Performance Of Thermoelectric Cooler Research Articles

Optimizing the performance of Bi2Te3 TECs through numerical simulations using COMSOL multiphysics

Manufacturers need to determine the best geometries for thermoelectric coolers (TECs) to achieve optimal performance. In this study, we employed the COMSOL Multiphysics software to simulate the performance enhancement of Bi2Te3 TEC. The TEC is constructed with alumina (Al2O3), copper (Cu), and bismuth telluride (Bi2Te3) materials. In particular, Al2O3 acts as an electric insulator for the top and bottom layers, Cu functions as a conductor, and Bi2Te3 serves as the p- and n-type thermoelectric (TE) legs between the Cu layers. The study examined how different TE leg heights (1.5 mm, 2 mm, and 2.5 mm) and shapes (square and rectangular) affected the TEC's performance. It looked at various factors, such as temperature gradient, electric potential, normalized current density, and total net energy rate. Additionally, the thickness effects of the insulator, conductor, and the TE leg pitch of the TEC have also been investigated. According to the obtained results, it has been determined that the square type of leg geometry has provided the best performance among the tested geometries, and it has been recommended that its leg geometry be 1.00 mm × 1.00 mm × 1.5 mm, the thickness be 0.375 mm for Al2O3 and 0.125 mm for Cu, and the pitch be 0.50 mm, as they are expected to yield satisfactory performance. The research study involved obtaining performance parameters for 18 TE elements utilized in the fabrication of TEC. The TEC-simulated results revealed the following performance metrics: ΔTmax = 73.94 K, Umax = 2.52 V, Imax = 3.00 A, Qmax = 4.42 W, R = 0.84 Ω, and Z = 0.002377 1/K.

Optimized Thermoelectric Cooler Performance by the Structure-Matching Design of Asymmetrical p/n-Type Legs.

Commercial Bi2Te3-based thermoelectric (TE) coolers typically comprise equal-size p- and n-type legs. However, this traditional structure limits the cooling temperature differences of TE coolers (TECs) due to identical current density, when their electrical or thermal characteristics differ significantly. This work presents a novel design of p- and n-type TE legs to optimize the performance of TECs. The cooling properties of the materials are initially calculated by theoretical equations and then evaluated by using a combination of finite element simulations and experiments. The research findings suggest that by utilizing higher ZT p-type materials to enhance the TEC cooling performance, further optimization of the ratio of the cross-sectional area of the TE legs (Ap/An) improves the structural matching of the legs, which achieves the maximum figure of merit Z and leads to a 5.4% increase in cooling power density. Additionally, the TEC with optimized Ap/An increases the cooling temperature difference by 3.3 and 2.7 K for the same current at hot side temperatures of 300 and 315 K, respectively, while the coefficient of performance remains unchanged. Moreover, the maximum cooling temperature difference reaches 70 and 74 K, respectively. We anticipate that our results will guide the design and optimization of the TECs.

Solar thermoelectric generator and thermoelectric cooler performance: analysis and comparison using a different shape geometry

Abstract Thermoelectric devices are one of the technologies used either to generate electricity by applying a temperature difference using thermal energy or as a heating/cooling system by applying an electrical voltage. The number of materials required to produce a product is an important factor in determining its price. Production costs associated with these materials, as well as their availability and quality, play a crucial role in price determination by manufacturers. In this context, a method that employs a uniform volume distribution was implemented. This approach enabled the analysis to focus on other variables, thereby promoting a more precise and relevant evaluation of overall performance. Based on the finite element method, this study investigated the influence of geometric shape, including Rect-leg, Y-leg, Pin-leg and X-leg designs, on the performance of solar thermoelectric generators and thermoelectric coolers. The study was conducted considering the same hot alumina junction surface that receives solar radiation; however, the effective surface, which corresponded to the heat flow area and had a similar area near the exposed surface, varied depending on the chosen leg geometry, thus impacting the heat flux due to the variation in thermal resistance. In the case of a solar thermoelectric generator, the Rect-leg model, having the same effective surface area, presented the lowest heat loss value resulting from convection and radiation in the heat spreader and the hot alumina plate. Under the same conditions, the Y-leg showed the highest value. The Rect-leg design generated, by using thermal and optical concentration, the highest output power of 0.028 and 0.054 W, and efficiency of 3.47% and 4.7%, respectively, whereas the Y-leg generated lower values of 0.006523 and 0.018744 W for power, and 2.83% and 2.71% for efficiency, respectively. In the case of the thermoelectric coolers, the Y-leg generated the highest temperature difference between the hot and cold sides of 67.28 K at an electric current value of 1.8 A, whereas the Rect-leg, Pin-leg and X-leg generated ~66.25, ~67.02 and ~67.19 K at 6.1, 2.7 and 2.6 A.

Design and performance analysis of hot side heat sink of thermoelectric cooler device based on simulation and experiment

AbstractAs for improving the heat diversion capacity of the hot side heat sink of the thermoelectric cooler (TEC), thereby improving the operational performance of the TEC, this study designed a type of double‐embedded flat heat pipe (EFHP) finned heat sink and compared with a standard aluminum (Al) heat sink. In experimental studies, TEC under two heat sinks were placed under different operating currents for heat transfer analysis and performance comparison. The experimental results demonstrated that the EFHP heat sink had better heat diversion ability, effectively improving the operational performance of TEC. When the TEC was input with a current of 6A, the thermal resistance of the double EFHP finned heat sink decreased by 19% compared to the Al heat sink; cooling capacity and coefficient of performance increased by 8.3% and 9.46%, respectively. Further, TEC's cold and hot surface temperatures decreased by 10.83% and 10.2%, respectively, and the heat uniformity of the heat sink improved. In addition, the CFD software Icepak was used to analyze the effects of double flat heat pipe spacing and length on the heat sink and TEC and the performance of two heat sinks and TEC under different heat dissipation conditions and obtained good agreement. This study can provide further guidance and assistance in designing the TEC cooling system.

Characterizing the thermoelectric cooling performance across a broad temperature range.

Thermoelectric cooling plays an essential role in precisely controlling the temperature of electronics. Characterizing the performance of thermoelectric coolers (TECs) is of great significance for the development of advanced solid-state cooling devices. However, the existing setup for characterizing the cooling performance of TECs has mainly been limited to the near room temperature range. Herein, we report the development of a new setup that is capable of characterizing thermoelectric cooling performance across a broad temperature range (80-350K). With precise and steady control of the hot-side temperature, measurements of the coefficient of performance and maximum temperature difference at room temperature have been conducted on commercial devices. By comparing the results with the commercial datasheet, it shows that our setup can accurately evaluate the cooling performance of thermoelectric devices. In addition, we further extend the characterization to different hot-side temperatures, e.g., 173, 325, and 350K, thus demonstrating the capability of our setup for evaluating the thermoelectric performance across a broad temperature range.

Study on the performance of thermoelectric refrigerator under natural convection heat transfer condition

Refrigeration using thermoelectric cooler (TEC) is a hotspot and frontier issue, but the forced heat dissipation apparatus poses problems that limit its application. In this paper, a thermoelectric refrigerator used under natural convection heat transfer conditions is presented, and numerical simulations and experimental analyses are performed. The maximum error between the simulation results and experimental results is 6.3%. The distributions of the temperature and velocity field in the refrigerator chamber are obtained, and the influences of the operating current and the height of fins on the temperature are analyzed. The novel design is that the number of thermoelectric legs in a single TEC is reduced to five pairs to reduce the heat generated on the hot side during operation. The performance of TEC is improved by increasing the average heat dissipation area. The results show that the air temperature in the chamber is finally stabilized at 12.2 ℃ under the ambient temperature of 29 ℃ and input electric power of 10.8 W. The air temperature difference inside and outside the thermoelectric refrigerator increases from 16.8 ℃ to 19.5 ℃ with the fin's height increasing, but the coefficient of performance (COP) changes little.

Use of an earthen clay pot refrigerator with a thermoelectric cooler for extending farm produce shelf life

Conventional cold storage systems increase the risk of damage and are no longer used for the long-term storage of agricultural products. Thus, newer affordable and energy-efficient storage systems are required for enhancing the shelf life of farm produce. We investigated the coefficient of performance (COP) of an earthen clay pot refrigerator with a thermoelectric cooler (TEC) and explored cooling strategies to enhance cooling and electrical performance for increasing the shelf life of farm produce. We used MATLAB Simulink to analyze Peltier TEC module efficiency. The intrinsic characteristics, including the Seebeck coefficient (α), thermal conductivity (K), and electrical resistance (R), were determined, forming the basis of the Peltier module in MATLAB Simulink. Thermal characteristics such as COP and cooling capacity were studied as a function of system voltage (Vin) and current (Iin). The model was equipped with a 12 V/6 A, 60 W TEC and was verified by simulation investigation. We also used psychrometric measures (e.g., wet bulb, dry bulb, and dew point temperatures and relative humidity) to determine the extent of wetness or dryness of an object and monitor other temperatures of the clay pot refrigerator. The results revealed that the ambient temperature and cold and hot side temperatures fundamentally affected TEC performance. The TEC extended the shelf life of tomatoes, potatoes, and spinach by 60% compared to those stored under ambient conditions, thereby reducing their wastage. In conclusion, earthen refrigeration using TEC doubled the shelf life of farm produce compared to storage under ambient conditions, saving money, resources, labor, and supplies and enabling the development of efficient and environmentally friendly refrigeration systems.

Investigation of continuous pulse current source on the performance of phase change material-thermoelectric cooler system

In this particle, the influence of phase change materials (PCM) on the property of thermoelectric cooler (TEC) is studied by numerical simulation. The heat sink integrated with PCM is placed on the hot side of TEC to reduce the fluctuation of temperature under a continuous pulse current source. The performance of a single-layer PCM-TEC system with that of a single TEC system under continuous pulse current source is firstly compared. Based on this, the effects of current source type, PCM layer, pulse width, cooling load and pulse amplitude on the cooling performance of TEC are investigated in depth. The results show that, compared to a single TEC system, PCM is able to considerably enhance the cooling performance of the TEC during the phase transition period. Besides, increasing PCM layer or decreasing cooling load improves the phase change interval, which increases threefold when the cooling load increases from 0.02 W to 0.06 W. In addition, it is found that lower temperature can be achieved by increasing pulse width or pulse amplitude.

Thermoelectric cooler (TEC) based thermal control system for space applications: Numerical study

The present study devises and numerically investigates a new thermal control system for detectors of optical payloads for spacecraft systems. The system uses thermoelectric coolers (TECs) as the active element which maintains the cold finger at the required set point such that temperature of detectors is maintained within the required range throughout its operation. The system doesn’t utilize any heat pipe network, but instead, uses radiators attached to the hot-side of TEC to dissipate the heat load into the ambient space environment. System level modelling using effective properties are used to model the performance of TEC without modelling any internal intricate geometry. Temperature dependent current profiles are used as input conditions for the TECs such that the TEC consume only the required amount of external power. Effect of TEC set point and geometrical parameters of the radiator is studied and it is observed that considerable reduction in power consumption or improvement in coefficient of performance is obtained by utilizing a larger set point or a radiator with larger dimensions. The system is further investigated for different heat loads and duty cycles (upto 50% for an orbit period of 100 mins) to evaluate its efficacy under varying operating conditions. The system is also investigated for successive operating cycles and it is observed that the cyclic error between successive cycles eventually diminishes to zero thus implying that the temperature control requirements are met for successive cycles throughout the life of the system.

Multi-stage thermoelectric coolers for cooling wearables

• Multi-stage TECs are shown to perform better than single-stage TECs for use against skin. • Multi-stage TECs can achieve lower temperature, while maintaining power requirement. • Results are validated using experiment, finite element analysis and analytical solutions. Over the last decade, there has been significant interest in the use of thermoelectric coolers (TECs) in cooling wearables. While there has been notable work on optimizing single-stage TECs for use against human skin, much less attention is given to multi-stage TECs. In this contribution, analytical computations are performed to show that multi-stage TECs can achieve lower cold side temperatures while maintaining the coefficient of performance as compared to single-stage TECs when used against human skin. The findings are confirmed with detailed FEA analysis and experiments. The results therefore imply that multi-stage TECs have the potential of providing more cooling sensation to the human skin, while maintaining the power required per unit cooling power provided. This paper provides a detailed parametric studies on how key design parameters of the TECs (number of stages, current ratio, fill factor, aspect ratio and leg area) affect the performance of the multi-stage TECs. A guideline on the optimal design parameters is provided to guide the design of multi-stage TECs for use in cooling wearables.

Numerical simulation of hybrid battery thermal management system combining of thermoelectric cooler and phase change material

In this study, a hybrid BTMS (battery thermal management system) that combines TEC (thermoelectric cooler) and PCM (phase change material) is shown. The PCM absorbs heat and occurs in phase change, which stores the heat from batteries. The TECs act as a heat pump, takes away the excess heat in the PCM through the fins, and control the temperature of the PCM below the phase transition temperature as much as possible, which can prevent it from melting completely and losing the ability to keep the battery temperature stable. By comparative analysis, the addition of PCM can obtain better temperature uniformity, the temperature difference was controlled below 6 °C, and CPCM with higher thermal conductivity was more suitable for the hybrid BTMS, at 1200 s, the maximum temperature of the model with 30% EG/RT44HC was 10.3 °C lower than that with pure RT44HC. When the fill thickness of CPCM increases, the temperature control time can be extended, but the performance of TEC will decrease. For this model, the arrangement direction of the fins should be perpendicular to the direction of the battery which has higher thermal conductivity, heat from batteries can be effectively transferred to the fins more and faster.

Enhanced performance of thermoelectric cooler with phase change materials: An experimental study

The thermal management of a thermoelectric cooler (TEC) has a significant impact on its cooling performance. The heat generated in the hot side of the TEC system reduces the performance and lifespan. Therefore, an efficient thermal management technique is vital for ensuring the TEC to operate at optimum temperature. In this study the performance of TEC is investigated by varying input voltage, air velocity at hot side, heat sink configuration and fill volume of PCM in the heat sink. A 54 W Bismuth Telluride based TEC was chosen for this study and OM35 was used as the phase change material (PCM). The three configurations of aluminium heat sink used in this study are square pocket, rectangle pocket and circular pocket. The input voltage to TEC is varied from 2.5 V to 12.5 V. The results show that, both the cold and hot side temperature of TEC increases when the input voltage is increased. The changes in air velocity at the hot side of the TEC from 1 m/s to 3 m/s reduced the temperature on both the cold and hot side of TEC. Among the three configurations of heat sink, square pocket heat sink with fully filled PCM showed better performance compared to other configurations. Moreover, the heat sink with a square pocket filled with PCM provided cold and hot side temperatures of 27 °C and 58.7 °C respectively when compared to 34 °C and 68.3 °C for the similar operating conditions without PCM. The results indicate that the performance of TEC can be significantly improved by the use of heat sinks filled with PCM.

Thermoelectric coolers for high-power-density 3D electronics heat management

Future advancements in three-dimensional (3D) electronics require robust thermal management methodology. Thermoelectric coolers (TECs) are reliable and solid-state heat pumping devices with high cooling capacity that can meet the requirements of emerging 3D microelectronic devices. Here, we first provide the design of TECs for electronics cooling using a computational model and then experimentally validate the main predictions. Key device parameters such as device thickness, leg density, and contact resistance were studied to understand their influence on the performance of TECs. Our results show that it is possible to achieve high cooling power density through optimization of TE leg height and packing density. Scaling of TECs is shown to provide ultra-high cooling power density.

A Model to Evaluate the Device-Level Performance of Thermoelectric Cooler with Thomson Effect Considered

A Model to Evaluate the Device-Level Performance of Thermoelectric Cooler with Thomson Effect Considered

Performance of TEC Cascade on Input Voltage Variations in Fish Cooler Box

The refrigeration system used to meet the needs of human life can be in the form of a thermoelectric cooler (TEC). Due to its small volume, environmental friendliness and several other advantages, TEC can be widely applied such as in fish cooler box. In this study, the cooler box used had dimensions of 290mm x 205mm x 254mm and were given twelve stacked 3 TEC modules with varied DC voltages. The purpose of this study is to determine the voltage that can provide the best TEC performance. This performance will be indicated by the Coefficient of Performance (COP) value of each voltage variation. The experimental results show that the best performance of the TEC is at 42 Volts. The lowest temperature achieved during the experiment was 7.74℃ on the cold-side.

An innovated method to monitor the health condition of the thermoelectric cooling system using nanocomposite‐based CNTs

Many crucial applications use the thermoelectric coolers (TECs) system because they have some desirable properties, including durability, reliability, simple structure, and quietness. However, the performance of TECs is sensitive to any form of change and needs to be monitored constantly to ensure that they are working at their optimal. This paper proposes a novel approach for condition monitoring. This novel approach, unlike other attempts, does not need additional sensors but is directly carried out through the exploitation of the multi-wall carbon nanotubes (MWCNTs) piezoresistive property. For the suggested approach, a polyurethane (PU) resin was altered using various MWCNTs concentrations with the aim of constructing self-sensing nanocomposites sensors whose electrical conductivity is high. To investigate the electrical properties and microstructure of the constructed sensor, electrical resistance measurement, and scanning electron microscopy were used. From the results, it can be concluded that as the thickness increased, conductivity exhibited a monotonic increase. The peak electrical conductivity was 2.55 S.cm−1 for the 3.1 mm-thick MWCNTs sensors. This is approximately 5.1 above that of the 0.6 mm-thick MWCNTs sensors. Added to this, the MWCNT/PU sensors exhibited a high-temperature sensitivity with a negative temperature coefficient of resistance. The normalised resistance obtained from the sensor with the uppermost MWCNTs concentration is lower in comparison to the sensors with lower concentrations of MWCNTs. Additionally, the TEC cooling temperature influence on the tunnelling distance between MWCNTs was analytically estimated. This study's numerical results indicate that there is a potential correlation between TEC cooling generated temperature and the variations noted in the tunnelling distance between MWCNTs with an explicit impact on the general nanocomposite sensors changes in electric resistance when the TEC system is in service.

Simulation and experimental study on performance analysis of solar photovoltaic integrated thermoelectric cooler using MATLAB Simulink

The present study investigates the performance of solar photovoltaic integrated thermoelectric cooler using MATLAB Simulink. The enhancement of efficiency has been achieved using an effective heat removal mechanism from the hot side heat sink. Since the hot side temperature is a crucial parameter. The intrinsic material properties like Seebeck coefficient, ?, thermal conductance, K, and electrical resistance, R, of the thermoelectric module are carefully estimated using analytical method and reported. The MATLAB Simulink Peltier module is developed based on the estimated intrinsic properties. The effect of system voltage (V) and current (A) on the thermal parameters like cooling capacity, QC, and coefficient of performance has been investigated. The simulation study is validated by conducting a series of experimental analysis. The experimental model is equipped with a 100 Wp polycrystalline solar photovoltaic module to integrate and power the 12V/5A of the 60 W thermoelectric cooler. Moreover, the results reveal that there is a significant effect of ambient and hot side temperature on the thermoelectric cooler performance. The fin-type conductive mode of heat transfer mechanism is adopted along with the convective forced air-cooling system to achieve effective heat removal from the hot side. The infrared thermographic investigation is carried out for ascertaining effective heat removal.

Analytical model-based optimization of the thermoelectric cooler with temperature-dependent materials under different operating conditions

This paper presents a novel general single/multi-parameter optimization model for the thermoelectric cooler (TEC) based on the 1D resistance method, which precisely captures all the thermoelectrical effects and the impacts of temperature-dependent thermoelectric properties, thermal operating conditions, and contact resistance at the solder layer, respectively. The explicit analytical expressions of designed optimal parameters, including the applied current, thermoelectric leg length, the cross-section area ratio of P/N-type thermoelectrical legs, and the number of leg pairs, are derived to maximize TEC performances (such as cooling capacity, coefficient of performance, or temperature difference between the cold/hot sides) under different operating conditions. The validation of the developed model is conducted through comparisons with the reported experimental data or 3D simulation results. The inherent correlations between the designed parameters are demonstrated and used to clarify the conflicting results in the literature. The ratio of leg length and its area cannot be assumed as an independent optimal parameter for large contact resistance. The filling ratio of thermoelectrical legs should be chosen as large as possible and limited by the manufacturing technology. It is demonstrated that the multiplication of applied current and number of leg pairs could be considered an independent optimal parameter, which provides a new strategy to design the available applied current for practical applications. The correlation between applied current and leg length is also discussed in detail. Multi-parameter optimization could remarkably improve the TEC performance compared with the single-parameter model, such as a significant improvement by 31% for the optimal cooling capacity. The cooling capacity is enhanced by 98% when the convective heat transfer coefficient of 1000 W/m2K at the cold/hot sides increases to 2000 W/m2K. A decrease of 15% for cooling capacity induced by the contact resistance is also observed. The present work provides a promising comprehensive tool for intensifying TEC performance maximization and clarifying its impact factors and the multi-parameter inherent correlation.

An Enhanced Thermoelectric Collaborative Cooling System With Thermoelectric Generator Serving as a Supplementary Power Source

Thermoelectric coolers (TECs) are widely used in state-of-the-art thermal management systems. Recently, there is a big trend to power TECs using thermoelectric generators (TEGs). Mainstream research efforts focus on attaining a higher figure of merit ( ZT ) of thermoelectric material, which now faces a great challenge. Alternatively, this article proposes a different approach to improve the performance of TEC, that is, integration of a TEG with a TEC. The TEG converts the collected heat energy into electric current, which reduces the power consumption and enhances the cooling capacity of the TEC. Using different methods of connecting the TEC and TEG, two thermoelectric collaborative cooling systems are proposed. Accurate SPICE models of the two cooling systems are established. The experimental results demonstrate that the discrepancy between the currents flowing through the TEC in the experiments and in the SPICE models is less than 4.8% on average. Based on the verified SPICE models, the proposed TEC-TEG collaborative cooling systems are assessed in terms of power consumption, cooling capacity, coefficient of performance, and cooling efficiency. Compared with a typical Peltier cooling system, the two collaborative cooling systems achieve significant performance improvements.

Performance assessment of nanostructured thermoelectric cooler

In this research study, 1D numerical simulation for p-type (Bi0.2Sb0.8)2Te3 nanocomposite thermoelectric cooler (TEC) is conducted by utilising a finite volume method. The model is verified through a comparison with the published analytical data and good agreement is observed. Multiwall carbon nanotube (MWCNT) is used to enhance the thermal characteristics of TEC which is represented by the figure of merit. In this context, three separate scenarios are developed for different MWCNT compositions in order to investigate the influence of various design parameters on the performance of TEC. It is found that the most efficient performance is achieved for nanocomposite containing 0.12 wt% of MWCNT with a figure of merit equal to 1.4. Moreover, the maximum value of exergy efficiency for this nanocomposite is found to be 0.195 at a current value of 0.7 A.