Thermal Calculations Research Articles

Thermal calculation and experimental study of a double-disk magnetic coupler

Aiming to tackle the difficulties and inaccuracies in calculating the temperature field of double-disk magnetic coupler, a novel thermal calculation method is proposed, integrating the equivalent thermal network method and CFD method. This approach deviates from traditional methods that substitute empirical formulas with rotational speed. An equivalent thermal network model is established to ascertain the temperature rise at each network node. Additionally, a fluid-solid coupling model is constructed, and the impact of uneven air temperature distribution on air density, specific heat capacity, dynamic viscosity, and thermal conductivity is analyzed using the least squares method. The results reveal that after incorporating variable temperature air physical properties, the high-temperature area of the copper conductor decreases, the calculated temperature rise aligns closer to actual values, and air friction loss on the copper surface is reduced by 6.5 %. Experimental verification, conducted on a 55 kW double-disk magnetic coupler, demonstrates maximum errors of 8.86 % and 6.53 % when comparing experimental values to those calculated by the equivalent thermal network method and CFD method, respectively, thereby validating the proposed method. This research provides a theoretical reference for thermal calculations in double-disk magnetic coupler.

An innovative strategy to enhance the interfacial interaction and effective contribution of BN in thermal conductivity in aramid based composites films

With the escalating concern over electronic device overheating, BN/polymer based thermal conductive composites have experienced remarkable growth in the field of heat dissipation. However, it is challenging to enhance the thermal conductivity of composites while preserving strong interfacial interaction due to the dilemma of chemical inertness of BN, interfacial thermal resistance and filler-polymer interaction. Herein, we utilized the adjustable surface charge of polydopamine under varying pH to fabricate composite films comprising polydopamine-modified boron nitride nanosheets and aramid sheets (BNNS@PDA/ANFS) by electrostatic assembly. The thermal conductivity of the composite rose to 36.9 W/m⋅K−1 with only 20 wt% filler. According to Density functional theory (DFT) simulation and interface thermal resistance calculation, the electrostatic assembly enhanced interface interactions and greatly reduced thermal resistance barrier. Furthermore, the optimal tensile strength of 304 MPa, is 2.32 times higher than pure ANFS film, accompanied by toughness of 33.2 MJ/m−3. These superior performances are the results of a synergistic strategy, combining interfacial and topological enhancements. This work provides an innovative approach to enhance effective filler contribution in matrix and underscores the significant potential of BNNS@PDA/ANFS composite films in applications related to heat management.

The energy output equilibrium scheme with intermediate energy storage for tokamak fusion power plant

Different from the design of nuclear fission power plant, the design of fusion power plant needs to consider the problem of discontinuous fusion energy output from nuclear island. This paper proposed an energy output equilibrium scheme for fusion power plant. Based on analysis and comparison, thermal energy storage method was adopted, and two system operation schemes for fusion power plant were further proposed. Finally, system thermal storage calculation and analysis were conducted under WCCB blanket and HCCB blanket respectively, and conclusions were drawn on the applicable system operation scheme under different blankets. This study provides research foundation and engineering reference for the design and construction of future fusion power plants.

A precise prediction of structure stability and hydrogen storage capability of KCdH3 perovskite hydride using density functional theory calculations

Perovskite hydrides materials are acknowledged for hydrogen storage due to their high capacity, reversibility, thermodynamic stability, tunable nature, and potential low-cost solutions. In the current investigation, the four distinct cubic structures of perovskite hydride KCdH3 for the hydrogen storage are investigated with the help of density functional theory and providing valuable insights into stable phases. Electronic, thermal and entropy calculations are performed. Two out of four cubic structure are founded mechanically stable with the gravimetric storage capacity of be 5.5 cwt% and the volumetric storage capacity of 67.69 gH2l−1 which align with the standard situated by the U.S. Department of Energy for the year 2025. Notably, this study is the first comprehensive investigation of all four cubic phases of the KCdH3 compound. The promising hydrogen storage capabilities of these compounds shows the credibility for their effective use as a solid-state hydrogen storage material, and the research aims to further ascertain its stability and storage capacities.

RESEARCH OF THE DESTRUCTION CONDITIONS OF GLAZING OF ENCLOSING STRUCTURES UNDER THE CONDITIONS OF THERMAL INFLUENCE OF FIRE

The article presents the main results of mathematical modelling of the destruction of glazing of enclosing building structures with translucent elements under fire conditions. The authors analyse literature data on calculating the fire resistance of enclosing building structures with glazing. The results show that improving methods for predicting the fire resistance of glazing is relevant. Mathematical models for the numerical study of the behaviour of glazing under the thermal influence of the standard fire temperature regime are substantiated. Mathematical models of the heat transfer process involve using a non-stationary differential equation of heat conduction with boundary conditions of the third kind, accounting for the convective and radiant heat exchange between the air in the room with the fire and the glazing. As a criterion for the destruction of glazing under the influence of fire, the authors establish the temperature resistance parameter, which is determined based on the mechanical characteristics of the glass. The article highlights the relevant data on the study of temperature indicators and the mechanism of glazing failure, using mathematical modelling with well-founded mathematical models. It obtains the results of the thermal calculation by applying the finite difference method for solving the non-stationary differential equation of thermal conductivity. The methodology for determining the time of glazing failure under the influence of the standard temperature regime of a fire using the calculation parameters obtained based on well-founded mathematical models is substantiated. An analysis of the adequacy of the obtained calculation data was carried out by comparing them with the results of experimental studies using statistical criteria. As a result of the analysis, the authors confirmed the validity of the calculation data. A complete factorial experiment was conducted based on well-founded mathematical models, which revealed the regularities of the dependence of the parameters of thermomechanical processes in single-layer glass on its structural characteristics. The revealed regularities have the form of linear regression dependences of the destruction time on the thickness of the glazing and the maximum length of the glass panel without bars. Using the regularities of the dependence of the parameters of thermomechanical processes in single-layer glazing on its structural characteristics, the authors constructed reference tables for evaluating the fire resistance of enclosing structures with glazing. The research obtained new scientific data on the study of the behaviour of glazing of enclosing building structures under the thermal influence of fire through mathematical modelling, which is the basis for improving the methods of calculating the fire resistance of enclosing structures with translucent elements. Keywords: enclosing building structures, glazing, fire resistance limit, calculation method, glass heat resistance.

Review and Thermal Calculation of a Shell and Tube Heat Exchanger with Baffles in Cross - Counter Flow Arrangement

In one pass shell and tube heat exchanger with baffles one fluid flows inside of parallel tubes and other fluid flows outside of tubes in perpendicular to tube axis changing alternately its direction. Passing the window of the baffles the shell side fluid deviates its flow direction rapidly. This creates just behind the window of each baffle a so-called “dead volume” which renders a stagnation of flow. This dead volume assumed to be triangular in shape causing the flow behind the window to be conical.In this thermal model the “dead volume” taken into account and change of temperature of the shell side fluid during its flow from tube to tube is considered. The thermal analysis of the cross- counter flow arrangement for any number of tube in bundle with progressive changes in tube length has been carried out. The numerical computations with different tube and baffle numbers are performed. It is found that at the beginning the effectiveness of the heat exchanger increases distinctly with increasing tube number and baffle number. But after certain number of tube and baffles the increasing rate weakens and it becomes very small. Due to the presence of “dead volume” there is reduction in the thermally active heat transfer surface area which leads to a smaller value of Number of Transfer Units (NTU). Hence, the results of computation obtained in this paper with the consideration of the “dead volume” will provide lower value of the effectiveness than that of without the consideration of it.

Development of multi-physics calculation method in lead cooled fast reactor code system MOSASAUR

A full-core three-dimensional multi-physics calculation method was researched based on the Lead cooled fast reactor (LFR) code system MOSASAUR, which is focused on both core steady-state and transient analyses of LFR. In the previous version of MOSASAUR, cross-sections generation module and core steady-state simulation module have been developed. In this research, the stiffness confinement method is employed to solve the time-dependent multi-group neutron transport equation to expand the capabilities of core transient analyses. And the thermal hydraulic calculation method is developed as thermal feedback module for core steady-state and transient analyses. Based on the fixed-point iteration scheme, the neutron module and thermal hydraulic module are coupled at each time step. The LMW benchmark and the problem based on ORAL 19-rod bundle are employed to verify the accuracy of transient calculation and thermal hydraulic module respectively. Finally, the multi-physics calculation method is utilized to simulate the transient process of the MicroURANUS core. The simulation results demonstrate the capability of the constructed multi-physics calculation framework to accurately simulate the transient behaviors of LMRs. Numerical results showed the good accuracy of the newly-developed multi-physics calculation module with MOSASAUR.

Anomalous lattice thermal conductivity increase with temperature in cubic GeTe correlated with strengthening of second-nearest neighbor bonds

Understanding thermal transport mechanisms in phase change materials is critical to elucidating the microscopic picture of phase transitions and advancing thermal energy conversion and storage. Experiments consistently show that cubic phase germanium telluride (GeTe) has an unexpected increase in lattice thermal conductivity with rising temperature. Despite its ubiquity, resolving its origin has remained elusive. In this work, we carry out temperature-dependent lattice thermal conductivity calculations for cubic GeTe through efficient, high-order machine-learned models and additional corrections for coherence effects. We corroborate the calculated phonon properties with our inelastic X-ray scattering measurements. Our calculated lattice thermal conductivity values agree well with experiments and show a similar increasing trend. Through additional bonding strength calculations, we propose that a major contributor to the increasing lattice thermal conductivity is the strengthening of second-nearest neighbor interactions. The findings herein serve to deepen our understanding of thermal transport in phase-change materials.

An Assessment Tool for Energy Audit of Buildings in Jordan Using Simulation

In developed nations, there's a growing concern for sustainable energy management, particularly regarding enhancing energy efficiency in both existing and new buildings. The methodology presented considers the energy modelling and simulation of manufacturing buildings through thermal and electrical loads calculations using Dymola/Modelica software. The thermal model is built with the primary components of Dymola along with available models to calculate the heating and cooling loads, whereas the electrical model was calculated using consumption patterns, then the total model was validated against real measurements where the error percentage was 9.96 %. The yearly heating load baseline was 6295 kWh/y and for cooling 46276 kWh/y., the exciting potential for energy- savings and load flexibility, and some suggestions for improving consumption were pointed out and identified. It found that the highest influence on the thermal load reduction was using the double glaze with shading with 61% of the energy-saving options, then replacing the fluorescent with LED with 30%, and finally, the roof insulation was the least influence with 9.5%. For the total consumption, the highest percentage was for replacing the fluorescent with LED with 78% of energy-saving options, then double glaze with shading, and finally the lowest is for the roof insulation.

Estimation of the Reduction Coefficient When Calculating the Seismic Resistance of a Reinforced Concrete Frame Building after a Fire

The consequences of destructive earthquakes show that the problem of analyzing the response of reinforced concrete frames under seismic loads after a fire is relevant. The calculation models used for individual elements and buildings as a whole must take into account the nonlinear properties of concrete and reinforcement. In the spectral calculation method, the nonlinear properties of materials are taken into account by introducing a reduction coefficient to the elastic spectrum. When determining the reduction coefficient, a common deformation criterion is based on the use of the plasticity coefficient. The seismic resistance of a three-span, five-story reinforced concrete frame under four different fire exposure options is considered. The residual strength and stiffness of frame elements after a fire is assessed by performing a thermal engineering calculation in the SOLIDWORKS software for a standard fire. For the central sections of the elements, the highest temperatures were obtained after heating—during the cooling stage. The reduction coefficient is estimated by performing a nonlinear static analysis of reinforced concrete frames in OpenSees and constructing load-bearing capacity curves. Fracture patterns and damage levels in plastic hinges are analyzed. Based on the numerical modeling of reinforced concrete frames after exposure to fire, it was revealed that the most dangerous scenario is the occurrence of a fire on the first floor of the building. Based on the obtained plasticity coefficients, reduction coefficients were determined in the range of 2.62 to 2.44. The influence of fire on the permissible damage coefficient of a reinforced concrete frame is assessed using the coefficient φK—the coefficient of additional damage after a fire, which is equal to the ratio of the reduction coefficients for the control and fire-damaged frames. Depending on the percentage of damaged structures on the first floor, the following values were obtained: 50% or less—φK = 1.09; 100%—φK = 1.17. The obtained coefficients are recommended to be used when assessing the seismic resistance of a reinforced concrete frame after a local fire.

500 kW closed cycle gas turbine unit with different working fluids

This article considers a 500 kW closed cycle gas turbine unit. In contrast to open or semi-closed cycles, a closed cycle implies a working fluid circulating continuously within a closed loop. In other words, a working fluid (any working fluid) with the required initial parameters depending on the properties of the selected working fluid is injected into a closed circuit consisting of a compressor, heat exchangers of various purposes and a turbine. A unit with recirculation of combustion products at high pressure can be created based on existing units with minor modifications. Instead of emission into the atmosphere, the exhaust gases enter the high-temperature heat exchanger, where it gives heat to the closed-cycle gas turbine unit. First of all, the application of such units is relevant at compressor stations in conjunction with the gas turbine drive of the blower. The study involved thermal calculation of a closed-cycle gas turbine unit with different working fluids: carbon dioxide, helium and argon. The main objective is to study the advantages and disadvantages of alternative working fluids with their subsequent comparison. Since the main chemical and physical properties of alternative working fluids differ from the classical ones, there is a possibility of obtaining higher parameters of the unit. According to the results of calculations it is established that the most promising working fluid is carbon dioxide, because this can be used at a wide range of temperatures and pressures. It should also be noted that the consumption of carbon dioxide is the lowest compared to other working fluids. The efficiency of such an installation is 28%, but there is a possibility of improvement if regeneration is added.

INFLUENCE OF CLIMATE ON THE COUPLED HEAT AND MOISTURE TRANSFER THERMAL CALCULATION IN CHINA

ABSTRACT The climate in China varies substantially across its extensive territory. However, the traditional thermal design of buildings is primarily based on pure heat calculation that considers only heat transfer. Therefore, the heat transfer of a building envelope should be clarified under the action of periodic external disturbance circulation. In this study, four different climatic factors were selected for heat transfer simulation, including season, solar radiation, air temperature, and relative humidity. The results indicate that the outdoor relative humidity has a significant impact on the difference between coupled heat and moisture calculation and pure thermal calculation. This influence becomes evident in the cooling conditions in summer but weakens in the winter heating conditions. Accordingly, the meteorological data of 270 cities in China were statistically analyzed using Python programming language. The concept of “cooling high-humidity days” was proposed as a zoning indicator for coupled heat and humidity thermal calculation zoning. The coupled heat and moisture thermal calculation design zoning map of China is provided, which affords the specific calculation method in building thermal design.

Multi-Criteria Decision-Making Method for Simple and Fast Dimensioning and Selection of Glass Tube Collector Type Based on the Iterative Thermal Resistance Calculation Algorithm with Experimental Validation

This paper presents an analytical method for the dimensioning and selection of the four glass tube collector types: single-glazed with an air layer, single-glazed with a vacuum layer, double-glazed with an air layer, and double-glazed with a vacuum layer. In the first part of the paper (dimensioning phase), the iterative thermal resistance calculation algorithms were developed for all glass tube collector types, whereby the iterative thermal resistance calculation algorithm of the single-glazed tube collector with an air layer was experimentally tested and validated. The second part of the paper (selection phase) uses a multi-criteria decision-making method to determine the optimal glass tube collector design. Unlike other papers, three indicator groups are taken into account in this case: geometric (mass, surface occupation, total surface occupation, volume occupation), economic (manufacturing and exploitation costs), and ecological (embodied energy and greenhouse gas emission). The proposed method is characterized by simple and fast calculations with satisfactory accuracy, which avoids high investment costs (experimental research), approximation and discretization of physical models (numerical research), and a large number of input parameters with boundary conditions (theoretical research). It should be noted that, with certain additions and changes, it can also be applied to other solar thermal collectors, so the authors believe such tools are handy for the global scientific public.

Thermo-mechanical coupled three-dimensional finite element simulation analysis of drilling thermoplastic braided carbon fiber composite and optimization of process parameters

Optimizing the process parameters of thermoplastic composites during drilling is paramount for mitigating tearing, delamination, and other forms of damage, while simultaneously enhancing the tensile strength and extending the long-term service life of the overall structure. This study focuses on exploring a thermal-mechanical coupling method for predicting dynamic mechanical progressive failure and determining optimal process parameters during the drilling of Braided Carbon Fiber Reinforced Polyether Ether Ketone (BCF/PEEK). Initially, a thermal conduction constitutive model of BCF/PEEK was developed based on the proposed thermal distribution ratio calculation method. Concurrently, a user-defined material subroutine VUMAT and a bilinear cohesive element model, were implemented on the ABAQUS/Explicit platform to simulate the delamination behaviors of drilling BCF/PEEK using a tapered drill-reamer. Subsequently, a comprehensive BCF/PEEK drilling experiment platform was constructed, and the simulation accuracy of the drilling finite element (FE) model was verified through temperature, thrust force, and hole-wall morphology analyses. Finally, response surface regression models were established for process parameters, and the optimal parameters were predicted and validated. The results indicate that minimum thrust force and temperature can be achieved using the tapered drill-reamer with a spindle speed set at 4878.79/3000 r/min and a feed speed of 34.04/30 mm/min, respectively, with a maximum error of only 8.78 %.

Optimizing heat pump unit selection for recirculating aquaculture workshops through computational fluid dynamics.

The selection of water temperature regulation equipment plays a crucial role in the design of workshops. At present, the choice of water temperature control equipment is usually based on the volume of the fish pond and thermal parameter calculation, combined with aquaculture experience. Empirical formulas only work in specific conditions due to factors like the environment, climate, and fish types,resulting in inaccurate equipment selection outcomes. Recognizing this limitation, this paper proposes to apply CFD simulation of the temperature field to accurately calculate the heat exchange value between indoor air and water, thereby predicting the heat exchange values during aquaculture activities in the aquaculture workshop. providing a new approach for equipment selection. This paper selects a puffer fish breeding workshop in Dalian as the simulation object, establishing a 3D unsteady-state Computational Fluid Dynamics model. The model considers outdoor temperature, solar radiation, and phase-change heat transfer in water. Comparison with experimental data reveals a root mean square error of 0.46°C for the simulated results. During summer, the highest cooling load occurs at 16:00, reaching 94.6 kW. It is recommended to employ the Daikin GCHP-40MAH ground source heat pump as the water temperature control equipment. CFD simulation validates its effectiveness in shaping the indoor temperature field post-installation. the investment in water temperature control equipment can be reduced to a certain degree. This provides a reference value for the selection of water temperature equipment in aquaculture workshops.

Математическое моделирование термодинамических процессов в вентиляционных шахтах метрополитена

Objective: To develop recommendations for performing thermal engineering calculations during the ventilation shafts renovation with the creation of internal thermal insulation made of foam glass concrete. Methods: Mathematical modeling by the Metrogiprotrans method of the shaft lining in an elastic medium for specified movements from expanding ice; mathematical modeling by the finite elements method of a system including a ground massive, shaft lining and a load from convection (cold air flow). Results: The criteria for the risk of the ventilation shafts lining destruction during freezing of water-saturated soil behind the lining have been established. It has been established that the destruction of cast-iron lining from the ice expansion depends on the amount of soil resistance and the size of voids behind the lining, but not on the depth of the location of the section under consideration. An influence assessment of the soil thermodynamic characteristics during the ventilation shafts operation in conditions of alternating temperatures has been performed. It was found that as a result of a very wide change in the thermal characteristics of the medium, the temperature behind the lining during thermodynamic calculations changes insignificantly — within 1 °C, and the thermal characteristics of the foam glass concrete layer play a decisive role in heat distribution. Practical importance: The results of the study can be used during the inspection of subway ventilation shafts, as well as an algorithm for conducting thermodynamic calculations for projecting shafts renovation with an insulation made of foam glass concrete.

Theoretical study on gas‐phase reactions during chemical vapor deposition of TixAl1–xN from TiCl4, AlCl3, and NH3

AbstractFcc‐TixAl1–xN (TiAlN) coatings synthesized via chemical vapor deposition (CVD) reduce cutting tool wear. Although CVD conditions reportedly influence coating quality, no quantitative guidelines are yet available. To quantitatively study the film‐forming mechanism of TiAlN CVD, the gas composition over the surface must be known. Therefore, we developed a gas‐phase elementary reaction model for TiAlN CVD derived from TiCl4/AlCl3/NH3. First, we constructed a novel thermodynamic dataset including molecules that contained both Ti and Al, and calculated the equilibrium composition. Thermal equilibrium calculations in the gas phase showed that the most stable species were AlCl3 and TiCl3 rather than TiCl4. An elementary reaction model was constructed based on the kinetics of the gas‐phase species that were generated. Kinetic analysis revealed that gas‐phase reactions were largely absent under our reactor conditions. The thermal equilibrium calculations indicated that TiCl4 may have given rise to TiCl3. Thus, other reaction pathways of TiCl4 to TiCl3 were explored. We calculated the reaction rate constants of 12 reactions of Ti species and added them to the model, which revealed that TiCl4 decomposed to TiCl3 via TiCl3NH2. Under our conditions, TiCl4 and TiCl3NH2 are the major Ti species and AlCl3 and AlCl2NH2 are the major Al species, which suggests that some of these species may form films. Unlike in the earlier reaction model, NH2 and H radicals were produced, which may have contributed to the surface reactions. For reactors with large Surface/Volume ratio of reactor, the effects of gas‐phase reactions should be considered. Our reaction model enables estimation of the partial pressures of reactor gas species and will therefore aid study of the TiAlN deposition mechanism.

CHOICE OF THERMAL INSULATION MATERIAL PRESS FORM FOR MANUFACTURING PRODUCTS FROM COMPOSITE MATERIALS

Purpose. The development of a method of thermal calculation of molds for the manufacture of products from composite materials, which allows you to choose an insulating material that ensures effective savings in heat consumption. Research methods. A theoretical analysis of the existing thermal calculations of the molds was carried out; an analysis of the theory of heat exchange based on the theory of similarity was carried out, using dimensionless criteria of Nusselt, Grashof and Prandtl; an analysis of reference data on the properties of insulating materials was carried out. Results. In the course of the work, the processes of convective heat transfer from the side surface of the mold were clarified and described; a method of calculating energy losses through heat transfer at a certain temperature on the outer surface of an uninsulated mold was developed; it was established that the temperature of the wall, from which the heat transfer is actually carried out, plays a decisive role in the selection of the insulating material; a method of reducing energy consumption is determined by applying a layer of heat-insulating material on the heat transfer surface of the mold, reaching a given temperature on the isolated surface of the mold; on the example of a mold of specific dimensions, the optimal materials were selected and their effectiveness in reducing heat consumption was determined. Scientific novelty. Developed methods for evaluating the effectiveness of heat-insulating material by calculating the temperature on the insulated surface of the mold; in this connection, the reduction of heat loss through heat transfer is achieved with the help of the selected optimal heat-insulating material, which has the appropriate thermophysical and technological properties. Practical value. Information on the impact of the design of the mold matrix and reference information on the thermal conductivity of heat-insulating materials are provided; the proposed calculation method can be used in the design of energy-saving molds for the manufacture of products from composite materials.

A novel coupled algorithm for Studying the performance characteristics of water ramjet in the flight of supercavitating vehicle

When a supercavitating vehicle performs a flight, the water ramjet of the vehicle exploits the water in the surrounding environment as an oxidiser and is inevitably affected by the vehicle motions. In this study, the characteristics of the performance change in a water ramjet were investigated when a supercavitating vehicle performs a flight to gain more insights into the design of underwater power systems. Given the principle of independent cross-section expansion of cavities, a longitudinal ventilated supercavity model was built to predict the development of a ventilated cavity and its interaction with the body. A thermal calculation model was developed based on the minimum free energy method to calculate the performance parameters of water ramjets. A novel coupling algorithm was proposed based on the aforementioned model to integrate the motion of a supercavitating vehicle with the operation of a water ramjet. The integration described above was achieved by linking the water intake and body motion and calculating the performance change characteristics of the water ramjet during the flight of the supercavitating vehicle. The operating characteristics of the water ramjet with changes in the designed water-fuel ratios were investigated to provide a basis for exploring the unperturbed flight of the vehicle, depth regulation, and underwater environmental changes. The thrust of the water ramjet is less affected by external factors, and its performance feedback tends to exacerbate external disturbances at a designed water-fuel ratio lower than the optimal water-fuel ratio. A water ramjet with a designed water-fuel ratio higher than the optimal water-fuel ratio has a rapid response time, adaptive thrust, and stable combustion chamber pressure. External disturbances slightly affected the thrust and combustion chamber pressure of the water ramjet when the designed water-fuel ratio was equal to the optimal water-fuel ratio. The results of this study provide technical support for optimising the design of water ramjet.

Effects of joint tolerances on thermal bridging in precast concrete shear walls: Field tests and numerical simulations

Prefabricated buildings are gaining momentum due to their ecological benefits, speedy construction, and precision. However, unlike conventional cast-in-place structures, precast concrete shear walls are more susceptible to thermal and quality defects due to inherent tolerances. Four precast concrete shear wall connections prone to thermal bridges were identified through case studies of factories and real projects. Steady-state and dynamic modeling was conducted using determinant and stochastic matrices to assess the impact of joint tolerances on thermal distribution. The effects of joint tolerance magnitude and insulation material properties on linear thermal transmittance were investigated, complemented by a polynomial-based sensitivity analysis. A versatile prediction model was developed, integrating physical modeling and data-driven approaches to quickly quantify the thermal bridges of precast concrete shear wall connections. The results revealed a significant positive correlation between thermal bridges and joint tolerances, leading to extensive low-temperature regions within precast concrete shear walls. In dynamic modeling, joint tolerances contributed to additional heat dissipation, with a peak heat flux of 20.07 W/m. The sensitivity analysis demonstrated that joint tolerances greatly influence the correlation between linear thermal transmittance and insulation layer properties. Leveraging Categorical Boosting and Extreme Gradient Boosting, the prediction of linear thermal transmittance for precast concrete shear wall connections exhibited exceptional accuracy while significantly reducing computational costs. This research aids designers and policymakers by providing rapid and precise linear thermal transmittance calculations, offering valuable guidance for manufacturing prefabricated components to ensure enhanced energy efficiency and sustainability.