جستجوی مقالات مرتبط با کلیدواژه « thermoelectric » در نشریات گروه « مکانیک »

The importance of direct conversion of energy and the use of new and renewable energies is no secret nowadays in photoelectric phenomena the energy of sunlight is converted directly to electricity after radiation to the cell surface. In thermoelectric phenomena, power or cooling can be generated by absorption of heat or electric current, respectively. The applications of photoelectric phenomena in the sea can be power generation, water purification, navigation systems, lighting, driving force of surveillance drones and new micro-birds, photoelectric sensors and ... He named her. Thermoelectric cooling is also used to cool electronic equipment in vessels such as processors and power generators for marine radars. It is also capable of generating power in drones and micro-birds, hydrogen production, satellites and space equipment. These new systems and types of semiconductors are on the path of development and optimization. In this research, we try to investigate these two types of phenomena and their benefits.

Nowadays, the use of thermoelectric as one of the methods of recovering waste heat energy has received much attention. In this research, while presenting a new thermal energy recovery system in the molten slag of steel Industry, thermodynamic analysis of the proposed system from the perspective of energy and exergy is also presented. Then the effect of various parameters including Seebeck coefficient on the performance of the proposed system is investigated. The results of modeling in both power cycle and thermoelectric cycles have been validated by previous research. The results of thermodynamic analysis show that the largest contribution to the exergy destruction of the proposed system is related to the heat recovery system. According to the results, the production capacity of the heat recovery system from the total production capacity is about 49% and the efficiency of the first law of thermodynamics for the proposed system is 24.7% and the efficiency of the second law of thermodynamics is 32.88%. Economic analysis indicates that with thermoelectric generator cost of 1 $/W the payback rate of investment is less than 2 years.

In this study, we analyzed the energy, exergy of a multiple energy production system based on geothermal energy. The system under study consists of geothermal subsystems, Rankin organic cycle and PEM electrolyzer and thermoelectric application. The organic fluid used in the Rankin organic cycle contains refrigerant R123. The products of this system produce multiple energy, including electricity and hydrogen. Thermodynamic software for solving engineering equations (EES) was used to model the studied system and also to obtain the results of system analysis. The results were calculated and evaluated using the ambient temperature of Bandar Abbas for the hottest day. According to the studies of the parameters affecting the system outputs, we can name the turbine efficiency, inlet temperature to the evaporator, thermoelectric suitability criterion, pump efficiency and mass flow inlet to the evaporator. The results also showed that the current work geothermal system in a year compared to the ambient temperature of Bandar Abbas can produce 352816.2 kWh of power per year and as a result this system can meet the electricity needs of about 12 Iranian families during the year.

In a thermoelectric air-handling unit, a number of thermoelectric modules with forced convection heat sinks are used. In this research, it is tried to investigate the effect of module arrangement and air flow pattern on thermal performance of the system. For this purpose, the thermal performance of an air-handling unit including four thermoelectric modules with three different heat sinks layouts; parallel, series with unidirectional flow and series with counter flow were compared. The entropy analysis has been used to study the thermal performance and pressure drop imposed on the system. In addition, the effect of the electric current applied to the modules and the hot and cold air flows on the coefficient of performance of the system has been studied for three different layouts. Results indicated that, heat sinks layout and air flow pattern through the fins have significant effects on the thermal performance of a thermoelectric air-handling unit. The coefficient of performance for cooling and heating in the series arrangement are 1.4 and 1.1 times of those in parallel arrangement, respectively. The results of the entropy analysis showed that although the pressure drop imposed on the system in the layout of the series is greater than the parallel arrangement, this cannot reduce the advantage of using the series layout.

Thermoelectrics are solid-state devices. They are semiconductors that produce electricity using based on the Seebeck and Peltier effect as semiconductor cooler. Thermoelectric has interesting features compared to conventional cooler and electrical appliances. The absence of moving parts result in increasing reliability, reducing maintenance, and increasing the system life. Lack of fluid reduces environmental pollution as well as being quiet which is a great advantage. With rapid development of technology in the field of semiconductor materials, thermoelectric has attracted a lot of attention these days. In this paper the thermoelectric technology, materials, application in the field of cooling has briefly reviewed.

Thermoelectric systems have many advantages, including environmentally friendly, without noise and high reliability. Due to the reduction of fossil fuel resources and emissions resulting them, using of thermoelectric systems both of cooling and generator are increasing. But one of the main disadvantages of thermoelectric cooling is low coefficient of performance. Today, researchers have a particular focus on the coefficient of performance and are trying to improve it. To learn more about the coefficient of performance parameters that are discussed in this paper to review. For this purpose, the first effects of electrical contact resistances and thermal resistances are investigated at small thermoelectric modules that by ignoring it will not reach the desired results. Also, by decreasing the electrical contact resistance can increasing the coefficient of performance 50 to 60 percent. Then correlation between the coefficient of performance and thermoelement length, temperature difference and electric current is provided. Finally the multi-stage modules has been discussed as a result of increasing stages, coefficient of performance also increased.

In this paper, investigation the parameters that affect the coefficient of performance (COP) and features of thermoelectric cooling devices to help a number of recent research in this field has been provided. Specific aspects included practical considerations on figure of merit, cooling capacity and coefficient of performance respectively. This paper starts by thematic categories from recent articles, and then describes in detail the parameters of cooling capacity and coefficient of performance. In addition, the cooling capacity for single-stage and multi-stage thermoelectric cooler is mentioned. Concerning the COP, its dedicated expressions are constructed starting from the classical formulation and introducing additional factors or modifications in order to take into account the Thomson effect. Finally, has been investagted the coefficient of performance in different applications of thermoelectric cooling.

Thermoelectric is the science of heat conversion into electrical energy or electrical energy conversion into heating or cooling inversely. Currently the mass application of thermoelectric is in the coolers. The most important characteristic of these chips is the lack of mechanical parts, enabling the use of clean and silent, small size and light weight, reliability and also provides simple maintenance and repair. The main obstacle in the commercialization of this technology is its low efficiency. In this paper, the theoretical approach to obtain a thermoelectric internal parameters has been studied. This method is validated by examining the results obtained from this procedure with catalog values. The results show the error of this method is 3.17%.