, and the corresponding COP after degradation can be calculated using formula (10). k,true value.

[0103] Remember R COP R is the ratio of the true COP value to the baseline value, within the k-th interval. COP With R T The mapping relationship is as follows:

[0104] R T =h(R) COP (10)

[0105] In the formula, h(4) represents R COP With R T The mapping relationship.

[0106] Step 403: Based on the first and second conversion relationships, determine the third conversion relationship between the ratio of the calculated value of the heat transfer coefficient to the baseline value of the heat transfer coefficient and the energy efficiency ratio.

[0107] After obtaining the first and second transformation relationships, by combining formulas (7) and (10), R can be realized. COP With R KA The mapping relationship between them, that is, the third transformation relationship.

[0108] Step 404: Set up a grade lookup table based on the energy efficiency ratio and the third conversion relationship.

[0109] Finally, a grade lookup table can be set up based on the changes in the energy efficiency ratio and the third conversion relationship. For example, different fault levels can be divided according to the changes in the energy efficiency ratio, and the ratio range corresponding to each fault level can be calculated, thereby completing the construction of the grade lookup table.

[0110] Based on the above embodiments, step 404, which sets up a level lookup table according to the energy efficiency ratio and the third conversion relationship, includes:

[0111] Step 4041: Determine the range of multiple energy efficiency ratios based on the changes in energy efficiency ratio.

[0112] In one embodiment, the corresponding R can be calculated based on the change in energy efficiency ratio. COP And according to R COP The magnitude of the value determines the range of multiple energy efficiency ratios R. COP,th .

[0113] Step 4042: Calculate the ratio interval corresponding to each change interval based on the third transformation relationship.

[0114] Then, based on the third conversion relationship, the variation range R of each energy efficiency ratio can be calculated. COP,th The corresponding ratio interval R KA,th .

[0115] Step 4043: Determine the fault level corresponding to each ratio interval.

[0116] Finally, the fault level corresponding to each ratio interval can be determined. For example, in one embodiment, R... COP,th Divided into 0.05 intervals, R COPth By taking values ​​of 0.95, 0.9, 0.85, 0.8, and 0.75 respectively, five fault levels are determined for the load factor PLR in the k-th interval, as shown in Table 2.

[0117]

[0118] Table 2

[0119] Calculate the ratio interval R within each PLR interval. th,k, After that, you can obtain the complete level lookup table.

[0120] As described above, in this embodiment of the invention, after calculating the ratio of the calculated heat transfer coefficient to the baseline heat transfer coefficient, the severity of the calculated ratio is further queried in a grade lookup table based on the calculated ratio. This allows users to intuitively understand the impact of the calculated ratio on the performance of the chiller unit. Furthermore, in setting up the grade lookup table, this embodiment of the invention correlates the calculated ratio with the degree of energy efficiency ratio decay, making the grade lookup table setting more reasonable and intuitive.

[0121] like Figure 6 As shown, Figure 6 A schematic diagram of a condenser heat exchange performance testing device provided in an embodiment of the present invention includes:

[0122] The data acquisition module 501 is used to acquire the operating data of the chiller unit under stable conditions;

[0123] The first calculation module 502 is used to extract first target data from the operating data and calculate the heat transfer coefficient of the condenser based on the first target data. The first target data includes the condenser state parameters of the condenser in a steady state.

[0124] The second calculation module 503 is used to extract the second target data from the operating data, input the second target data into the pre-set prediction model, and obtain the reference value of the heat transfer coefficient of the condenser. The second target data includes the cooling water state parameters, chilled water state parameters and chiller unit state parameters of the condenser in a steady state.

[0125] The heat transfer performance determination module 504 is used to determine the heat transfer performance of the condenser based on the relative magnitude of the calculated value and the reference value.

[0126] Based on the above embodiments, the first computing module 502 includes:

[0127] The heat transfer average temperature difference calculation submodule is used to extract the first target data from the operating data and calculate the heat transfer average temperature difference between the cooling water side and the refrigerant side of the condenser based on the first target data.

[0128] The calculation value calculation submodule is used to calculate the heat transfer coefficient of the condenser based on the average temperature difference of heat transfer.

[0129] Based on the above embodiments, the heat exchange performance determination module 504 is specifically used to calculate the calculated value of the ratio between the calculated value and the reference value, and to determine the heat exchange performance of the condenser based on the calculated value of the ratio.

[0130] Based on the above embodiments, the heat transfer performance determination module 504 includes:

[0131] The high-level determination submodule is used to determine the heat exchange performance of the condenser as high-level when the calculated value of the ratio is greater than or equal to a preset threshold.

[0132] The low-level determination submodule is used to determine the heat exchange performance of the condenser as low-level when the calculated value of the ratio is less than a preset threshold.

[0133] Based on the above embodiments, it also includes:

[0134] The ratio range determination module is used to query the target ratio range in the preset level lookup table where the calculated value of the ratio is located. The level lookup table includes multiple ratio ranges, and each ratio range corresponds to a fault level and the range of change of the energy efficiency ratio.

[0135] The fault level determination module is used to determine the corresponding target fault level in the level lookup table based on the target ratio range.

[0136] Based on the above embodiments, it also includes:

[0137] The first relationship determination module is used to determine the first conversion relationship between the ratio of the calculated value of the heat transfer coefficient to the reference value of the heat transfer coefficient and the saturated condensation temperature.

[0138] The second relationship determination module is used to determine the second conversion relationship between the saturated condensation temperature and the energy efficiency ratio of the condenser.

[0139] The third relationship determination module is used to determine the third conversion relationship between the ratio of the calculated value of the heat transfer coefficient to the reference value of the heat transfer coefficient and the energy efficiency ratio based on the first conversion relationship and the second conversion relationship.

[0140] The query table setting module is used to set up a level query table based on the energy efficiency ratio and the third conversion relationship.

[0141] Based on the above embodiments, the query table setting module includes:

[0142] The variation range determination submodule is used to determine the variation range of multiple energy efficiency ratios based on the magnitude of the energy efficiency ratio;

[0143] The ratio interval determination submodule is used to calculate the ratio interval corresponding to each change interval based on the third transformation relationship;

[0144] The fault level determination submodule is used to determine the fault level corresponding to each ratio range.

[0145] This embodiment also provides a terminal device, such as Figure 7 As shown, the terminal device 60 includes a processor 600 and a memory 601;

[0146] The memory 601 is used to store the computer program 602 and to transmit the computer program 602 to the processor 600;

[0147] The processor 600 is used to execute the steps in the above embodiment of a condenser heat exchange performance testing method according to the instructions in the computer program 602.

[0148] For example, the computer program 602 may be divided into one or more modules / units, which are stored in the memory 601 and executed by the processor 600 to complete this application. The one or more modules / units may be a series of computer program instruction segments capable of performing a specific function, which describe the execution process of the computer program 602 in the terminal device 60.

[0149] The terminal device 60 may be a desktop computer, laptop, handheld computer, or cloud server, etc. The terminal device 60 may include, but is not limited to, a processor 600 and a memory 601. Those skilled in the art will understand that... Figure 7 This is merely an example of terminal device 60 and does not constitute a limitation on terminal device 60. It may include more or fewer components than shown, or combine certain components, or different components. For example, terminal device 60 may also include input / output devices, network access devices, buses, etc.

[0150] The processor 600 may be a Central Processing Unit (CPU), or other 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 devices, discrete hardware components, etc. A general-purpose processor may be a microprocessor or any conventional processor.

[0151] The memory 601 can be an internal storage unit of the terminal device 60, such as a hard disk or memory of the terminal device 60. The memory 601 can also be an external storage device of the terminal device 60, such as a plug-in hard disk, smart media card (SMC), secure digital card (SD), flash card, etc., equipped on the terminal device 60. Furthermore, the memory 601 can include both internal and external storage units of the terminal device 60. The memory 601 is used to store the computer program and other programs and data required by the terminal device 60. The memory 601 can also be used to temporarily store data that has been output or will be output.

[0152] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0153] In the several embodiments provided in this application, it should be understood that the disclosed systems, apparatuses, and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of units is only a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection between apparatuses or units through some interfaces, and may be electrical, mechanical, or other forms.

[0154] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0155] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0156] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing computer programs, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0157] This invention also provides a storage medium containing computer-executable instructions, which, when executed by a computer processor, are used to perform a method for detecting the heat exchange performance of a condenser, the method comprising the following steps:

[0158] Obtain operating data of the chiller unit under stable conditions;

[0159] Extract the first target data from the operating data, and calculate the heat transfer coefficient of the condenser based on the first target data. The first target data includes the condenser state parameters under steady-state conditions.

[0160] The second target data is extracted from the operating data and input into the pre-set prediction model to obtain the baseline value of the heat transfer coefficient of the condenser. The second target data includes the cooling water state parameters, chilled water state parameters and chiller unit state parameters of the condenser under steady state.

[0161] The heat exchange performance of the condenser is determined based on the relative magnitude of the calculated value and the benchmark value.

[0162] Note that the above are merely preferred embodiments and the technical principles applied in this invention. Those skilled in the art will understand that the embodiments of this invention are not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the protection scope of this invention. Therefore, although the embodiments of this invention have been described in detail above, the embodiments of this invention are not limited to the above embodiments. More other equivalent embodiments may be included without departing from the concept of the embodiments of this invention, and the scope of the embodiments of this invention is determined by the scope of the appended claims.

Claims

1. A method for testing the heat exchange performance of a condenser, characterized in that, include: Obtain operating data of the chiller unit under stable conditions; First target data is extracted from the operating data, and the calculated value of the heat transfer coefficient of the condenser is calculated based on the first target data. The first target data includes the condenser state parameters of the condenser in a steady state. The second target data is extracted from the operating data and input into the pre-set prediction model to obtain the reference value of the heat transfer coefficient of the condenser. The second target data includes the cooling water state parameters, chilled water state parameters and chiller unit state parameters of the condenser under steady state. The heat exchange performance of the condenser is determined based on the relative magnitude of the calculated value and the benchmark value. The step of determining the heat exchange performance of the condenser based on the relative magnitude of the calculated value and the benchmark value includes: calculating the calculated value and the benchmark value; when the calculated value of the ratio is greater than or equal to a preset threshold, the heat exchange performance of the condenser is determined to be of a high level; when the calculated value of the ratio is less than the preset threshold, the heat exchange performance of the condenser is determined to be of a low level; querying the target ratio range in a preset level lookup table, the level lookup table including multiple ratio ranges, and each ratio range corresponding to a fault level and an energy efficiency ratio variation range; and determining the corresponding target fault level in the level lookup table based on the target ratio range. The grade lookup table is pre-set in the following manner: determining a first conversion relationship between the ratio of the calculated value of the heat transfer coefficient to the baseline value of the heat transfer coefficient and the saturated condensing temperature; determining a second conversion relationship between the saturated condensing temperature and the energy efficiency ratio of the condenser; determining a third conversion relationship between the ratio of the calculated value of the heat transfer coefficient to the baseline value of the heat transfer coefficient and the energy efficiency ratio based on the first and second conversion relationships; and setting the grade lookup table based on the energy efficiency ratio and the third conversion relationship.

2. The method for testing the heat exchange performance of a condenser according to claim 1, characterized in that, The step of extracting first target data from the operating data and calculating the heat transfer coefficient of the condenser based on the first target data includes: Extract first target data from the operating data, and calculate the average temperature difference of heat transfer between the cooling water side and the refrigerant side of the condenser based on the first target data; The heat transfer coefficient of the condenser is calculated based on the average temperature difference of the heat transfer.

3. The method for testing the heat exchange performance of a condenser according to claim 1, characterized in that, Setting the grade lookup table based on the energy efficiency ratio and the third conversion relationship includes: Based on the magnitude of the energy efficiency ratio, multiple ranges of variation for the energy efficiency ratio are determined; Based on the third transformation relationship, calculate the ratio interval corresponding to each of the change intervals; The fault level corresponding to each of the ratio intervals is determined.

4. A condenser heat exchange performance testing device, characterized in that, include: The data acquisition module is used to acquire the operating data of the chiller unit under stable conditions; The first calculation module is used to extract first target data from the operating data and calculate the heat transfer coefficient of the condenser based on the first target data. The first target data includes the condenser state parameters of the condenser in a steady state. The second calculation module is used to extract the second target data from the operating data, input the second target data into the pre-set prediction model, and obtain the reference value of the heat transfer coefficient of the condenser. The second target data includes the cooling water state parameters, chilled water state parameters and chiller unit state parameters of the condenser in a steady state. The heat exchange performance determination module is used to calculate the calculated value and the benchmark value. When the calculated value of the ratio is greater than or equal to a preset threshold, the heat exchange performance of the condenser is determined to be of a high level; when the calculated value of the ratio is less than the preset threshold, the heat exchange performance of the condenser is determined to be of a low level. The ratio range determination module is used to query the target ratio range in a preset level lookup table where the calculated value of the ratio falls. The level lookup table includes multiple ratio ranges, and each ratio range corresponds to a fault level and a range of energy efficiency ratio changes. The level lookup table is preset using the following methods: determining a first conversion relationship between the ratio of the calculated heat transfer coefficient to the baseline value of the heat transfer coefficient and the saturated condensing temperature; determining a second conversion relationship between the saturated condensing temperature and the energy efficiency ratio of the condenser; determining a third conversion relationship between the ratio of the calculated heat transfer coefficient to the baseline value of the heat transfer coefficient and the energy efficiency ratio based on the first and second conversion relationships; and setting the level lookup table based on the energy efficiency ratio and the third conversion relationship. The fault level determination module is used to determine the corresponding target fault level in the level lookup table based on the target ratio range.

5. A terminal device, characterized in that, The terminal device includes a processor and a memory; The memory is used to store computer programs and to transfer the computer programs to the processor; The processor is used to execute a condenser heat exchange performance testing method as described in any one of claims 1-3 according to instructions in the computer program.

6. A storage medium for storing computer-executable instructions, characterized in that, The computer-executable instructions, when executed by a computer processor, are used to perform a condenser heat exchange performance testing method as described in any one of claims 1-3.

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