Thermal conduction generator, also known as Seebeck generator, is a device that uses the thermoelectric effect (Seebeck effect) to directly convert heat (temperature difference) into electrical energy. Generally speaking, the conversion efficiency is about 5-8.
Older devices based on the Seebeck effect used bimetal junctions and were very bulky. More recent devices use semiconductor PN junctions made of bismuth telluride (Bi2Te3), lead telluride (PbTe), calcium manganese oxide, or combinations of these selected based on temperature.
Extended information:
Power generation technology
After more than ten years of development, China's cement kiln waste heat power generation technology has made great progress and is now close to the international advanced level. A variety of power generation systems have been born that can meet the requirements of different kiln types. In the long term in the future, the development trend of China's cement kiln waste heat power generation technology will mainly focus on the following aspects:
Secondary waste heat power generation using vertical waste heat boilers and steam-supplemented steam turbine generator units system. The vertical waste heat boiler completely solves the problems of air leakage in the horizontal waste heat boiler and the actual distribution of the temperature field in the furnace is completely different from the temperature assumed during the boiler design, which can greatly increase the boiler steam output.
The waste heat of about 200℃ exhaust gas discharged from the grate cooler or vertical waste heat boiler can be fully recovered and used to generate electricity. In this way, the waste heat power generation capacity per ton of clinker can be increased to more than 195 kilowatt hours under the premise that the clinker heat consumption remains unchanged.
The comprehensive energy consumption of cement kilns reaches the energy consumption level of precalcining kilns of the same scale, and the economic benefits are much higher than that of precalcining kilns.
The secondary waste heat supplementary combustion power generation system of the waste heat power kiln not only has the advantages of the secondary waste heat power generation system, but also can solve the operational safety and environmental protection issues of the cement kiln pulverized coal preparation system. At the same time, for cement plants in areas with serious power shortages or with other kiln types such as vertical kilns, vertical kilns, wet kilns, dry rotary kilns, etc., the power supply problem can also be solved and the economic benefits can be further improved.
In order to overcome the shortcomings of medium and low-temperature waste heat power generation systems with supplementary combustion boilers, a supplementary steam turbine unit is used to fully recover the waste heat of the exhaust gas below 200°C. At the same time, the supplementary combustion boiler should be powered by low-quality coal such as coal gangue. Or garbage can be used as fuel. In addition to saving high-quality coal, it can also provide raw materials for cement production, reduce power generation costs, and further improve economic benefits.
Baidu Encyclopedia-Thermal conduction generator