共查询到20条相似文献,搜索用时 15 毫秒
1.
In order to further studies on thermoelectric generation, an experimental thermoelectric generator unit incorporating the commercially available thermoelectric modules with the parallel-plate heat exchanger has been constructed. The experiments are carried out to examine the influences of the main operating conditions, the hot and cold fluid inlet temperatures, flow rates and the load resistance, on the power output and conversion efficiency. The two operation parameters such as the hot fluid inlet temperature and flow rate are found to significantly affect the maximum power output and conversion efficiency. A comparison of the experimental results with those from the previously published numerical model is also presented. The meaningful results obtained here may serve as a good guide for further improving the numerical model and conducting a system level optimization study in the next step. Also, the present study shows the promising potential of using this kind of thermoelectric generator for low-temperature waste heat recovery. 相似文献
2.
半导体温差发电技术在低品位余热回收技术领域具有重要的应用价值。汽车尾气温度高,带走的热量约占发动机总量的40%,温差发电技术能直接将废热能量转化为电能回收利用。介绍温差发电装置的设计原理,结构参数对性能影响以及装置输出性能参数,并结合试验对温差发电装置的传热性能和电功率输出性能进行分析以及提出有效的改进方案。 相似文献
3.
Theoretical Investigation of Waste Heat Recovery from an IC Engine Using Vapor Absorption Refrigeration System and Thermoelectric Converter
下载免费PDF全文
![点击此处可从《亚洲传热研究》网站下载免费的PDF全文](/ch/ext_images/free.gif)
This study proposes the preliminary simulation of a single cylinder spark ignition engine with waste heat recovery system. To harvest waste heat energy from the engine exhaust a thermoelectric generator coupled to a vapor absorption refrigeration (VAR) system was proposed in this simulation work. Parametric simulation of engine, thermoelectric generator and VAR using thermodynamic relations was carried out in MATLAB – Simulink software. An attempt has been made mathematically to integrate engine, thermoelectric generator and VAR system to study the effect of engine load, speed, equivalence ratio on thermoelectric output and coefficient of performance (COP) of a VAR system. In this study, the VAR system runs by taking heat energy from the exhaust gas and the electric power produced by a thermoelectric generator was utilized to run the pump of the refrigeration system. It was found that COP of the absorption refrigeration system depends on engine load, speed and air fuel equivalence ratio. The study also reveals that about 10% to 15% of the total exhaust energy can be harvested using this system. 相似文献
4.
In this case study, a system to recover waste heat comprised 24 thermoelectric generators (TEG) to convert heat from the exhaust pipe of an automobile to electrical energy has been constructed. Simulations and experiments for the thermoelectric module in this system are undertaken to assess the feasibility of these applications. A slopping block is designed on the basis of simulation results to uniform the interior thermal field that improves the performance of TEG modules. Besides simulations, the system is designed and assembled. Measurements followed the connection of the system to the middle of an exhaust pipe. Open circuit voltage and maximum power output of the system are characterized as a function of temperature difference. Through these simulations and experiments, the power generated with a commercial TEG module is presented. Overview this case study and our previous work, the results establish the fundamental development of low-temperature waste heat thermoelectric generator system that enhances the TEG efficiency for vehicles. 相似文献
5.
This study developed an integral thermoelectric generator system with high-performance heat transfer and thermoelectric conversion functions, using the metal pin-fin array coupling with the forced convection heat transfer technique to be the heat absorber and heat sink. A one-dimensional steady heat conduction model with internal Joule heat generation and Seebeck effect was proposed to predict the power generation performance of the present thermoelectric system including the heat absorber and heat sink at various operation conditions. Critical heat-transfer parameters on the design of the integral thermoelectric generator system were derived and discussed. Finally, a series of systematical experiments were performed to simulate an integral thermoelectric generator system operating at the exhaust pipe. The experimental results also demonstrated the validity of the proposed theoretical model. 相似文献
6.
7.
Simiao Tang Chenglong Wang Xiao Liu Guanghui Su Wenxi Tian Suizheng Qiu Qihao Zhang Ruiheng Liu Shengqiang Bai 《国际能源研究杂志》2020,44(9):7450-7463
Waste heat recovery helps reduce energy consumption, decreases carbon emissions, and enhances sustainable energy development. In China, energy-intensive industries dominate the industrial sector and have significant potential for waste heat recovery. We propose a novel waste heat recovery system assisted by a heat pipe and thermoelectric generator (TEG) namely, heat pipe TEG (HPTEG),to simultaneously recover waste heat and achieve electricity generation. Moreover, the HPTEG provides a good approach to bridging the mismatch between energy supply and demand. Based on the technical reserve on high-temperature heat pipe manufacturing and TEG device integration, a laboratory-scale HPTEG prototype was established to investigate the coupling performances of the heat pipes and TEGs. Static energy conversion and passive thermal transport were achieved with the assistance of skutterudite TEGs and potassium heat pipes. Based on the HPTEG prototype, the heat transfer and the thermoelectric conversion performances were investigated. Potassium heat pipes exhibited excellent heat transfer performance with 95% thermal efficiency. The isothermality of such a heat pipe was excellent, and the heat pipe temperature gradient was within 15°C. The TEG's thermoelectric conversion efficiency of 7.5% and HPTEG's prototype system thermoelectric conversion efficiency of 6.2% were achieved. When the TEG hot surface temperature reached 625°C, the maximum electrical output power of the TEG peaked at 183.2 W, and the open-circuit voltage reached 42.2 V. The high performances of the HPTEG prototype demonstrated the potential of the HPTEG for use in engineering applications. 相似文献
8.
《Applied Thermal Engineering》2003,23(6):757-767
A large amount of consumed energy is released to the environment as waste heat, which may be used directly in some applications for useful purposes. Thus, from the standpoint of energy conservation, it will be meaningful to investigate systems with waste heat utilization. It has long been indicated that absorption cycles may have good potential applications for enhancing energy conservation via waste heat recovery. As such they have often been identified as an appropriate subject for research and development. Along this line, this paper also examines the development of an absorption cycle with waste heat utilization. More specifically, this study investigates a double-effect LiBr–water absorption cycle which uses exhaust gases from the burner of the high-temperature generator to preheat the weak absorbent solution on its way from the absorber to the low-temperature generator. The overall performance of the absorption heater/chiller system is analyzed and discussed on the basis of experimental results. 相似文献
9.
Tao Li Guangfa Tang Guangcai Gong Guangqiang Zhang Nianping Li Lin Zhang 《Applied Thermal Engineering》2009,29(10):2016-2021
Applications of thermoelectrics had been enlarged from conventional single refrigeration or generation to waste heat recovery with tough energy consumption of the world. With improvement of living standard more and more domestic air-conditioners are used in Chinese families now. Percentage of power consumption of domestic air-conditioner caused by heat load of fresh air supply increased after SARS, which could be prevented efficiently with sufficient fresh air supply, broke out in China in 2003. A novel prototype thermoelectric domestic-ventilator with heat recovery of exhaust of air-conditioned room had been made in Hunan University thermoelectric lab. A thermoelectric heat exchanger and a flat-fin cross flow heat exchanger were integrated in this ventilator. This ventilator was investigated and its cooling (and heating) performance were evaluated in terms of the coefficient of performance, cooling and heating powers, and being handled temperature difference of fresh air. The coefficient of performance of this ventilator was found to be over 2.5 in the whole experiment. The optimal working parameters of this ventilator were studied in this paper. The potential improvements in performances and market prospects were also discussed in this work. 相似文献
10.
W.A.N.W. Mohamed B. Singh M.F. Mohamed A.M. Aizuwan A.B.M. Zubair 《International Journal of Hydrogen Energy》2021,46(50):25634-25649
A thermoelectric generator (TEG) module is designed to harvest low grade waste heat from a 2 kW fuel cell vehicle and improve its energy utilization. The module integrates a TEG cell with a heat pipe and a finned heat sink. A numerical model is developed based on an experiment setup where the fuel cell temperature is 45–60 °C while the cruise speed is 25 kmh?1. The numerical model is validated with less than 5% deviation. Extended cases are simulated for series and parallel power train configuration under changes to the waste heat temperature and vehicle speeds to evaluate the power and heat recovery ratio. A single TEG cell output between 2 and 3 W is achievable even at low grade heat. The parallel drive generates 50% more power than the series drive at 100 kmh?1 speed. A 2% heat recovery is theoretically achievable for a 16 cell module assembly. 相似文献
11.
《Journal of power sources》1998,73(2):193-198
A procedure is developed to assess the potential of thermoelectric modules when used for electrical power generation. The generating performance of a thermoelectric module is evaluated in terms of its power output, conversion efficiency and reliability, while the potential for improving its performance is investigated based upon the power-per-area, cost-per-watt and manufacture quality factor. The methods employed in determining these parameters are described and used to evaluate several commercially available modules. The results show that a thermoelectric module is a promising device for low temperature waste heat recovery. 相似文献
12.
A new type of thermoelectric generator (TEG) system based on liquid metal which serves to harvest and transport waste heat, is proposed in this paper. To demonstrate the feasibility of the new TEG system, an experimental prototype which combined commercially available thermoelectric (TE) modules with the electromagnetic pump was set up. Output voltage from TE modules and temperature changes of the main parts (waste heat source, liquid metal heating plate, water-cooling plates I and II) of the liquid metal based TEG system were experimentally measured, as well as the flow rate of cooling water and the load resistance. It was shown that the maximum open-circuit voltage of 34.7 V was obtained when the temperature of the waste heat source was 195.9 °C and the temperature gap between liquid metal heating plate and cooling-water plates was nearly 100 °C. These experimental results obviously verify that using liquid metal based TEG system for waste heat recovery is highly feasible. In addition, the TEG system performance is discussed and a calculated efficiency of 2% in the whole TEG system is obtained. Possible suggestions to further improve this type of generator in the future are given. 相似文献
13.
《International Journal of Heat and Mass Transfer》2007,50(11-12):2355-2363
In the present paper the performance of a waste heat recovery power generation system based on second law analysis is investigated for various operating conditions. The temperature profiles across the heat recovery steam generator (HRSG), network output, second law efficiency and entropy generation number are simulated for various operating conditions. The variation in specific heat with exhaust gas composition and temperature are accounted in the analysis and results. The effect of pinch point on the performance of HRSG and on entropy generation rate and second law efficiency are also investigated. The second law efficiency of the HRSG and power generation system decreases with increasing pinch point. The first and second law efficiency of the power generation system varies with exhaust gas composition and with oxygen content in the gas. Approximating the exhaust gas as air, and the air standard analysis leads to either underestimation or overestimation of power plant performance on both first law and second law point of view. Actual gas composition and specific heat should be used to accurately predict the second law performance. The present results contribute further information on the role of gas composition, specific heat and pinch point influence on the performance of a waste heat recovery based power generation system based on first and second law of thermodynamics. 相似文献
14.
15.
ABSTRACTThe electric power produced by a thermoelectric generator (TEG) is strongly influenced by the applied heat sink. While a TEG is aimed at harvesting waste heat, the optimization of the efficiency of the heat sink is a key task for the design of waste heat recovery systems implementing TEG. A TEG model is proposed and implemented in an open source toolbox for field operation and manipulation (OpenFOAM) for the purpose of performing optimizations of the heat sink, using a commercially available TEG as basis. This model includes the multi-physics thermoelectric coupled effects. Conservation principles of energy and current are considered simultaneously. This includes the thermal and electric conduction, Seebeck effect, Peltier effect, Thomson effect, and Joule heating. Particular attention is given to a proper modeling of the boundary conditions. The thermoelectric model is implemented in such a way that it can readily be combined with other physical models in OpenFOAM. The model is validated by comparing the predictions to analytical results, measurements as well as the simulation data of other authors. 相似文献
16.
17.
18.
设计了一种回收工业转炉余热的半导体温差发电装置。针对转炉转动的特点,研究设计了风冷式的冷端结构。采用Fluent软件对温度分布及速度分布进行了数值模拟,并对计算结果进行了分析。结果表明,采用风扇顸部冲击冷却的形式可达到良好的效果,可使温差发电元件两端温差高达70℃,满足了半导体温差发电温差基本要求,该设计也满足自带风扇负载的要求。 相似文献
19.
20.
Performance review of a novel combined thermoelectric power generation and water desalination system
A novel combined thermoelectric power generation and water desalination system is described with a system schematic. The proposed system utilises low grade thermal energy to heat thermoelectric generators for power generation and water desalination. A theoretical analysis presents the governing equations to estimate the systems performance characteristics combined with experimental validation. Experimental set-up consists of an electric heat source, thermoelectric modules, heat pipes, a heat sink and an evaporator vessel. Four heat pipes are embedded in a heat spreader block to passively cool the bottom side of the thermoelectric cells. The condenser of these four heat pipes is immersed in a pool of saline water stored in an evaporation vessel which is maintained at sub-atmospheric pressure. The liquid to vapour phase change cooling method achieve low saturation temperature and offers a high heat transfer coefficient for the cooling of the thermoelectric generators. At the same time this method utilises the low temperature heat extracted from the cold side of the thermoelectric generator for water desalination. It was observed that at low saturation temperatures greater heat flux could be supplied to the thermoelectric generators with less heat losses to the atmosphere. 相似文献