Data center multi-grade waste heat recovery heat exchanger type selection method, system, equipment and medium

Abstract

The invention relates to the technical field of data center energy recovery and energy conservation, in particular to a data center multi-grade waste heat recovery heat exchanger model selection method, system, equipment and medium, which identifies multi-grade waste heat sources and energy consumption ends, divides types, collects parameters in a hybrid integration mode, establishes a data center waste heat list, and provides a data center multi-grade waste heat recovery heat exchanger model selection method and system. Respectively calculating the average temperature of the waste heat source and the average temperature of the energy consumption end to obtain a heat transfer temperature difference, carrying out space-time matching evaluation and heat exchanger compatibility pre-evaluation, and pre-screening heat exchanger types based on the heat transfer temperature difference and the results of the space-time matching evaluation and the heat exchanger compatibility pre-evaluation to obtain a heat exchanger type pre-screening result; according to the screened heat exchanger type, single-stream heat transfer parameters and investment cost are calculated, and multi-stream special calculation is carried out; according to the method, multi-dimensional evaluation is carried out according to the single-stream heat transfer parameters, the investment cost and the stream special calculation result, and a final heat exchanger model selection scheme is output, so that the model selection accuracy is improved, the cost controllability is greatly optimized, and the standard compatibility and universality are enhanced.

Description

Technical Field

[0001] This invention relates to the field of data center energy recovery and energy saving technology, and in particular to a method, system, equipment and medium for selecting multi-grade waste heat recovery heat exchangers for data centers. Background Technology

[0002] With the development of the digital economy, approximately 99% of the energy consumption of data center IT equipment is converted into waste heat, with cooling energy accounting for 40% of total energy consumption. However, traditional cooling methods directly discharge waste heat, resulting in near-zero energy utilization. Existing waste heat recovery technologies suffer from the following core bottlenecks, and the lack of scientific rigor in heat exchanger selection is a key pain point: In engineering practice, the selection of heat exchangers often fails to match the waste heat grade. Different heat exchangers exhibit fundamental differences in heat transfer efficiency and pressure adaptability, necessitating precise selection based on operating conditions. Existing technologies do not consider the waste heat temperature, pressure, and medium characteristics when selecting the appropriate type: for example, using a high-pressure printed circuit board heat exchanger to treat low-grade liquid waste heat results in overkill, or using a plate heat exchanger to treat particulate-containing gas waste heat leads to flow channel blockage.

[0003] Traditional heat transfer-cost coupling models for heat exchanger selection lack a clear focus, concentrating only on heat exchanger efficiency without establishing a linkage between heat load, average temperature difference, and investment cost. For example, a data center might choose a shell-and-tube heat exchanger to handle low-load waste heat. However, due to the high fixed costs of shell-and-tube heat exchangers, the payback period is as long as 5 years, far exceeding industry expectations (typically ≤3 years).

[0004] Data centers lack adaptability to multi-stream scenarios, have excess heat sources and multiple energy consumption terminals, and are typical multi-stream systems. However, existing technologies use the design method of two-stream heat exchangers and do not calculate the volume of multi-stream heat exchangers through volumetric heat transfer coefficients, resulting in a waste heat recovery rate of less than 30% for multi-stream systems.

[0005] Traditional selection methods for calculating the average temperature difference are not accurate enough. The logarithmic average temperature difference does not take into account the heat exchanger flow pattern correction factor. Under non-counterflow conditions, deviations in the F-value can lead to an error of more than 20% in the calculation of the heat transfer area. For example, without correction for the F-value, the actual heat transfer capacity of a co-flow plate heat exchanger is only 70% of the design value. Summary of the Invention

[0006] In view of the aforementioned existing problems, the present invention is proposed.

[0007] Therefore, this invention provides a method, system, equipment, and medium for selecting multi-grade waste heat recovery heat exchangers for data centers to address issues such as mismatch between heat exchanger selection and waste heat grade, lack of heat transfer-cost coupling model, insufficient adaptability to multi-stream scenarios, and insufficient accuracy in average temperature difference calculation.

[0008] To solve the above-mentioned technical problems, the present invention provides the following technical solution: In a first aspect, the present invention provides a method for selecting a multi-grade waste heat recovery heat exchanger for a data center, comprising: Identify and classify multi-grade waste heat sources and energy consumption terminals, collect parameters through hybrid integration, establish a waste heat inventory for data centers, calculate the average temperature of waste heat sources and the average temperature of energy consumption terminals, obtain the heat transfer temperature difference, and conduct spatiotemporal matching assessment and heat exchanger compatibility pre-assessment. Based on the results of heat transfer temperature difference, spatiotemporal matching assessment and heat exchanger compatibility pre-assessment, heat exchanger types are pre-screened, and single-stream heat transfer parameters and investment costs are calculated based on the screened heat exchanger types. Based on the obtained single-flow heat transfer parameters and investment costs, multi-flow special calculations are performed; based on the single-flow heat transfer parameters, investment costs and multi-flow special calculation results, a multi-dimensional evaluation is conducted, and the final heat exchanger selection scheme is output.

[0009] As a preferred embodiment of the data center multi-grade waste heat recovery heat exchanger selection method described in this invention, the method includes: identifying and classifying multi-grade waste heat sources and energy-consuming terminals; collecting parameters through a hybrid integration approach; establishing a data center waste heat inventory; calculating the average temperature of the waste heat sources and the average temperature of the energy-consuming terminals; obtaining the heat transfer temperature difference; and performing spatiotemporal matching assessment and heat exchanger compatibility pre-assessment, including: Identify and classify multi-grade waste heat sources and energy consumption terminals, collect parameters through a hybrid integration method, and establish a waste heat inventory for data centers; Based on the waste heat inventory of the data center, the average temperature of the waste heat source and the average temperature of the energy consumption end are calculated to obtain the heat transfer temperature difference. Based on the heat transfer temperature difference, the recoverable waste heat source is calculated using a first-level algorithm, and spatiotemporal matching evaluation and heat exchanger compatibility pre-evaluation are performed based on the calculated recoverable waste heat source.

[0010] As a preferred embodiment of the data center multi-grade waste heat recovery heat exchanger selection method described in this invention, the method includes: pre-screening of heat exchanger types based on the results of heat transfer temperature difference, spatiotemporal matching evaluation, and heat exchanger compatibility pre-evaluation; and calculating single-stream heat transfer parameters and investment costs based on the screened heat exchanger types, including: Based on the results of heat transfer temperature difference, spatiotemporal matching assessment and heat exchanger compatibility pre-assessment, heat exchanger types are pre-screened. Based on the pre-selected heat exchanger types, the overall heat transfer coefficient, average temperature difference, and heat transfer area were calculated respectively. Based on the calculated total heat transfer coefficient, average temperature difference, and heat transfer area, the C value is calculated using a two-stage algorithm, and the setup cost, installation cost, and correction cost are calculated respectively.

[0011] As a preferred embodiment of the data center multi-grade waste heat recovery heat exchanger selection method described in this invention, the method includes: performing multi-flow-specific calculations based on the obtained single-flow heat transfer parameters and investment costs; conducting multi-dimensional evaluations based on the single-flow heat transfer parameters, investment costs, and multi-flow-specific calculation results; and outputting the final heat exchanger selection scheme, including: Based on the obtained single-flow heat transfer parameters and investment costs, the local volume heat transfer coefficient, total volume heat transfer coefficient, active volume, total volume, and multi-flow cost are calculated respectively to complete the multi-flow special calculation. Based on the single-flow heat transfer parameters, investment cost, and flow-specific calculation results, calculate the heat transfer efficiency, investment payback period, and annual return. Emission reductions, and based on heat transfer efficiency, investment payback period, and annual... Emission reductions should be assessed from multiple dimensions. Based on the multi-dimensional evaluation results, the final heat exchanger selection scheme is selected and output.

[0012] As a preferred embodiment of the data center multi-grade waste heat recovery heat exchanger selection method described in this invention, the method includes: performing spatiotemporal matching evaluation and heat exchanger compatibility pre-evaluation based on the calculated recoverable waste heat source, including: The matching amount between waste heat source supply and energy demand is described by an overlap function, expressed as: The matching degree of the entire time window is quantified by the recycling index, and the expression is: in, For overlapping functions, The energy demand at time t, To supply waste heat at time t For the recovery index, The start time of the time window. The time window ends at the time of integration, the trapezoidal rule is used, the step size is equal to the data acquisition resolution, and the selection process begins when RI≥0.5; The NTU-Effectiveness heat transfer calculation is performed, and the effectiveness expression is as follows: Where, |ΔT| max This represents the maximum temperature difference between the hot and cold fluids. For the performance expression, The inlet temperature of the waste heat source. This refers to the inlet temperature at the energy consumption end. The expression for the number of heat transfer units is: in, The number of heat transfer units, is the minimum heat capacity in the hot and cold flows, U is the overall heat transfer coefficient, and A is the heat transfer area of ​​the heat exchanger. Where Q is the heat load, ΔT m U represents the actual average temperature difference, U is the overall heat transfer coefficient, and A is the heat transfer area of ​​the heat exchanger. The number of heat transfer units, This represents the minimum heat capacity in the hot and cold flows; The evaluation is conducted from the dimensions of media compatibility, pressure adaptability, and spatial compatibility. In terms of media compatibility, liquid-liquid media groups are suitable for plate or shell-and-tube heat exchangers, while gas-liquid media groups are suitable for plate-fin heat exchangers. In terms of pressure adaptability, the upper limit of system pressure adaptability is evaluated based on plate heat exchangers, shell and tube heat exchangers, and printed circuit board heat exchangers. In terms of space compatibility, compact heat exchangers are selected for small computer room scenarios, while shell-and-tube heat exchangers are selected for scenarios with ample space.

[0013] Heat exchanger types that meet the requirements in all three dimensions will proceed to the pre-screening stage.

[0014] The beneficial effects of this preferred technical solution are as follows: By introducing an overlap function and a recovery index, a quantitative assessment of the matching characteristics between the waste heat source and the energy consumption end in the time dimension is achieved, providing a criterion for identifying operating conditions with continuous recovery potential. Furthermore, by combining the NTU-efficiency method for heat transfer calculations, a mapping relationship from thermodynamic parameters to key dimensions of the heat exchanger is established, improving the reliability of the selection process in complex engineering scenarios.

[0015] As a preferred embodiment of the data center multi-grade waste heat recovery heat exchanger selection method described in this invention, the C value is calculated through a two-stage algorithm, including: Calculated using logarithmic interpolation: Where C is the value of C. Corresponding to engineering measurements Cost factors, Parameters representing the heat transfer capacity of a heat exchanger , These are two different heat transfer capacity parameter values ​​measured in engineering practice.

[0016] As a preferred embodiment of the data center multi-grade waste heat recovery heat exchanger selection method described in this invention, the heat transfer efficiency, investment payback period, and annual return are calculated based on the single-stream heat transfer parameters, investment cost, and specific calculation results of the stream. Emission reductions include: The heat transfer efficiency η is calculated using the following expression: in, For heat transfer efficiency, the actual heat transfer is based on the heat load calculation results. The design heat transfer is the rated heat transfer capacity of the heat exchanger. The qualified standard is η≥85%. If it is not achieved, the heat exchanger type needs to be re-selected and the heat transfer parameters need to be adjusted. The formula for calculating the payback period (PBP) is: in, This is the investment recovery period; The total cost is the calculated total correction cost; in, For waste heat source recovery, RI is the recovery index, 8760 is the annual operating hours, and the qualified standard is PBP≤2.5 years. If it exceeds, the cost correction factor needs to be adjusted and a low-cost suitable heat exchanger needs to be re-screened. Calculation year Emission reduction, the formula is: in, For the year Emission reduction, emission factor of 0.2 kg / kWh, Exergy is recyclable material, RI is the recovery index, 8760 is the annual operating hours, and the target value is annual. Emissions reduction ≥ 100 tons. If the target value is not achieved, the combination of waste heat source and energy consumption end needs to be optimized and the configuration of multiple streams needs to be adjusted.

[0017] The beneficial effects of this preferred technical solution are as follows: by introducing three key indicators—heat transfer efficiency, investment payback period, and annual emission reduction—the selection of heat exchangers is expanded from a single thermal performance judgment to a multi-dimensional decision-making process that considers investment feasibility and carbon emission reduction contribution, and the calculation methods and qualification thresholds for each indicator are clarified.

[0018] Secondly, the present invention provides a selection system for multi-grade waste heat recovery heat exchangers in data centers, comprising: The quantitative inventory establishment and evaluation module identifies and classifies multi-grade waste heat sources and energy-consuming terminals, collects parameters, establishes a waste heat inventory for the data center, calculates the average temperature of waste heat sources and the average temperature of energy-consuming terminals, obtains the heat transfer temperature difference, and performs spatiotemporal matching evaluation and heat exchanger compatibility pre-evaluation. The cost quantification module, based on the results of heat transfer temperature difference, spatiotemporal matching assessment and heat exchanger compatibility pre-assessment, pre-screens heat exchanger types and calculates single-stream heat transfer parameters and investment costs according to the screened heat exchanger types. The multi-flow adaptation and decision output module performs multi-flow-specific calculations based on the obtained single-flow-specific heat transfer parameters and investment costs; it conducts multi-dimensional evaluations based on the single-flow-specific heat transfer parameters, investment costs, and multi-flow-specific calculation results, and outputs the final heat exchanger selection scheme.

[0019] Thirdly, the present invention provides an electronic device, comprising: Memory and processor; The memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions. When the computer-executable instructions are executed by the processor, they implement the steps of a method for selecting a multi-grade waste heat recovery heat exchanger for a data center.

[0020] Fourthly, the present invention provides a computer-readable storage medium storing computer-executable instructions that, when executed by a processor, implement the steps of the method for selecting a multi-grade waste heat recovery heat exchanger for a data center.

[0021] Compared with existing technologies, the beneficial effects of this invention are as follows: By establishing a multi-grade waste heat inventory and calculating the heat transfer temperature difference, combined with the quantitative analysis of recyclable heat, this invention achieves the spatiotemporal matching assessment of waste heat sources and energy-consuming ends, as well as the prediction of heat exchanger compatibility. Based on the pre-screening results, the single-flow heat transfer parameters and investment costs are further calculated, and through multi-flow specialized analysis, the heat transfer efficiency, investment payback period, and emission reduction performance are comprehensively evaluated, forming a multi-dimensional selection basis. Attached Figure Description

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 This is a schematic diagram of the overall process of a method for selecting a multi-grade waste heat recovery heat exchanger for a data center, according to an embodiment of the present invention.

[0024] Figure 2 This is a reference cost curve for a shell-and-tube heat exchanger, as described in an embodiment of the present invention, for a method of selecting a multi-grade waste heat recovery heat exchanger for a data center.

[0025] Figure 3 This is a reference cost curve for a plate heat exchanger in a data center multi-grade waste heat recovery heat exchanger selection method according to an embodiment of the present invention.

[0026] Figure 4This is a diagram illustrating the heat exchanger optimization selection effect of a multi-grade waste heat recovery heat exchanger selection method for data centers according to an embodiment of the present invention.

[0027] Figure 5 This is a schematic diagram illustrating the performance improvement rate of a data center multi-grade waste heat recovery heat exchanger selection method according to an embodiment of the present invention. Detailed Implementation

[0028] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0029] Example 1, referring to Figure 1 As an embodiment of the present invention, a method for selecting a multi-grade waste heat recovery heat exchanger for a data center is provided, comprising: To address the issues of mismatch between heat exchanger selection and waste heat grade, lack of heat transfer-cost coupling model, insufficient adaptability to multi-flow scenarios, and insufficient accuracy in average temperature difference calculation, this invention provides a method for selecting multi-grade waste heat recovery heat exchangers for data centers.

[0030] S1: Identify and classify multi-grade waste heat sources and energy consumption terminals, collect parameters through hybrid integration, establish a waste heat inventory for the data center, calculate the average temperature of waste heat sources and the average temperature of energy consumption terminals respectively, obtain the heat transfer temperature difference, and conduct spatiotemporal matching assessment and heat exchanger compatibility pre-assessment. S2: Based on the results of heat transfer temperature difference, spatiotemporal matching assessment and heat exchanger compatibility pre-assessment, pre-screening of heat exchanger types is carried out, and single-stream heat transfer parameters and investment costs are calculated according to the screened heat exchanger types. S3: Based on the obtained single-flow heat transfer parameters and investment costs, perform multi-flow special calculations; conduct multi-dimensional evaluation based on the single-flow heat transfer parameters, investment costs and multi-flow special calculation results, and output the final heat exchanger selection scheme.

[0031] Therefore, by identifying and integrating the parameters of various waste heat sources and energy-consuming terminals, a waste heat inventory is established and the heat transfer temperature difference is calculated, thereby implementing spatiotemporal matching and heat exchanger compatibility pre-assessment. Subsequently, based on the assessment results, heat exchanger types are pre-screened, and single-flow heat transfer parameters and investment costs are calculated simultaneously. On this basis, multi-flow specialized calculations are carried out, and the final heat exchanger selection scheme is output through multi-dimensional comprehensive evaluation. This solves the problems of inaccurate grade matching, low system integration, and insufficient economic efficiency in traditional waste heat utilization.

[0032] Example 2, refer to Figure 1 As an embodiment of the present invention, based on the above embodiment, a method for selecting a multi-grade waste heat recovery heat exchanger for a data center is provided.

[0033] In this embodiment of the application, step S1 identifies and classifies multi-grade waste heat sources and energy-consuming terminals, collects parameters through a hybrid integration method, establishes a waste heat inventory for the data center, calculates the average temperature of the waste heat sources and the average temperature of the energy-consuming terminals respectively, obtains the heat transfer temperature difference, and performs spatiotemporal matching assessment and heat exchanger compatibility pre-assessment, including the following steps A1-A3: A1: Identify and classify multi-grade waste heat sources and energy consumption terminals, collect parameters through hybrid integration, and establish a waste heat inventory for data centers.

[0034] A2: Based on the waste heat inventory of the data center, calculate the average temperature of the waste heat source and the average temperature of the energy consumption end to obtain the heat transfer temperature difference.

[0035] A3: Based on the heat transfer temperature difference, the recoverable waste heat source is calculated using a first-level algorithm, and spatiotemporal matching evaluation and heat exchanger compatibility pre-evaluation are performed based on the calculated recoverable waste heat source.

[0036] In this embodiment of the application, the parameter acquisition method in step S1, which combines invasive and non-invasive approaches, specifically employs a parameter acquisition method that integrates both methods. Waste heat sources and energy consumers are categorized using a grade-medium classification method: High-grade waste heat comes from server cold plate outlets and UPS cooling, with a temperature range of 30–35℃ (303.15–308.15K), and the medium type is liquid or gas, suitable for plate-fin or printed circuit board heat exchangers; Medium-grade waste heat comes from chiller condenser drain and CRAC return air, with a temperature range of 25–30℃ (298.15–303.15K), and the medium type is liquid or gas, suitable for shell-and-tube or plate heat exchangers; Low-grade waste heat comes from computer room fresh air exhaust and battery cabinet cooling, with a temperature below 25℃ (298.15K), and the medium type is gas, suitable for plate heat exchangers. Alternatively, plate-fin heat exchangers can be used; high-temperature energy demand includes domestic hot water preheating and district heating, with a temperature requirement of 60–80℃ (333.15–353.15K), and the medium type is liquid, suitable for shell-and-tube or printed circuit board heat exchangers; medium-temperature energy demand includes swimming pool heating and floor radiant heating, with a temperature requirement of 35–60℃ (308.15–333.15K), and the medium type is liquid, suitable for plate or shell-and-tube heat exchangers; low-temperature energy demand is auxiliary refrigeration (absorption generator preheating), with a temperature requirement of 10–35℃ (283.15–308.15K), and the medium type is liquid or gas, suitable for plate-fin or plate heat exchangers.

[0037] A combined invasive and non-invasive parameter acquisition method is employed. In invasive measurements, a platinum resistance thermometer (PT100) is used to acquire the inlet and outlet temperatures of the waste heat source and energy-consuming end, with an accuracy requirement of ±0.5℃ (±0.5K), meeting the temperature difference calculation requirement of ≥±0.5℃. An electromagnetic flowmeter (suitable for liquids) is used to acquire the medium flow rate (V), with an accuracy requirement of ±1% of the range (unit: m³ / s or m³ / h), ensuring that the flow rate error in heat load calculation is ≤1%. In non-invasive measurements, an infrared thermal imager with a resolution ≥640×512 is used to acquire the equipment surface temperature, with an accuracy of ±2% of the reading (unit: ℃ or K), for material temperature adaptability assessment. A wireless temperature sensor is used to acquire the ambient temperature, with an accuracy of ±0.3℃ (±0.3K), meeting the ambient temperature accuracy requirement of ≥±0.3℃ for temperature difference calculation.

[0038] Data should be recorded according to unified standards. Recorded information includes: type (waste heat source or energy consumer), name (e.g., server cold plate circuit, domestic hot water circuit), unit, measurement time, waste heat source inlet temperature (unit: °C or K), waste heat source outlet temperature (unit: °C or K), medium flow rate (V, unit: m³ / s or m³ / h), ambient temperature (unit: °C or K), and medium characteristics (e.g., density of deionized water ρ = 1000 kg / m³, specific heat capacity at constant pressure of tap water). =4.186 kJ / (kg·K)).

[0039] In an optional implementation, the parameters collected in step S1 through a hybrid integration method can also be obtained using ultrasonic flow monitoring. When measuring the flow of an existing pipeline that is inconvenient to shut down, the sensor is clamped on the outer wall of the pipeline, and the flow velocity and flow rate are calculated by measuring the time difference between the propagation of ultrasonic waves in the fluid in the downstream and upstream directions.

[0040] In another alternative implementation, the parameters collected in step S1 through a hybrid integration method can also be obtained using a distributed optical fiber temperature measurement method. Temperature-sensing optical cables are laid along the monitoring path, and the scattering effect of laser light in the optical fiber is used to achieve continuous and real-time temperature measurement.

[0041] In this embodiment of the application, step S1 calculates the average temperature of the waste heat source and the average temperature of the energy consumption end, respectively, and the heat transfer temperature difference is specifically reflected as follows: The formula for calculating the average temperature of the waste heat source is: in, The average temperature of the waste heat source is expressed in °C or K. This refers to the inlet temperature of the waste heat source, expressed in °C or K. This refers to the outlet temperature of the waste heat source, expressed in °C or K.

[0042] The formula for calculating the average temperature at the energy consumption end is: in, The average temperature at the energy consumption end is expressed in °C or K. The inlet temperature of the energy-consuming end is expressed in °C or K. The outlet temperature of the energy consumption end is expressed in °C or K.

[0043] The formula for calculating the heat transfer temperature difference is: in, This refers to the temperature difference for heat transfer, expressed in °C or K. The average temperature of the waste heat source. This represents the average temperature at the energy consumption end.

[0044] The screening criterion is ΔT≥5K. If it is below 5K, the overall heat transfer coefficient U will drop sharply, resulting in a heat transfer efficiency of <50%. Auxiliary heating is required to bring ΔT≥5K before proceeding to the next process.

[0045] In one optional implementation, the average temperature of the waste heat source and the average temperature of the energy consumption end are calculated separately in step S1. The heat transfer temperature difference can also be obtained using the effective average temperature difference method. When a phase change occurs in the fluid on one side, its temperature remains at the saturation temperature across the entire heat transfer surface. The calculation of the heat transfer temperature difference can be simplified to the difference between a constant temperature and the logarithmic average temperature of the fluid on the other side, or an effective temperature difference calculation method that specifically considers phase change can be used.

[0046] In another optional implementation, the average temperature of the waste heat source and the average temperature of the energy consumption end are calculated in step S1 respectively. The heat transfer temperature difference can also be obtained by using the logarithmic average temperature difference method. When the temperatures of both the waste heat source and the energy consumption end change significantly and continuously during the heat exchange process, the nonlinear relationship of the temperature change along the surface of the heat exchanger is considered to truly reflect the average driving force in the entire heat exchange process.

[0047] In this embodiment of the application, the calculation of the recoverability of the waste heat source using a first-level algorithm in step A3 is specifically manifested as follows: The recoverability of waste heat sources reflects the coupling relationship between energy quality and the heat transfer capacity of heat exchangers, and the expression is: in, Waste heat source can be recovered. For heat load, The actual average temperature difference is given by U, where U is the overall heat transfer coefficient. The heat transfer area of ​​the heat exchanger; For ambient temperature, The average temperature of the waste heat source.

[0048] In an optional implementation, the waste heat source recoverable energy calculated in step A3 using a first-level algorithm can also be calculated using an energy calculation method based on thermodynamic ideal states. In the early stages of system planning, before heat exchanger selection and detailed heat transfer calculations are performed, the waste heat source is regarded as a constant-temperature heat source, and the maximum work that can be done in theory is calculated based solely on the difference between the temperature level and the ambient temperature.

[0049] In another optional implementation, the waste heat source recoverable heat (UHZ) calculated in step A3 using a first-level algorithm can also be calculated using a UHZ calculation method based on the characteristics of the flow stream. When the waste heat source medium is gas, or when parameters such as flow rate and specific heat capacity affect the UHZ value, the thermophysical properties such as the mass flow rate and constant pressure specific heat capacity of the medium are comprehensively considered to calculate the UHZ released when the flow stream itself changes reversibly from its initial state to a state of equilibrium with the environment.

[0050] In this embodiment of the application, step A3, which involves performing spatiotemporal matching evaluation and heat exchanger compatibility pre-evaluation based on the calculated recoverable waste heat source, is specifically manifested as follows: The matching amount between waste heat source supply and energy demand is described by an overlap function, expressed as: The matching degree of the entire time window is quantified by the recycling index, and the expression is: in, For overlapping functions, The energy demand at time t, To supply waste heat at time t For the recovery index, The start time of the time window. The time window ends at the time of integration, which uses the trapezoidal rule. The step size is equal to the data acquisition resolution. When RI ≥ 0.5, the selection process begins.

[0051] The NTU-Effectiveness heat transfer calculation is performed, and the effectiveness expression is as follows: in, This represents the maximum temperature difference between the hot and cold fluids. For the performance expression, The inlet temperature of the waste heat source. This refers to the inlet temperature at the energy consumption end.

[0052] The expression for the number of heat transfer units is: in, The number of heat transfer units, U is the minimum heat capacity in the hot and cold flow, U is the overall heat transfer coefficient, and A is the heat transfer area of ​​the heat exchanger.

[0053] Where Q is the heat load, ΔT m U represents the actual average temperature difference, U is the overall heat transfer coefficient, and A is the heat transfer area of ​​the heat exchanger. The number of heat transfer units, This represents the minimum heat capacity in the hot and cold flow.

[0054] The evaluation is conducted from the perspectives of media compatibility, pressure adaptability, and spatial compatibility.

[0055] In terms of media compatibility, liquid-liquid media groups are suitable for plate or shell-and-tube heat exchangers, while gas-liquid media groups are suitable for plate-fin heat exchangers. In terms of pressure adaptability, the upper limit of system pressure adaptability for plate heat exchangers is 2.5MPa, for shell and tube heat exchangers it is 10MPa, and for printed circuit board heat exchangers it is 40MPa. In terms of space compatibility, compact heat exchangers are selected for small computer room scenarios, while shell-and-tube heat exchangers are selected for scenarios with ample space.

[0056] Heat exchanger types that meet the requirements in all three dimensions will proceed to the pre-screening stage.

[0057] It should be noted that by employing a grade-medium classification method to systematically divide waste heat sources and energy-consuming ends, and combining invasive and non-invasive hybrid measurement technologies to obtain accurate parameters, based on the calculation of heat transfer temperature difference, recyclability is introduced as a core evaluation index. A quantitative assessment of spatiotemporal matching is achieved through overlap functions and recovery indices, and the NTU-Effectiveness method is used for heat transfer efficiency analysis. Heat exchanger types are pre-screened from three dimensions: media compatibility, pressure adaptability, and spatial compatibility, ensuring that the selected scheme is optimal in terms of thermodynamic performance, system matching, and engineering feasibility. This effectively solves problems such as inaccurate grade matching, low system integration, and poor equipment adaptability that exist in traditional selection processes.

[0058] In this embodiment of the application, step S2 involves pre-screening heat exchanger types based on the results of heat transfer temperature difference, spatiotemporal matching assessment, and heat exchanger compatibility pre-assessment. The single-stream heat transfer parameters and investment costs are then calculated according to the screened heat exchanger types, including the following steps B1-B3: B1: Based on the results of heat transfer temperature difference, spatiotemporal matching assessment, and heat exchanger compatibility pre-assessment, pre-screening of heat exchanger types is carried out.

[0059] Based on the evaluation results (medium type, pressure, temperature difference, space requirements, etc.), and with reference to engineering design standards, incompatible heat exchanger types are excluded, and suitable plate, shell and tube, plate-fin, or printed circuit board heat exchangers are retained.

[0060] The specific filtering logic is as follows: For scenarios involving liquid-liquid media combinations, heat transfer temperature difference ΔT = 5–20K, and system pressure P ≤ 2.5MPa (25bar), plate heat exchangers are suitable, while printed circuit board heat exchangers are excluded (due to their high cost). The engineering basis is that plate heat exchangers have high heat transfer efficiency and low cost in scenarios with small temperature differences.

[0061] For scenarios involving liquid-gas media combinations, heat transfer temperature difference ΔT = 20–50K, and system pressure P ≤ 10MPa (100bar), shell-and-tube heat exchangers are suitable, while plate heat exchangers are excluded (because gas has low heat transfer efficiency in plate heat exchangers). The engineering basis is that shell-and-tube heat exchangers provide sufficient gas-liquid contact and are suitable for medium and high pressure scenarios. For multi-flow scenarios, heat transfer temperature difference ΔT=10–30K, and space constraints, plate-fin heat exchangers are suitable, while shell-and-tube heat exchangers are excluded (due to their large size). The engineering basis is that plate-fin heat exchangers have a compact structure and strong adaptability to multi-flow scenarios. For scenarios with system pressure P>10MPa (100bar) and high-grade waste heat (temperature T>35℃, 308.15K), printed circuit board heat exchangers are suitable, while plate heat exchangers are excluded (because they are not resistant to high pressure). The engineering basis is that printed circuit board heat exchangers have excellent high pressure resistance and are suitable for high-grade waste heat recovery.

[0062] B2: Based on the pre-selected heat exchanger types, calculate the overall heat transfer coefficient, average temperature difference, and heat transfer area respectively.

[0063] Based on the pre-selected heat exchanger types, combined with data such as heat load and temperature difference, heat transfer parameters and investment costs are calculated, and a heat transfer-cost coupling relationship is established.

[0064] Determine the overall heat transfer coefficient U. The basic reference standard range for the overall heat transfer coefficient U is: 1500–3000 W / (m²·K) for plate heat exchangers, 500–1500 W / (m²·K) for shell-and-tube (E-type shell) heat exchangers, and 800–2500 W / (m²·K) for plate-fin heat exchangers.

[0065] A media correction factor needs to be introduced according to the media type: the correction factor is 1.0 for water-water media combination, 0.6 for water-oil media combination, and 0.3 for water-air media combination.

[0066] The final overall heat transfer coefficient is: For plate heat exchangers handling water-water media combinations, the median value of the standard U value range is taken as 2000 W / (m²·K), and the media correction factor is 1.0. Therefore, U = 2000 × 1.0 = 2000 W / (m²·K).

[0067] The logarithmic mean temperature difference is calculated using the following expression: in, The logarithmic mean temperature difference The inlet temperature at the energy consumption end. The outlet temperature of the energy consumption end. The inlet temperature of the waste heat source. This refers to the outlet temperature of the waste heat source.

[0068] Determine the flow pattern correction factor based on the heat exchanger flow pattern. (Dimensionless) The F-value range for counter-flow plate heat exchangers is 0.95–1.0, the F-value range for shell-and-tube (E-type shell) heat exchangers (shell side 1 and tube side 2) is 0.7–0.9, and the F-value range for cross-flow plate-fin heat exchangers is 0.8–0.95.

[0069] The actual average temperature difference is: Where, ΔT m This represents the actual average temperature difference. For flow pattern correction factor, The temperature difference is the logarithmic mean.

[0070] The formula for calculating the heat transfer area A is: in, Represents the heat transfer area, in m². Indicates heat load, ΔT represents the overall heat transfer coefficient. m This represents the actual average temperature difference.

[0071] B3: Based on the calculated total heat transfer coefficient, average temperature difference, and heat transfer area, the C value is calculated using a two-level algorithm, and the setup cost, installation cost, and correction cost are calculated respectively.

[0072] In this embodiment of the application, the C value calculated by the secondary algorithm in step B3 is specifically manifested as follows: C is the unit. The cost is calculated using logarithmic interpolation: Where C is the value of C. Corresponding to engineering measurements The cost factor, in this invention, is taken as . ; Parameters representing the heat transfer capacity of a heat exchanger , These are two different heat transfer capacity parameter values ​​measured in engineering practice. In this invention, the value is taken as... .

[0073] In an alternative implementation, the C value calculated by the secondary algorithm in step B3 can also be obtained by linear regression. When there are many sets of historical purchase data from different suppliers or different specifications of heat exchangers, the heat transfer capacity parameters and cost data are plotted as points on a coordinate system, and a straight line that best represents the data trend is found. A general C value estimation formula is obtained by using linear regression.

[0074] In another alternative implementation, the C value calculated by the secondary algorithm in step B3 can also be obtained by the itemized estimation method. When cost composition analysis and sensitivity analysis are required, instead of directly calculating the overall C value, the total cost of the heat exchanger is decomposed into several main parts for estimation, such as material costs, manufacturing and processing costs, R&D and design costs, etc. Finally, the total investment cost is obtained by summing them up, and then the unit cost is calculated in reverse.

[0075] In this embodiment of the application, the calculation of setup cost, installation cost, and correction cost in step B3 is specifically reflected as follows: The total cost includes three parts: equipment cost, installation cost, and correction cost. Calculate equipment cost The expression is: in, For equipment costs, This represents the parameters related to the heat transfer capacity of the heat exchanger, where C is the C value.

[0076] Installation costs Taking 30% of the equipment cost, the expression is: in, For installation costs, For equipment costs.

[0077] Correction factors are introduced based on material, structure, and multi-flow configuration. The correction factor ranges from 1.3 to 1.8 for changing the material from carbon steel to stainless steel, from 1.2 to 1.5 for changing the structure from a fixed tube sheet to a floating head, and from 1.3 to 1.4 for changing the multi-flow configuration from two to three flow channels. The engineering basis for the correction factors is the difference in processing difficulty and material cost corresponding to different materials, structures, and flow channel numbers (e.g., the material cost of stainless steel is 1.3 to 1.8 times that of carbon steel, the higher processing complexity of floating head type leads to a cost increase of 20% to 50%, and the complex design of multi-flow channel leads to a cost increase of 30% to 40%).

[0078] The total correction cost expression is: in, Total repair cost, For installation costs, For equipment costs.

[0079] In this embodiment of the application, step S3 involves performing multi-flow-specific calculations based on the obtained single-flow heat transfer parameters and investment costs; a multi-dimensional evaluation is conducted based on the single-flow heat transfer parameters, investment costs, and multi-flow-specific calculation results, and the final heat exchanger selection scheme is output, including the following steps C1-C3: C1: Based on the obtained single-flow heat transfer parameters and investment cost, calculate the local volumetric heat transfer coefficient, total volumetric heat transfer coefficient, active volume, total volume, and multi-flow cost respectively, and complete the multi-flow special calculation.

[0080] Calculate the local volumetric heat transfer coefficient : in, Local volumetric heat transfer coefficient, The center distance of the flow channel is 10mm, 0.01m, standard value for plate-fin type. , The surface areas of wingless and winged individuals are respectively ( =0.1m² / m², =500m² / m², serrated fins). For fin efficiency, The convective heat transfer coefficient (water α=5000W / (m²·K)) Thermal conductivity of the material (aluminum) =130W / (m·K)).

[0081] in, For fin efficiency, For fin parameters, Fin height , For fin thickness, =0.2032mm, The convective heat transfer coefficient (water α=5000W / (m²·K)) Thermal conductivity of the material (aluminum) =130W / (m·K)).

[0082] The overall volumetric heat transfer coefficient in a multi-flow system is the series combination of the local coefficients: in, The total volumetric heat transfer coefficient is . Local volumetric heat transfer coefficient.

[0083] Calculate the active volume The expression is: in, Active volume, For the total heat load of multiple streams, The average temperature difference between zones (calculated by composite curve for a given zone) is the average temperature difference between zones. =30K), The total volumetric heat transfer coefficient is denoted as .

[0084] Considering the volume of the connection between the end cap and the flow channel, the formula for calculating the total volume is: in, Total volume The active volume is 15%, which is the volume percentage of the connection between the end cap and the flow channel.

[0085] Cost and volume have a logarithmic relationship, expressed as: in, To increase the cost of multiple shares, For coefficients (k=10000 yuan / m³ for aluminum plate fin type). For the index (cost decreases as volume increases). This is the total volume.

[0086] C2: Based on the single-flow heat transfer parameters, investment cost, and flow-specific calculation results, calculate the heat transfer efficiency, investment payback period, and annual return. Emission reductions, and based on heat transfer efficiency, investment payback period, and annual... Emission reductions are assessed from multiple dimensions.

[0087] Based on single-flow heat transfer parameters, cost data, and multi-flow specific calculation results, this study examines heat transfer efficiency, payback period, and annual return on investment. The three core indicators of emission reduction are evaluated from multiple dimensions to output the optimal heat exchanger selection scheme.

[0088] The heat transfer efficiency η is calculated using the following expression: in, For heat transfer efficiency, the actual heat transfer is based on the heat load calculation results. The designed heat transfer is the rated heat transfer capacity of the heat exchanger, and the qualified standard is η≥85%. If it is not achieved, the heat exchanger type needs to be re-selected and the heat transfer parameters need to be adjusted.

[0089] The formula for calculating the payback period (PBP) is: in, This is the investment recovery period; The total cost is the calculated total correction cost; in, The waste heat source is recoverable, RI is the recovery index, 8760 is the annual operating hours, and the qualified standard is PBP≤2.5 years. If it exceeds, the cost correction factor needs to be adjusted and a low-cost adaptive heat exchanger needs to be re-screened.

[0090] Calculation year Emission reduction, the formula is: in, For the year Emission reduction, emission factor of 0.2 kg / kWh, Exergy is recyclable material, RI is the recovery index, 8760 is the annual operating hours, and the target value is annual. Emissions reduction ≥ 100 tons. If the target value is not achieved, the combination of waste heat source and energy consumption end needs to be optimized and the configuration of multiple streams needs to be adjusted.

[0091] C3: Based on the multi-dimensional evaluation results, select and output the final heat exchanger selection scheme.

[0092] If the three indicators of heat transfer efficiency, investment payback period, and annual CO2 emission reduction all meet the qualified standards or target values, the corresponding heat exchanger selection scheme (including heat exchanger type, heat transfer parameters, cost, volume, etc.) will be output. If any indicator is not met, the previous steps will be adjusted in reverse until all indicators meet the standards, forming a complete logical closed loop.

[0093] In summary, this invention, through specialized calculations, establishes local and total volume heat transfer coefficient models, quantitative methods for active volume and total volume, and combines the logarithmic relationship between cost and volume to characterize the heat transfer characteristics and economic efficiency under multi-flow coupling. Furthermore, it conducts a comprehensive evaluation from three key dimensions: heat transfer efficiency, investment payback period, and annual emission reduction. By setting clear indicator thresholds and a reverse adjustment mechanism, it ensures that the final selected scheme meets the requirements of high-efficiency heat transfer while also possessing investment feasibility and emission reduction benefits. This effectively solves the problems of insufficient multi-flow coupling analysis and a single comprehensive decision-making dimension in traditional selection methods.

[0094] Example 3, Reference Figures 2-5 Taking a medium-sized data center in Northwest China (5MW IT load, cooling method: cold plate type) as an example, the waste heat sources of this data center include server cold plates (temperature range 30–35℃ / 303.15–308.15K, medium is water) and chiller condensers (temperature range 28–32℃ / 301.15–305.15K, medium is water); the energy consumption ends include district heating (temperature requirement 45–60℃ / 318.15–333.15K, medium is water) and domestic hot water (temperature requirement 15–45℃ / 288.15–318.15K, medium is water). The implementation steps are as follows: Step 1: Establish a waste heat inventory.

[0095] The data acquisition period is 7 days, the data acquisition resolution is 1 hour, and the core parameters acquired are as follows: the inlet temperature of the server cold plate. =35℃ / 308.15K, outlet temperature =30℃ / 303.15K, medium flow rate V=0.02m³ / s (72m³ / h); inlet temperature of the chiller unit condenser =32℃ / 305.15K, outlet temperature =28℃ / 301.15K, medium flow rate V=0.03m³ / s (10⁸m³ / h); inlet temperature of domestic hot water =15℃ / 288.15K, outlet temperature =45℃ / 318.15K, medium flow rate V=0.015m³ / s (54m³ / h); inlet temperature for district heating =45℃ / 318.15K, outlet temperature =60℃ / 333.15K, medium flow rate V=0.025m³ / s (90m³ / h); ambient temperature T am ᵦ =18–22℃ / 291.15–295.15K, taking the average of 20℃ / 293.15K; Regarding the medium characteristics, all flow channels use water, with a density ρ=1000kg / m³ and a constant pressure specific heat capacity. =4.186 kJ / (kg·K).

[0096] Step 2: Quantitative assessment.

[0097] Temperature difference assessment: Average temperature of server cold plate =(35+30) / 2=32.5℃ / 305.65K, the average temperature of domestic hot water =(15+45) / 2=30℃ / 303.15K, initial heat transfer temperature difference ΔT=32.5-30=2.5K, through auxiliary heating, the average temperature of domestic hot water is raised to 37.5℃ / 310.65K, and the absolute value of ΔT=32.5-37.5 after adjustment is 5K (meeting the requirement of ΔT≥5K); the average temperature of the chiller unit condenser. =(32+28) / 2=30℃ / 303.15K, the average temperature of district heating. =(45+60) / 2=52.5℃ / 325.65K, heat transfer temperature difference ΔT=52.5-30=22.5K (satisfies the requirement of ΔT≥5K).

[0098] Value calculation: The server cooling plate uses a plate heat exchanger with an overall heat transfer coefficient U = 2000 W / (m²·K) and a logarithmic mean temperature difference. =[(35-45)-(30-15)] / ln[(35-45) / (30-15)]≈32.3K, manifold correction factor F=1.0.

[0099] Actual average temperature difference =32.3K, Heat load Q = 1000 × 0.02 × 4186 × (35 - 30) = 418600 W U·A=Q / =418600 / 32.3≈12960W / K The power output (Exergy) is approximately 32.2 kW (1 - 293.15 / (32.5 + 273.15)). The chiller unit uses a shell-and-tube heat exchanger as the condenser, with an overall heat transfer coefficient (U) of 1000 W / (m²·K) and a logarithmic mean temperature difference. =[(32-60)-(28-45)] / ln[(32-60) / (28-45)]≈20.5K, flow pattern correction factor F=0.85, actual average temperature difference =20.5×0.85≈17.4K, heat load Q=1000×0.03×4186×(32-28)=502320W, U·A=502320 / 17.4≈28870W / K.

[0100] The power output is calculated as follows: Exergy = 28870 × 17.4 × (1 - 293.15 / (30 + 273.15)) ≈ 45.8 kW.

[0101] Spatiotemporal matching evaluation: The overlap function O(t) and recovery index RI were calculated using 7 days of data. The RI for server cold plates and domestic hot water was 0.776, and the RI for chiller condensers and district heating was 0.821, both of which meet the requirement of RI≥0.5.

[0102] NTU-Effectiveness Validation: Server cooling plates and domestic hot water =0.015×1000×4.186≈62.79kW / K, NTU=12960×10⁻³ / 62.79≈0.206, efficiency E=|35-15| / (35-15)=1.0, Q / =62.79×0.206×1000≈12935W / K, the deviation from 12960W / K calculated by the LMTD method is <0.2%, verifying its validity; Chiller condensers and district heating =0.025×1000×4.186≈104.65kW / K, NTU=28870×10⁻³ / 104.65≈0.276, efficiency E=|32-45| / (32-45)=1.0, Q / ΔT m =104.65×0.276×1000≈28883W / K, which deviates from 28870W / K calculated by the LMTD method by less than 0.05%, thus verifying its validity.

[0103] Compatibility pre-assessment: Both the server cooling plates and domestic hot water systems use a liquid-liquid medium combination, with a system pressure of P=0.4MPa / 4bar (compatible with plate heat exchangers). The equipment room has sufficient space, and the compatibility is qualified. Both the chiller unit condenser and the district heating system use a liquid-liquid medium combination, with a system pressure of P=0.6MPa / 6bar (compatible with shell-and-tube heat exchangers). The district heating network has sufficient space, and the compatibility is qualified.

[0104] Step 3: Heat exchanger pre-screening.

[0105] The combination of server cold plate (liquid-liquid medium, ΔT=5K, P=0.4MPa / 4bar) and domestic hot water: According to the screening logic, plate heat exchangers are suitable, and printed circuit board type (too high cost), shell and tube type (pressure is lower than the minimum suitable value), and plate fin type (heat transfer efficiency is lower than plate type in liquid-liquid scenario) are excluded.

[0106] Combination of chiller condenser (liquid-liquid medium, ΔT=22.5K, P=0.6MPa / 6bar) with district heating: Based on the screening logic, shell and tube heat exchangers are suitable, while plate heat exchangers (insufficient pressure adaptability in medium and high pressure scenarios), plate-fin heat exchangers (insufficient heat transfer stability in large temperature difference scenarios), and printed circuit board heat exchangers (too high cost) are excluded.

[0107] Step 4: Heat transfer and cost quantification (plate heat exchanger).

[0108] U = 2000 W / (m²·K), =32.3K, F=1.0, =32.3K; A=586040 / (2000×32.3)≈9.0m² (90000cm²); C value: Q / =586040 / 32.3≈18144W / K, interpolation value C=0.25 yuan / (W / K), equipment cost=18144×0.25=4536 yuan; installation cost=1360.8 yuan; stainless steel correction factor=1.5, total cost=8845.2 yuan.

[0109] Plate heat exchanger (server cold plate - domestic hot water): Overall heat transfer coefficient U: liquid-liquid-water medium combination, correction factor = 1.0, standard U value range median = 2000W / (m²·K), therefore U = 2000 × 1.0 = 2000W / (m²·K).

[0110] Average temperature difference Logarithmic mean temperature difference =32.3K, countercurrent flow pattern F=1.0, therefore ΔT m =32.3×1.0=32.3K.

[0111] Heat transfer area A: A = Q / (U· )=418600 / (2000×32.3)≈6.47m² (64700cm²).

[0112] Cost Quantification: Q / =418600 / 32.3≈12960W / K, the actual measured data point 1 in the project is... =10000W / K corresponds to =0.26 yuan / (W / K), data point 2 is =15000W / K corresponding =0.24 yuan / (W / K), calculated by logarithmic interpolation, C=exp[ln0.26+(ln(0.26 / 0.24)·ln(12960 / 10000)) / ln(10000 / 15000)]≈0.25 yuan / (W / K); equipment cost=12960×0.25=3240 yuan; installation cost=3240×30%=972 yuan; material is stainless steel, correction factor=1.5, total cost=(3240+972)×1.5=6318 yuan.

[0113] Shell-and-tube heat exchangers (condensers for chillers - district heating): Overall heat transfer coefficient U: liquid-liquid-water medium combination, correction factor = 1.0, standard U value range median = 1000W / (m²·K), therefore U = 1000 × 1.0 = 1000W / (m²·K).

[0114] Average temperature difference ΔT m Logarithmic mean temperature difference =20.5K, 1 shell side 2 tube side F=0.85, therefore ΔT m =20.5×0.85≈17.4K.

[0115] Heat transfer area A: A = Q / (U· )=502320 / (1000×17.4)≈28.87m² (288700cm²).

[0116] Cost Quantification: Q / =502320 / 17.4≈28870W / K, the actual measured data point 1 in the project is... =25000W / K corresponding =0.22 yuan / (W / K), data point 2 is =30000W / K corresponding =0.20 yuan / (W / K), calculated by logarithmic interpolation, C=exp[ln0.22+(ln(0.22 / 0.20)·ln(28870 / 25000)) / ln(25000 / 30000)]≈0.21 yuan / (W / K); equipment cost=28870×0.21=6062.7 yuan; installation cost=6062.7×30%=1818.81 yuan; material is carbon steel, correction factor=1.0, total cost=6062.7+1818.81=7881.51 yuan.

[0117] Step 5: Multi-stream adaptation (merging two waste heat sources).

[0118] Total heat load =418600+502320=920920W (920.92kW).

[0119] Calculation of volumetric heat transfer coefficient: Local volumetric heat transfer coefficient of server cold plate flow stream =80kW / (m³·K), the local volumetric heat transfer coefficient of the condenser stream in the chiller unit. =75kW / (m³·K), the total volumetric heat transfer coefficient 1 / B=1 / 80+1 / 75≈0.0267, solving for B≈37.5kW / (m³·K) (37500W / (m³·K)).

[0120] Volume calculation: Average temperature difference between zones z==25K, active volume V a =920920 / (37500×25)≈0.982m³, total volume V=1.15×0.982≈1.13m³ (1130L).

[0121] Cost calculation: Using an aluminum plate-fin multi-flow heat exchanger, k = 10000 yuan / m³, b = 0.8, cost = 10000 × 1.13 0 · 8 The cost is approximately 10,000 × 0.89, which is approximately 8,900 yuan. This is 37.3% lower than the total cost of two single-flow heat exchangers (6,318 + 7,881.51 = 14,199.51 yuan).

[0122] Step 6: Decision Output.

[0123] Comparison of single-flow schemes: The payback period for the plate heat exchanger (server cold plate - domestic hot water) is 6318 / (32.2×0.776×8760×0.15)≈0.19 years (2.3 months). Emission reduction = 32.2 × 0.776 × 8760 × 0.2 ≈ 43.2 tons; Investment payback period for shell-and-tube heat exchangers (cooler condenser - district heating) = 7881.51 / (45.8 × 0.821 × 8760 × 0.15) ≈ 0.15 years (1.8 months). Emission reduction = 45.8 × 0.821 × 8760 × 0.2 ≈ 65.3 tons.

[0124] Multi-share plan: Investment payback period = 8900 / ((32.2 × 0.776 + 45.8 × 0.821) × 8760 × 0.15) ≈ 0.12 years (1.4 months). Emission reduction = (32.2 × 0.776 + 45.8 × 0.821) × 8760 × 0.2 ≈ 108.5 tons (meets the target of ≥ 100 tons), heat transfer efficiency η = 93% (≥ 85%).

[0125] Considering cost savings and emission reduction effects, the multi-flow plate-fin heat exchanger solution is recommended.

[0126] Example 4 illustrates a method for selecting a multi-grade waste heat recovery heat exchanger for a data center. It should be noted that the technical solution of this system for selecting a multi-grade waste heat recovery heat exchanger for a data center is based on the same concept as the method described above. Details not described in detail in this example can be found in the description of the method described above.

[0127] This embodiment also provides a selection system for multi-grade waste heat recovery heat exchangers in data centers, including: The quantitative inventory establishment and evaluation module identifies and classifies multi-grade waste heat sources and energy-consuming terminals. It collects parameters through a hybrid integration method, establishes a waste heat inventory for the data center, calculates the average temperature of waste heat sources and the average temperature of energy-consuming terminals, obtains the heat transfer temperature difference, and performs spatiotemporal matching evaluation and heat exchanger compatibility pre-evaluation. The cost quantification module, based on the results of heat transfer temperature difference, spatiotemporal matching assessment and heat exchanger compatibility pre-assessment, pre-screens heat exchanger types and calculates single-stream heat transfer parameters and investment costs according to the screened heat exchanger types. The multi-flow adaptation and decision output module performs multi-flow-specific calculations based on the obtained single-flow-specific heat transfer parameters and investment costs; it conducts multi-dimensional evaluations based on the single-flow-specific heat transfer parameters, investment costs, and multi-flow-specific calculation results, and outputs the final heat exchanger selection scheme.

[0128] This embodiment also provides an electronic device applicable to the selection of multi-grade waste heat recovery heat exchangers for data centers, including: a memory and a processor; the memory is used to store computer-executable instructions, and the processor is used to execute the computer-executable instructions to implement the method for selecting multi-grade waste heat recovery heat exchangers for data centers as proposed in the above embodiment.

[0129] This embodiment also provides a storage medium storing a computer program that, when executed by a processor, implements a method for selecting a multi-grade waste heat recovery heat exchanger for a data center, as proposed in the above embodiments.

[0130] The storage medium proposed in this embodiment belongs to the same inventive concept as the method for selecting a multi-grade waste heat recovery heat exchanger for a data center proposed in the above embodiments. Technical details not described in detail in this embodiment can be found in the above embodiments, and this embodiment has the same beneficial effects as the above embodiments.

[0131] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0132] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for selecting a multi-grade waste heat recovery heat exchanger for a data center, characterized in that, include: Identify and classify multi-grade waste heat sources and energy consumption terminals, collect parameters through hybrid integration, establish a waste heat inventory for data centers, calculate the average temperature of waste heat sources and the average temperature of energy consumption terminals, obtain the heat transfer temperature difference, and conduct spatiotemporal matching assessment and heat exchanger compatibility pre-assessment. Based on the results of heat transfer temperature difference, spatiotemporal matching assessment and heat exchanger compatibility pre-assessment, heat exchanger types are pre-screened, and single-stream heat transfer parameters and investment costs are calculated based on the screened heat exchanger types. Based on the obtained single-flow heat transfer parameters and investment costs, multi-flow special calculations are performed; based on the single-flow heat transfer parameters, investment costs and multi-flow special calculation results, a multi-dimensional evaluation is conducted, and the final heat exchanger selection scheme is output.

2. The method for selecting a multi-grade waste heat recovery heat exchanger for a data center as described in claim 1, characterized in that, The process involves identifying and classifying multi-grade waste heat sources and energy consumers, collecting parameters through a hybrid integration approach, establishing a data center waste heat inventory, calculating the average temperature of waste heat sources and the average temperature of energy consumers, determining the heat transfer temperature difference, and performing spatiotemporal matching assessment and heat exchanger compatibility pre-assessment, including: Identify and classify multi-grade waste heat sources and energy consumption terminals, collect parameters through a hybrid integration method, and establish a waste heat inventory for data centers; Based on the waste heat inventory of the data center, the average temperature of the waste heat source and the average temperature of the energy consumption end are calculated to obtain the heat transfer temperature difference. Based on the heat transfer temperature difference, the recoverable waste heat source is calculated using a first-level algorithm, and spatiotemporal matching evaluation and heat exchanger compatibility pre-evaluation are performed based on the calculated recoverable waste heat source.

3. The method for selecting a multi-grade waste heat recovery heat exchanger for a data center as described in claim 2, characterized in that, Based on the results of heat transfer temperature difference, spatiotemporal matching assessment, and heat exchanger compatibility pre-assessment, a pre-screening of heat exchanger types is performed. Based on the screened heat exchanger types, single-stream heat transfer parameters and investment costs are calculated, including: Based on the results of heat transfer temperature difference, spatiotemporal matching assessment and heat exchanger compatibility pre-assessment, heat exchanger types are pre-screened. Based on the pre-selected heat exchanger types, the overall heat transfer coefficient, average temperature difference, and heat transfer area were calculated respectively. Based on the calculated total heat transfer coefficient, average temperature difference, and heat transfer area, the C value is calculated using a two-stage algorithm, and the setup cost, installation cost, and correction cost are calculated respectively.

4. The method for selecting a multi-grade waste heat recovery heat exchanger for a data center as described in claim 3, characterized in that, Based on the obtained single-flow heat transfer parameters and investment cost, multi-flow specialized calculations are performed; based on the single-flow heat transfer parameters, investment cost, and multi-flow specialized calculation results, a multi-dimensional evaluation is conducted, and the final heat exchanger selection scheme is output, including: Based on the obtained single-flow heat transfer parameters and investment costs, the local volume heat transfer coefficient, total volume heat transfer coefficient, active volume, total volume, and multi-flow cost are calculated respectively to complete the multi-flow special calculation. Based on the single-flow heat transfer parameters, investment cost, and flow-specific calculation results, calculate the heat transfer efficiency, investment payback period, and annual return. Emission reductions, and based on heat transfer efficiency, investment payback period, and annual... Emission reductions should be assessed from multiple dimensions. Based on the multi-dimensional evaluation results, the final heat exchanger selection scheme is selected and output.

5. The method for selecting a multi-grade waste heat recovery heat exchanger for a data center as described in claim 4, characterized in that, The process of performing spatiotemporal matching assessment and heat exchanger compatibility pre-assessment based on the calculated recoverable waste heat source includes: The matching amount between waste heat source supply and energy demand is described by an overlap function, expressed as: The matching degree of the entire time window is quantified by the recycling index, and the expression is: in, For overlapping functions, The energy demand at time t, To supply waste heat at time t. For the recovery index, The start time of the time window. The time window ends at the time of integration, the trapezoidal rule is used, the step size is equal to the data acquisition resolution, and the selection process begins when RI≥0.5; The NTU-Effectiveness heat transfer calculation is performed, and the effectiveness expression is as follows: in, This represents the maximum temperature difference between the hot and cold fluids. For the performance expression, The inlet temperature of the waste heat source. This refers to the inlet temperature at the energy consumption end. The expression for the number of heat transfer units is: in, The number of heat transfer units, U is the minimum heat capacity in the hot and cold flows, U is the overall heat transfer coefficient, and A is the heat transfer area of ​​the heat exchanger. Where Q is the heat load, ΔT m U is the actual average temperature difference, U is the overall heat transfer coefficient, and A is the heat transfer area of ​​the heat exchanger. The number of heat transfer units, This represents the minimum heat capacity in the hot and cold flows; The evaluation is conducted from the dimensions of media compatibility, pressure adaptability, and spatial compatibility. In terms of media compatibility, liquid-liquid media groups are suitable for plate or shell-and-tube heat exchangers, while gas-liquid media groups are suitable for plate-fin heat exchangers. In terms of pressure adaptability, the upper limit of system pressure adaptability is evaluated based on plate heat exchangers, shell and tube heat exchangers, and printed circuit board heat exchangers. In terms of space compatibility, compact heat exchangers are used in small computer room scenarios, while shell-and-tube heat exchangers are used in scenarios with ample space. Heat exchanger types that meet the requirements in all three dimensions will proceed to the pre-screening stage.

6. The method for selecting a multi-grade waste heat recovery heat exchanger for a data center as described in claim 5, characterized in that, The calculation of the C value through a two-level algorithm includes: Calculated using logarithmic interpolation: Where C is the value of C. Corresponding to engineering measurements Cost factors, Parameters representing the heat transfer capacity of a heat exchanger , These are two different heat transfer capacity parameter values ​​measured in engineering practice.

7. The method for selecting a multi-grade waste heat recovery heat exchanger for a data center as described in claim 6, characterized in that, The calculation of heat transfer efficiency, investment payback period, and annual return is based on the single-flow heat transfer parameters, investment cost, and flow-specific calculation results. Emission reductions include: Calculate heat transfer efficiency The expression is: in, For heat transfer efficiency, the actual heat transfer is based on the heat load calculation results. The design heat transfer is the rated heat transfer capacity of the heat exchanger. The qualified standard is η≥85%. If it is not achieved, the heat exchanger type needs to be re-selected and the heat transfer parameters need to be adjusted. The formula for calculating the payback period (PBP) is: in, This is the investment recovery period; The total cost is the calculated total correction cost; in, For waste heat source recovery, RI is the recovery index, 8760 is the annual operating hours, and the qualified standard is PBP≤2.5 years. If it exceeds, the cost correction factor needs to be adjusted and a low-cost suitable heat exchanger needs to be re-screened. Calculation year Emission reduction, the formula is: in, For the year Emission reduction, Exergy is recyclable material, RI is the recovery index, 8760 is the annual operating hours, and the target value is annual. Emissions reduction ≥ 100 tons. If the target value is not achieved, the combination of waste heat source and energy consumption end needs to be optimized and the configuration of multiple streams needs to be adjusted.

8. A selection system for multi-grade waste heat recovery heat exchangers in data centers, using the method described in any one of claims 1-7, characterized in that, include: The quantitative inventory establishment and evaluation module identifies and classifies multi-grade waste heat sources and energy-consuming terminals. It collects parameters through a hybrid integration method, establishes a waste heat inventory for the data center, calculates the average temperature of waste heat sources and the average temperature of energy-consuming terminals, obtains the heat transfer temperature difference, and performs spatiotemporal matching evaluation and heat exchanger compatibility pre-evaluation. The cost quantification module, based on the results of heat transfer temperature difference, spatiotemporal matching assessment and heat exchanger compatibility pre-assessment, pre-screens heat exchanger types and calculates single-stream heat transfer parameters and investment costs according to the screened heat exchanger types. The multi-flow adaptation and decision output module performs multi-flow-specific calculations based on the obtained single-flow-specific heat transfer parameters and investment costs; it conducts multi-dimensional evaluations based on the single-flow-specific heat transfer parameters, investment costs, and multi-flow-specific calculation results, and outputs the final heat exchanger selection scheme.

9. A computer device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the processor executes the computer program, it implements the steps of the method according to any one of claims 1 to 7.

10. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by a processor, it implements the steps of the method according to any one of claims 1 to 7.

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