Efficient Use of Residual Heat in Combined Heat and Power Systems
When generating electricity, a fossil fuel - gas, coal, or oil - is converted into heat and subsequently used to generate high pressure, high temperature steam. Then, in a steam turbine connected to a generator, a significant part of the energy in this steam is converted into electrical energy which is then supplied to the power grid.
In large modern power stations, approximately 40% of the energy in fossil fuel is converted into electrical energy, the remainder being discharged in (cooling) water as waste heat, and / or into the air. That waste energy does nothing other than heat the planet.
It is physically and technically almost impossible to convert a higher percentage than the above mentioned 40% of the energy from fossil fuel into electrical energy. It is, however, possible to make efficient use of the waste heat - for example, for district heating.
However, this solution also has negative consequences, because it usually means that an even smaller proportion of the energy in the fuel is converted into electrical energy. In most cases, just one third (33%) of the potential energy in fossil fuel is converted into electrical energy. But in these applications, a larger proportion of the remaining two-thirds of the waste heat can be used for heating greenhouses, buildings, or processes. This waste heat can also be stored underground as a seasonal energy supply. Processes making efficient use of part of the waste heat, are called CHP (combined heat and power).
Download for free to read more...
Download to find out more.