Uniform Thermal Distribution Research Articles

Experimental study on the charging and discharging performance of a thermal energy storage unit using low temperature phase change material

The latent heat thermal energy storage (LHTES) unit offers a versatile solution for storing waste heat and solar thermal energy across various temperature ranges. Despite its potential, limited experimental research has been conducted on LHTES units operating at low temperature ranges. This study addresses this gap by experimentally investigating the performance of an LHTES unit using water as the heat transfer fluid (HTF) and myristic acid (PCM) with a phase change temperature of 53–55 °C. The rectangular configuration of the TES unit was chosen for its practical advantages in industrial and residential applications, facilitating efficient space utilization and uniform thermal distribution. Experiments were conducted with various HTF volumetric flow rates (200, 300, and 400 LPH) using a constant temperature heat source. PCM and HTF temperature profiles at three segments of the TES unit were used to evaluate key parameters essential for designing a storage system, including thermodynamic analysis, Nusselt number, stratification analysis, storage/recovery efficiency, and charging/discharging efficiency. These parameters provide valuable insights into the performance of the LHTES unit. The outcomes indicate that increasing the HTF flow rate from 200 to 400 LPH decreases the charging/discharging duration by 40.73 % and 38.24 %, respectively. At the higher flow rate (400 LPH), convective mixing increases, reducing stratified layer stability. Furthermore, increasing the HTF flow rate leads to a reduction in peak Richardson numbers by 31.6 % and 27.8 % during charging/discharging, indicating a transition towards diminished stratification and increased turbulence in the HTF flow. In conclusion, while the TES unit exhibited better performance at a lower HTF flow rate (200 LPH), practical applications demand efficient fast charging and discharging. Despite this, minimal differences in efficiencies, energy, and exergy rates across flow rates suggest practical viability in various test conditions.

Investigation of printing turn angle effects on structural deformation and stress in selective laser melting

Additive manufacturing (AM) technology facilitates the creation of complex structures, where the printing path significantly impacts thermal distribution, subsequently influencing stress distribution and structural deformation. The primary challenge in path planning is to determine a printing turn angle that ensures uniform thermal distribution, thereby minimizing structural deformation while maintaining printing efficiency. To address this issue, we propose a composite function, which comprehensively characterizes the effects of the printing turn angle and the length of the printing path on the printing results. Combining a specific cubic porous structure, we calculate the maximum (Pmax) and minimum (Pmin) values of the composite function P, and compare the structural deformation and stress of the Pmax and Pmin paths with those of the typical Pzigzag path. Finite element method (FEM) simulation and experimental validation show that the Pmax path achieves significantly lower structural deformation and residual stress compared to the Pzigzag path and Pmin path.

A high-safety lithium-ion battery electrospun separator with Si3N4-assisted sulfonated poly(ether ether ketone) for regulating lithium flux

The uncontrolled lithium (Li) dendrite growth significantly impacts the safety performance of polymer separators. To mitigate this growth, this study introduces Si3N4 into sulfonated poly(ether Ether Ketone) (SPEEK) and prepares Si3N4/SPEEK composite separators via electrospinning. At the interface between the Si3N4/SPEEK separator and the Li anode, the Si nanowires that form impede Li dendrite growth, thereby enhancing the electrochemical performance of lithium-ion batteries (LIBs). The Li deposition test of the 10 % Si3N4/SPEEK separator can operate for 1000 h without short-circuiting. Additionally, the LiFePO4||Li cell with the 10 % Si3N4/SPEEK separator shows improved initial discharge capacity (157.8 mAh g−1 at 1C) and superior rate performance (125 mAh g−1 at 10C). Moreover, the nano-scale Si3N4 endows the separator with robust thermal and mechanical properties. The FLIR observations reveal that the 10 % Si3N4/SPEEK separator maintains uniform thermal distribution and structural integrity even at 300 °C, ensuring safe battery operation at high temperatures. The additional load of the 10 % Si3N4/SPEEK separator can reach 10.2 mN, which enhances the puncture resistance of the separator. This work provides a solid approach for the application of SPEEK as a high-safety and high-rate LIB separator.

Stabilization of polyacrylonitrile-based fiber with a quasi-traveling microwave applicator

This study introduces a novel microwave applicator and optimized processing conditions to enhance the stability of Polyacrylonitrile (PAN)-based precursor fiber (PF). The innovative microwave applicator facilitates the propagation of the electromagnetic (EM) field akin to a quasi-traveling wave, thus circumventing standing wave nodes. This ensures a uniform thermal distribution and broadens the heating zone. Utilizing this applicator, the PF undergoes thermal stabilization in a streamlined two-step process, completing in just 13 min, a significant improvement over the conventional 90-min process. This not only saves manufacturing time, promoting energy efficient manufacturing but also aligns with the global trend towards green energy and lightweight carbon fiber-reinforced polymer matrix composites, potentially catalyzing rapid economic growth. Fiber characterization through Raman spectroscopy (RS), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and complex permittivity measurements reveals that the microwave-processed fiber meets the standard of commercial stabilization fiber (SF).

Thermal enhancement of PEM fuel cell cooling with novel configurations of Tesla valve and hybrid nanofluids: A numerical study

The operating temperature and thermal distribution play a significant role in the appropriate performance of the proton exchange membrane fuel cell (PEMFC). A suitable cell cooling method can guarantee uniform temperature distribution and preservation of membrane water content under harsh conditions in a PEMFC. The compact structure of PEM fuel cells and the size of the cooling system impose a great challenge to achieve a proper design of cooling plate. In this numerical study, four designs of the multi-stage Tesla valve with straight and reverse configuration are proposed to be employed as a cooling channel in which three different hybrid nanofluids such as TiO2–Cu, Al2O3–CuO, and Ag–MgO dispersed in water and Ethylene glycol flow inside the channels. A validated numerical model is developed using a commercial computational fluid dynamics (CFD) code to investigate the effect of inlet temperatures and mass flow rates of cooling fluid and volume fraction of nanoparticles on heat transfer coefficient, pressure drop, index of uniform temperature (IUT), and performance evaluation criteria (PEC). The results demonstrated that the reverse configuration of the Tesla valve (CASE E) experienced outstanding uniform thermal distribution while the heat transfer coefficient increased by 15% in this case compared to the straight-line cooling channel. The Ag–MgO hybrid nanoparticles showed better thermal performance than the two other nanoparticles with a 4% reduction in temperature difference in the cooling plate.

The Role of Network Topology on Electro‐Thermal and Optical Characteristics of Transparent Thermal Heaters Based on Embedded Random Metallic Mesh

AbstractTransparent thermal heaters based on metallic networks have gained considerable attention in the last few years as a result of their superior response time, low sheet resistance, and low cost of manufacturing. To increase the mechanical stability and reliability of the thermal heater, it is desirable to embed the metallic network in some form of matrix. Embedding the network, however, changes the nature of thermal conduction making both in‐plane and out‐of‐plane thermal conduction important for ensuring reliability and uniform thermal distribution. The performance of embedded thermal heaters is also significantly influenced by the geometry of the metallic network, both in terms of optical transparency and thermal performance. In this paper, a coupled electro‐thermal model and an electromagnetic model are developed to investigate the properties of an embedded metallic mesh in a polymer matrix. Infrared thermal imaging and ultraviolet‐visible spectrophotometry are used to quantify thermal transport and transparency in the system and to verify the performance of finite element models. A systematic study is then performed to assess the role of network topology both on in‐plane and out‐of‐plane thermal distribution and optical performance. According to numerical analysis, a structure‐property relationship is established which can provide desirable network configurations to optimize performance.

A highly integrated digital PCR system with on-chip heating for accurate DNA quantitative analysis

Digital polymerase chain reaction (dPCR) is extensively used for highly sensitive disease diagnosis due to its single-molecule detection ability. However, current dPCR systems require intricate DNA sample distribution, rely on cumbersome external heaters, and exhibit sluggish thermal cycling, hampering efficiency and speed of the dPCR process. Herein, we presented the development of a microwell array based dPCR system featuring an integrated self-heating dPCR chip. By utilizing hydrodynamic and electrothermal simulations, the chip's structure is optimized, resulting in improved partitioning within microwells and uniform thermal distribution. Through strategic hydrophilic/hydrophobic modifications on the chip's surface, we effectively secured the compartmentalization of sample within the microwells by employing an overlaying oil phase, which renders homogeneity and independence of samples in the microwells. To achieve precise, stable, uniform, and rapid self-heating of the chip, the ITO heating layer and the temperature control algorithm are deliberately designed. With a capacity of 22,500 microwells that can be easily expanded, the system successfully quantified EGFR plasmid solutions, exhibiting a dynamic linear range of 105 and a detection limit of 10 copies per reaction. To further validate its performance, we employed the dPCR platform for quantitative detection of BCR-ABL1 mutation gene fragments, where its performance was compared against the QuantStudio 3D, and the self-heating dPCR system demonstrated similar analytical accuracy to the commercial dPCR system. Notably, the individual chip is produced on a semiconductor manufacturing line, benefiting from mass production capabilities, so the chips are cost-effective and conducive to widespread adoption and accessibility.

Thermal conductive aramid nanofiber/surface-decorated alumina microsphere composite separator

The development of lithium-sulfur (Li–S) batteries is hindered by inhomogeneous Li plating and irreversible loss of active materials. In this work, a thermal conductive and electrocatalytic aramid nanofiber (ANF) composite separator containing surface-decorated alumina (Al2O3) microspheres is prepared through a simple filtration approach using ZnO nanosheets decorated Al2O3 microspheres (Al2O3@ZnO) as the thermal conductive filler and electrocatalyst. Compared with the separators fabricated by surface modification of commercial polyolefin separators, the as-prepared ANF/Al2O3@ZnO composite separator features homogeneous compositions and ensures uniform thermal distribution in both the through-plane and in-plane directions of the membrane. By rationally designing the structure of Al2O3@ZnO and adjusting the mass ratio of Al2O3@ZnO to ANF, excellent thermal conduction networks are formed by overlapping the ZnO nanosheets. Hence, the prepared ANF/Al2O3@ZnO composite separator possesses higher thermal conductivity than ANF/Al2O3 composite separator, which benefits uniform thermal distribution and homogeneous Li plating within the battery. Moreover, the electrocatalytic ZnO nanosheets catalyze the conversion of lithium polysulfides, efficiently inhibiting the shuttle effect and improving sulfur utilization. When subjected to a temperature gradient, the ANF/Al2O3@ZnO composite separator assembled cells display high initial capacity, low decay rate, and superb cycle stability. This novel composite separator integrates both thermal conductive and electrocatalytic functional components with the heat-resistant ANF matrix, offering a new design strategy of separator towards high-performance Li–S batteries.

Dendrite‐Free Lithium Metal Batteries Enabled by Coordination Chemistry in Polymer‐Ceramic Modified Separators

AbstractIssues with lithium dendrite growth and dead lithium formation limit the practical application of lithium metal batteries, especially under high current conditions where uneven temperature distribution leads to serious safety concerns. Herein, In situ assembly of polydopamine (PDA) and aluminum nitride (AlN) coatings on polypropylene (PP) separator is introduced to address these challenges. The AlN particles are encapsulated by PDA, and the functional groups in PDA form Al‐O coordination bonds with Al3+, which promote uniform Li+ flux and reduce the migration barrier of Li+, thereby enabling dendrite‐free lithium deposition. In addition, the designed PDA@AlN@PP separator exhibits excellent electrolyte wettability, enhanced mechanical performance, and stable thermal resistance, providing a uniform thermal distribution and serving as a robust barrier against dendrite penetration. As a result, symmetric Li||Li cells (over 1800 h at 1 mA cm−2 and 1 mAh cm−2) and Li||Cu cells (over 600 cycles at 0.5 mA cm−2 and 0.5 mAh cm−2, coulombic efficiency over 98%) demonstrate outstanding long cycle performance and high coulombic efficiency. Moreover, the corresponding Li||LiFePO4 cells exhibit a high specific capacity of 91.3 mAh g−1 at 5 C. This work provides a new approach for designing functionalized separators for high‐performance lithium metal batteries.

Oblique microchannel merged with circle micro pin-fin as a novel hybrid heat sink for cooling of electronic devices

Recently, the advantages of microchannel and micro pin-fin heat sinks for cooling have become clear. This study delves into the effects of hybrid designs on electronic chip cooling by combining microchannel and pin-fin patterns. The research contrasts the performance of a straight microchannel heat sink (Case Ⅰ), circular pin-fin (Case Ⅱ), straight-circular pin-fin-straight (Case Ⅲ), and oblique grooved straight-circular pin-fin-oblique grooved straight (Case Ⅳ). Results show that Case Ⅳ's Nu number reaches 61 at Re = 1250, surpassing Case Ⅰ, Case Ⅱ, and Case Ⅲ by 517 %, 32 %, and 235 %, respectively. Case Ⅳ also has the highest pressure drop. The study calculates each Case's performance evaluation index (ƞ), highlighting the balance between enhanced Nu numbers and pressure drops. Case Ⅳ's ƞ is notably higher than Case Ⅱ and Case Ⅲ. To achieve a more uniform thermal distribution across the entire heat sink, the orientation of the oblique grooves is modified in Case Ⅳ, resulting in a new design labeled Case Ⅴ. While Cases Ⅳ and Ⅴ have similar Nusselt numbers, Case Ⅴ's design ensures consistent temperature distribution, reducing hotspot risks on the chip.

Joining of 304 stainless steel to PET by semiconductor laser conduction welding

304 stainless steel (304SS) and polyethylene terephthalate (PET) were lapped joined by laser conduction welding using a semiconductor laser with a flat-top thermal distribution. Experimental investigation and numerical simulation were conducted to analyze the weld morphology, pores distribution, interfacial microstructure, temperature field, joint strength and fracture behavior of the laser dissimilar joints. Because of the uniform thermal distribution of the laser, the decomposition of the PET base material was well controlled with pore-free joints obtaining at the welding speed over 25 mm/s. Besides, a compound layer was generated at the interface between 304SS and PET with its thickness decreased when the welding speed increased. Chemical reactions and mechanical anchoring were both observed at the interface suggesting a dual joining mechanism. The joint fracture load first increased then decreased with the increased welding speed. Besides, a ductile to brittle failure transition was clearly seen. The underlying mechanism was also discussed.

Convective heat transfer from a spherical concave surface due to swirling impinging jets issuing from a circular pipe

Impinging jet heat transfer from curved surfaces is available in many industrial applications, such as cooling of gas turbine leading edge and deicing of airplane wing leading edge (heating). Most of the published studies on this topic involve non-swirling jet impingement from flat surfaces. Swirling jets are also used in some applications with the anticipation of heat transfer augmentation. Swirling impinging jet flow characteristics are significantly different from that of the non-swirling jet. However, fundamental studies of swirling jet impingement onto curved surfaces are very limited. As such, flow dynamics and convective heat transfer from a heated concave surface due to swirling impinging jets from a circular nozzle are numerically investigated using the RANS approach and the realizable k-ε turbulence model. Various flow and geometric parameters, such as the jet Reynolds number (Re) in the range of 11,600–35,000; the swirl number (Sw) in the range of 0–2.4; and the jet-to-surface separation distance (H) of 0.5–8 times the nozzle diameter, at a fixed impingement surface curvature (diameter) are studied. The results show that two counter-rotating recirculation zones appear near the target surface for near-field impingement (H ≤ 1) and higher swirl numbers (Sw ≥ 1.2), whereas for far-field impingements (H > 2), they are formed inside and outside of the main jet stream. An intense surface heat transfer zone develops only for near-field impingement in the range 1 ≤ S ≤ 3 at higher swirl numbers, where S is the distance along the impingement surface from the domain axis. More uniform thermal distribution along the curved surface is found for far-field impingement at Sw ≥ 0.8. Whilst the transitional Sw and H for Re = 11,600 are 0.8 and 2 respectively, the transitional Sw and H for Re = 35,000 are 0.8–1.2 and 4, respectively. Maximum heat transfer zones are found to be correlated with strong turbulence. Correlations are developed for the average Nusselt number as a function of the jet Reynolds number, jet exit to impingement surface separation distance, and swirling strength.

An effective method for hot spot temperature optimization in heat conduction problem

Heat conduction problem for the optimization of thermal conductivity distribution is gaining considerable concerns in electronics cooling. Previous studies usually adopted optimization criteria to solve this problem. However, it still remains a big challenge for minimization of hot spot temperature, which is a core issue for electronics cooling. In this study, an iterative method based on a novel criterion is developed to minimize the hot spot temperature of customized regions in heat conduction problems. The optimization criterion for minimizing the hot spot temperature is derived using variational principle, which reveals that the optimization mechanism is the synergy of temperature gradient field and multiplier gradient field. An iterative method based on this criterion is developed to adjust the thermal conductivity field for minimization of hot spot temperature. The volume-to-point (VP) heat conduction problem is introduced to validate the proposed method. The results show that the proposed method reduces the hot spot temperature rise in customized regions by 44 %–47 % compared with those with uniform thermal conductivity distribution. Moreover, the developed criterion is also adopted in an allocation and reallocation method for the VP problems with discrete thermal conductivities, reducing the hot spot temperature rise by 88% ∼ 89%.

Uniform Thermal Energy Distribution Scheme for Wireless Heat Transfer System Based on Inherent Topology and Thermal Coupling

The wireless heat transfer (WHT) system is proposed to ensure the reliability and flexibility of the electrical heat tracing for domestic and industrial applications. In this article, the inherent coupling relationship among coil dimension, resistance, distance, and inductance of a WHT system is investigated, which illustrates the intrinsic link between thermal energy and electromagnetic feature of the WHT system under multiple mediums. Besides, the magnitude and distribution of the thermal energy among different coils are analyzed according to equivalent circuits and magnetic coupling mechanisms. For further studying the power distribution characteristic, the power flow model of the multiple coil system is established. On this basis, the uniform thermal energy distribution scheme of the WHT system is proposed to ensure all coils have equal heating power. Moreover, the heating power in the partial compensation condition is also investigated. The result indicates the compensation states of the transmitter coil only affect the magnitude of the heating power. Thus, the transmitter coil compensation states which can be used to adjust the heating capacity of the WHT system. The simulation and experiments are carried out to validate the feasibility of the proposed uniform thermal energy distribution scheme.

The analysis and validation of natural frequencies and mode shapes of 3D plates in the framework of the generalized thermoelastic theory

This article considers thermal effects that induce thermoelastic damping and, which, consequently, because of the absorbed thermal energy, cause thermal stresses. The problem is stated in the framework of the generalized thermoelastic theory. The natural frequency and mode shape analyzes of 3D plates are presented under uniform and nonuniform heating. From the modeling point of view, this results in the quadratic eigenvalue problem where complex frequencies and modes are obtained. Moreover, the quality factor related to the thermoelastic damping is also calculated in terms of the imaginary and the real parts of the frequencies for both the uniform and nonuniform thermal distributions. The variation of natural frequencies with temperature is investigated and compared with the experimental results for the plates with free boundary conditions. The first two mode shapes are also examined for all clamped edges for the uniform and nonuniform cases. Complex frequencies and complex modes are observed due to the thermal effects. For the uniform case, the real part of the modes decreases and the complex part increases, while the mode’s norm remains the same as in the classical modes as temperature increases. For the nonuniform case, the mode shape analysis is performed under the assumption that the elasticity modulus, thermal expansion, and specific heat parameters are functions of temperature. The peak point of the out-of-plane displacement is shown to be shifted toward the warm zone. The obtained outcomes may help design thermal structures and allow for future extensions.

Research progress on heteromorphic structure parts fabricated by additive manufacturing based on inside-laser coaxial powder feeding

Inside-laser material feeding laser cladding deposition (IMF-LCD) is a directed energy deposition technology featuring “hollow beam, annular spot, centered powder, and coaxial powder feeding.” IMF-LCD offers distinct advantages over traditional outside laser material feeding laser cladding deposition (OMF-LCD), such as a good laser-powder coupling effect, high powder utilization, high forming flexibility, uniform thermal field distribution in molten pools, and excellent forming surface quality. IMF-LCD would significantly improve forming efficiency and surface quality while it was applied to rapid direct manufacturing and repair of complex metallic parts compared to OMF-LCD. In this manuscript, the working principle of IMF-LCD technology is briefly introduced. Mostly, the research progress on heteromorphic structure parts fabricated by IMF-LCD was summarized, focusing on layered design, posture change, forming strategy optimization, and process parameter adjustment. The heteromorphic structure included a twisted thin-walled structure, variant height/width structure, overhanging structure, and closed structure. Based on the excellent characteristics of this technology, the exploration of high forming quality heteromorphic structural parts is carried out by changing the process parameters and forming processes such as the variable attitude stacking method, the conformal discrete layering method and the normal layering method, and the surface roughness is as low as 1.323 μm, the dimensional accuracy is as high as 1.6%. Simultaneously, the powder utilization rate of IMF-LCD reached 60%–80% on average, in accordance with the advantages of the laser-powder coupling effect. Finally, the remarkable research and application of IMF-LCD technology in high flexibility, high precision, high surface quality, and high material utilization would further promote the development of additive manufacturing with higher performance, higher quality, and lower cost in the future.

Intensity-modulated irradiation for superficial tumors by overlapping irradiation fields using intensity modulators in accelerator-based BNCT.

The distribution of the thermal neutron flux has a significant impact on the treatment efficacy. We developed an irradiation method of overlapping irradiation fields using intensity modulators for the treatment of superficial tumors with the aim of expanding the indications for accelerator-based boron neutron capture therapy (BNCT). The shape of the intensity modulator was determined and Monte Carlo simulations were carried out to determine the uniformity of the resulting thermal neutron flux distribution. The intensity modulators were then fabricated and irradiation tests were conducted, which resulted in the formation of a uniform thermal neutron flux distribution. Finally, an evaluation of the tumor dose distribution showed that when two irradiation fields overlapped, the minimum tumor dose was 27.4Gy-eq, which was higher than the tumor control dose of 20Gy-eq. Furthermore, it was found that the uniformity of the treatment was improved 47% as compared to the treatment that uses a single irradiation field. This clearly demonstrates the effectiveness of this technique and the possibility of expanding the indications to superficially located tumors.

A novel hybrid half‐bridge LLC resonant converter with double resonant tanks for high step‐down applications

AbstractConventional half‐bridge (HB) LLC converters have been a good candidate for the first stage in the two‐stage conversion structure because of its high conversion efficiency and high frequency operation ability. However, the voltage gain is only 0.5 exclusive of the transformer, resulting in the reduced efficiency for high step‐down applications. In order to solve this issue, in this paper, a novel hybrid HB LLC converter with double resonant tanks is firstly presented for high step‐down ratio applications. The distinctive features of the proposed converter are as follows: (1) the voltage gain of 0.25 is achieved by incorporating the switched capacitor circuit. Thus, the primary turns number for the transformer is halved compared with conventional HB LLC converters. Correspondingly, the smaller primary side winding losses and transformer volume can be implemented. (2) The power splitting and low input current ripple can be obtained due to the employed double resonant tanks. Thus, the uniform thermal distribution and low input filter capacitance are the second advantage for the proposed converter. (3) Soft switching over the entire operation range still can be maintained with larger magnetics inductance. The detailed operation principles, circuit analysis, and resonant tank design for the proposed converter are introduced and presented. A hardware prototype with 36–60 V input, 3 V/50 A‐output is built to demonstrate the declared features of the proposed hybrid converter.

Thermal Buckling of Laminated Plates using Modified Mantari Function

Critical buckling temperature of laminated plate under thermal load varied linearly along the thickness, is developed using a higher-order shape function which depends on a parameter ‘‘m’’, which is improved to obtain results for thin and thick plates. Laminated plates’ equations of motion are obtained using virtual work principle and solved for simply supported boundary conditions. Angle and cross laminates thermal buckled mode shapes with different E1/E2 proportion, number of plies, (α2/α1) proportion, aspect ratios, are investigated. It is observed that this shape function gives thermal buckling for thin and thick plates but with m = 0.05 that agree well with other theories and linear distribution of temperature gives a rise to critical temperature approach to 50% than those caused by uniform thermal distribution.

Thermal Performance Investigation at Different Temperature and Airflow Settings in a Conference Hall of Expo Building

The airflow distribution for a large space, such as a conference hall, is quite challenging to achieve a good and uniform thermal distribution. In the recent study, insufficient quantitative knowledge has been provided, notably for the appropriate supply air temperature and air velocity for the conference hall environment. In this study, a full-scale conference hall was simulated extensively for an expo building in Taiwan. A total of nine experiment numbers were carried out with various supply air temperature and air velocity settings. Through the use of a CFD approach, this study seeks to identify the ideal parameters for a comfortable and acceptable airflow distribution and temperature, with an eye toward potential compromises with an energy-efficient approach. The results demonstrate that the temperature distribution ranges from 18 to 26 °C, indicating an acceptable indoor thermal environment, depending on the parameter settings. The best settings for providing a pleasant indoor thermal environment are with a supply air temperature and air velocity of 15 °C and 1 m/s, which can keep the PMV index between −0.5 and 0.5. Utilizing a greater temperature setting may save energy, but sufficient air velocity must be addressed in order to meet the indoor thermal conditions. Furthermore, a greater air velocity may generate more noise and disrupt the situation in the conference hall, so it must be selected specifically.